Variability of reflectance measurements with sensor altitude and canopy type

NASA Technical Reports Server (NTRS)

Daughtry, C. S. T.; Vanderbilt, V. C.; Pollara, V. J.

1981-01-01

Data were acquired on canopies of mature corn planted in 76 cm rows, mature soybeans planted in 96 cm rows with 71 percent soil cover, and mature soybeans planed in 76 cm rows with 100 percent soil cover. A LANDSAT band radiometer with a 15 degree field of view was used at ten altitudes ranging from 0.2 m to 10 m above the canopy. At each altitude, measurements were taken at 15 cm intervals also a 2.0 m transect perpendicular to the crop row direction. Reflectance data were plotted as a function of altitude and horizontal position to verify that the variance of measurements at low altitudes was attributable to row effects which disappear at higher altitudes where the sensor integrate across several rows. The coefficient of variation of reflectance decreased exponentially as the sensor was elevated. Systematic sampling (at odd multiples of 0.5 times the row spacing interval) required fewer measurements than simple random sampling over row crop canopies.

Evaluation of native bees as pollinators of cucurbit crops under floating row covers.

PubMed

Minter, Logan M; Bessin, Ricardo T

2014-10-01

Production of cucurbit crops presents growers with numerous challenges. Several severe pests and diseases can be managed through the use of rotation, trap cropping, mechanical barriers, such as row covers, and chemical applications. However, considerations must also be made for pollinating insects, as adequate pollination affects the quantity and quality of fruit. Insecticides may negatively affect pollinators; a concern enhanced in recent years due to losses in managed Apis melifera L. colonies. Row covers can be used in place of chemical control before pollination, but when removed, pests have access to fields along with the pollinators. If pollination services of native bees could be harnessed for use under continuous row covers, both concerns could be balanced for growers. The potential of two bee species which specialize on cucurbit flowers, Peponapis pruinosa Say and Xenoglossa strenua Cresson, were assessed under continuous row covers, employed over acorn squash. Experimental treatments included plots with either naturally or artificially introduced bees under row covers and control plots with row covers either permanently removed at crop flowering, or employed continuously with no added pollinating insects. Pests in plots with permanently removed row covers were managed using standard practices used in certified organic production. Marketable yields from plots inoculated with bees were indistinguishable from those produced under standard practices, indicating this system would provide adequate yields to growers without time and monetary inputs of insecticide applications. Additionally, application of this technique was investigated for muskmelon production and discussed along with considerations for farm management.

Row-crop planter requirements to support variable-rate seeding of maize

USDA-ARS?s Scientific Manuscript database

Current planting technology possesses the ability to increase crop productivity and improve field efficiency by precisely metering and placing crop seeds. Planter performance depends on using the correct planter and technology setup which consists of determining optimal settings for different planti...

Effect of rainfall timing and tillage on the transport of steroid hormones in runoff from manure amended row crop fields.

PubMed

Biswas, Sagor; Kranz, William L; Shapiro, Charles A; Snow, Daniel D; Bartelt-Hunt, Shannon L; Mamo, Mitiku; Tarkalson, David D; Zhang, Tian C; Shelton, David P; van Donk, Simon J; Mader, Terry L

2017-02-15

Runoff generated from livestock manure amended row crop fields is one of the major pathways of hormone transport to the aquatic environment. The study determined the effects of manure handling, tillage methods, and rainfall timing on the occurrence and transport of steroid hormones in runoff from the row crop field. Stockpiled and composted manure from hormone treated and untreated animals were applied to test plots and subjected to two rainfall simulation events 30days apart. During the two rainfall simulation events, detection of any steroid hormone or metabolites was identified in 8-86% of runoff samples from any tillage and manure treatment. The most commonly detected hormones were 17β-estradiol, estrone, estriol, testosterone, and α-zearalenol at concentrations ranging up to 100-200ngL -1 . Considering the maximum detected concentrations in runoff, no more than 10% of the applied hormone can be transported through the dissolved phase of runoff. Results from the study indicate that hormones can persist in soils receiving livestock manure over an extended period of time and the dissolved phase of hormone in runoff is not the preferred pathway of transport from the manure applied fields irrespective of tillage treatments and timing of rainfall. Copyright © 2016 Elsevier B.V. All rights reserved.

Development and Evaluation of a Combined Cultivator and Band Sprayer with a Row-Centering RTK-GPS Guidance System

PubMed Central

Perez-Ruiz, Manuel; Carballido, Jacob; Agüera, Juan; Rodríguez-Lizana, Antonio

2013-01-01

Typically, low-pressure sprayers are used to uniformly apply pre- and post-emergent herbicides to control weeds in crop rows. An innovative machine for weed control in inter-row and intra-row areas, with a unique combination of inter-row cultivation tooling and intra-row band spraying for six rows and an electro-hydraulic side-shift frame controlled by a GPS system, was developed and evaluated. Two weed management strategies were tested in the field trials: broadcast spraying (the conventional method) and band spraying with mechanical weed control using RTK-GPS (the experimental method). This approach enabled the comparison between treatments from the perspective of cost savings and efficacy in weed control for a sugar beet crop. During the 2010–2011 season, the herbicide application rate (112 L ha−1) of the experimental method was approximately 50% of the conventional method, and thus a significant reduction in the operating costs of weed management was achieved. A comparison of the 0.2-trimmed means of weed population post-treatment showed that the treatments achieved similar weed control rates at each weed survey date. Sugar beet yields were similar with both methods (p = 0.92). The use of the experimental equipment is cost-effective on ≥20 ha of crops. These initial results show good potential for reducing herbicide application in the Spanish beet industry. PMID:23478600

Development and evaluation of a combined cultivator and band sprayer with a row-centering RTK-GPS guidance system.

PubMed

Perez-Ruiz, Manuel; Carballido, Jacob; Agüera, Juan; Rodríguez-Lizana, Antonio

2013-03-11

Typically, low-pressure sprayers are used to uniformly apply pre- and post-emergent herbicides to control weeds in crop rows. An innovative machine for weed control in inter-row and intra-row areas, with a unique combination of inter-row cultivation tooling and intra-row band spraying for six rows and an electro-hydraulic side-shift frame controlled by a GPS system, was developed and evaluated. Two weed management strategies were tested in the field trials: broadcast spraying (the conventional method) and band spraying with mechanical weed control using RTK-GPS (the experimental method). This approach enabled the comparison between treatments from the perspective of cost savings and efficacy in weed control for a sugar beet crop. During the 2010-2011 season, the herbicide application rate (112 L ha(-1)) of the experimental method was approximately 50% of the conventional method, and thus a significant reduction in the operating costs of weed management was achieved. A comparison of the 0.2-trimmed means of weed population post-treatment showed that the treatments achieved similar weed control rates at each weed survey date. Sugar beet yields were similar with both methods (p = 0.92). The use of the experimental equipment is cost-effective on ≥20 ha of crops. These initial results show good potential for reducing herbicide application in the Spanish beet industry.

Ethoprophos fate on soil-water interface and effects on non-target terrestrial and aquatic biota under Mediterranean crop-based scenarios.

PubMed

Leitão, Sara; Moreira-Santos, Matilde; Van den Brink, Paul J; Ribeiro, Rui; José Cerejeira, M; Sousa, José Paulo

2014-05-01

The present study aimed to assess the environmental fate of the insecticide and nematicide ethoprophos in the soil-water interface following the pesticide application in simulated maize and potato crops under Mediterranean agricultural conditions, particularly of irrigation. Focus was given to the soil-water transfer pathways (leaching and runoff), to the pesticide transport in soil between pesticide application (crop row) and non-application areas (between crop rows), as well as to toxic effects of the various matrices on terrestrial and aquatic biota. A semi-field methodology mimicking a "worst-case" ethoprophos application (twice the recommended dosage for maize and potato crops: 100% concentration v/v) in agricultural field situations was used, in order to mimic a possible misuse by the farmer under realistic conditions. A rainfall was simulated under a slope of 20° for both crop-based scenarios. Soil and water samples were collected for the analysis of pesticide residues. Ecotoxicity of soil and aquatic samples was assessed by performing lethal and sublethal bioassays with organisms from different trophic levels: the collembolan Folsomia candida, the earthworm Eisenia andrei and the cladoceran Daphnia magna. Although the majority of ethoprophos sorbed to the soil application area, pesticide concentrations were detected in all water matrices illustrating pesticide transfer pathways of water contamination between environmental compartments. Leaching to groundwater proved to be an important transfer pathway of ethoprophos under both crop-based scenarios, as it resulted in high pesticide concentration in leachates from Maize (130µgL(-1)) and Potato (630µgL(-1)) crop scenarios, respectively. Ethoprophos application at the Potato crop scenario caused more toxic effects on terrestrial and aquatic biota than at the Maize scenario at the recommended dosage and lower concentrations. In both crop-based scenarios, ethoprophos moved with the irrigation water flow to the soil between the crop rows where no pesticide was applied, causing toxic effects on terrestrial organisms. The two simulated agricultural crop-based scenarios had the merit to illustrate the importance of transfer pathways of pesticides from soil to groundwater through leaching and from crop rows to the surrounding soil areas in a soil-water interface environment, which is representative for irrigated agricultural crops under Mediterranean conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

Water, sediment, and metolachlor transport between wide- and narrow row cotton production systems

USDA-ARS?s Scientific Manuscript database

Planting cotton [Gossypium hirsutum (L.)] in narrow rather than wide rows could reduce erosion and off-site agrochemical transport, but this hypothesis needs to be evaluated under Mid-South cropping conditions. Field studies were conducted near Stoneville, MS on a Dundee silty clay loam from 2006 t...

Integrated palmer amaranth management in glufosinate-resistant cotton: II. primary, secondary, and conservation tillage

USDA-ARS?s Scientific Manuscript database

A three-year field experiment was conducted to evaluate the role of inversion tillage, cover crops and spring tillage methods for Palmer amaranth between-row (BR) and within-row (WR) management in glufosinate-resistant cotton. Main plots were two inversion tillage systems: fall inversion tillage (IT...

A novel integrated cropping system for efficient grain production, improved soil quality, and enhanced beneficial arthropod communities

USDA-ARS?s Scientific Manuscript database

The solar corridor crop system (SCCS) is designed for improved crop productivity by using broad strips (corridors or skip rows) that promote highly efficient use of solar radiation and ambient carbon dioxide by C-4 plants including corn. Field trials in 2013 and 2014 showed that yields of selected c...

The relationship of nitrate concentrations in streams to row crop land use in Iowa

USGS Publications Warehouse

Schilling, K.E.; Libra, R.D.

2000-01-01

The relationship between row crop land use and nitrate N concentrations in surface water was evaluated for 15 Iowa watersheds ranging from 1002 to 2774 km2 and 10 smaller watersheds ranging from 47 to 775 km2 for the period 1996 to 1998. The percentage of land in row crop varied from 24 to >87% in the 15 large watersheds, and mean annual NO3-N concentrations ranged from 0.5 to 10.8 mg/L. In the small watersheds, row crop percentage varied from 28 to 87% and mean annual NO3-N concentrations ranged from 3.0 to 10.5 mg/L. In both cases, nitrate N concentrations were directly related to the percentage of row crop in the watershed (p 87% in the 15 large watersheds, and mean annual NO3-N concentrations ranged from 0.5 to 10.8 mg/L. In the small watersheds, row crop percentage varied from 28 to 87% and mean annual NO3-N concentrations ranged from 3.0 to 10.5 mg/L. In both cases, nitrate N concentrations were directly related to the percentage of row crop in the watershed (p<0.0003). Linear regression showed similar slope for both sets of watersheds (0.11) suggesting that average annual surface water nitrate concentrations in Iowa, and possibly similar agricultural areas in the midwestern USA, can be approximated by multiplying a watershed's row crop percentage by 0.1. Comparing the Iowa watershed data with similar data collected at a subwatershed scale in Iowa (0.1 to 8.1 km2) and a larger midcontinent scale (7300 to 237 100 km2) suggests that watershed scale affects the relationship of nitrate concentration and land use. The slope of nitrate concentration versus row crop percentage decreases with increasing watershed size.Mean nitrate concentrations and row crop land use were summarized for 15 larger and ten smaller watersheds in Iowa, and the relationship between NO3 concentration and land use was examined. Linear regression of mean NO3 concentration and percent row crop was highly significant for both sets of watershed data, but a stronger correlation was noted in the small-watershed data. Both data sets suggested that mean annual surface-water NO3 concentrations in the state could be approximated by multiplying the watershed's percent row crop by 0.1. The slope of NO3 concentration versus row crop percentage appeared to decrease with increasing watershed size.

Combining spatial and spectral information to improve crop/weed discrimination algorithms

NASA Astrophysics Data System (ADS)

Yan, L.; Jones, G.; Villette, S.; Paoli, J. N.; Gée, C.

2012-01-01

Reduction of herbicide spraying is an important key to environmentally and economically improve weed management. To achieve this, remote sensors such as imaging systems are commonly used to detect weed plants. We developed spatial algorithms that detect the crop rows to discriminate crop from weeds. These algorithms have been thoroughly tested and provide robust and accurate results without learning process but their detection is limited to inter-row areas. Crop/Weed discrimination using spectral information is able to detect intra-row weeds but generally needs a prior learning process. We propose a method based on spatial and spectral information to enhance the discrimination and overcome the limitations of both algorithms. The classification from the spatial algorithm is used to build the training set for the spectral discrimination method. With this approach we are able to improve the range of weed detection in the entire field (inter and intra-row). To test the efficiency of these algorithms, a relevant database of virtual images issued from SimAField model has been used and combined to LOPEX93 spectral database. The developed method based is evaluated and compared with the initial method in this paper and shows an important enhancement from 86% of weed detection to more than 95%.

Effects of field variables on infield biomass bales aggregation strategies

USDA-ARS?s Scientific Manuscript database

Infield aggregation of bales, an essential logistics operation of clearing the field for subsequent cropping, is influenced by several field variables, such as field shape, area, randomness on bale layout, biomass yield per unit area, bale row spacing, number of bales handled simultaneously, collect...

Is it working? A look at the changing nutrient practices in Oregon's Southern Willamette Valley Groundwater Management Area

NASA Astrophysics Data System (ADS)

Pearlstein, S.; Compton, J.; Eldridge, A.; Henning, A.; Selker, J. S.; Brooks, J. R.; Schmitz, D.

2016-12-01

Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 due to nitrate levels in the groundwater exceeding the human health standard of 10 mg nitrate-N L-1. Much of the nitrogen inputs to the GWMA comes from agricultural nitrogen use, and thus efforts to reduce N inputs to groundwater are focused upon improving N management. Previous work in the 1990s in the Willamette Valley by researchers at Oregon State University determined the importance of cover crops and irrigation practices and made recommendations to the local farm community for reducing nitrogen (N) leaching. We are currently re-sampling many of the same fields studied by OSU to examine the influence of current crops and nutrient management practices on nitrate leaching below the rooting zone. This study represents important crops currently grown in the GWMA and includes four grass fields, three vegetable row-crop fields, two peppermint and wheat fields, and one each of hazelnuts and blueberries. New nutrient management practices include slow release fertilizers and precision agriculture approaches in some of the fields. Results from the first two years of sampling show nitrate leaching is lower in some crops like row crops grown for seed and higher in others like perennial rye grass seed when compared to the 1990s data. We will use field-level N input-output balances in order to determine the N use efficiency and compare this across crops and over time. The goal of this project is to provide information and tools that will help farmers, managers and conservation groups quantify the water quality benefits of management practices they are conducting or funding.

Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems

PubMed Central

Ladoni, Moslem; Kravchenko, Alexandra N.; Robertson, G. Phillip

2015-01-01

Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover) and non-leguminous (winter rye) cover crops on potentially mineralizable N (PMN) and NO3--N levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4–5 times during each growing season and analyzed for NO3--N and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3 —N. Red clover cover crop increased NO3--N by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on NO3--N in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management in row-crop agricultural systems. PMID:26600462

Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems.

PubMed

Ladoni, Moslem; Kravchenko, Alexandra N; Robertson, G Phillip

2015-01-01

Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover) and non-leguminous (winter rye) cover crops on potentially mineralizable N (PMN) and [Formula: see text] levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4-5 times during each growing season and analyzed for [Formula: see text] and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3-N. Red clover cover crop increased [Formula: see text] by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on [Formula: see text] in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management in row-crop agricultural systems.

Radiometer footprint model to estimate sunlit and shaded components for row crops

USDA-ARS?s Scientific Manuscript database

This paper describes a geometric model for computing the relative proportion of sunlit vegetation, shaded vegetation, sunlit soil, and shaded soil appearing in a circular or elliptical radiometer footprint for row crops, where the crop rows were modeled as continuous ellipses. The model was validate...

Effects of enhanced efficiency fertilizers on cotton growth characteristics

USDA-ARS?s Scientific Manuscript database

The use of enhanced-efficiency N fertilizers (EENFs) in row crop agriculture has not been well studied despite increasing interest in these N sources to increase crop yield while also decreasing N loss. Therefore, a field study was conducted in Central Alabama from 2009 to 2011 to compare EENFs to s...

Evaluation of seeding depth and guage-wheel load effects on maize emergence and yield

USDA-ARS?s Scientific Manuscript database

Planting represents perhaps the most important field operation with errors likely to negatively affect crop yield and thereby farm profitability. Performance of row-crop planters are evaluated by their ability to accurately place seeds into the soil at an adequate and pre-determined depth, the goal ...

Environmental impacts of conversion of cropland to biomass production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, T.H.; Brown, G.F.; Bingham, L.

1996-12-31

A study was initiated to determine the effects of conversion of row crop land to biomass production on runoff quality and quantity. Treatments were: (1) remain in row crop (no-till corn); (2) convert to short rotation woody crop (SRWC) production with sweetgum (Liquidambar styraciflua L.) planted in a 1.5 in by 3 in spacing maintaining complete weed control; (3) convert to SRWC with a tall fescue (Festuca eliator L.) cover crop planted in a 2.4 in strip centered between rows of trees to reduce erosion; and (4) convert to switchgrass (Panicum virgatum L.) as a biomass energy crop. Plots withinmore » a block similar in size (approximately 0.45 ha in block 1 and 0.20 ha in block 2), slope, soils, topographic position, recent land use history, etc. Although switchgrass plots eroded more early in the growing season, erosion was low once it became well established. Conversely, plots where trees were grown with no cover continued to erode throughout the growing season. These results indicate that growing short-rotation intensively cultured hardwoods with complete weed control will provide little erosion relief in agricultural fields, at least during the first growing season. Planting switchgrass for bioenergy production, however, does protect the soil. Nutrient runoff was related to fertilization.« less

Effects of Crop Canopies on Rain Splash Detachment

PubMed Central

Ma, Bo; Yu, Xiaoling; Ma, Fan; Li, Zhanbin; Wu, Faqi

2014-01-01

Crops are one of the main factors affecting soil erosion in sloping fields. To determine the characteristics of splash erosion under crop canopies, corn, soybean, millet, and winter wheat were collected, and the relationship among splash erosion, rainfall intensity, and throughfall intensity under different crop canopies was analyzed through artificial rainfall experiments. The results showed that, the mean splash detachment rate on the ground surface was 390.12 g/m2·h, which was lower by 67.81% than that on bare land. The inhibiting effects of crops on splash erosion increased as the crops grew, and the ability of the four crops to inhibit splash erosion was in the order of winter wheat>corn>soybeans>millet. An increase in rainfall intensity could significantly enhance the occurrence of splash erosion, but the ability of crops to inhibit splash erosion was 13% greater in cases of higher rainfall intensity. The throughfall intensity under crop canopies was positively related to the splash detachment rate, and this relationship was more significant when the rainfall intensity was 40 mm/h. Splash erosion tended to occur intensively in the central row of croplands as the crop grew, and the non-uniformity of splash erosion was substantial, with splash erosion occurring mainly between the rows and in the region directly under the leaf margin. This study has provided a theoretical basis for describing the erosion mechanisms of cropland and for assisting soil erosion prediction as well as irrigation and fertilizer management in cultivated fields. PMID:24992386

Effects of crop canopies on rain splash detachment.

PubMed

Ma, Bo; Yu, Xiaoling; Ma, Fan; Li, Zhanbin; Wu, Faqi

2014-01-01

Crops are one of the main factors affecting soil erosion in sloping fields. To determine the characteristics of splash erosion under crop canopies, corn, soybean, millet, and winter wheat were collected, and the relationship among splash erosion, rainfall intensity, and throughfall intensity under different crop canopies was analyzed through artificial rainfall experiments. The results showed that, the mean splash detachment rate on the ground surface was 390.12 g/m2 · h, which was lower by 67.81% than that on bare land. The inhibiting effects of crops on splash erosion increased as the crops grew, and the ability of the four crops to inhibit splash erosion was in the order of winter wheat>corn>soybeans>millet. An increase in rainfall intensity could significantly enhance the occurrence of splash erosion, but the ability of crops to inhibit splash erosion was 13% greater in cases of higher rainfall intensity. The throughfall intensity under crop canopies was positively related to the splash detachment rate, and this relationship was more significant when the rainfall intensity was 40 mm/h. Splash erosion tended to occur intensively in the central row of croplands as the crop grew, and the non-uniformity of splash erosion was substantial, with splash erosion occurring mainly between the rows and in the region directly under the leaf margin. This study has provided a theoretical basis for describing the erosion mechanisms of cropland and for assisting soil erosion prediction as well as irrigation and fertilizer management in cultivated fields.

The extension of a uniform canopy reflectance model to include row effects

NASA Technical Reports Server (NTRS)

Suits, G. H. (Principal Investigator)

1981-01-01

The effect of row structure is assumed to be caused by the variation in density of vegetation across rows rather than to a profile in canopy height. The calculation of crop reflectance using vegetation density modulation across rows follows a parallel procedure to that for a uniform canopy. Predictions using the row model for wheat show that the effect of changes in sun to row azimuth are greatest in Landsat Band 5 (red band) and can result in underestimation of crop vigor.

Field scale evaluation of spray drift reduction technologies from ground and aerial application systems

USDA-ARS?s Scientific Manuscript database

The objective of this work is to evaluate a proposed Test Plan for the validation testing of pesticide spray drift reduction technologies for row and field crops, focusing on the testing of ground and aerial application systems under full-scale field evaluations. The measure of performance for a gi...

Partitioning evapotranspiration via continuous sampling of water vapor isotopes over common row crops and candidate biofuel crops.

NASA Astrophysics Data System (ADS)

Miller, J. N.; Black, C. K.; Bernacchi, C.

2014-12-01

Global demand for renewable energy is accelerating land conversion from common row crops such as maize and soybean to cellulosic biofuel crops such as miscanthus and switchgrass. This land conversion is expected to alter ecohydrology via changes in evapotranspiration (ET). However, the direction in which evapotranspiration will shift, either partitioning more moisture through soil evaporation (E) or through plant transpiration (T) is uncertain. To investigate how land conversion from maize to miscanthus affects ET partitioning we measured the isotopic composition of water vapor via continuous air sampling. We obtained continuous diurnal measurements of δ2H and δ18O for miscanthus and maize on multiple days over the course of the growing season. Water vapor isotopes drawn from two heights were measured at 2 Hz using a cavity ringdown spectrometer and partitioned into components of E and T using a simple mixing equation. A second approach to partitioning was accomplished by subtracting transpiration measurements, obtained through sap flow sensors, from total ET, measured via eddy covariance. Preliminary results reveal that both methods compare favorably and that transpiration dominates variations in ET in miscanthus fields more so than in fields of maize.

Profitability of cover crops for single and twin row cotton

USDA-ARS?s Scientific Manuscript database

With the increased interest in cover crops, the impact of adoption on profitability of cash crops is a common question from producers. The objective of this study was to evaluate the profitability of cover crops for single and twin row cotton (Gossypium hirsutum L.) in Alabama. This experiment inclu...

Environmental Technology Verification: Pesticide Spray Drift Reduction Technologies for Row and Field Crops

EPA Pesticide Factsheets

The Environmental Technology Verification Program, established by the EPA, is designed to accelerate the development and commercialization of new or improved technologies through third-party verification and reporting of performance.

Relation of baseflow to row crop intensity in Iowa

USGS Publications Warehouse

Schilling, K.E.

2005-01-01

Increasing baseflow and baseflow percentage over the second half of the 20th century in Iowa has contributed to increasing nitrate-nitrogen concentrations measured in Iowa rivers because nitrate is primarily delivered to streams as baseflow and tile drainage. The relation of baseflow and baseflow percentage to row crop land use was evaluated for 11 Iowa rivers and their watersheds for their period of streamflow record (58-73 years period). Results indicated increasing baseflow in Iowa's rivers is significantly related to increasing row crop intensity. A 13-52% increase in row crop percentage in many Iowa watersheds has contributed to an increase of 33-135 mm increase in baseflow and 7-31% increase in baseflow percentage. Limited historical water quality data from two larger Iowa rivers (Cedar and Raccoon rivers) suggest that increasing row crop land use over the 20th century has produced more baseflow and contributed to increasing nitrate concentrations in Iowa's rivers. ?? 2004 Elsevier B.V. All rights reserved.

Opportunities for Energy Crop Production Based on Subfield Scale Distribution of Profitability

DOE PAGES

Bonner, Ian J.; Cafferty, Kara G.; Muth, Jr., David J.; ...

2014-10-01

Incorporation of dedicated herbaceous energy crops into row crop landscapes is a promising means to supply an expanding biofuel industry while increasing biomass yields, benefiting soil and water quality, and increasing biodiversity. Despite these positive traits energy crops remain largely unaccepted due to concerns over their practicality and cost of implementation. This paper presents a case study on Hardin County, Iowa to demonstrate how subfield decision making can be used to target candidate areas for conversion to energy crop production. The strategy presented integrates switchgrass (Panicum virgatum L.) into subfield landscape positions where corn (Zea mays L.) grain is modeledmore » to operate at a net economic loss. The results of this analysis show that switchgrass integration has the potential to increase sustainable biomass production from 48 to 99% (depending on the rigor of conservation practices applied to corn stover collection) while also improving field level profitability. Candidate land area is highly sensitive to grain price (0.18 to 0.26 US$ kg-1) and dependent on the acceptable net profit for corn production (ranging from 0 to -1,000 US$ ha-1). This work presents the case that switchgrass can be economically implemented into row crop production landscapes when management decisions are applied at a subfield scale and compete against areas of the field operating at a negative net profit.« less

Directional reflectance factor distributions of a cotton row crop

NASA Technical Reports Server (NTRS)

Kimes, D. S.; Newcomb, W. W.; Schutt, J. B.; Pinter, P. J., Jr.; Jackson, R. D.

1984-01-01

The directional reflectance factor distribution spanning the entire exitance hemisphere was measured for a cotton row crop (Gossypium barbadense L.) with 39 percent ground cover. Spectral directional radiances were taken in NOAA satellite 7 AVHRR bands 1 and 2 using a three-band radiometer with restricted 12 deg full angle field of view at half peak power points. Polar co-ordinate system plots of directional reflectance factor distributions and three-dimensional computer graphic plots of scattered flux were used to study the dynamics of the directional reflectance factor distribution as a function of spectral band, geometric structure of the scene, solar zenith and azimuth angles, and optical properties of the leaves and soil. The factor distribution of the incomplete row crops was highly polymodal relative to that for complete vegetation canopies. Besides the enhanced reflectance for the antisolar point, a reflectance minimum was observed towards the forwardscatter direction in the principle plane of the sun. Knowledge of the mechanics of the observed dynamics of the data may be used to provide rigorous validation for two- or three-dimensional radiative transfer models, and is important in interpreting aircraft and satellite data where the solar angle varies widely.

Row and forage crop rotation effects on maize mineral nutrition and yield

USDA-ARS?s Scientific Manuscript database

Extended crop rotations provide many attributes in support of sustainable agriculture. Objectives were to investigate rotations that included row crops and forages in terms of their effects on soil characteristics as well as on maize (Zea mays L.) stover biomass, grain yield, and mineral components...

Applications of UAVs in row-crop agriculture: advantages and limitations

NASA Astrophysics Data System (ADS)

Basso, B.; Putnam, G.; Price, R.; Zhang, J.

2016-12-01

The application of Unmanned Aerial Vehicles (UAV) to monitor agricultural fields has increased over the last few years due to advances in the technology, sensors, post-processing software for image analysis, along with more favorable regulations that allowed UAVs to be flown for commercial use. UAV have several capabilities depending on the type of sensors that are mounted onboard. The most widely used application remains crop scouting to identify areas within fields where the crops underperform for various reasons (nutritional status and water stress, presence of weeds, poor stands etc). In this talk, we present the preliminary results of UAVs field based research to better understand spatial and temporal variability of crop yield. Their advantage in providing timely information is critical, but adaptive management requires a system approach to account for the interactions occurring between genetics, environment and management.

77 FR 69823 - Agency Information Collection Activities; Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-21

... application equipment manufacturers, chemical manufacturers, pesticide registrants, university researchers... Production 111 Research and Development in the Physical, Engineering, Life 541710 Sciences Colleges... drift reducing adjuvant chemicals used for aerial or groundboom applications to row and field crops...

Concentrated Animal Feeding Operations, Row Crops and their Relationship to Nitrate in Eastern Iowa Rivers

PubMed Central

Weldon, Mark B.; Hornbuckle, Keri C.

2009-01-01

Concentrated animal feeding operations (CAFO) and fertilizer application to row crops may contribute to poor water quality in surface waters. To test this hypothesis, we evaluated nutrient concentrations and fluxes in four Eastern Iowa watersheds sampled between 1996-2004. We found that these watersheds contribute nearly 10% of annual nitrate flux entering the Gulf of Mexico, while representing only 1.5% of the contributing drainage basin. Mass budget analysis shows stream flow to be a major loss of nitrogen (18% of total N output), second only to crop harvest (63%). The major watershed inputs of nitrogen include applied fertilizer for corn (54% of total N input) and nitrogen fixation by soybeans (26%). Despite the relatively small input from animal manure (~5%), the results of spatial analysis indicate that row crop and CAFO densities are significantly and independently correlated to higher nitrate concentration in streams. Pearson correlation coefficients of 0.59 and 0.89 were found between nitrate concentration and row crop and CAFO density, respectively. Multiple linear regression analysis produced a correlation for nitrate concentration with an R2 value of 85%. High spatial density of row crops and CAFOs are linked to the highest river nitrate concentrations (up to 15 mg/l normalized over five years). PMID:16749677

Response of anurans to wetland restoration on a midwestern agriculture landscape

USGS Publications Warehouse

Bartelt, Paul E.; Klaver, Robert W.

2017-01-01

Since the early 1990s, >5,000 ha of historic wetlands (and adjacent prairie) have been restored on the row-crop agricultural landscape of Winnebago County, Iowa, USA. From 2008–2011, we surveyed 22 of these sites for probabilities of occupancy and colonization by Boreal Chorus Frogs (BCF; Pseudacris maculata), Northern Leopard Frogs (NLF; Lithobates pipiens), and American Toads (AT; Anaxyrus americanus). We used radio telemetry to measure patterns of movement and habitat use by 22 NLF and 54 AT and deployed biophysical models in available habitats to estimate their physiological costs. The BCF occupied 100% of restored wetlands; NLF and AT occupied 59–91% and 71–89%, respectively, varying according to annual weather conditions. The BCF colonized new sites within a year; NLF and AT required 3 and 2 yr, respectively. These differences were related to distances from the nearest established population and costs of intervening cover types, and were statistically related to the size and orientation of restored wetlands. The ranges of maximum straight-line distances moved by NLF and AT were 31–857 m and 42–2,932 m, respectively. Both NLF and AT selected wetlands and surrounding prairies, though NLF were nine times more likely to select wetland habitats than all others combined. About 24% of AT used row-crop fields extensively, but not until crops had grown sufficiently to reduce the physiological costs of these fields similar to that of prairies. Both BCF and AT navigated the dramatically altered row-crop landscape, but NLF depended more heavily on roadside ditches to find and colonize restored wetlands.

Farm residence and lymphohematopoietic cancers in the Iowa Women’s Health Study

PubMed Central

Jones, Rena R.; Yu, Chu-Ling; Nuckols, John R.; Cerhan, James R.; Airola, Matthew; Ross, Julie A.; Robien, Kim; Ward, Mary H.

2014-01-01

Background Cancer incidence in male farmers has been studied extensively; however, less is known about risk among women residing on farms or in agricultural areas, who may be exposed to pesticides by their proximity to crop fields. We extended a previous follow-up of the Iowa Women’s Health Study cohort to examine farm residence and the incidence of lymphohematopoietic cancers. Further, we investigated crop acreage within 750 m of residences, which has been associated with higher herbicide levels in Iowa homes. Methods We analyzed data for a cohort of 37,099 Iowa women aged 55–69 years who reported their residence location (farm, rural (not a farm), town size based on population) at enrollment in 1986. We identified incident lymphohematopoietic cancers (1986–2009) by linkage with the Iowa Cancer Registry. Using a geographic information system, we geocoded addresses and calculated acreage of pasture and row crops within 750 m of homes using the 1992 National Land Cover Database. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) in multivariate analyses of cancer risk in relation to both residence location and crop acreage. Results As found in an earlier analysis of residence location, risk of acute myeloid leukemia (AML) was higher among women living on farms (HR= 2.23, 95%CI: 1.25–3.99) or rural areas (but not on a farm) (HR= 1.95, 95%CI: 0.89–4.29) compared with women living in towns of > 10,000 population. We observed no association between farm or rural residence and non-Hodgkin lymphoma (NHL; overall or for major subtypes) or multiple myeloma. In analyses of crop acreage, we observed no association between pasture or row crop acreage within 750 m of homes and risk of leukemia overall or for the AML subtype. Chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) risk was nonsignificantly elevated among women with pasture acreage within 750 m of their home (HRs for increasing tertiles= 1.8, 1.8 and 1.5) and with row crop acreage within 750 m (HRs for increasing tertiles of acreage= 1.4, 1.5 and 1.6) compared to women with no pasture or row crop acreage, respectively. Conclusions Iowa women living on a farm or in a rural area were at increased risk of developing AML, which was not related to crop acreage near the home. Living near pasture or row crops may confer an increased risk of CLL/SLL regardless of residence location. Further investigation of specific farm-related exposures and these cancers among women living on farms and in agricultural areas is warranted. PMID:25038451

Farm residence and lymphohematopoietic cancers in the Iowa Women's Health Study.

PubMed

Jones, Rena R; Yu, Chu-Ling; Nuckols, John R; Cerhan, James R; Airola, Matthew; Ross, Julie A; Robien, Kim; Ward, Mary H

2014-08-01

Cancer incidence in male farmers has been studied extensively; however, less is known about risk among women residing on farms or in agricultural areas, who may be exposed to pesticides by their proximity to crop fields. We extended a previous follow-up of the Iowa Women's Health Study cohort to examine farm residence and the incidence of lymphohematopoietic cancers. Further, we investigated crop acreage within 750 m of residences, which has been associated with higher herbicide levels in Iowa homes. We analyzed data for a cohort of 37,099 Iowa women aged 55-69 years who reported their residence location (farm, rural (not a farm), town size based on population) at enrollment in 1986. We identified incident lymphohematopoietic cancers (1986-2009) by linkage with the Iowa Cancer Registry. Using a geographic information system, we geocoded addresses and calculated acreage of pasture and row crops within 750 m of homes using the 1992 National Land Cover Database. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) in multivariate analyses of cancer risk in relation to both residence location and crop acreage. As found in an earlier analysis of residence location, risk of acute myeloid leukemia (AML) was higher among women living on farms (HR=2.23, 95%CI: 1.25-3.99) or rural areas (but not on a farm) (HR=1.95, 95%CI: 0.89-4.29) compared with women living in towns of >10,000 population. We observed no association between farm or rural residence and non-Hodgkin lymphoma (NHL; overall or for major subtypes) or multiple myeloma. In analyses of crop acreage, we observed no association between pasture or row crop acreage within 750 m of homes and risk of leukemia overall or for the AML subtype. Chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) risk was nonsignificantly elevated among women with pasture acreage within 750 m of their home (HRs for increasing tertiles=1.8, 1.8 and 1.5) and with row crop acreage within 750 m (HRs for increasing tertiles of acreage=1.4, 1.5 and 1.6) compared to women with no pasture or row crop acreage, respectively. Iowa women living on a farm or in a rural area were at increased risk of developing AML, which was not related to crop acreage near the home. Living near pasture or row crops may confer an increased risk of CLL/SLL regardless of residence location. Further investigation of specific farm-related exposures and these cancers among women living on farms and in agricultural areas is warranted. Copyright © 2014. Published by Elsevier Inc.

Parametric analysis of synthetic aperture radar data acquired over truck garden vegetation

NASA Technical Reports Server (NTRS)

Wu, S. T.

1984-01-01

An airborne X-band SAR acquired multipolarization and multiflight pass SAR images over a truck garden vegetation area. Based on a variety of land cover and row crop direction variations, the vertical (VV) polarization data contain the highest contrast, while cross polarization contains the least. When the radar flight path is parallel to the row direction, both horizontal (HH) and VV polarization data contain very high return which masks out the specific land cover that forms the row structure. Cross polarization data are not that sensitive to row orientation. The inclusion of like and cross polarization data help delineate special surface features (e.g., row crop against non-row-oriented land cover, very-rough-surface against highly row-oriented surface).

Effect of Tillage System, Row Spacing and Herbicide Technologies on Plant Growth and Lint Yield in Cotton

USDA-ARS?s Scientific Manuscript database

A field study was conducted from 2004 through 2006 growing seasons at the E.V. Smith Research Center, Field Crops Unit near Shorter, AL, to compare a conventional variety, a glyphosate tolerant variety, and a glufosinate tolerant variety under both the conventional tillage and the conservation tilla...

Planter closing wheel effects on cotton emergence in a conservation tillage system

USDA-ARS?s Scientific Manuscript database

Closing wheels on a row crop planter help provide good seed-soil contact during planting and can influence emergence and crop stand. Various types of closing wheels are available to producers for use on planters. Seven closing wheel types were used on a row crop planter planting cotton in a conser...

Effect of population density of lettuce intercropped with rocket on productivity and land-use efficiency

PubMed Central

2018-01-01

The objective of this study was to evaluate the influence of the spacing of lettuce rows on the production of a lettuce-rocket intercropping system over two growing seasons (11 August to 25 September 2011 and 12 January to 24 February 2012) in Jaboticabal, São Paulo, Brazil. We evaluated 11 treatments in each season: lettuce-rocket intercrops with five row spacings for the lettuce (0.20, 0.25, 0.30, 0.35 and 0.40 m) and the rocket planted midway between the lettuce rows, sole crops of lettuce at the same five row spacings and a sole crop of rocket. Fresh and dry masses of the lettuce and rocket and number of lettuce leaves per plant were highest with a lettuce row spacing of 0.40 m, but the productivities of the lettuce and rocket were higher with a lettuce row spacing of 0.20 m. The productivities and fresh and dry weights of the lettuce and rocket and the number of lettuce leaves per plant were highest in the sole crops, but the fresh and dry weights of the rocket were higher with intercropping. The land equivalent ratios were >1.0 in both seasons in all intercrops and were highest for the densest crop (1.41). Intercropping was therefore 41% more efficient than sole cropping for the production of lettuce and rocket. PMID:29698401

Effect of population density of lettuce intercropped with rocket on productivity and land-use efficiency.

PubMed

Nascimento, Camila Seno; Cecílio Filho, Arthur Bernardes; Mendoza-Cortez, Juan Waldir; Nascimento, Carolina Seno; Bezerra Neto, Francisco; Grangeiro, Leilson Costa

2018-01-01

The objective of this study was to evaluate the influence of the spacing of lettuce rows on the production of a lettuce-rocket intercropping system over two growing seasons (11 August to 25 September 2011 and 12 January to 24 February 2012) in Jaboticabal, São Paulo, Brazil. We evaluated 11 treatments in each season: lettuce-rocket intercrops with five row spacings for the lettuce (0.20, 0.25, 0.30, 0.35 and 0.40 m) and the rocket planted midway between the lettuce rows, sole crops of lettuce at the same five row spacings and a sole crop of rocket. Fresh and dry masses of the lettuce and rocket and number of lettuce leaves per plant were highest with a lettuce row spacing of 0.40 m, but the productivities of the lettuce and rocket were higher with a lettuce row spacing of 0.20 m. The productivities and fresh and dry weights of the lettuce and rocket and the number of lettuce leaves per plant were highest in the sole crops, but the fresh and dry weights of the rocket were higher with intercropping. The land equivalent ratios were >1.0 in both seasons in all intercrops and were highest for the densest crop (1.41). Intercropping was therefore 41% more efficient than sole cropping for the production of lettuce and rocket.

Agroforestry buffers for nonpoint source pollution reductions from agricultural watersheds.

PubMed

Udawatta, Ranjith P; Garrett, Harold E; Kallenbach, Robert

2011-01-01

Despite increased attention and demand for the adoption of agroforestry practices throughout the world, rigorous long-term scientific studies confirming environmental benefits from the use of agroforestry practices are limited. The objective was to examine nonpoint-source pollution (NPSP) reduction as influenced by agroforestry buffers in watersheds under grazing and row crop management. The grazing study consists of six watersheds in the Central Mississippi Valley wooded slopes and the row crop study site consists of three watersheds in a paired watershed design in Central Claypan areas. Runoff water samples were analyzed for sediment, total nitrogen (TN), and total phosphorus (TP) for the 2004 to 2008 period. Results indicate that agroforestry and grass buffers on grazed and row crop management sites significantly reduce runoff, sediment, TN, and TP losses to streams. Buffers in association with grazing and row crop management reduced runoff by 49 and 19%, respectively, during the study period as compared with respective control treatments. Average sediment loss for grazing and row crop management systems was 13.8 and 17.9 kg ha yr, respectively. On average, grass and agroforestry buffers reduced sediment, TN, and TP losses by 32, 42, and 46% compared with the control treatments. Buffers were more effective in the grazing management practice than row crop management practice. These differences could in part be attributed to the differences in soils, management, and landscape features. Results from this study strongly indicate that agroforestry and grass buffers can be designed to improve water quality while minimizing the amount of land taken out of production. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

High-Throughput 3-D Monitoring of Agricultural-Tree Plantations with Unmanned Aerial Vehicle (UAV) Technology

PubMed Central

Torres-Sánchez, Jorge; López-Granados, Francisca; Serrano, Nicolás; Arquero, Octavio; Peña, José M.

2015-01-01

The geometric features of agricultural trees such as canopy area, tree height and crown volume provide useful information about plantation status and crop production. However, these variables are mostly estimated after a time-consuming and hard field work and applying equations that treat the trees as geometric solids, which produce inconsistent results. As an alternative, this work presents an innovative procedure for computing the 3-dimensional geometric features of individual trees and tree-rows by applying two consecutive phases: 1) generation of Digital Surface Models with Unmanned Aerial Vehicle (UAV) technology and 2) use of object-based image analysis techniques. Our UAV-based procedure produced successful results both in single-tree and in tree-row plantations, reporting up to 97% accuracy on area quantification and minimal deviations compared to in-field estimations of tree heights and crown volumes. The maps generated could be used to understand the linkages between tree grown and field-related factors or to optimize crop management operations in the context of precision agriculture with relevant agro-environmental implications. PMID:26107174

High-Throughput 3-D Monitoring of Agricultural-Tree Plantations with Unmanned Aerial Vehicle (UAV) Technology.

PubMed

Torres-Sánchez, Jorge; López-Granados, Francisca; Serrano, Nicolás; Arquero, Octavio; Peña, José M

2015-01-01

The geometric features of agricultural trees such as canopy area, tree height and crown volume provide useful information about plantation status and crop production. However, these variables are mostly estimated after a time-consuming and hard field work and applying equations that treat the trees as geometric solids, which produce inconsistent results. As an alternative, this work presents an innovative procedure for computing the 3-dimensional geometric features of individual trees and tree-rows by applying two consecutive phases: 1) generation of Digital Surface Models with Unmanned Aerial Vehicle (UAV) technology and 2) use of object-based image analysis techniques. Our UAV-based procedure produced successful results both in single-tree and in tree-row plantations, reporting up to 97% accuracy on area quantification and minimal deviations compared to in-field estimations of tree heights and crown volumes. The maps generated could be used to understand the linkages between tree grown and field-related factors or to optimize crop management operations in the context of precision agriculture with relevant agro-environmental implications.

An analysis of spectral discrimination between corn and soybeans using a row crop reflectance model

NASA Technical Reports Server (NTRS)

Suits, G. H.

1983-01-01

Reflectance calculations of soybeans and corn crops at two times during the growing season indicate that the high sensitivity of the thematic mapper mid-infrared band to exposed bare soil between soybean rows is most likely responsible for early season spectral discrimination of corn and soybean crops by this band.

An analysis of spectral discrimination between corn and soybeans using a row crop reflectance model

NASA Technical Reports Server (NTRS)

Suits, G. H.

1985-01-01

Reflectance calculations of soybeans and corn crops at two times during the growing season indicate that the high sensitivity of the thematic mapper mid-infrared band to exposed bare soil between soybean rows is most likely responsible for early season spectral discrimination of corn and soybean crops by this band.

Generic Verification Protocol for Testing Pesticide Application Spray Drift Reduction Technologies for Row and Field Crops

EPA Pesticide Factsheets

This generic verification protocol provides a detailed method to conduct and report results from a verification test of pesticide application technologies that can be used to evaluate these technologies for their potential to reduce spray drift.

Estimating plant distance in maize using Unmanned Aerial Vehicle (UAV).

PubMed

Zhang, Jinshui; Basso, Bruno; Price, Richard F; Putman, Gregory; Shuai, Guanyuan

2018-01-01

Distance between rows and plants are essential parameters that affect the final grain yield in row crops. This paper presents the results of research intended to develop a novel method to quantify the distance between maize plants at field scale using an Unmanned Aerial Vehicle (UAV). Using this method, we can recognize maize plants as objects and calculate the distance between plants. We initially developed our method by training an algorithm in an indoor facility with plastic corn plants. Then, the method was scaled up and tested in a farmer's field with maize plant spacing that exhibited natural variation. The results of this study demonstrate that it is possible to precisely quantify the distance between maize plants. We found that accuracy of the measurement of the distance between maize plants depended on the height above ground level at which UAV imagery was taken. This study provides an innovative approach to quantify plant-to-plant variability and, thereby final crop yield estimates.

Reducing soil erosion and nutrient loss on sloping land under crop-mulberry management system.

PubMed

Fan, Fangling; Xie, Deti; Wei, Chaofu; Ni, Jiupai; Yang, John; Tang, Zhenya; Zhou, Chuan

2015-09-01

Sloping croplands could result in soil erosion, which leads to non-point source pollution of the aquatic system in the Three Gorges Reservoir Region. Mulberry, a commonly grown cash plant in the region, is traditionally planted in contour hedgerows as an effective management practice to control soil erosion and non-point source pollution. In this field study, surface runoff and soil N and P loss on sloping land under crop-mulberry management were investigated. The experiments consisted of six crop-mulberry treatments: Control (no mulberry hedgerow with mustard-corn rotation); T1 (two-row contour mulberry with mustard-corn rotation); T2 (three-row contour mulberry with mustard-corn rotation); T3 (border mulberry and one-row contour mulberry with mustard-corn rotation); T4 (border mulberry with mustard-corn rotation); T5 (two-row longitudinal mulberry with mustard). The results indicated that crop-mulberry systems could effectively reduce surface runoff and soil and nutrient loss from arable slope land. Surface runoff from T1 (342.13 m(3) hm(-2)), T2 (260.6 m(3) hm(-2)), T3 (113.13 m(3) hm(-2)), T4 (114 m(3) hm(-2)), and T5 (129 m(3) hm(-2)) was reduced by 15.4, 35.6, 72.0, 71.8, and 68.1%, respectively, while soil loss from T1 (0.21 t hm(-2)), T2 (0.13 t hm(-2)), T3 (0.08 t hm(-2)), T4 (0.11 t hm(-2)), and T5 (0.12 t hm(-2)) was reduced by 52.3, 70.5, 81.8, 75.0, and 72.7%, respectively, as compared with the control. Crop-mulberry ecosystem would also elevate soil N by 22.3% and soil P by 57.4%, and soil nutrient status was contour-line dependent.

Row Ratios of Intercropping Maize and Soybean Can Affect Agronomic Efficiency of the System and Subsequent Wheat

PubMed Central

Zhang, Yitao; Liu, Jian; Zhang, Jizong; Liu, Hongbin; Liu, Shen; Zhai, Limei; Wang, Hongyuan; Lei, Qiuliang; Ren, Tianzhi; Yin, Changbin

2015-01-01

Intercropping is regarded as an important agricultural practice to improve crop production and environmental quality in the regions with intensive agricultural production, e.g., northern China. To optimize agronomic advantage of maize (Zea mays L.) and soybean (Glycine max L.) intercropping system compared to monoculture of maize, two sequential experiments were conducted. Experiment 1 was to screening the optimal cropping system in summer that had the highest yields and economic benefits, and Experiment 2 was to identify the optimum row ratio of the intercrops selected from Experiment 1. Results of Experiment 1 showed that maize intercropping with soybean (maize || soybean) was the optimal cropping system in summer. Compared to conventional monoculture of maize, maize || soybean had significant advantage in yield, economy, land utilization ratio and reducing soil nitrate nitrogen (N) accumulation, as well as better residual effect on the subsequent wheat (Triticum aestivum L.) crop. Experiment 2 showed that intercropping systems reduced use of N fertilizer per unit land area and increased relative biomass of intercropped maize, due to promoted photosynthetic efficiency of border rows and N utilization during symbiotic period. Intercropping advantage began to emerge at tasseling stage after N topdressing for maize. Among all treatments with different row ratios, alternating four maize rows with six soybean rows (4M:6S) had the largest land equivalent ratio (1.30), total N accumulation in crops (258 kg ha-1), and economic benefit (3,408 USD ha-1). Compared to maize monoculture, 4M:6S had significantly lower nitrate-N accumulation in soil both after harvest of maize and after harvest of the subsequent wheat, but it did not decrease yield of wheat. The most important advantage of 4M:6S was to increase biomass of intercropped maize and soybean, which further led to the increase of total N accumulation by crops as well as economic benefit. In conclusion, alternating four maize rows with six soybean rows was the optimum row ratio in maize || soybean system, though this needs to be further confirmed by pluri-annual trials. PMID:26061566

Assessing the spatial distribution of Tuta absoluta (Lepidoptera: Gelechiidae) eggs in open-field tomato cultivation through geostatistical analysis.

PubMed

Martins, Júlio C; Picanço, Marcelo C; Silva, Ricardo S; Gonring, Alfredo Hr; Galdino, Tarcísio Vs; Guedes, Raul Nc

2018-01-01

The spatial distribution of insects is due to the interaction between individuals and the environment. Knowledge about the within-field pattern of spatial distribution of a pest is critical to planning control tactics, developing efficient sampling plans, and predicting pest damage. The leaf miner Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is the main pest of tomato crops in several regions of the world. Despite the importance of this pest, the pattern of spatial distribution of T. absoluta on open-field tomato cultivation remains unknown. Therefore, this study aimed to characterize the spatial distribution of T. absoluta in 22 commercial open-field tomato cultivations with plants at the three phenological development stages by using geostatistical analysis. Geostatistical analysis revealed that there was strong evidence for spatially dependent (aggregated) T. absoluta eggs in 19 of the 22 sample tomato cultivations. The maps that were obtained demonstrated the aggregated structure of egg densities at the edges of the crops. Further, T. absoluta was found to accomplish egg dispersal along the rows more frequently than it does between rows. Our results indicate that the greatest egg densities of T. absoluta occur at the edges of tomato crops. These results are discussed in relation to the behavior of T. absoluta distribution within fields and in terms of their implications for improved sampling guidelines and precision targeting control methods that are essential for effective pest monitoring and management. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Comprehensive Understanding for Vegetated Scene Radiance Relationships

NASA Technical Reports Server (NTRS)

Kimes, D. S.; Deering, D. W.

1984-01-01

Directional reflectance distributions spanning the entire existent hemisphere were measured in two field studies; one using a Mark III 3-band radiometer and one using the rapid scanning bidirectional field instrument called PARABOLA. Surfaces measured included corn, soybeans, bare soils, grass lawn, orchard grass, alfalfa, cotton row crops, plowed field, annual grassland, stipa grass, hard wheat, salt plain shrubland, and irrigated wheat. Analysis of field data showed unique reflectance distributions ranging from bare soil to complete vegetation canopies. Physical mechanisms causing these trends were proposed. A 3-D model was developed and is unique in that it predicts: (1) the directional spectral reflectance factors as a function of the sensor's azimuth and zenith angles and the sensor's position above the canopy; (2) the spectral absorption as a function of location within the scene; and (3) the directional spectral radiance as a function of the sensor's location within the scene. Initial verification of the model as applied to a soybean row crop showed that the simulated directional data corresponded relatively well in gross trends to the measured data. The model was expanded to include the anisotropic scattering properties of leaves as a function of the leaf orientation distribution in both the zenith and azimuth angle modes.

Automatic segmentation of trees in dynamic outdoor environments

USDA-ARS?s Scientific Manuscript database

Segmentation in dynamic outdoor environments can be difficult when the illumination levels and other aspects of the scene cannot be controlled. Specifically in agricultural contexts, a background material is often used to shield a camera's field of view from other rows of crops. In this paper, we ...

The importance of temporal inequality in quantifying vegetated filter strip removal efficiencies

USDA-ARS?s Scientific Manuscript database

Vegetated filter strips (VFSs) are best management practices (BMPs) commonly implemented adjacent to row-cropped fields to trap overland transport of sediment and other constituents often present in agricultural runoff. VFSs are generally reported to have high sediment removal efficiencies (i.e., 70...

GENERIC VERIFICATION PROTOCOL FOR THE VERIFICATION OF PESTICIDE SPRAY DRIFT REDUCTION TECHNOLOGIES FOR ROW AND FIELD CROPS

EPA Science Inventory

This ETV program generic verification protocol was prepared and reviewed for the Verification of Pesticide Drift Reduction Technologies project. The protocol provides a detailed methodology for conducting and reporting results from a verification test of pesticide drift reductio...

APEX Model Simulation for Row Crop Watersheds with Agroforestry and Grass Buffers

USDA-ARS?s Scientific Manuscript database

Watershed model simulation has become an important tool in studying ways and means to reduce transport of agricultural pollutants. Conducting field experiments to assess buffer influences on water quality are constrained by the large-scale nature of watersheds, high experimental costs, private owner...

Investigation of crop canopy temperature in apple study orchard

NASA Astrophysics Data System (ADS)

Tökei, L.; Dunkel, Z.

2003-04-01

The paper shows a sophisticated case study for the possible determination of transpiration of apple orchard. A 'Scheduler' type water stress instrument originally developed for crops was used in the study apple orchard of the university. The air and crop canopy temperatures, the relative humidity and the radiation were measured. The aim was to determine the influence of these factors at different level of the canopy, with various exposures of the tree crowns. The measurements were made on several trees in certain selected rows and on those planted in concentric rows in a round field. The relationship between crop canopy and sir temperatures appeared to depend primarily on illumination. This can be greatly affected by shading conditions, but air motion cannot be neglected, the effect of which increases when its direction is in agreement with the direction of the rows. Its efficiency also has a significant effect on air humidity conditions. The relative humidity and air temperature values were used to calculate the equivalent temperature, also considering latent heat flux, and finally the evapotranspiration of plantation. From differences in the equivalent and air temperatures, conclusions can be drawn on the intensity and daily course of transpiration. Using this method differences at given level could not be demonstrated in the relatively opera orchards studied. According to the results, transpiration is the strongest in the morning, after which it significantly decreases by the afternoon and becomes more intense again early at night.

Comperative investigations of non chemical weed management methods in Hungary.

PubMed

Pali, Orsolya; Reisinger, Peter; Pomsar, Peter

2007-01-01

Organic farming has an increasing tendency in Hungary because of growing consumers' demands according to organic products not only in inland but also in the countries of the European Union. Developments of weed control methods in organically cropped field plants have become conspicuous next to developing chemical weed management methods of convencionally cropped cultural plants. The aim of our investigations was to make comperative investigations of non chemical weed control methods in wide rowed plants.

Effects of watershed-scale land use change on stream nitrate concentrations

USGS Publications Warehouse

Schilling, K.E.; Spooner, J.

2006-01-01

The Walnut Creek Watershed Monitoring Project was conducted from 1995 through 2005 to evaluate the response of stream nitrate concentrations to changing land use patterns in paired 5000-ha Iowa watersheds. A large portion of the Walnut Creek watershed is being converted from row crop agriculture to native prairie and savanna by the U.S. Fish and Wildlife Service at the Neal Smith National Wildlife Refuge (NSNWR). Before restoration, land use in both Walnut Creek (treatment) and Squaw Creek (control) watersheds consisted of 70% row crops. Between 1990 and 2005, row crop area decreased 25.4% in Walnut Creek due to prairie restoration but increased 9.2% in Squaw Creek due to Conservation Reserve Program (CRP) grassland conversion back to row crop. Nitrate concentrations ranged between <0.5 to 14 mg L-1 at the Walnut Creek outlet and 2.1 to 15 mg L-1 at the downstream Squaw Creek outlet. Nitrate concentrations decreased 1.2 mg L-1 over 10 yr in the Walnut Creek watershed but increased 1.9 mg L-1 over 10 yr in Squaw Creek. Changes in nitrate were easier to detect and more pronounced in monitored subbasins, decreasing 1.2 to 3.4 mg L-1 in three Walnut Creek subbasins, but increasing up to 8.0 and 11.6 mg L-1 in 10 yr in two Squaw Creek subbasins. Converting row crop lands to grass reduced stream nitrate levels over time in Walnut Creek, but stream nitrate rapidly increased in Squaw Creek when CRP grasslands were converted back to row crop. Study results highlight the close association of stream nitrate to land use change and emphasize that grasslands or other perennial vegetation placed in agricultural settings should be part of a long-term solution to water quality problems. ?? ASA, CSSA, SSSA.

The Corps of Engineers and Prairie Restoration: Synopsis of the First Corps Prairie Workshop, Follow-up Actions, and Thoughts on the Future of Prairie Restoration and Management on Operational Projects

DTIC Science & Technology

2009-06-01

Corps super- vision regarding management practices such as cropping systems and cattle grazing. Also, the Corps’ focus at the time was on tree planting...on crop rotation and removal of grazing. Changes included the installation of 100-ft-wide warm-season native grass strips between each agricultural...brood-rearing habitat, but it was not always possible to put that much land aside. Idle fields consisted of 5- to 15-acre blocks centered in row crop

Tine cultivation effects on weed control, productivity, and economics of peanut under organic management

USDA-ARS?s Scientific Manuscript database

Identifying effective weed control regimes for organic peanut has become paramount for improving the feasibility of organic production. Tine cultivation is a proven effective method at reducing in-row weed populations in several crops. Field trials were therefore conducted in 2008 and 2009 to asse...

Spatiotemporal Distribution of Chinavia hilaris (Hemiptera: Pentatomidae) in Corn Farmscapes

USDA-ARS?s Scientific Manuscript database

The green stink bug, Chinavia hilaris (Say) (Hemiptera: Pentatomidae), is an economic pest of cotton across the southeastern U.S., however, little is known concerning its spatial distribution in corn fields of this region. It is likely that the proximity of other adjacent row crops, i.e., cotton an...

Advances in greenhouse automation and controlled environment agriculture: A transition to plant factories and urban farming

USDA-ARS?s Scientific Manuscript database

Greenhouse cultivation has evolved from simple covered rows of open-fields crops to highly sophisticated controlled environment agriculture (CEA) facilities that projected the image of plant factories for urban farming. The advances and improvements in CEA have promoted the scientific solutions for ...

Propelled abrasive grit for weed control in organic silage corn

USDA-ARS?s Scientific Manuscript database

Weed management in organic farming requires many strategies to accomplish acceptable control and maintain crop yields. This two-year field study used air propelled abrasive grit for in-row weed control in a silage corn system. Corncob grit was applied as a single application at corn vegetative growt...

The effects of disproportional load contributions on quantifying vegetated filter strip sediment trapping efficiencies

USDA-ARS?s Scientific Manuscript database

Vegetated filter strips (VFSs) are a best management practice (BMP) commonly implemented adjacent to row-cropped fields to trap overland transport of sediment and other constituents present in agricultural runoff. Although they have been widely adopted, insufficient data exist to understand their sh...

Effects of tillage and N fertilizer on cotton growth, yield, and fiber quality

USDA-ARS?s Scientific Manuscript database

Increasing restrictions on ammonium nitrate have spurred interest in alternative sources of N fertilizer, including urea-ammonium sulfate (UAS). However, UAS has not been widely tested, particularly in row crop agriculture. A cotton (Gossypium hirsutum L.) field study was conducted in Central Alabam...

Field Evaluations of Commercial Humic Products: Current Knowledge and Future Needs.

USDA-ARS?s Scientific Manuscript database

Humic products are extracts of lignite or leonardite, which are immature coals. Humic products are sold commercially; their advertisements claim they will improve plant growth when applied to plants or soil. They are bought by small proportions of row crop farmers and growers of flowers, vegetables,...

Attraction of stink bug (Hemiptera: Pentatomidae) nymphs to Euschistus aggregation pheromone in the field

USDA-ARS?s Scientific Manuscript database

Phytophagous stink bugs (Hemiptera: Pentatomidae) are primary pests in most fruit, vegetable, grain, and row crops worldwide. Pheromones have been identified and synthesized for several species of economically important stink bug pests. When yellow pyramid traps are baited with lures containing thes...

Field research on the spectral properties of crops and soils, volume 1. [Purdue Agronomy Farm

NASA Technical Reports Server (NTRS)

Bauer, M. E. (Principal Investigator); Biehl, L. L.; Robinson, B. F.

1980-01-01

The experiment design, data acquisition and preprocessing, data base management, analysis results and development of instrumentation for the AgRISTARS Supporting Research Project, Field Research task are described. Results of several investigations on the spectral reflectance of corn and soybean canopies as influenced by cultural practices, development stage and nitrogen nutrition are reported as well as results of analyses of the spectral properties of crop canopies as a function of canopy geometry, row orientation, sensor view angle and solar illumination angle are presented. The objectives, experiment designs and data acquired in 1980 for field research experiments are described. The development and performance characteristics of a prototype multiband radiometer, data logger, and aerial tower for field research are discussed.

Soil Functional Zone Management: A Vehicle for Enhancing Production and Soil Ecosystem Services in Row-Crop Agroecosystems.

PubMed

Williams, Alwyn; Kane, Daniel A; Ewing, Patrick M; Atwood, Lesley W; Jilling, Andrea; Li, Meng; Lou, Yi; Davis, Adam S; Grandy, A Stuart; Huerd, Sheri C; Hunter, Mitchell C; Koide, Roger T; Mortensen, David A; Smith, Richard G; Snapp, Sieglinde S; Spokas, Kurt A; Yannarell, Anthony C; Jordan, Nicholas R

2016-01-01

There is increasing global demand for food, bioenergy feedstocks and a wide variety of bio-based products. In response, agriculture has advanced production, but is increasingly depleting soil regulating and supporting ecosystem services. New production systems have emerged, such as no-tillage, that can enhance soil services but may limit yields. Moving forward, agricultural systems must reduce trade-offs between production and soil services. Soil functional zone management (SFZM) is a novel strategy for developing sustainable production systems that attempts to integrate the benefits of conventional, intensive agriculture, and no-tillage. SFZM creates distinct functional zones within crop row and inter-row spaces. By incorporating decimeter-scale spatial and temporal heterogeneity, SFZM attempts to foster greater soil biodiversity and integrate complementary soil processes at the sub-field level. Such integration maximizes soil services by creating zones of 'active turnover', optimized for crop growth and yield (provisioning services); and adjacent zones of 'soil building', that promote soil structure development, carbon storage, and moisture regulation (regulating and supporting services). These zones allow SFZM to secure existing agricultural productivity while avoiding or minimizing trade-offs with soil ecosystem services. Moreover, the specific properties of SFZM may enable sustainable increases in provisioning services via temporal intensification (expanding the portion of the year during which harvestable crops are grown). We present a conceptual model of 'virtuous cycles', illustrating how increases in crop yields within SFZM systems could create self-reinforcing feedback processes with desirable effects, including mitigation of trade-offs between yield maximization and soil ecosystem services. Through the creation of functionally distinct but interacting zones, SFZM may provide a vehicle for optimizing the delivery of multiple goods and services in agricultural systems, allowing sustainable temporal intensification while protecting and enhancing soil functioning.

Soil Functional Zone Management: A Vehicle for Enhancing Production and Soil Ecosystem Services in Row-Crop Agroecosystems

PubMed Central

Williams, Alwyn; Kane, Daniel A.; Ewing, Patrick M.; Atwood, Lesley W.; Jilling, Andrea; Li, Meng; Lou, Yi; Davis, Adam S.; Grandy, A. Stuart; Huerd, Sheri C.; Hunter, Mitchell C.; Koide, Roger T.; Mortensen, David A.; Smith, Richard G.; Snapp, Sieglinde S.; Spokas, Kurt A.; Yannarell, Anthony C.; Jordan, Nicholas R.

2016-01-01

There is increasing global demand for food, bioenergy feedstocks and a wide variety of bio-based products. In response, agriculture has advanced production, but is increasingly depleting soil regulating and supporting ecosystem services. New production systems have emerged, such as no-tillage, that can enhance soil services but may limit yields. Moving forward, agricultural systems must reduce trade-offs between production and soil services. Soil functional zone management (SFZM) is a novel strategy for developing sustainable production systems that attempts to integrate the benefits of conventional, intensive agriculture, and no-tillage. SFZM creates distinct functional zones within crop row and inter-row spaces. By incorporating decimeter-scale spatial and temporal heterogeneity, SFZM attempts to foster greater soil biodiversity and integrate complementary soil processes at the sub-field level. Such integration maximizes soil services by creating zones of ‘active turnover’, optimized for crop growth and yield (provisioning services); and adjacent zones of ‘soil building’, that promote soil structure development, carbon storage, and moisture regulation (regulating and supporting services). These zones allow SFZM to secure existing agricultural productivity while avoiding or minimizing trade-offs with soil ecosystem services. Moreover, the specific properties of SFZM may enable sustainable increases in provisioning services via temporal intensification (expanding the portion of the year during which harvestable crops are grown). We present a conceptual model of ‘virtuous cycles’, illustrating how increases in crop yields within SFZM systems could create self-reinforcing feedback processes with desirable effects, including mitigation of trade-offs between yield maximization and soil ecosystem services. Through the creation of functionally distinct but interacting zones, SFZM may provide a vehicle for optimizing the delivery of multiple goods and services in agricultural systems, allowing sustainable temporal intensification while protecting and enhancing soil functioning. PMID:26904043

WEED SURVEYING OF PHACELIA (PHACELIA TANACETIFOLIA L.) AND EVALUATING THE EFFICIENCY OF THE WEED CONTROL.

PubMed

Horváth, E; Szabó, R

2014-01-01

The experiment was set up in an area of 9 ha that was split into 4 plots: in plot 1 the row spacing was 12 cm and the seeding rate was 10 kg; in plot 2 the row spacing was 24 cm and the seeding rate was 10 kg; in plot 3 the row spacing was 24 cm and the seeding rate was 8 kg; in plot 4 the row spacing was 12 cm and the seeding rate was 8 kg. After the weed surveying, the total weed coverage was established as follows: in plot 1 the total weed coverage was 11.34%, in plot 2 it was 12.3%, in plot 3 it was 18%, and in plot 4 the total weed coverage was 15%. Based on the weed survey, on the test area the following dicotyledon weeds belonging to the T4 Raunkiaer plant life-form category occupied the highest percentage: heal-all, black-bindweed, goosefoot. The proportion of the perennial dicotyledons: field bindweed (G3), tuberous pea (G1), white campion (H3) was negligible. In all four cases the weed control was executed using the same herbicide in the same doses and with regard to the weed species it showed the same level of efficiency. The smaller row spacing and higher seeding rate has a beneficial effect on the weed suppressing capacity of the crop, the crop's weed suppressing capacity is better and the development of the weeds becomes worse.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nair, Shyam; Hartley, Damon S; Hays, Ross D

LEAF Version 2.0 is a framework comprising of three models RUSLE2, WEPS, and AGNPS. The framework can predict row crop, crop residue, and energy crop yields at a sub-field resolutions for various combinations of soil, climate and crop management and residue harvesting practices. It estimates the loss of soil, carbon, and nutrients to the atmosphere, to the groundwater, and to runoff. It also models the overland flow of water and washed-off sediments, nutrients and other chemicals to provide estimates of sediment, nutrient, and chemical loadings to water bodies within a watershed. AGNPS model and wash-off calculations are the new additionsmore » to this version of LEAF. Development of LEAF software is supported by DOE's BETO program.« less

Candidate perennial bioenergy grasses have a higher albedo than annual row crops in the Midwestern US

USDA-ARS?s Scientific Manuscript database

The production of perennial cellulosic feedstocks for bioenergy presents the potential to diversify regional economies and the national energy supply, while also serving as climate ‘regulators’ due to a number of biogeochemical and biogeophysical differences relative to row crops. Numerous observati...

Soil quality parameters for row-crop and grazed pasture systems with agroforestry buffers

USDA-ARS?s Scientific Manuscript database

Incorporation of trees and establishment of buffers are practices that can improve soil quality. Soil enzyme activities and water stable aggregates are sensitive indices for assessing soil quality by detecting early changes in soil management. However, studies comparing grazed pasture and row crop...

Radar backscattering properties of corn and soybeans at frequencies of 1.6, 4.75, and 13.3. GHz

NASA Technical Reports Server (NTRS)

Paris, J. F.

1983-01-01

The NASA Johnson Space Center made an observational study of the radar-backscattering properties of corn and soybeans in commercial fields in a test site in Webster County, IA. Aircraft-based radar scatterometers measured the backscattering coefficient of the crops at three frequencies, 1.6 GHz (L-band), 4.75 GHz (C-band), and 13.3 GHz (Ku-band), at 10 sensor look-angles (5 to 50 degrees from the nadir in steps of 5 degrees), and with several polarization combinations. Among other findings, it was determined that: (1) row direction differences among fields affected significantly the radar-backscattering coefficient of the fields when the radar system used like-polarization at look-angles from 5 to 25 degrees; (2) row-direction differences had no effect on radar backscattering when the system used either cross-polarization or look-angles greater than 25 degrees regardless of the polarization; (3) wet surface-soil moisture conditions resulted in significantly poorer spectral separability of the two crops as compared to dry-soil conditions; and (4) on the dry-soil date, the best channel for separating corn from soybeans was the C-band cross-polarized measurement at a look-angle of 50 degrees.

Development of Sustainable Landscape Designs for Improved Biomass Production in the U.S. Corn Belt

NASA Astrophysics Data System (ADS)

Bonner, Ian J.

Demand for renewable and sustainable energy options has resulted in a significant commitment by the US Government to research pathways for fuel production from biomass. The research presented in this thesis describes one potential pathway to increase the amount of biomass available for biofuel production by integrating dedicated energy crops into agricultural fields. In the first chapter an innovative landscape design method based on subfield placement of an energy crop into row crop fields in central Iowa is used to reduce financial loss for farmers, increase and diversify biomass production, and improve soil resources. The second chapter explores how subfield management decisions may be made using high fidelity data and modeling to balance concerns of primary crop production and economics. This work provides critical forward looking support to agricultural land managers and stakeholders in the biomass and bioenergy industry for pathways to improving land stewardship and energy security.

Does spatial arrangement of 3D plants affect light transmission and extinction coefficient within maize crops?

USDA-ARS?s Scientific Manuscript database

Row spacing effects on light interception and extinction coefficient have been inconsistent for maize (Zea mays L.) when calculated with field measurements. To avoid inconsistencies due to variable light conditions and variable leaf canopies, we used a model to describe three-dimensional (3D) shoot ...

Evaluation of spray drift using low speed wind tunnel measurements and dispersion modeling

USDA-ARS?s Scientific Manuscript database

The objective of this work was to evaluate the EPA’s proposed Test Plan for the validation testing of pesticide spray drift reduction technologies (DRTs) for row and field crops, focusing on the evaluation of ground application systems using the low-speed wind tunnel protocols and processing the dat...

Generic Verification Protocol for Testing Pesticide Application Spray Drift Reduction Technologies for Row and Field Crops (Version 1.4)

EPA Science Inventory

This generic verification protocol provides a detailed method for conducting and reporting results from verification testing of pesticide application technologies. It can be used to evaluate technologies for their potential to reduce spray drift, hence the term “drift reduction t...

Establishment of three permanent cover crop seed mixtures in Hungarian vineyards

NASA Astrophysics Data System (ADS)

Miglécz, Tamas; Valkó, Orsolya; Donkó, Ádám; Deák, Balázs; Török, Péter; Kelemen, András; Drexler, Dóra; Tóthmérész, Béla

2015-04-01

In organic vineyard farming sowing high diversity cover crop seed mixtures offers a great opportunity to overcome high-priority problems mitigating vineyard cultivation, such as gain erosion control, save soil fertility, improve soil microbial activity and control weeds. Furthermore, we can also improve the biodiversity and ecosystem services of vineyards. Mainly non-native or low diversity seed mixtures are used for cover cropping containing some grass, grain or Fabaceae species. We studied vegetation development after sowing native high-diversity seed mixtures in four vineyards in an on farm field trial. We compared the effects of 4 treatments: (i) Biocont-Ecowin mixture (12 species), (ii) Fabaceae mixture (9 species), (iii) Grass-forb mixture (16 species) and control (no seed sowing). Study sites were located in Tokaj wine region, East Hungary. Seed mixtures were sown in March, 2012. After sowing, we recorded the percentage cover of vascular plant species in the end of June 2012, 2013 and 2014 in altogether 80 permanent plots. In the first year the establishment and weed control of Biocont-Ecowin and Legume seed mixture was the best. For the second year in inter-rows sown with Grass-herb and Legume seed mixtures we detected decreasing weed cover scores, while in inter-rows sown with Biocont-Ecowin seed mixture and in control inter-rows we detected higher weed cover scores. In the third year we still detected lower weed cover scores in inter-rows sown with Grass-forb and Legume seed mixtures, however on several sites we also detected decreasing cover of sown species. All sown species were detected in our plots during the time of the study, however some species were present only with low cover scores or only in a few plots. Out of the sown species Lotus corniculatus, Medicago lupulina, Plantago lanceolata, Trifolium repens, T. pratense and Coronilla varia established the most successfully, and had high cover scores on most sites even in the second and third year. Our trial to develop species rich cover crops was successful. According to our findings sowing high-diversity seed mixtures in cover cropping offers a good opportunity to gain weed control.

Two-source energy balance model to calculate row crop E.T. and ET:Advances at ARS, Bushland, TX 2010-2015

USDA-ARS?s Scientific Manuscript database

The two-source energy balance (TSEB) model has undergone several advances recently that improved its accuracy in calculating evaporation (E), transpiration (T), and evapotranspiration (ET) for row crops. These advances were tested using microlysimeter, sap flow, and large weighing lysimeter measurem...

Economic assessment of conventional and conservation tillage practices in different wheat-based cropping systems of Punjab, Pakistan.

PubMed

Shahzad, Muhammad; Hussain, Mubshar; Farooq, Muhammad; Farooq, Shahid; Jabran, Khawar; Nawaz, Ahmad

2017-11-01

Wheat productivity and profitability is low under conventional tillage systems as they increase the production cost, soil compaction, and the weed infestation. Conservation tillage could be a pragmatic option to sustain the wheat productivity and enhance the profitability on long term basis. This study was aimed to evaluate the economics of different wheat-based cropping systems viz. fallow-wheat, rice-wheat, cotton-wheat, mung bean-wheat, and sorghum-wheat, with zero tillage, conventional tillage, deep tillage, bed sowing (60/30 cm beds and four rows), and bed sowing (90/45 cm beds and six rows). Results indicated that the bed sown wheat had the maximum production cost than other tillage systems. Although both bed sowing treatments incurred the highest production cost, they generated the highest net benefits and benefit: cost ratio (BCR). Rice-wheat cropping system with bed sown wheat (90/45 cm beds with six rows) had the highest net income (4129.7 US$ ha -1 ), BCR (2.87), and marginal rate of return compared with rest of the cropping systems. In contrast, fallow-wheat cropping system incurred the lowest input cost, but had the least economic return. In crux, rice-wheat cropping system with bed sown wheat (90/45 cm beds with six rows) was the best option for getting the higher economic returns. Moreover, double cropping systems within a year are more profitable than sole planting of wheat under all tillage practices.

Black plastic mulch combined with summer cover crop increases the yield and water use efficiency of apple tree on the rainfed Loess Plateau

PubMed Central

Zheng, Wei; Wen, Meijuan; Zhao, Zhiyuan; Liu, Jie; Wang, Zhaohui; Li, Ziyan

2017-01-01

Water deficit significantly limits dryland rainfed fruit production, so increasing water conservation is crucial for improving fruit productivity in arid and semiarid areas. In this study, we tested two treatments in an apple orchard: 1) PC treatment comprising black plastic mulch (BPM) (in-row) with weed control (inter-row); 2) and PGC treatment comprising BPM (in-row) combined with a summer cover crop (inter-row) of rape (Brassica campestris L.), which was sown in mid-June and was living from July to September. Under PGC, the inter-row soil water storage increased by 17.9% and 11.5% compared with PC after the harvest in 2013 and 2014, respectively, but there was no significant increase in 2015. The evapotranspiration (ET) from the inter-row areas during the cover crop period was lower under PGC than PC in 2013 (19.6%), 2014 (11.3%), and 2015 (13.3%). However, the differences in the total ET from the inter-row areas between the two treatments were not obvious, and the total ET from in-row areas was higher under PGC than PC due to the increased water uptake by apple trees under PGC. The apple yield, water use efficiency during the cover crop period (WUEg) and total water use efficiency (WUE) fluctuated during the experimental years. Compared with PC, the apple yield increased by 14.1%, 18.8%, and 26.7% under PGC in 2013, 2014, and 2015, respectively. In addition, the WUEg was 26.4%, 24.7%, and 32.7% higher under PGC compared with PC in 2013, 2014, and 2015, respectively. Thus, the WUE under PGC was 13.8% and 11.7% higher than that under PC in 2013 and 2014, respectively, but the difference was not significant in 2015 (p = 0.0527). Thus, BPM combined with a summer cover crop is recommended for decreasing the summer ET and promoting apple production in rainfed dryland areas where the rainy season is usually the hot season. PMID:28957428

Corn blight review: Sampling model and ground data measurements program

NASA Technical Reports Server (NTRS)

Allen, R. D.

1972-01-01

The sampling plan involved the selection of the study area, determination of the flightline and segment sample design within the study area, and determination of a field sample design. Initial interview survey data consisting of crop species acreage and land use were collected. On all corn fields, additional information such as seed type, row direction, population, planting date, ect. were also collected. From this information, sample corn fields were selected to be observed through the growing season on a biweekly basis by county extension personnel.

Effect of skip row planting configuration on grain sorghum water use

USDA-ARS?s Scientific Manuscript database

Grain sorghum (Sorghum bicolor L. [Moench]) is grown as a dryland crop in the semi-arid Central Great Plains. Growing the crop in a skip row configuration has been proposed as a means of delaying water use during the vegetative stage such that more water will be available to be used during the more ...

Effect of rainfall timing and tillage on the transport of steroid hormones in runoff from manure amended row crop fields

USDA-ARS?s Scientific Manuscript database

Manure generated from concentrated animal feeding operations (CAFOs) represents one of the major sources of steroid hormones found in surface water. This paper presents results of a study conducted near Concord, NE to determine the effects of manure handling (compost vs. stockpile), tillage (no-till...

Water quality of surface runoff and lint yield in cotton under furrow irrigation in Northeast Arkansas

USDA-ARS?s Scientific Manuscript database

Use of furrow irrigation in row crop production is a common practice through much of the Midsouth US and yet, nutrients can be transported off-site through surface runoff. A field study with cotton (Gossypium hirsutum, L.) was conducted to understand the impact of furrow tillage practices and nitrog...

Spray Toxicity and Risk Potential of 42 Commonly Used Formulations of Row Crop Pesticides to Adult Honey Bees (Hymenoptera: Apidae).

PubMed

Zhu, Yu Cheng; Adamczyk, John; Rinderer, Thomas; Yao, Jianxiu; Danka, Robert; Luttrell, Randall; Gore, Jeff

2015-12-01

To combat an increasing abundance of sucking insect pests, >40 pesticides are currently recommended and frequently used as foliar sprays on row crops, especially cotton. Foraging honey bees may be killed when they are directly exposed to foliar sprays, or they may take contaminated pollen back to hives that maybe toxic to other adult bees and larvae. To assess acute toxicity against the honey bee, we used a modified spray tower to simulate field spray conditions to include direct whole-body exposure, inhalation, and continuing tarsal contact and oral licking after a field spray. A total of 42 formulated pesticides, including one herbicide and one fungicide, were assayed for acute spray toxicity to 4-6-d-old workers. Results showed significantly variable toxicities among pesticides, with LC50s ranging from 25 to thousands of mg/liter. Further risk assessment using the field application concentration to LC1 or LC99 ratios revealed the risk potential of the 42 pesticides. Three pesticides killed less than 1% of the worker bees, including the herbicide, a miticide, and a neonicotinoid. Twenty-six insecticides killed more than 99% of the bees, including commonly used organophosphates and neonicotinoids. The remainder of the 13 chemicals killed from 1-99% of the bees at field application rates. This study reveals a realistic acute toxicity of 42 commonly used foliar pesticides. The information is valuable for guiding insecticide selection to minimize direct killing of foraging honey bees, while maintaining effective control of field crop pests. Published by Oxford University Press [on behalf of Entomological Society of America] 2015. This work is written by US Government employees and is in the public domain in the US.

Analysis of data acquired by synthetic aperture radar over Dade County, Florida, and Acadia Parish, Louisiana

NASA Technical Reports Server (NTRS)

Wu, S. T.

1983-01-01

Results of digital processing of airborne X-band synthetic aperture radar (SAR) data acquired over Dade County, Florida, and Acadia Parish, Louisiana are presented. The goal was to investigate the utility of SAR data for land cover mapping and area estimation under the AgRISTARS Domestic Crops and Land Cover Project. In the case of the Acadia Paris study area, LANDSAT multispectral scanner (MSS) data were also used to form a combined SAR and MSS data set. The results of accuracy evaluation for the SAR, MSS, and SAR/MSS data using supervised classification show that the combined SAR/MSS data set results in an improved classification accuracy of the five land cover classes as compared with SAR-only and MSS-only data sets. In the case of the Dade County study area, the results indicate that both HH and VV polarization data are highly responsive to the row orientation of the row crop but not to the specific vegetation which forms the row structure. On the other hand, the HV polarization data are relatively insensitive to the orientation of row crop. Therefore, the HV polarization data may be used to discriminate the specific vegetation that forms the row structure.

Distillation irrigation: a low-energy process for coupling water purification and drip irrigation

USGS Publications Warehouse

Constantz, J.

1989-01-01

A method is proposed for combining solar distillation and drip irrigation to simultaneously desalinize water and apply this water to row crops. In this paper, the basic method is illustrated by a simple device constructed primarily of sheets of plastic, which uses solar energy to distill impaired water and apply the distillate to a widely spaced row crop. To predict the performance of the proposed device, an empirical equation for distillate production, dp, is developed from reported solar still production rates, and a modified Jensen-Haise equation is used to calculate the potential evapotranspiration, et, for a row crop. Monthly values for et and dp are calculated by using a generalized row crop at five locations in the Western United States. Calculated et values range from 1 to 22 cm month-1 and calculated dp values range from 2 to 11 cm month-1, depending on the location, the month, and the crop average. When the sum of dp plus precipitation, dp + P, is compared to et for the case of 50% distillation irrigation system coverage, the results indicate that the crop's et is matched by dp + P, at the cooler locations only. However, when the system coverage is increased to 66%, the crop's et is matched by dp + P even at the hottest location. Potential advantages of distillation irrigation include the ability: (a) to convert impaired water resources to water containing no salts or sediments; and (b) to efficiently and automatically irrigate crops at a rate that is controlled primarily by radiation intensities. The anticipated disadvantages of distillation irrigation include: (a) the high costs of a system, due to the large amounts of sheeting required, the short lifetime of the sheeting, and the physically cumbersome nature of a system; (b) the need for a widely spaced crop to reduce shading of the system by the crop; and (c) the production of a concentrated brine or precipitate, requiring proper off-site disposal. ?? 1989.

Elevated CO2 and nitrogen effects on soil CO2 flux from a pasture upon return to cultivation

USDA-ARS?s Scientific Manuscript database

Soil CO2 efflux patterns associated with converting pastures back to row crop production remain understudied in the Southeastern U.S. A 10-year study of bahiagrass (Paspalum notatum Flüggé) response to elevated CO2 was conducted using open top field chambers on a Blanton loamy sand (loamy siliceous,...

A double row alley-cropping system for establishing nut orchards

Treesearch

Jerry Van Sambeek; William. Reid

2017-01-01

One of the greatest deterrents to establishing a new nut orchard is the long period of time it takes from tree planting to first commercial nut harvest. At the Pecan Experiment Field, a pecan or walnut must grow ten seasons or more and maybe a little less for Chinese chestnuts before the trees produces enough nuts to warrant mechanical harvesting.

Accelerating Planted Green Ash Establishment on an Abandoned Soybean Field

Treesearch

John W. Groninger; Didier A. Babassana

2002-01-01

Planted green ash seedlings exhibit high survival rates on most bottomland sites that have recently come out of row crop production, making this species a popular choice for afforestation. Sub-optimal growth of planted hardwood tree species, including green ash, often delays the realization of many of the economic and environmental benefits that are used to justify the...

High clearance phenotyping systems for season-long measurement of corn, sorghum and other row crops to complement unmanned aerial vehicle systems

NASA Astrophysics Data System (ADS)

Murray, Seth C.; Knox, Leighton; Hartley, Brandon; Méndez-Dorado, Mario A.; Richardson, Grant; Thomasson, J. Alex; Shi, Yeyin; Rajan, Nithya; Neely, Haly; Bagavathiannan, Muthukumar; Dong, Xuejun; Rooney, William L.

2016-05-01

The next generation of plant breeding progress requires accurately estimating plant growth and development parameters to be made over routine intervals within large field experiments. Hand measurements are laborious and time consuming and the most promising tools under development are sensors carried by ground vehicles or unmanned aerial vehicles, with each specific vehicle having unique limitations. Previously available ground vehicles have primarily been restricted to monitoring shorter crops or early growth in corn and sorghum, since plants taller than a meter could be damaged by a tractor or spray rig passing over them. Here we have designed two and already constructed one of these self-propelled ground vehicles with adjustable heights that can clear mature corn and sorghum without damage (over three meters of clearance), which will work for shorter row crops as well. In addition to regular RGB image capture, sensor suites are incorporated to estimate plant height, vegetation indices, canopy temperature and photosynthetically active solar radiation, all referenced using RTK GPS to individual plots. These ground vehicles will be useful to validate data collected from unmanned aerial vehicles and support hand measurements taken on plots.

Supporting Energy Transitions and Miscanthus Program Development at the University of Iowa

NASA Astrophysics Data System (ADS)

Lain, Kayley Christina

Miscanthus is a highly productive, low-input biofuel crop that supports agricultural diversification with improved performance for climate commitment, energy security, and water quality over first generation biofuels. Despite its high performance, no local or regional markets for the feedstock have formed in North America, and current climate-based productivity assessment methods lack the information farmers and decision-makers need to establish commercial scale bioenergy markets, programs, and thermal co-firing plans. This study develops a Miscanthus Suitability Rating and a transferable field-scale siting method, applied at 10 m resolution across the State of Iowa to assess miscanthus production potential and identify individual farms that are highly suitable for large-scale miscanthus cultivation while maintaining a majority of existing row cropping acreage. Results show that highly suitable fields within 50 miles (84 km) of each of Iowa's coal-fired electrical generating units (EGUs) can displace up to 43% of current coal consumption. Every EGU in Iowa has land resource to produce local miscanthus to co-fire with other solid fuels at industry-leading levels without significantly impacting local row crop production. Seven of the state's smaller facilities could even operate exclusively on local miscanthus with advancements in densification technology. The energy evaluation tool developed in this work estimates the energy return on investment (EROI) of Iowa miscanthus for existing thermal generation facilities between 37 and 59, depending on transportation requirements and chemical field applications. This transition would diversify local agribusiness and energy feedstocks, reduce greenhouse gas emissions and provide a sustainable, dispatchable, in-state fuel source to complement wind and solar energy.

Stream Health Sensitivity to Landscape Changes due to Bioenergy Crops Expansion

NASA Astrophysics Data System (ADS)

Nejadhashemi, A.; Einheuser, M. D.; Woznicki, S. A.

2012-12-01

Global demand for bioenergy has increased due to uncertainty in oil markets, environmental concerns, and expected increases in energy consumption worldwide. To develop a sustainable biofuel production strategy, the adverse environmental impacts of bioenergy crops expansion should be understood. To study the impact of bioenergy crops expansion on stream health, the adaptive neural-fuzzy inference system (ANFIS) was used to predict macroinvertebrate and fish stream health measures. The Hilsenhoff Biotic Index (HBI), Family Index of Biological Integrity (Family IBI), and Number of Ephemeroptera, Plecoptera, and Trichoptera taxa (EPT taxa) were used as macroinvertebrate measures, while the Index of Biological Integrity (IBI) was used for fish. A high-resolution biophysical model built using the Soil and Water Assessment Tool was used to obtain water quantity and quality variables for input into the ANFIS stream health predictive models. Twenty unique crop rotations were developed to examine impacts of bioenergy crops expansion on stream health in the Saginaw Bay basin. Traditional intensive row crops generated more pollution than current landuse conditions, while second-generation biofuel crops associated with less intensive agricultural activities resulted in water quality improvement. All three macroinvertebrate measures were negatively impacted during intensive row crop productions but improvement was predicted when producing perennial crops. However, the expansion of native grass, switchgrass, and miscanthus production resulted in reduced IBI relative to first generation row crops. This study demonstrates that ecosystem complexity requires examination of multiple stream health measures to avoid potential adverse impacts of landuse change on stream health.

Six-rowed barley originated from a mutation in a homeodomain-leucine zipper I-class homeobox gene

PubMed Central

Komatsuda, Takao; Pourkheirandish, Mohammad; He, Congfen; Azhaguvel, Perumal; Kanamori, Hiroyuki; Perovic, Dragan; Stein, Nils; Graner, Andreas; Wicker, Thomas; Tagiri, Akemi; Lundqvist, Udda; Fujimura, Tatsuhito; Matsuoka, Makoto; Matsumoto, Takashi; Yano, Masahiro

2007-01-01

Increased seed production has been a common goal during the domestication of cereal crops, and early cultivators of barley (Hordeum vulgare ssp. vulgare) selected a phenotype with a six-rowed spike that stably produced three times the usual grain number. This improved yield established barley as a founder crop for the Near Eastern Neolithic civilization. The barley spike has one central and two lateral spikelets at each rachis node. The wild-type progenitor (H. vulgare ssp. spontaneum) has a two-rowed phenotype, with additional, strictly rudimentary, lateral rows; this natural adaptation is advantageous for seed dispersal after shattering. Until recently, the origin of the six-rowed phenotype remained unknown. In the present study, we isolated vrs1 (six-rowed spike 1), the gene responsible for the six-rowed spike in barley, by means of positional cloning. The wild-type Vrs1 allele (for two-rowed barley) encodes a transcription factor that includes a homeodomain with a closely linked leucine zipper motif. Expression of Vrs1 was strictly localized in the lateral-spikelet primordia of immature spikes, suggesting that the VRS1 protein suppresses development of the lateral rows. Loss of function of Vrs1 resulted in complete conversion of the rudimentary lateral spikelets in two-rowed barley into fully developed fertile spikelets in the six-rowed phenotype. Phylogenetic analysis demonstrated that the six-rowed phenotype originated repeatedly, at different times and in different regions, through independent mutations of Vrs1. PMID:17220272

Soil quality and the solar corridor crop system

USDA-ARS?s Scientific Manuscript database

The solar corridor crop system (SCCS) is designed for improved crop productivity based on highly efficient use of solar radiation by integrating row crops with drilled or solid-seeded crops in broad strips (corridors) that also facilitate establishment of cover crops for year-round soil cover. The S...

Soil Quality and the Solar Corridor Crop System

USDA-ARS?s Scientific Manuscript database

The solar corridor crop system (SCCS) is designed for improved crop productivity based on highly efficient use of solar radiation by integrating row crops with drilled or solid-seeded crops in broad strips (corridors) that also facilitate establishment of cover crops for year-round soil cover. The S...

Biology and management of two important Conyza weeds: a global review.

PubMed

Bajwa, Ali Ahsan; Sadia, Sehrish; Ali, Hafiz Haider; Jabran, Khawar; Peerzada, Arslan Masood; Chauhan, Bhagirath Singh

2016-12-01

Weed management is one of the prime concerns for sustainable crop production. Conyza bonariensis and Conyza canadensis are two of the most problematic, noxious, invasive and widespread weeds in modern-day agriculture. The biology, ecology and interference of C. bonariensis and C. canadensis have been reviewed here to highlight pragmatic management options. Both these species share a unique set of biological features, which enables them to invade and adapt a wide range of environmental conditions. Distinct reproductive biology and an efficient seed dispersal mechanism help these species to spread rapidly. Ability to interfere strongly and to host crop pests makes these two species worst weeds of cropping systems. These weed species cause 28-68 % yield loss in important field crops such as soybean and cotton every year. These weeds are more prevalent in no-till systems and, thus, becoming a major issue in conservation agriculture. Cultural practices such as crop rotations, seed rate manipulation, mulching, inter-row tillage and narrow row spacing may provide an effective control of these species. However, such methods are not feasible and applicable under all types of conditions. Different herbicides also provide a varying degree of control depending on crop, agronomic practices, herbicide dose, application time and season. However, both these species have evolved resistance against multiple herbicides, including glyphosate and paraquat. The use of alternative herbicides and integrated management strategies may provide better control of herbicide-resistant C. bonariensis and C. canadensis. Management plans based on the eco-biological interactions of these species may prove sustainable in the future.

Interception of spray drift by border structures. Part 1: wind tunnel experiments.

PubMed

De Schampheleire, M; Nuyttens, D; Dekeyser, D; Verboven, P; Cornelis, W; Gabriels, D; Spanoghe, P

2008-01-01

This research investigated the drift-intercepting potential of structures surrounding the field borders, like artificial screens and crops, which are not yet a part of the drift mitigation measures for field crop sprayers in Belgium. Drift-interception experiments were performed in the wind tunnel of the International Centre for Eremology (Ghent University, Belgium) with various interception structures: Artificial screens with heights of 0.5, 0.75 and 1 m and screen open areas of 16, 36 and 63%; a row of plastic Christmas trees with heights of 0.5 and 0.75 m; and a potato canopy. The interception structure was positioned at 1 m from the field border. From the results it was found that type of border structure has a pronounced effect on the drift interception, while the height of the border structure had no significant effect.

Implements and cultivation frequency to improve in-row weed control in organic peanut production

USDA-ARS?s Scientific Manuscript database

Weed control in organic peanut production is difficult and costly, which limits expansion of the production system. Sweep cultivation in the row middles is effective, but weeds remain in the crop row causing yield loss. Research trials were conducted in Tifton, GA to evaluate implements and freque...

Weed Mapping in Early-Season Maize Fields Using Object-Based Analysis of Unmanned Aerial Vehicle (UAV) Images

PubMed Central

Peña, José Manuel; Torres-Sánchez, Jorge; de Castro, Ana Isabel; Kelly, Maggi; López-Granados, Francisca

2013-01-01

The use of remote imagery captured by unmanned aerial vehicles (UAV) has tremendous potential for designing detailed site-specific weed control treatments in early post-emergence, which have not possible previously with conventional airborne or satellite images. A robust and entirely automatic object-based image analysis (OBIA) procedure was developed on a series of UAV images using a six-band multispectral camera (visible and near-infrared range) with the ultimate objective of generating a weed map in an experimental maize field in Spain. The OBIA procedure combines several contextual, hierarchical and object-based features and consists of three consecutive phases: 1) classification of crop rows by application of a dynamic and auto-adaptive classification approach, 2) discrimination of crops and weeds on the basis of their relative positions with reference to the crop rows, and 3) generation of a weed infestation map in a grid structure. The estimation of weed coverage from the image analysis yielded satisfactory results. The relationship of estimated versus observed weed densities had a coefficient of determination of r2=0.89 and a root mean square error of 0.02. A map of three categories of weed coverage was produced with 86% of overall accuracy. In the experimental field, the area free of weeds was 23%, and the area with low weed coverage (<5% weeds) was 47%, which indicated a high potential for reducing herbicide application or other weed operations. The OBIA procedure computes multiple data and statistics derived from the classification outputs, which permits calculation of herbicide requirements and estimation of the overall cost of weed management operations in advance. PMID:24146963

Weed mapping in early-season maize fields using object-based analysis of unmanned aerial vehicle (UAV) images.

PubMed

Peña, José Manuel; Torres-Sánchez, Jorge; de Castro, Ana Isabel; Kelly, Maggi; López-Granados, Francisca

2013-01-01

The use of remote imagery captured by unmanned aerial vehicles (UAV) has tremendous potential for designing detailed site-specific weed control treatments in early post-emergence, which have not possible previously with conventional airborne or satellite images. A robust and entirely automatic object-based image analysis (OBIA) procedure was developed on a series of UAV images using a six-band multispectral camera (visible and near-infrared range) with the ultimate objective of generating a weed map in an experimental maize field in Spain. The OBIA procedure combines several contextual, hierarchical and object-based features and consists of three consecutive phases: 1) classification of crop rows by application of a dynamic and auto-adaptive classification approach, 2) discrimination of crops and weeds on the basis of their relative positions with reference to the crop rows, and 3) generation of a weed infestation map in a grid structure. The estimation of weed coverage from the image analysis yielded satisfactory results. The relationship of estimated versus observed weed densities had a coefficient of determination of r(2)=0.89 and a root mean square error of 0.02. A map of three categories of weed coverage was produced with 86% of overall accuracy. In the experimental field, the area free of weeds was 23%, and the area with low weed coverage (<5% weeds) was 47%, which indicated a high potential for reducing herbicide application or other weed operations. The OBIA procedure computes multiple data and statistics derived from the classification outputs, which permits calculation of herbicide requirements and estimation of the overall cost of weed management operations in advance.

Foliar nutrient responses of oak saplings to nitrogen treatments on alkaline soils within the Missouri River Floodplain

Treesearch

J.W. Van Sambeek; John M. Kabrick; Daniel C. Dey

2017-01-01

Bottomland afforestation is frequently unsuccessful, partly because of low-quality planting stock and low soil fertility following row cropping. In autumn 1999, two 16.2-ha fields at two conservation areas in central Missouri were seeded to redtop grass or allowed to revegetate from the seedbank. In spring 2004, one of five nitrogen (N) treatments was applied to one...

Impact of living mulches on the physical properties of Planosol in monocropped maize cultivation

NASA Astrophysics Data System (ADS)

Romaneckas, Kęstutis; Adamavičienė, Aida; Šarauskis, Egidijus; Kriaučiūnienė, Zita; Marks, Marek; Vaitauskienė, Kristina

2018-04-01

The complex mutual interactions between soil properties and plants in high-biodiversity mono-cropping agro ecosystems have not been widely investigated. For this purpose, during 2009-2011, a stationary field experiment was conducted at the Experimental Station of the Aleksandras Stulginskis University to establish the effect of a multi-component agrocenose (maize, living mulch, weeds) on the physical properties of the soil. Spring oilseed rape, white mustard, spring barley, Italian ryegrass, black medic, Persian clover and red clover were sown as living mulch into maize inter-rows. The stability of >1.0 mm aggregates increased between the beginning and end of the maize vegetative period in almost all of the crops containing living mulch. The greatest competition for moisture content between the inter-crops and maize was observed at the beginning of the vegetative period because of living mulches of long growing seasons using the most moisture. In many cases, the shear strength of the soil was significantly reduced by the living mulch in the middle of summer, when it covered the maize inter-rows. These findings show that the monocropping of maize with living mulch stabilises or improves the physical characteristics of the soil, highlighting its potential for sustainable maize growing.

Hyperspectral imaging for differentiating glyphosate-resistant and glyphosate-susceptible Italian Ryegrass

USDA-ARS?s Scientific Manuscript database

Glyphosate is widely used in row crop weed control programs of glyphosate-resistant (GR) crops. With the accumulation of glyphosate use, several weeds have evolved resistance to glyphosate. In order to control GR weeds for profitable crop production, it is critical to first identify them in crop fie...

Light-mediated self-organization of sunflower stands increases oil yield in the field

PubMed Central

López Pereira, Mónica; Sadras, Victor O.; Batista, William; Casal, Jorge J.; Hall, Antonio J.

2017-01-01

Here, we show a unique crop response to intraspecific interference, whereby neighboring sunflower plants in a row avoid each other by growing toward a more favorable light environment and collectively increase production per unit land area. In high-density stands, a given plant inclined toward one side of the interrow space, and the immediate neighbors inclined in the opposite direction. This process started early as an incipient inclination of pioneer plants, and the arrangement propagated gradually as a “wave” of alternate inclination that persisted until maturity. Measurements and experimental manipulation of light spectral composition indicate that these responses are mediated by changes in the red/far-red ratio of the light, which is perceived by phytochrome. Cellular automata simulations reproduced the patterns of stem inclination in field experiments, supporting the proposition of self-organization of stand structure. Under high crop population densities (10 and 14 plants per m2), as yet unachievable in commercial farms with current hybrids due to lodging and diseases, self-organized crops yielded between 19 and 47% more oil than crops forced to remain erect. PMID:28696316

Light-mediated self-organization of sunflower stands increases oil yield in the field.

PubMed

López Pereira, Mónica; Sadras, Victor O; Batista, William; Casal, Jorge J; Hall, Antonio J

2017-07-25

Here, we show a unique crop response to intraspecific interference, whereby neighboring sunflower plants in a row avoid each other by growing toward a more favorable light environment and collectively increase production per unit land area. In high-density stands, a given plant inclined toward one side of the interrow space, and the immediate neighbors inclined in the opposite direction. This process started early as an incipient inclination of pioneer plants, and the arrangement propagated gradually as a "wave" of alternate inclination that persisted until maturity. Measurements and experimental manipulation of light spectral composition indicate that these responses are mediated by changes in the red/far-red ratio of the light, which is perceived by phytochrome. Cellular automata simulations reproduced the patterns of stem inclination in field experiments, supporting the proposition of self-organization of stand structure. Under high crop population densities (10 and 14 plants per m 2 ), as yet unachievable in commercial farms with current hybrids due to lodging and diseases, self-organized crops yielded between 19 and 47% more oil than crops forced to remain erect.

Evapotranspiration of annual and perennial biofuel crops in a variable climate

DOE PAGES

Abraha, Michael; Chen, Jiquan; Chu, Housen; ...

2015-02-06

Eddy covariance measurements were made in seven fields in the Midwest USA over 4 years (including the 2012 drought year) to estimate evapotranspiration (ET) of newly established rain-fed cellulosic and grain biofuel crops. Four of the converted fields had been managed as grasslands under the USDA’s Conservation Reserve Program (CRP) for 22 years, and three had been in conventional agriculture (AGR) soybean/corn rotation prior to conversion. In 2009, all sites were planted to no-till soybean except one CRP grassland that was left unchanged as a reference site; in 2010, three of the former CRP sites and the three former AGRmore » sites were planted to annual (corn) and perennial (switchgrass and mixed-prairie) grasslands. The annual ET over the 4 years ranged from 45% to 77% (mean = 60%) of the annual precipitation (848–1063 mm; November–October), with the unconverted CRP grassland having the highest ET (622–706 mm). In the fields converted to annual and perennial crops, the annual ET ranged between 480 and 639 mm despite the large variations in growing-season precipitation and in soil water contents, which had strong effects on regional crop yields. Results suggest that in this humid temperate climate, which represents the US Corn Belt, water use by annual and perennial crops is not greatly different across years with highly variable precipitation and soil water availability. Thus, large-scale conversion of row crops to perennial biofuel cropping systems may not strongly alter terrestrial water balances.« less

Evapotranspiration of annual and perennial biofuel crops in a variable climate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abraha, Michael; Chen, Jiquan; Chu, Housen

Eddy covariance measurements were made in seven fields in the Midwest USA over 4 years (including the 2012 drought year) to estimate evapotranspiration (ET) of newly established rain-fed cellulosic and grain biofuel crops. Four of the converted fields had been managed as grasslands under the USDA’s Conservation Reserve Program (CRP) for 22 years, and three had been in conventional agriculture (AGR) soybean/corn rotation prior to conversion. In 2009, all sites were planted to no-till soybean except one CRP grassland that was left unchanged as a reference site; in 2010, three of the former CRP sites and the three former AGRmore » sites were planted to annual (corn) and perennial (switchgrass and mixed-prairie) grasslands. The annual ET over the 4 years ranged from 45% to 77% (mean = 60%) of the annual precipitation (848–1063 mm; November–October), with the unconverted CRP grassland having the highest ET (622–706 mm). In the fields converted to annual and perennial crops, the annual ET ranged between 480 and 639 mm despite the large variations in growing-season precipitation and in soil water contents, which had strong effects on regional crop yields. Results suggest that in this humid temperate climate, which represents the US Corn Belt, water use by annual and perennial crops is not greatly different across years with highly variable precipitation and soil water availability. Thus, large-scale conversion of row crops to perennial biofuel cropping systems may not strongly alter terrestrial water balances.« less

Overestimation of Crop Root Biomass in Field Experiments Due to Extraneous Organic Matter.

PubMed

Hirte, Juliane; Leifeld, Jens; Abiven, Samuel; Oberholzer, Hans-Rudolf; Hammelehle, Andreas; Mayer, Jochen

2017-01-01

Root biomass is one of the most relevant root parameters for studies of plant response to environmental change, soil carbon modeling or estimations of soil carbon sequestration. A major source of error in root biomass quantification of agricultural crops in the field is the presence of extraneous organic matter in soil: dead roots from previous crops, weed roots, incorporated above ground plant residues and organic soil amendments, or remnants of soil fauna. Using the isotopic difference between recent maize root biomass and predominantly C3-derived extraneous organic matter, we determined the proportions of maize root biomass carbon of total carbon in root samples from the Swiss long-term field trial "DOK." We additionally evaluated the effects of agricultural management (bio-organic and conventional), sampling depth (0-0.25, 0.25-0.5, 0.5-0.75 m) and position (within and between maize rows), and root size class (coarse and fine roots) as defined by sieve mesh size (2 and 0.5 mm) on those proportions, and quantified the success rate of manual exclusion of extraneous organic matter from root samples. Only 60% of the root mass that we retrieved from field soil cores was actual maize root biomass from the current season. While the proportions of maize root biomass carbon were not affected by agricultural management, they increased consistently with soil depth, were higher within than between maize rows, and were higher in coarse (>2 mm) than in fine (≤2 and >0.5) root samples. The success rate of manual exclusion of extraneous organic matter from root samples was related to agricultural management and, at best, about 60%. We assume that the composition of extraneous organic matter is strongly influenced by agricultural management and soil depth and governs the effect size of the investigated factors. Extraneous organic matter may result in severe overestimation of recovered root biomass and has, therefore, large implications for soil carbon modeling and estimations of the climate change mitigation potential of soils.

An evaluation of the physiochemical and biological characteristics of foaming swine manure

USDA-ARS?s Scientific Manuscript database

Incorporation of dedicated herbaceous energy crops into row crop landscapes is a promising means to supply an expanding biofuel industry while increasing biomass yields, benefiting soil and water quality, and increasing biodiversity. Despite these positive traits, energy crops remain largely unaccep...

Hydrology of a zero-order Southern Piedmont watershed through 45 years of changing agricultural land use. Part 1. Monthly and seasonal rainfall-runoff relationships

NASA Astrophysics Data System (ADS)

Endale, Dinku M.; Fisher, Dwight S.; Steiner, Jean L.

2006-01-01

Few studies have reported runoff from small agricultural watersheds over sufficiently long period so that the effect of different cover types on runoff can be examined. We analyzed 45-yrs of monthly and annual rainfall-runoff characteristics of a small (7.8 ha) zero-order typical Southern Piedmont watershed in southeastern United States. Agricultural land use varied as follows: 1. Row cropping (5-yrs); 2. Kudzu ( Pueraria lobata; 5-yrs); 3. Grazed kudzu and rescuegrass ( Bromus catharticus; 7-yrs); and 4. Grazed bermudagrass and winter annuals ( Cynodon dactylon; 28-yrs). Land use and rainfall variability influenced runoff characteristics. Row cropping produced the largest runoff amount, percentage of the rainfall partitioned into runoff, and peak flow rates. Kudzu reduced spring runoff and almost eliminated summer runoff, as did a mixture of kudzu and rescuegrass (KR) compared to row cropping. Peak flow rates were also reduced during the kudzu and KR. Peak flow rates increased under bermudagrass but were lower than during row cropping. A simple process-based 'tanh' model modified to take the previous month's rainfall into account produced monthly rainfall and runoff correlations with coefficient of determination ( R2) of 0.74. The model was tested on independent data collected during drought. Mean monthly runoff was 1.65 times the observed runoff. Sustained hydrologic monitoring is essential to understanding long-term rainfall-runoff relationships in agricultural watersheds.

A repellent net as a new technology to protect cabbage crops.

PubMed

Martin, T; Palix, R; Kamal, A; Delétré, E; Bonafos, R; Simon, S; Ngouajio, M

2013-08-01

Floating row covers or insect-proof nets with fine mesh are effective at protecting vegetable crops against aphids but negatively impact plant health, especially under warm conditions. Furthermore, in control of cabbage insect pests, aphid parasitoids cannot enter the fine-mesh nets, leading to frequent aphid outbreaks. To surmount these difficulties, a 40-mesh-size repellent net treated with alphacypermethrin was studied in laboratory and field tests. Results showed both irritant and repellent effects of the alphacypermethrin-treated net on Myzus persicae (Sulzer) (Hemiptera: Aphididae) and its parasitoid Aphidius colemani (Haliday) (Hymenoptera: Braconidae). Under field conditions, there were no pests on cabbage protected with the repellent net. The repellent net allowed combining a visual and repellent barrier against aphids. Because of this additive effect, repellent nets allowed covering cabbage permanently with adequate protection against all pests.

[Main interspecific competition and land productivity of fruit-crop intercropping in Loess Region of West Shauxi].

PubMed

Yun, Lei; Bi, Hua-Xing; Tian, Xiao-Ling; Cui, Zhe-Wei; Zhou, Hui-Zi; Gao, Lu-Bo; Liu, Li-Xia

2011-05-01

Taking the four typical fruit-crop intercropping models, i.e., walnut-peanut, walnut-soybean, apple-peanut, and apple-soybean, in the Loess Region of western Shanxi Province as the objects, this paper analyzed the crop (peanut and soybean) photosynthetic active radiation (PAR), net photosynthetic rate (P(n)), yield, and soil moisture content. Comparing with crop monoculture, fruit-crop intercropping decreased the crop PAR and P(n). The smaller the distance from tree rows, the smaller the crop PAR and P(n). There was a significantly positive correlation between the P(n) and crop yield, suggesting that illumination was one of the key factors affecting crop yield. From the whole trend, the 0-100 cm soil moisture content had no significant differences between walnut-crop intercropping systems and corresponding monoculture cropping systems, but had significant differences between apple-crop intercropping systems and corresponding monoculture cropping systems, indicating that the competition for soil moisture was more intense in apple-crop intercropping systems than in walnut-crop intercropping systems. Comparing with monoculture, fruit-crop intercropping increased the land use efficiency and economic benefit averagely by 70% and 14%, respectively, and walnut-crop intercropping was much better than apple-crop intercropping. To increase the crop yield in fruit-crop intercropping systems, the following strategies should be taken: strengthening the management of irrigation and fertilization, increasing the distances or setting root barriers between crop and tree rows, regularly and properly pruning, and planting shade-tolerant crops in intercropping.

Water and nitrogen requirements of subsurface drip irrigated pomegranate

USDA-ARS?s Scientific Manuscript database

Surface drip irrigation is a well-developed practice for both annual and perennial crops. The use of subsurface drip is a well-established practice in many annual row crops, e.g. tomatoes, strawberries, lettuce. However, the use of subsurface drip on perennial crops has been slow to develop. With th...

APEX simulation of runoff and total phosphorous for three adjacent row-crop watersheds with claypan soils

USDA-ARS?s Scientific Manuscript database

The Agricultural Policy Environmental Extender (APEX) model can simulate crop yields, runoff, and the transport of sediment and nutrients in small watersheds that have combinations of farm level landscapes, cropping systems and/or management practices. The objectives of the study were to parameteri...

Irrigation and fertilizer placement effects on trace gas emissions from an ornamental crop

USDA-ARS?s Scientific Manuscript database

Agriculture is a large contributor of trace gas emissions and much of the work on reducing greenhouse gas (GHG) emissions has focused on row crops, pastures, forestry, and animal production systems; however, little emphasis has been placed on specialty crop industries such as horticulture. A horticu...

Reduce pests, enhance production: benefits of intercropping at high densities for okra farmers in Cameroon.

PubMed

Singh, Akanksha; Weisser, Wolfgang W; Hanna, Rachid; Houmgny, Raissa; Zytynska, Sharon E

2017-10-01

Intercropping can help reduce insect pest populations. However, the results of intercropping can be pest- and crop-species specific, with varying effects on crop yield, and pest suppression success. In Cameroon, okra vegetable is often grown in intercropped fields and sown with large distances between planting rows (∼ 2 m). Dominant okra pests include cotton aphids, leaf beetles and whiteflies. In a field experiment, we intercropped okra with maize and bean in different combinations (okra monoculture, okra-bean, okra-maize and okra-bean-maize) and altered plant densities (high and low) to test for the effects of diversity, crop identity and planting distances on okra pests, their predators and yield. We found crop identity and plant density, but not crop diversity to influence okra pests, their predators and okra yield. Only leaf beetles decreased okra yield and their abundance reduced at high plant density. Overall, okra grown with bean at high density was the most economically profitable combination. We suggest that when okra is grown at higher densities, legumes (e.g. beans) should be included as an additional crop. Intercropping with a leguminous crop can enhance nitrogen in the soil, benefiting other crops, while also being harvested and sold at market for additional profit. Manipulating planting distances and selecting plants based on their beneficial traits may thus help to eliminate yield gaps in sustainable agriculture. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Seasonal Soil Nitrogen Mineralization within an Integrated Crop and Livestock System in Western North Dakota, USA

NASA Astrophysics Data System (ADS)

Landblom, Douglas; Senturklu, Songul; Cihacek, Larry; Pfenning, Lauren; Brevik, Eric C.

2015-04-01

Protecting natural resources while maintaining or maximizing crop yield potential is of utmost importance for sustainable crop and livestock production systems. Since soil organic matter and its decomposition by soil organisms is at the very foundation of healthy productive soils, systems research at the North Dakota State University Dickinson Research Extension Center is evaluating seasonal soil nitrogen fertility within an integrated crop and livestock production system. The 5-year diverse crop rotation is: sunflower (SF) - hard red spring wheat (HRSW) - fall seeded winter triticale-hairy vetch (THV; spring harvested for hay)/spring seeded 7-species cover crop (CC) - Corn (C) (85-90 day var.) - field pea-barley intercrop (PBY). The HRSW and SF are harvested as cash crops and the PBY, C, and CC are harvested by grazing cattle. In the system, yearling beef steers graze the PBY and C before feedlot entry and after weaning, gestating beef cows graze the CC. Since rotation establishment, four crop years have been harvested from the crop rotation. All crops have been seeded using a JD 1590 no-till drill except C and SF. Corn and SF were planted using a JD 7000 no-till planter. The HRSW, PBY, and CC were seeded at a soil depth of 3.8 cm and a row width of 19.1 cm. Seed placement for the C and SF crops was at a soil depth of 5.1 cm and the row spacing was 0.762 m. The plant population goal/ha for C, SF, and wheat was 7,689, 50,587, and 7,244 p/ha, respectively. During the 3rd cropping year, soil bulk density was measured and during the 4th cropping year, seasonal nitrogen fertility was monitored throughout the growing season from June to October. Seasonal nitrate nitrogen (NO3-N), ammonium nitrogen (NH4-N), total season mineral nitrogen (NO3-N + NH4-N), cropping system NO3-N, and bulk density were measured in 3 replicated non-fertilized field plot areas within each 10.6 ha triple replicated crop fields. Within each plot area, 6 - 20.3 cm x 0.61 m aluminum irrigation pipes were pressed into the soil as enclosures to restrict root access to soil nitrogen. Soil samples were taken as close to 2-week intervals as possible from both inside and outside the enclosures. The crop rotation N values were also compared to triple replicated perennial native grassland plot areas (predominate sp. Western wheatgrass - Pascopyrum smithii, Blue grama - Bouteloua gracilis, Little bluestem - Schizachyrium scoparium, Switchgrass - Panicum virgatum). Trends identified for both NH4-N and NO3-N indicate that the values are relatively similar with respect to seasonal change over time. There was a greater amount of soil nitrogen accumulation inside the enclosures indicating that outside the enclosures roots scavenge nitrogen for plant growth and production. Seasonally, comparing the cropping system crops, NO3-N declined mid-July and then rebounded by mid-August and continued to increase until leveling off in September. Corn NO3-N, however, did not follow this pattern, but increased from early June to the end of June and remained high until the first of September. We will present the results of bulk density data and seasonal N fertility data providing evidence for the impact of previous CC on corn production. Probable explanation for the mid-summer nitrogen decline will be presented and justification for reduced fertilizer application will be discussed.

Optical Sensing to Determine Tomato Plant Spacing for Precise Agrochemical Application: Two Scenarios

PubMed Central

Martínez-Guanter, Jorge; Garrido-Izard, Miguel; Valero, Constantino; Slaughter, David C.; Pérez-Ruiz, Manuel

2017-01-01

The feasibility of automated individual crop plant care in vegetable crop fields has increased, resulting in improved efficiency and economic benefits. A systems-based approach is a key feature in the engineering design of mechanization that incorporates precision sensing techniques. The objective of this study was to design new sensing capabilities to measure crop plant spacing under different test conditions (California, USA and Andalucía, Spain). For this study, three different types of optical sensors were used: an optical light-beam sensor (880 nm), a Light Detection and Ranging (LiDAR) sensor (905 nm), and an RGB camera. Field trials were conducted on newly transplanted tomato plants, using an encoder as a local reference system. Test results achieved a 98% accuracy in detection using light-beam sensors while a 96% accuracy on plant detections was achieved in the best of replications using LiDAR. These results can contribute to the decision-making regarding the use of these sensors by machinery manufacturers. This could lead to an advance in the physical or chemical weed control on row crops, allowing significant reductions or even elimination of hand-weeding tasks. PMID:28492504

Erosion control in orchards and vineyards by a new soil and cover crop management method

NASA Astrophysics Data System (ADS)

Hartl, Wilfried; Guettler, Hans; Auer, Karl; Erhart, Eva

2016-04-01

Cover crops are the basis for an erosion-free soil management in orchards and vineyards. The soil cover provided by the foliage and the intensive root formation counteract erosion. Cover crops provide the soil microfauna with fresh organic matter which improves soil structure and porosity. The water demand of cover crops, however, may pose problems for the water supply of the trees and vines in dry seasons. Therefore it is necessary to adjust the growth of the cover crops to the actual water conditions. In years with ample precipitation cover crops may be allowed lush vegetative growth till flowering and formation of seeds. In dry years, the growth of the cover crop must be restricted to stop the competition for water, sometimes even by cutting off the cover crop roots. The course of the weather is incalculable and rainfall may be very variable during the year, so it is sometimes necessary to adust the cover crop management several times a year. A new special equipment, which can perform all the tasks necessary for the flexible cover crop management has been developed together with the agricultural machinery manufacturers Bodenwerkstatt Ertl-Auer GmbH and Güttler GmbH. The GreenManager® device consists of three modules, namely a specific type of cultivator, a harrow and a prismatic roller with seeding equipment, which can be used separately or in combination. The GreenManager® can reduce cover crops by flattening the plants in the whole row middle, by bringing down the cover crops with the harrow, or by horizontally cutting the cover crop roots a few centimetres beneath the soil surface in the central part of the row middle or in the whole row middle. These measures reduce the water competition by cover crops without generating further losses of soil moisture through intensive soil cultivation. At the same time the risk of soil erosion is kept to a minimum, because the soil remains covered by dead plant biomass. In one passage the GreenManager® can direct-drill large-grain cover crop seeds and simultaneously cut the roots of the standing vegetation in the row middle, plus at the same time sow small-grain seeds over the whole middle. The large grains are placed several centimetres deep with the cultivator, while the small grains are spread on the surface in a seedbed prepared by the prismatic roller or the harrow module. So it is secured that on rewetting of the soil the next generation of cover crops will be established straight away. In all cases, however, the soil remains covered with living or dead plant biomass, so that the erosion risk is minimized. Uppermost goals of the flexible cover crop management are the well-being of the fruit trees and vines and maximum erosion protection of the soil.

Watershed-Scale Cover Crops Reduce Nutrient Export From Agricultural Landscapes.

NASA Astrophysics Data System (ADS)

Tank, J. L.; Hanrahan, B.; Christopher, S. F.; Trentman, M. T.; Royer, T. V.; Prior, K.

2016-12-01

The Midwestern US has undergone extensive land use change as forest, wetlands, and prairies have been converted to agroecosystems. Today, excess fertilizer nutrients from farm fields enter Midwestern agricultural streams, which degrades both local and downstream water quality, resulting in algal blooms and subsequent hypoxic "dead zones" far from the nutrient source. We are quantifying the benefits of watershed-scale conservation practices that may reduce nutrient runoff from adjacent farm fields. Specifically, research is lacking on whether the planting of winter cover crops in watersheds currently dominated by row-crop agriculture can significantly reduce nutrient inputs to adjacent streams. Since 2013, farmers have planted cover crops on 70% of croppable acres in the Shatto Ditch Watershed (IN), and "saturation level" implementation of this conservation practice has been sustained for 3 years. Every 14 days, we have quantified nutrient loss from fields by sampling nutrient fluxes from multiple subsurface tile drains and longitudinally along the stream channel throughout the watershed. Cover crops improved stream water quality by reducing dissolved inorganic nutrients exported downstream; nitrate-N and DRP concentrations and fluxes were significantly lower in tiles draining fields with cover crops compared to those without. Annual watershed nutrient export also decreased, and reductions in N and P loss ( 30-40%) exceeded what we expected based on only a 6-10% reduction in runoff due to increased watershed water holding capacity. We are also exploring the processes responsible for increased nutrient retention, where they are occurring (terrestrial vs. aquatic) and when (baseflow vs. storms). For example, whole-stream metabolism also responded to cover crop planting, showing reduced variation in primary production and respiration in years after watershed-scale planting of cover crops. In summary, widespread land cover change, through cover crop planting, can significantly reduce annual watershed-scale nutrient export. Moreover, successful outcomes highlighted through demonstration projects may facilitate widespread adoption, making them powerful agents of change for advancing conservation success.

7 CFR 718.109 - Deductions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... requirement; or (3) For all other crops and land uses—one-tenth (.10) acre. Turn areas, terraces, permanent... deduction of 3 percent of the area devoted to a row crop and zero percent of the area devoted to a close...

Frequent Insect Visitors Are Not Always Pollen Carriers in Hybrid Carrot Pollination.

PubMed

Gaffney, Ann; Bohman, Björn; Quarrell, Stephen R; Brown, Philip H; Allen, Geoff R

2018-06-07

Insect crop visitations do not necessarily translate to carriage or transfer of pollen. To evaluate the potential of the various insects visiting hybrid carrot flowers to facilitate pollen transfer, this study examines insect visitation rates to hybrid carrot seed crops in relation to weather, time of day and season, pollen carrying capacity, inter-row movement, and visitation frequency to male-fertile and male-sterile umbels. The highest pollen loads were carried by nectar scarabs, honey bees, and the hover fly Eristalis tenax (Linnaeus). Honey bees and muscoid flies were observed to forage mostly within the male fertile carrot row while nectar scarabs and E. tenax foraged across rows, carrying equal pollen loads regardless of their distance from the pollen source. All observed insect taxa were more frequently seen visiting male-fertile than male-sterile umbels. In contrast to other visiting insects, honey bees were abundant and frequent visitors and were observed carrying high pollen loads. Consequently, we suggest both optimizing honey bee management and improving the attraction of carrot lines to honey bees to improve pollination rates for hybrid carrot seed crops.

Production of sugarcane and tropical grasses as a renewable energy source. Second annual report, 1978-1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-01-01

Reseach continued on tropical grasses from Saccharum and related genera as sources of intensively-produced, solar-dried biomass. Categories of candidate grasses include short-, intermediate-, and long-rotation species. These categories are based on the time interval required for maximum dry matter production, and on future management requirements of energy crops for intensive co-production with food crop commodities. Year 1 studies at the greenhouse and field-plot levels were continued and broadened during Year 2. This included candidate screening, importation and quarantine of new clones, breeding, controlled nitrogen and water regimes, chemical growth control, tissue expansion and maturation control, seeding rates, harvest frequency, andmore » variable row spacing. Second-year studies were extended to the project's field-scale and mechanized-harvest phases. These include initial economic anayses for the short-rotation phases. These include initial economic analyses for the short-rotation category of candidate species.« less

Using Google SketchUp to simulate tree row azimuth effects on alley shading

USDA-ARS?s Scientific Manuscript database

Effect of row azimuth on alley crop illumination is difficult to determine empirically. Our objective was to determine if Google SketchUp (Trimble Inc., Sunnyvale, CA) could be used to simulate effect of azimuth orientation on illumination of loblolly pine (Pinus taeda L.) alleys. Simulations were...

The Importance of Barley Genetics and Domestication in a Global Perspective

PubMed Central

Pourkheirandish, Mohammad; Komatsuda, Takao

2007-01-01

Background Archaeological evidence has revealed that barley (Hordeum vulgare) is one of the oldest crops used by ancient farmers. Studies of the time and place of barley domestication may help in understanding ancient human civilization. Scope The studies of domesticated genes in crops have uncovered the mechanisms which converted wild and unpromising wild species to the most important food for humans. In addition to archaeological studies, molecular studies are finding new insights into the process of domestication. Throughout the process of barley domestication human selection on wild species resulted in plants with more harvestable seeds. One of the remarkable changes during barley domestications was the appearance of six-rowed barley. The gene associated with this trait results in three times more seed per spike compared with ancestral wild barley. This increase in number of seed resulted in a major dichotomy in the evolution of barley. The identification of the six-rowed spike gene provided a framework for understanding how this character was evolved. Some important barley domestication genes have been discovered and many are currently being investigated. Conclusions Identification of domestication genes in crops revealed that most of the drastic changes during domestication are the result of functional impairments in transcription factor genes, and creation of new functions is rare. Isolation of the six-rowed spike gene revealed that this trait was domesticated more than once in the domestication history of barley. Six-rowed barley is derived from two-rowed ancestral forms. Isolation of photoperiod-response genes in barley and rice revealed that different genes belonging to similar genetic networks partially control this trait. PMID:17761690

Trace Gas and Carbon Sequestration Dynamics in Temperate Croplands and Successional Ecosystems: A Full-Cost Accounting

NASA Astrophysics Data System (ADS)

Robertson, G. P.; McSwiney, C. P.

2003-12-01

Agriculture is responsible for 21-25% of the global anthropic CO2 flux, 55-60% of the anthropic CH4 flux, and 65-80% of the anthopic flux of N2O. A number of CO2 stabilization strategies target agricultural production practices, and the potential for simultaneously abating fluxes of the non-CO2 greenhouse gases is substantial. But so is the potential for creating greenhouse gas (GHG) liabilities, the unintentional increase in one or more GHGs by activities that mitigate another. Whole-system accounting provides a means for including all GHG-contributing processes in the same cropping system analysis in order to illuminate major liabilities and synergies. We contrast a field crop system in the upper U.S. midwest with unmanaged successional ecosystems in the same landscape, and provide evidence that N2O flux - the major contributor to radiative forcing in row-crop systems - can be abated with little loss of crop productivity.

Steers grazing of a rye cover crop influences growth of rye and no-till cotton

USDA-ARS?s Scientific Manuscript database

Small grain cover crops offer opportunities for grazing but effects on following row crops are not well understood. From 1999 through 2008, stocker steers sequence grazed small grains in a 2-paddock rye-cotton-wheat-fallow- rye rotation. Treatments imposed on rye included 1) zero-grazing from 1999; ...

Crop advisor perceptions of giant ragweed distribution, herbicide-resistance, and management in the Corn Belt

USDA-ARS?s Scientific Manuscript database

Giant ragweed has been increasing as a major weed of row crops in North America. We conducted a web-based survey of Certified Crop Advisors in the Corn Belt to determine the current distribution of giant ragweed, the distribution of herbicide resistant populations, and management and ecological fact...

The Effects of Crop Intensification on the Diversity of Native Pollinator Communities.

PubMed

Mogren, Christina L; Rand, Tatyana A; Fausti, Scott W; Lundgren, Jonathan G

2016-08-01

Increases in agricultural conversion are leading to declines in native grasslands and natural resources critical for beneficial insects. However, little is known regarding how these changes affect pollinator diversity. Land use types were categorized within 300 m and 3 km radii of pollinator sampling locations in Brookings County, SD. Pollinator abundance and species richness were regressed on the proportion of the landscape dedicated to row crops, grass and pasture, forage crops, small grains, and aquatic habitats using variance components modeling. Row crops had a negative effect on bee abundance at 300 m, after fixed effects modeling accounted for outliers skewing this relationship. At 3 km, corn positively affected bee abundance and richness, while soybean acreage decreased species richness. The landscape matrix of outlying sites consisted of large monocultured areas with few alternative habitat types available, leading to inflated populations of Melissodes and Halictidae. Syrphids had a positive parabolic relationship between diversity and row crops, indicating potential for competitive exclusion from intermediate landscapes. Unlike other studies, landscape diversity within 300 m was not found to significantly benefit pollinator diversity. Within especially agriculturally developed areas of the region, high abundances of pollinators suggest selection for a few dominant species. There was no effect of forage crops or aquatic habitats on pollinator diversity, indicating that less highly managed areas still represent degraded habitat within the landscape. Incorporating pollinator-friendly crops at the farm level throughout the region is likely to enhance pollinator diversity by lessening the negative effects of large monocultures. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Classification and Mapping of Agricultural Land for National Water-Quality Assessment

USGS Publications Warehouse

Gilliom, Robert J.; Thelin, Gail P.

1997-01-01

Agricultural land use is one of the most important influences on water quality at national and regional scales. Although there is great diversity in the character of agricultural land, variations follow regional patterns that are influenced by environmental setting and economics. These regional patterns can be characterized by the distribution of crops. A new approach to classifying and mapping agricultural land use for national water-quality assessment was developed by combining information on general land-use distribution with information on crop patterns from agricultural census data. Separate classification systems were developed for row crops and for orchards, vineyards, and nurseries. These two general categories of agricultural land are distinguished from each other in the land-use classification system used in the U.S. Geological Survey national Land Use and Land Cover database. Classification of cropland was based on the areal extent of crops harvested. The acreage of each crop in each county was divided by total row-crop area or total orchard, vineyard, and nursery area, as appropriate, thus normalizing the crop data and making the classification independent of total cropland area. The classification system was developed using simple percentage criteria to define combinations of 1 to 3 crops that account for 50 percent or more or harvested acreage in a county. The classification system consists of 21 level I categories and 46 level II subcategories for row crops, and 26 level I categories and 19 level II subcategories for orchards, vineyards, and nurseries. All counties in the United States with reported harvested acreage are classified in these categories. The distribution of agricultural land within each county, however, must be evaluated on the basis of general land-use data. This can be done at the national scale using 'Major Land Uses of the United States,' at the regional scale using data from the national Land Use and Land Cover database, or at smaller scales using locally available data.

Pesticide occurrence in groundwater in areas of high-density row crop production in Alabama, 2009

USGS Publications Warehouse

Moreland, Richard S.

2011-01-01

High-density row crop production occurs in three areas of Alabama that are underlain by productive aquifers, northern Alabama, southeastern Alabama, and Baldwin County in southwestern Alabama. The U.S. Geological Survey collected five groundwater samples from each of these three areas during 2009 for analysis of selected pesticides. Results of these analyses showed detections for 37 of 152 analytes. The three most frequently detected compounds were atrazine, 2-Chloro-4-isopropylamino-6-amino-triazine (CIAT), and metolachlor. The highest concentration for any analyte was 4.08 micrograms per liter for metolachlor.

Isotopic and chemical composition of inorganic and organic water-quality samples from the Mississippi River Basin, 1997-98

USGS Publications Warehouse

Battaglin, William A.; Kendall, Carol; Chang, Cecily C.Y.; Silva, Steven R.; Campbell, Donald H.

2001-01-01

Nitrate (NO3) and other nutrients discharged by the Mississippi River combined with seasonal stratification of the water column are known to cause a zone of depleted dissolved oxygen (hypoxic zone) in the Gulf of Mexico each summer. About 120 water and suspended sediment samples collected in 1997 and 1998 from 24 locations in the Mississippi River Basin were analyzed for the isotope ratios δ15N and δ18O of dissolved NO3, and δ15N and δ13C of suspended particulate organic material (POM). Sampling stations include both large rivers (drainage areas more than 30,000 square kilometers) that integrate the effects of many land uses, and smaller streams (drainage areas less than 2,500 square kilometers) that have relatively uniform land use within their drainage areas. The data are used to determine sources and transformations of NO3 in the Mississippi River.Results of this study demonstrate that much of the NO3 in the Mississippi River originates in the agriculturally dominated basins of the upper midwestern United States and is transported without significant transformation or other loss to the Gulf of Mexico. Results from major tributaries that drain into the Mississippi River suggest that NO3 is not significantly altered by denitrification in its journey, ultimately, to the Gulf of Mexico. The spatial variability of isotope ratios among the smaller streams appears to be related to the dominant nitrogen source in the basins. There are some distinct isotope differences among land-use types. For example, for both NO3 and POM, the majority of δ15N isotope ratio values from basins dominated by urban and undeveloped land are less than +5 per mil, whereas the majority of values from basins dominated by row crops and row crops and/or livestock production are greater than +5 per mil. Also, the median δ18O of NO3 isotope ratio value (+14.0 per mil) from undeveloped basins is more than 6 per mil higher than the median value (+7.3 per mil) from the row crop dominated basins and 5 per mil higher than the median value (+9.0 per mil) from the row crop and/or livestock production dominated basins. The median δ18O of NO3 isotope ratio value (+21.5 per mil) from urban basins is 6.5 per mil higher than the median value (+14.0 per mil) from the undeveloped basins. The majority of NO3 concentrations are greater than 3 milligrams per liter (mg/L) in basins dominated by row crops and row crops and/or livestock production, whereas all NO3 concentrations are less than 2 mg/L in basins dominated by urban and undeveloped land.

Subfield profitability analysis reveals an economic case for cropland diversification

NASA Astrophysics Data System (ADS)

Brandes, E.; McNunn, G. S.; Schulte, L. A.; Bonner, I. J.; Muth, D. J.; Babcock, B. A.; Sharma, B.; Heaton, E. A.

2016-01-01

Public agencies and private enterprises increasingly desire to achieve ecosystem service outcomes in agricultural systems, but are limited by perceived conflicts between economic and ecosystem service goals and a lack of tools enabling effective operational management. Here we use Iowa—an agriculturally homogeneous state representative of the Maize Belt—to demonstrate an economic rationale for cropland diversification at the subfield scale. We used a novel computational framework that integrates disparate but publicly available data to map ˜3.3 million unique potential management polygons (9.3 Mha) and reveal subfield opportunities to increase overall field profitability. We analyzed subfield profitability for maize/soybean fields during 2010-2013—four of the most profitable years in recent history—and projected results for 2015. While cropland operating at a loss of US 250 ha-1 or more was negligible between 2010 and 2013 at 18 000-190 000 ha (<2% of row-crop land), the extent of highly unprofitable land increased to 2.5 Mha, or 27% of row-crop land, in the 2015 projection. Aggregation of these areas to the township level revealed ‘hotspots’ for potential management change in Western, Central, and Northeast Iowa. In these least profitable areas, incorporating conservation management that breaks even (e.g., planting low-input perennials), into low-yielding portions of fields could increase overall cropland profitability by 80%. This approach is applicable to the broader region and differs substantially from the status quo of ‘top-down’ land management for conservation by harnessing private interest to align profitability with the production of ecosystem services.

Fusion of pixel and object-based features for weed mapping using unmanned aerial vehicle imagery

NASA Astrophysics Data System (ADS)

Gao, Junfeng; Liao, Wenzhi; Nuyttens, David; Lootens, Peter; Vangeyte, Jürgen; Pižurica, Aleksandra; He, Yong; Pieters, Jan G.

2018-05-01

The developments in the use of unmanned aerial vehicles (UAVs) and advanced imaging sensors provide new opportunities for ultra-high resolution (e.g., less than a 10 cm ground sampling distance (GSD)) crop field monitoring and mapping in precision agriculture applications. In this study, we developed a strategy for inter- and intra-row weed detection in early season maize fields from aerial visual imagery. More specifically, the Hough transform algorithm (HT) was applied to the orthomosaicked images for inter-row weed detection. A semi-automatic Object-Based Image Analysis (OBIA) procedure was developed with Random Forests (RF) combined with feature selection techniques to classify soil, weeds and maize. Furthermore, the two binary weed masks generated from HT and OBIA were fused for accurate binary weed image. The developed RF classifier was evaluated by 5-fold cross validation, and it obtained an overall accuracy of 0.945, and Kappa value of 0.912. Finally, the relationship of detected weeds and their ground truth densities was quantified by a fitted linear model with a coefficient of determination of 0.895 and a root mean square error of 0.026. Besides, the importance of input features was evaluated, and it was found that the ratio of vegetation length and width was the most significant feature for the classification model. Overall, our approach can yield a satisfactory weed map, and we expect that the obtained accurate and timely weed map from UAV imagery will be applicable to realize site-specific weed management (SSWM) in early season crop fields for reducing spraying non-selective herbicides and costs.

Native prairie filter strips reduce runoff from hillslopes under annual row-crop systems in Iowa, USA

Treesearch

V. Hernandez-Santana; X. Zhou; M.J. Helmers; H. Asbjornsen; R. Kolka; M. Tomer

2013-01-01

Intensively managed annual cropping systems have produced high crop yields but have often produced significant ecosystem services alteration, in particular hydrologic regulation loss. Reconversion of annual agricultural systems to perennial vegetation can lead to hydrologic function restoration, but its effect is still not well understood. Therefore, our objective was...

Spatial 2D distribution of the proportion of soil phosphorus uptake by maize and soybean caused by tillage and fertilization

NASA Astrophysics Data System (ADS)

Li, Haixiao; Mollier, Alain; Ziadi, Noura; Messiga, Aimé Jean; Parent, Leon-Étienne; Morel, Christian

2017-04-01

Plant-available soil phosphorus (P) accumulates primarily in the topsoil due to P fertilization and P released from crop residues. In contrast with conventional tillage (moldboard plough, MP), conservation tillage [e.g. no-till, (NT)] often leads to higher P concentrations in the topsoil mainly due to the absence of mixing between soil, fertilizer, and crop residues. Our objective was to estimate the proportion of P uptake from a given soil mass across the soil profile under maize and soybean as the product of root surface density proportions and local plant-available soil P. This study was conducted on a long-term field experiment initiated in 1992 in southern Quebec, Canada, and established on a clay-loam soil under MP and NT systems. The experiment was factorially treated with three P doses (0, 17.5 and 35 kg P ha-1 applied as triple superphosphate on maize at 5 cm depth and at 5 cm on one side of the crop row). Soil was sampled at flowering stage at five depths (0-5, 5-10, 10-20, 20-30 and 30-40 cm) and three horizontal distances perpendicular to the crop row (5, 15 and 25 cm) in 2014 and 2015 to map a grid soil P availability to plants, e.g. phosphate ion concentrations in solution and the time-dependent amount of phosphate ions that can equilibrate- solution by diffusion, root distribution, and consequently crop P uptake, which was calculated as the fraction of plant-available soil P intercepted by surface roots. In general, NT tended to have higher soil P status in the upper soil layer and lower soil P status in the deeper soil layer compared to MP ; confirming previous results obtained from the same experimental site. This variation along the soil profile was significantly affected by sampling distance to crop row with higher concentration observed at 5-cm distance mainly because of the placement of P fertilizers. The 2D distribution of P uptake depended on tillage practice and P fertilization. There was higher proportions of P uptake from the 0-10 and 0-20 cm layers in NT (46% and 79%, respectively) compared to MP (25% and 68%, respectively). On average 8% of P uptake originated from the 30-40 cm layer irrespective of tillage, indicating that plant P uptake from deeper soil layers also influenced the P cycling in agroecosystems.

Effect of a 5-Year Multi-Crop Rotation on Mineral N and Hard Red Spring Wheat Yield, Protein, Test Weight and Economics in Western North Dakota, USA

NASA Astrophysics Data System (ADS)

Landblom, Douglas; Senturklu, Songul; Cihacek, Larry; Brevik, Eric

2016-04-01

The objectives of this non-irrigated cropping study was to employ the principles of soil health and determine the effect of rotation on seasonal mineral N, HRSW production, protein, test weight, and economics. Prior to the initiation of this research, the cropping study area had been previously seeded to hard red spring wheat (HRSW). The cropping systems consisted of a continuous HRSW control (C) compared to HRSW grown in a multi-crop 5-year rotation (R). The 5-yr rotation consisted of HRSW, cover crop (dual crop winter triticale-hairy vetch harvested for hay in June and immediately reseeded to a 7-species cover crop mix grazed by cows after weaning from mid-November to mid-December), forage corn, field pea-forage barley, and sunflower. The cereal grains, cover crops, and pea-barley intercrop were seeded using a JD 1590 no-till drill, 19 cm row spacing, and seed depth of 2.54 cm Cereal grain plant population was 3,088,750 plants/ha. The row crops were planted using a JD 7000 no-till planter, 76.2 cm row spacing, and seed depth of 5.08 cm. Plant population for the row crops was 46,947 plants/ha. Weeds were controlled using a pre-plant burn down and post-emergence control except for cover crops and pea-barley where a pre-plant burn down was the only chemical applied. Fertilizer application was based on soil test results and recommendations from the North Dakota State University Soil Testing Laboratory. During the 1st three years of the study 31.8 kg of N was applied to the C HRSW and then none the last two years of the 5-year period. The R HRSW was fertilized with 13.6 kg of N the 1st two years of the study and none the remaining three years of the 5-year period. However, chloride was low; therefore, 40.7-56.1 kg/ha were applied each year to both the C and R treatments. Based on 2014 and 2015 seasonal mineral N values, the data suggests that N levels were adequate to meet the 2690 kg/ha yield goal. In 2015, however, the R yield goal was exceeded by 673 kg/ha whereas the C yield goal of 2690 kg/ha was not achieved indicating that the multi-crop rotation enhanced soil quality and increased N cycling within the rotation management system. The 5-year average HRSW yield (C: 2690 vs. R: 2757 kg/ha; P=0.76), protein (C: 13.9 vs. R: 13.3%; P=0.06), and test weight (C: 28.1 vs. R: 28.0 kg/bu; P=0.81) did not differ between management treatments. Improved production is the result of enhanced nutrient cycling of available nutrients. Yields for crop years 1-5 were the same year 1, but in year 2, C wheat yield was 24.4% higher than R wheat (3,766 vs. 3,026 kg/ha). Change that started when the rotation was initiated became more evident in year three, when the yield margin between the two management practices began to narrow, but remained 20.5% higher for the C (3,161 vs. 2,623 kg/ha). Yield reversal became fully realized by year 4, when the R wheat yield was 9.1% higher (2,959 vs. 3,228 kg/ha), and by the 5th crop year R wheat yield was 38.9% higher than the C wheat yield (2,421 vs. 3,363 kg/ha). The 5-yr average input cost (C: 477 vs. R: 440/ha) and gross return (C: 650 vs. R: 638/ha) resulted in a net return that was 25 higher for R HRSW compared to the C HRSW (CTRL 173 vs. ROT 198/ha). The 5-yr net return from the C, R, and combination of all of the R crops was 173, 198, and 213/ha suggesting that growing continuous HRSW is less intensive, but also 14.5% less profitable.

Simulation of targeted pollutant-mitigation-strategies to reduce nitrate and sediment hotspots in agricultural watershed.

PubMed

Teshager, Awoke Dagnew; Gassman, Philip W; Secchi, Silvia; Schoof, Justin T

2017-12-31

About 50% of U.S. water pollution problems are caused by non-point source (NPS) pollution, primarily sediment and nutrients from agricultural areas, despite the widespread implementation of agricultural Best Management Practices (BMPs). However, the effectiveness of implementation strategies and type of BMPs at watershed scale are still not well understood. In this study, the Soil and Water Assessment Tool (SWAT) ecohydrological model was used to assess the effectiveness of pollutant mitigation strategies in the Raccoon River watershed (RRW) in west-central Iowa, USA. We analyzed fourteen management scenarios based on systematic combinations of five strategies: fertilizer/manure management, changing row-crop land to perennial grass, vegetative filter strips, cover crops and shallower tile drainage systems, specifically aimed at reducing nitrate and total suspended sediment yields from hotspot areas in the RRW. Moreover, we assessed implications of climate change on management practices, and the impacts of management practices on water availability, row crop yield, and total agricultural production. Our results indicate that sufficient reduction of nitrate load may require either implementation of multiple management practices (38.5% with current setup) or conversion of extensive areas into perennial grass (up to 49.7%) to meet and maintain the drinking water standard. However, climate change may undermine the effectiveness of management practices, especially late in the 21st century, cutting the reduction by up to 65% for nitrate and more for sediment loads. Further, though our approach is targeted, it resulted in a slight decrease (~5%) in watershed average crop yield and hence an overall reduction in total crop production, mainly due to the conversion of row-crop lands to perennial grass. Such yield reductions could be quite spatially heterogeneously distributed (0 to 40%). Copyright © 2017 Elsevier B.V. All rights reserved.

Agricultural conversion of floodplain ecosystems: implications for groundwater quality.

PubMed

Schilling, Keith E; Jacobson, Peter J; Vogelgesang, Jason A

2015-04-15

With current trends of converting grasslands to row crop agriculture in vulnerable areas, there is a critical need to evaluate the effects of land use on groundwater quality in large river floodplain systems. In this study, groundwater hydrology and nutrient dynamics associated with three land cover types (grassland, floodplain forest and cropland) were assessed at the Cedar River floodplain in southeastern Iowa. The cropland site consisted of newly-converted grassland, done specifically for our study. Our objectives were to evaluate spatial and temporal variations in groundwater hydrology and quality, and quantify changes in groundwater quality following land conversion from grassland to row crop in a floodplain. We installed five shallow and one deep monitoring wells in each of the three land cover types and recorded water levels and quality over a three year period. Crop rotations included soybeans in year 1, corn in year 2 and fallow with cover crops during year 3 due to river flooding. Water table levels behaved nearly identically among the sites but during the second and third years of our study, NO₃-N concentrations in shallow floodplain groundwater beneath the cropped site increased from 0.5 mg/l to more than 25 mg/l (maximum of 70 mg/l). The increase in concentration was primarily associated with application of liquid N during June of the second year (corn rotation), although site flooding may have exacerbated NO₃-N leaching. Geophysical investigation revealed differences in ground conductivity among the land cover sites that related significantly to variations in groundwater quality. Study results provide much-needed information on the effects of different land covers on floodplain groundwater and point to challenges ahead for meeting nutrient reduction goals if row crop land use expands into floodplains. Copyright © 2015 Elsevier Ltd. All rights reserved.

Overestimation of Crop Root Biomass in Field Experiments Due to Extraneous Organic Matter

PubMed Central

Hirte, Juliane; Leifeld, Jens; Abiven, Samuel; Oberholzer, Hans-Rudolf; Hammelehle, Andreas; Mayer, Jochen

2017-01-01

Root biomass is one of the most relevant root parameters for studies of plant response to environmental change, soil carbon modeling or estimations of soil carbon sequestration. A major source of error in root biomass quantification of agricultural crops in the field is the presence of extraneous organic matter in soil: dead roots from previous crops, weed roots, incorporated above ground plant residues and organic soil amendments, or remnants of soil fauna. Using the isotopic difference between recent maize root biomass and predominantly C3-derived extraneous organic matter, we determined the proportions of maize root biomass carbon of total carbon in root samples from the Swiss long-term field trial “DOK.” We additionally evaluated the effects of agricultural management (bio-organic and conventional), sampling depth (0–0.25, 0.25–0.5, 0.5–0.75 m) and position (within and between maize rows), and root size class (coarse and fine roots) as defined by sieve mesh size (2 and 0.5 mm) on those proportions, and quantified the success rate of manual exclusion of extraneous organic matter from root samples. Only 60% of the root mass that we retrieved from field soil cores was actual maize root biomass from the current season. While the proportions of maize root biomass carbon were not affected by agricultural management, they increased consistently with soil depth, were higher within than between maize rows, and were higher in coarse (>2 mm) than in fine (≤2 and >0.5) root samples. The success rate of manual exclusion of extraneous organic matter from root samples was related to agricultural management and, at best, about 60%. We assume that the composition of extraneous organic matter is strongly influenced by agricultural management and soil depth and governs the effect size of the investigated factors. Extraneous organic matter may result in severe overestimation of recovered root biomass and has, therefore, large implications for soil carbon modeling and estimations of the climate change mitigation potential of soils. PMID:28298919

Trapping fall armyworm in Africa

USDA-ARS?s Scientific Manuscript database

Fall armyworm, Spodoptera frugiperda, is a noctuid pest of row and vegetable crops throughout the Americas. It has recently invaded Africa and has been identified from almost all sub-Saharan countries. There is a strong expectation of significant damage to African maize crop yield and a high likel...

Tree fruit orchard of the future: An overview

USDA-ARS?s Scientific Manuscript database

Mechanization has been prevailing in row crops over the past decades, and now gradually in some fruit crops, with integration of innovative computers, robotics, mechanics, and precision orchard management. This talk will give an overview of challenges facing commercial fruit industries and needs of ...

POPULATION DYNAMICS OF AMBIENT AND ALTERED EARTHWORM COMMUNITIES IN ROW-CROP AGROECOSYSTEMS IN OHIO, USA

EPA Science Inventory

Although earthworms are known to influence agroecosystem processes, there are relatively few long-term studies addressing population dynamics under cropping systems in which earthworm populations were intentionally altered. We assessed earthworm communities from fall 1994 to spr...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meinke, Rainer

A method for manufacture of a conductor assembly. The assembly is of the type which, when conducting current, generates a magnetic field or in which, in the presence of a changing magnetic field, a voltage is induced. In an example embodiment one or more first coil rows are formed. The assembly has multiple coil rows about an axis with outer coil rows formed about inner coil rows. A determination is made of deviations from specifications associated with the formed one or more first coil rows. One or more deviations correspond to a magnitude of a multipole field component which departsmore » from a field specification. Based on the deviations, one or more wiring patterns are generated for one or more second coil rows to be formed about the one or more first coil rows. The one or more second coil rows are formed in the assembly. The magnitude of each multipole field component that departs from the field specification is offset.« less

Modeling the effects of different N fertilizer rates on N2O emissions and nitrate leaching from arable soils in Korea

NASA Astrophysics Data System (ADS)

Kim, Y.; Berger, S.; Tenhunen, J. D.; Gebauer, G.; Kiese, R.

2012-12-01

Process-based biogeochemical models can be used to predict the impact of various agricultural management practices on plant nitrogen use efficiency and nitrogen losses to the environment such as greenhouse gas emissions and nitrate leaching by analyzing the interactions between management practices, primary drivers such as climate, soil properties, crop types, etc., and biogeochemical reactions. In this study we applied the Landscape-DNDC model, which combines and uniforms functions of the agricultural-DNDC and the Forest-DNDC for simulation of C and N turnover, GHG emissions, nitrate leaching, and plant growth for a Korean arable field cultivated with radish (Raphanus sativus L.). The annual average temperature is app. 8.5°C and the annual precipitation is app. 1,500 mm. According to farmers practice the study field received a basal fertilizer application of app. 200 kg N ha-1 before setting up four fertilizer treatments i.e. additionally 50, 150, 250 and 350 kg N ha-1. All N treatment plots were tilled a week after application of specific N fertilizer in order to make row and interrow. Just before radish seeding rows were covered with black plastic mulch which was removed after harvest. In spite the widespread usage of black mulch in Korea or even Asia; so far biogeochemical models do not consider impacts of mulch on soil environmental conditions and soil biogeochemistry. Based on field measurements we adjusted input information and used only half of the annual precipitation and the maximum temperature for simulation of row conditions, whereas the actual weather data were used for the interrow simulations. Simulated N2O emissions agreed well with measurements; however peak emissions after fertilization were slightly underestimated in row and interrow. Annual N2O emissions of the fertilizer treatments increased with increasing fertilization rates from around 1.5 to 3 kg N ha-1 in the row and lower emissions of app. 1.5 kg N ha-1 (for all N treatments) in the interrow resulting in total direct emissions of about 1.5 to 2.3 kg N ha-1 yr-1 (area weighted average of row and interrow). Compared with the IPCC approach (EF = 0.01) these values are rather low which can be explained by high rates of simulated and measured nitrate leaching across all N treatments (row: 214 - 240 kg N ha-1 yr-1; interrow: 259 - 263 kg N ha-1 yr-1). Seasonal dynamic and magnitude of measured and simulated NO3 concentrations in soil water in different soil depths agreed well which give further evidence for the simulated nitrate leaching. Using the IPCC EF of 0.0075, nitrate leaching results in indirect N2O emissions of additionally 1.8 kg N ha-1 yr-1. Only slight increase of measured and simulated yields (4 to 5.2 t DW ha-1) with higher rates of N fertilization indicate that actual farmer practices can be improved and optimizing agricultural management considering the specific climatic and soil conditions has a high potential to reduce environmental impacts of crop cultivations in the study area of the Haean catchment.

A black color morph of adult Nezara viridula (L.)

USDA-ARS?s Scientific Manuscript database

The southern green stink bug is a worldwide pest of cotton and other row crops, affecting crop yield and transmitting diseases. Adult coloration is sometimes used to identify southern green stink bugs and to determine their physiological condition. Multiple colors occur in southern green stink bug. ...

First report of soybean pest, Euschistus quadrator (Hempitera: pentatomidae) in Mississippi

USDA-ARS?s Scientific Manuscript database

Here we report on the first state and county record of Euschistus quadrator Ralston (Hemiptera: Pentatomidae) in Washington County, Mississippi. The species has been documented from Honduras to Virginia primarily on soybeans, cotton, various row crops, fruit, and non-crop hosts. The local impact...

Hydrogeology and water quality of the Pepacton Reservoir Watershed in southeastern New York. Part 1. Concentrations of pesticides and their degradates in stream baseflow, 2000-2001

USGS Publications Warehouse

Phillips, Patrick J.; Heisig, Paul M.

2004-01-01

Baseflow samples were collected from 20 small streams in the Pepacton Reservoir watershed in Delaware County, N.Y., from December 2000 through November 2001 as part of an investigation to define the occurrence of pesticides in shallow ground water in watersheds containing either a recent (2001) corn crop, a previous (1993-94) corn crop, or no history of row-crop cultivation. Baseflow water quality was assumed to represent the chemical quality of shallow ground water within the drainage area above each sampling site.Baseflow samples were analyzed for 57 pesticides and pesticide degradates. Three herbicides (atrazine, metolachlor and simazine) and three herbicide degradates (alachlor ESA [ethanesulfonic acid], deethylatrazine, and metolachlor ESA) were detected, but no concentrations exceeded any Federal or State water-quality criteria, and the maximum concentrations of all compounds except metolachlor ESA were less than 0.10 microgram per liter. The most frequently detected compounds (atrazine, metolachlor, deethylatrazine and metolachlor ESA) are either those typically used on corn crops, or those whose parent compounds are commonly used on corn crops and have been detected in streams that drain row-crop settings elsewhere in New York State. The pesticide and pesticide-degradate concentrations in baseflow samples collected in December 2000 and July 2001 samples generally corresponded to the amount of cornfield acreage in each watershed in 2001.The types of pesticides detected, and their median concentrations, were similar to those noted in two previous ground-water studies in row-crop areas elsewhere in upstate New York. Also the SAM ratios (ratio of metolachlor ESA concentration to metolachlor concentration) for the Pepacton samples were similar to those for ground-water samples from other agricultural settings in upstate New York, but were significantly higher than that for stormflow and baseflow samples collected in 1997-98 from Canajoharie Creek, an upstate stream that drains row-crop farmland. These comparisons confirm that the baseflow samples were derived from, and were representative of, ground water in their respective watersheds. Late-summer decreases in atrazine and deethylatrazine concentrations at a site where corn was grown in 2001 may have resulted from the seasonally dry conditions and the accompanying decrease in ground-water discharge from the upper-most part of the surficial aquifer system to streams. The lack of a similar decrease in metolachlor ESA concentrations during this period may reflect the transport of metolachlor ESA to deeper parts of the surficial aquifer that continued to discharge to streams during the dry period.

Effect of tillage system on yield and weed populations of soybean ( Glycin Max L.).

PubMed

Hosseini, Seyed Z; Firouzi, Saeed; Aminpanah, Hashem; Sadeghnejhad, Hamid R

2016-03-01

Field experiment was conducted at Agricultural and Natural Resources Research Center of Golestan Province, Iran, to determine the effects of tillage system and weed management regime on yield and weed populations in soybean ( Glycin max L.). The experimental design was a split plot where the whole plot portion was a randomized complete block with three replicates. Main plots were tillage system: 1- No-till row crop seeding, 2- No-till seed drilling, 3- Tillage with disc harrow and drill planting, 4- Tillage with chisel packer and drill planting. The subplots were weed management regimes: 1-Weed control with herbicide application, 2- Hand weeding, 3- Herbicide application plus hand weeding, and 4- Non-weeding. Results indicated that the main effects of tillage system and weed management regime were significant for seed yield, pod number per plant, seed number per pod, weed density and biomass, while their interaction were significant only for weed density, weed biomass, and seed number per pod. The highest grain yields (3838 kg ha-1) were recorded for No-till row crop seeding. The highest seed yield (3877 kg ha-1) also was recorded for weed control with herbicide and hand weeding treatment, followed by hand weeding (3379 kg ha-1).

Interference between Redroot Pigweed (Amaranthus retroflexus L.) and Cotton (Gossypium hirsutum L.): Growth Analysis.

PubMed

Ma, Xiaoyan; Wu, Hanwen; Jiang, Weili; Ma, Yajie; Ma, Yan

2015-01-01

Redroot pigweed is one of the injurious agricultural weeds on a worldwide basis. Understanding of its interference impact in crop field will provide useful information for weed control programs. The effects of redroot pigweed on cotton at densities of 0, 0.125, 0.25, 0.5, 1, 2, 4, and 8 plants m(-1) of row were evaluated in field experiments conducted in 2013 and 2014 at Institute of Cotton Research, CAAS in China. Redroot pigweed remained taller and thicker than cotton and heavily shaded cotton throughout the growing season. Both cotton height and stem diameter reduced with increasing redroot pigweed density. Moreover, the interference of redroot pigweed resulted in a delay in cotton maturity especially at the densities of 1 to 8 weed plants m(-1) of row, and cotton boll weight and seed numbers per boll were reduced. The relationship between redroot pigweed density and seed cotton yield was described by the hyperbolic decay regression model, which estimated that a density of 0.20-0.33 weed plant m(-1) of row would result in a 50% seed cotton yield loss from the maximum yield. Redroot pigweed seed production per plant or per square meter was indicated by logarithmic response. At a density of 1 plant m(-1) of cotton row, redroot pigweed produced about 626,000 seeds m(-2). Intraspecific competition resulted in density-dependent effects on weed biomass per plant, a range of 430-2,250 g dry weight by harvest. Redroot pigweed biomass ha(-1) tended to increase with increasing weed density as indicated by a logarithmic response. Fiber quality was not significantly influenced by weed density when analyzed over two years; however, the fiber length uniformity and micronaire were adversely affected at density of 1 weed plant m(-1) of row in 2014. The adverse impact of redroot pigweed on cotton growth and development identified in this study has indicated the need of effective redroot pigweed management.

Interference between Redroot Pigweed (Amaranthus retroflexus L.) and Cotton (Gossypium hirsutum L.): Growth Analysis

PubMed Central

Ma, Xiaoyan; Wu, Hanwen; Jiang, Weili; Ma, Yajie; Ma, Yan

2015-01-01

Redroot pigweed is one of the injurious agricultural weeds on a worldwide basis. Understanding of its interference impact in crop field will provide useful information for weed control programs. The effects of redroot pigweed on cotton at densities of 0, 0.125, 0.25, 0.5, 1, 2, 4, and 8 plants m-1 of row were evaluated in field experiments conducted in 2013 and 2014 at Institute of Cotton Research, CAAS in China. Redroot pigweed remained taller and thicker than cotton and heavily shaded cotton throughout the growing season. Both cotton height and stem diameter reduced with increasing redroot pigweed density. Moreover, the interference of redroot pigweed resulted in a delay in cotton maturity especially at the densities of 1 to 8 weed plants m-1 of row, and cotton boll weight and seed numbers per boll were reduced. The relationship between redroot pigweed density and seed cotton yield was described by the hyperbolic decay regression model, which estimated that a density of 0.20–0.33 weed plant m-1 of row would result in a 50% seed cotton yield loss from the maximum yield. Redroot pigweed seed production per plant or per square meter was indicated by logarithmic response. At a density of 1 plant m-1 of cotton row, redroot pigweed produced about 626,000 seeds m-2. Intraspecific competition resulted in density-dependent effects on weed biomass per plant, a range of 430–2,250 g dry weight by harvest. Redroot pigweed biomass ha-1 tended to increase with increasing weed density as indicated by a logarithmic response. Fiber quality was not significantly influenced by weed density when analyzed over two years; however, the fiber length uniformity and micronaire were adversely affected at density of 1 weed plant m-1 of row in 2014. The adverse impact of redroot pigweed on cotton growth and development identified in this study has indicated the need of effective redroot pigweed management. PMID:26057386

Development of laser-guided precision sprayers for tree crop applications

USDA-ARS?s Scientific Manuscript database

Tree crops in nurseries and orchards have great variations in shapes, sizes, canopy densities and gaps between in-row trees. The variability requires future sprayers to be flexible to spray the amount of chemicals that can match tree structures. A precision air-assisted sprayer was developed to appl...

7 CFR 457.168 - Mustard crop insurance provisions.

Code of Federal Regulations, 2012 CFR

2012-01-01

.... Harvest. Combining or threshing for seed. A crop that is swathed prior to combining is not considered... contained in the Basic Provisions, mustard seed must be planted in rows. Acreage planted in any other manner... written agreement. Processor. Any business enterprise regularly engaged in buying and processing mustard...

7 CFR 457.168 - Mustard crop insurance provisions.

Code of Federal Regulations, 2014 CFR

2014-01-01

.... Harvest. Combining or threshing for seed. A crop that is swathed prior to combining is not considered... contained in the Basic Provisions, mustard seed must be planted in rows. Acreage planted in any other manner... written agreement. Processor. Any business enterprise regularly engaged in buying and processing mustard...

Advances in the two-source energy balance model:Partioning of evaporation and transpiration for row crops

USDA-ARS?s Scientific Manuscript database

Accurate partitioning of the evaporation (E) and transpiration (T) components of evapotranspiration (ET) in remote sensing models is important for evaluating strategies aimed at increasing crop water productivity. The two-source energy balance (TSEB) model solves the energy balance of the soil-plant...

Agricultural Policy Environmental eXtender simulation of three adjacent row-crop watersheds in the claypan region

USDA-ARS?s Scientific Manuscript database

The Agricultural Policy Environmental Extender (APEX) model can simulate crop yields, and pollutant loadings in whole farms or small watersheds with variety of management practices. The study objectives were to identify sensitive parameters and parameterize, calibrate and validate the APEX model fo...

Impact of tillage and fertilizer application method on gas emissions in a corn cropping system

USDA-ARS?s Scientific Manuscript database

Tillage and fertilization practices used in row crop production are thought to alter greenhouse gas emissions from soil. This study was conducted to determine the impact of fertilizer sources, land management practices, and fertilizer placement methods on greenhouse gas emissions. A new prototype i...

UAS imaging for automated crop lodging detection: a case study over an experimental maize field

NASA Astrophysics Data System (ADS)

Chu, Tianxing; Starek, Michael J.; Brewer, Michael J.; Masiane, Tiisetso; Murray, Seth C.

2017-05-01

Lodging has been recognized as one of the major destructive factors for crop quality and yield, particularly in corn. A variety of contributing causes, e.g. disease and/or pest, weather conditions, excessive nitrogen, and high plant density, may lead to lodging before harvesting season. Traditional lodging detection strategies mainly rely on ground data collection, which is insufficient in efficiency and accuracy. To address this problem, this research focuses on the use of unmanned aircraft systems (UAS) for automated detection of crop lodging. The study was conducted over an experimental corn field at the Texas A and M AgriLife Research and Extension Center at Corpus Christi, Texas, during the growing season of 2016. Nadir-view images of the corn field were taken by small UAS platforms equipped with consumer grade RGB and NIR cameras on a per week basis, enabling a timely observation of the plant growth. 3D structural information of the plants was reconstructed using structure-from-motion photogrammetry. The structural information was then applied to calculate crop height, and rates of growth. A lodging index for detecting corn lodging was proposed afterwards. Ground truth data of lodging was collected on a per row basis and used for fair assessment and tuning of the detection algorithm. Results show the UAS-measured height correlates well with the ground-measured height. More importantly, the lodging index can effectively reflect severity of corn lodging and yield after harvesting.

Method of reducing multipole content in a conductor assembly during manufacture

DOEpatents

Meinke, Rainer [Melbourne, FL

2011-08-09

A method for manufacture of a conductor assembly. The assembly is of the type which, when conducting current, generates a magnetic field or in which, in the presence of a changing magnetic field, a voltage is induced. In an example embodiment one or more first coil rows are formed. The assembly has multiple coil rows about an axis with outer coil rows formed about inner coil rows. A determination is made of deviations from specifications associated with the formed one or more first coil rows. One or more deviations correspond to a magnitude of a multipole field component which departs from a field specification. Based on the deviations, one or more wiring patterns are generated for one or more second coil rows to be formed about the one or more first coil rows. The one or more second coil rows are formed in the assembly. The magnitude of each multipole field component that departs from the field specification is offset.

Method of reducing multipole content in a conductor assembly during manufacture

DOEpatents

Meinke, Rainer

2013-08-20

A method for manufacture of a conductor assembly. The assembly is of the type which, when conducting current, generates a magnetic field or in which, in the presence of a changing magnetic field, a voltage is induced. In an example embodiment one or more first coil rows are formed. The assembly has multiple coil rows about an axis with outer coil rows formed about inner coil rows. A determination is made of deviations from specifications associated with the formed one or more first coil rows. One or more deviations correspond to a magnitude of a multipole field component which departs from a field specification. Based on the deviations, one or more wiring patterns are generated for one or more second coil rows to be formed about the one or more first coil rows. The one or more second coil rows are formed in the assembly. The magnitude of each multipole field component that departs from the field specification is offset.

Estimation of Wheat Plant Density at Early Stages Using High Resolution Imagery

PubMed Central

Liu, Shouyang; Baret, Fred; Andrieu, Bruno; Burger, Philippe; Hemmerlé, Matthieu

2017-01-01

Crop density is a key agronomical trait used to manage wheat crops and estimate yield. Visual counting of plants in the field is currently the most common method used. However, it is tedious and time consuming. The main objective of this work is to develop a machine vision based method to automate the density survey of wheat at early stages. RGB images taken with a high resolution RGB camera are classified to identify the green pixels corresponding to the plants. Crop rows are extracted and the connected components (objects) are identified. A neural network is then trained to estimate the number of plants in the objects using the object features. The method was evaluated over three experiments showing contrasted conditions with sowing densities ranging from 100 to 600 seeds⋅m-2. Results demonstrate that the density is accurately estimated with an average relative error of 12%. The pipeline developed here provides an efficient and accurate estimate of wheat plant density at early stages. PMID:28559901

Alternate row placement is ineffective for cultural control of Meloidogyne incognita in cotton

PubMed Central

2008-01-01

The objective of this study was to determine if planting cotton into the space between the previous year's rows reduces crop loss due to Meloidogyne incognita compared to planting in the same row every year. Row placement had a significant (P ≤ 0.05) effect on nematode population levels only on 8 July 2005. Plots receiving 1,3-dichloropropene plus aldicarb had lower nematode population levels than non-fumigated plots on 24 May and 8 July in 2005, but not in 2004. The effect of nematicide treatment on nematode populations was not affected by row placement. Row placement did not have a significant effect on root galling or yield in 2004 or 2005. Nematicide treatment decreased root galling in all years, and the decrease was not influenced by row placement. Yield was increased by nematicide application in 2004 and 2005, and the increase was not affected by row placement. Percentage yield loss was not affected by row placement. Changing the placement of rows reduced nematode population levels only on one sampling date in one year, but end-of-season root galling and lint yield were not affected by changing the placement of rows, nor was the effect of fumigation on yield influenced by row placement. Therefore, row placement is unlikely to contribute to M. incognita management in cotton. PMID:19440259

Development of remote sensing based site specific weed management for Midwest mint production

NASA Astrophysics Data System (ADS)

Gumz, Mary Saumur Paulson

Peppermint and spearmint are high value essential oil crops in Indiana, Michigan, and Wisconsin. Although the mints are profitable alternatives to corn and soybeans, mint production efficiency must improve in order to allow industry survival against foreign produced oils and synthetic flavorings. Weed control is the major input cost in mint production and tools to increase efficiency are necessary. Remote sensing-based site-specific weed management offers potential for decreasing weed control costs through simplified weed detection and control from accurate site specific weed and herbicide application maps. This research showed the practicability of remote sensing for weed detection in the mints. Research was designed to compare spectral response curves of field grown mint and weeds, and to use these data to develop spectral vegetation indices for automated weed detection. Viability of remote sensing in mint production was established using unsupervised classification, supervised classification, handheld spectroradiometer readings and spectral vegetation indices (SVIs). Unsupervised classification of multispectral images of peppermint production fields generated crop health maps with 92 and 67% accuracy in meadow and row peppermint, respectively. Supervised classification of multispectral images identified weed infestations with 97% and 85% accuracy for meadow and row peppermint, respectively. Supervised classification showed that peppermint was spectrally distinct from weeds, but the accuracy of these measures was dependent on extensive ground referencing which is impractical and too costly for on-farm use. Handheld spectroradiometer measurements of peppermint, spearmint, and several weeds and crop and weed mixtures were taken over three years from greenhouse grown plants, replicated field plots, and production peppermint and spearmint fields. Results showed that mints have greater near infrared (NIR) and lower green reflectance and a steeper red edge slope than all weed species. These distinguishing characteristics were combined to develop narrow band and broadband spectral vegetation indices (SVIs, ratios of NIR/green reflectance), that were effective in differentiating mint from key weed species. Hyperspectral images of production peppermint and spearmint fields were then classified using SVI-based classification. Narrowband and broadband SVIs classified early season peppermint and spearmint with 64 to 100% accuracy compared to 79 to 100% accuracy for supervised classification of multispectral images of the same fields. Broadband SVIs have potential for use as an automated spectral indicator for weeds in the mints since they require minimal ground referencing and can be calculated from multispectral imagery which is cheaper and more readily available than hyperspectral imagery. This research will allow growers to implement remote sensing based site specific weed management in mint resulting in reduced grower input costs and reduced herbicide entry into the environment and will have applications in other specialty and meadow crops.

Quantifying the effect of crop spatial arrangement on weed suppression using functional-structural plant modelling.

PubMed

Evers, Jochem B; Bastiaans, Lammert

2016-05-01

Suppression of weed growth in a crop canopy can be enhanced by improving crop competitiveness. One way to achieve this is by modifying the crop planting pattern. In this study, we addressed the question to what extent a uniform planting pattern increases the ability of a crop to compete with weed plants for light compared to a random and a row planting pattern, and how this ability relates to crop and weed plant density as well as the relative time of emergence of the weed. To this end, we adopted the functional-structural plant modelling approach which allowed us to explicitly include the 3D spatial configuration of the crop-weed canopy and to simulate intra- and interspecific competition between individual plants for light. Based on results of simulated leaf area development, canopy photosynthesis and biomass growth of the crop, we conclude that differences between planting pattern were small, particularly if compared to the effects of relative time of emergence of the weed, weed density and crop density. Nevertheless, analysis of simulated weed biomass demonstrated that a uniform planting of the crop improved the weed-suppression ability of the crop canopy. Differences in weed suppressiveness between planting patterns were largest with weed emergence before crop emergence, when the suppressive effect of the crop was only marginal. With simultaneous emergence a uniform planting pattern was 8 and 15 % more competitive than a row and a random planting pattern, respectively. When weed emergence occurred after crop emergence, differences between crop planting patterns further decreased as crop canopy closure was reached early on regardless of planting pattern. We furthermore conclude that our modelling approach provides promising avenues to further explore crop-weed interactions and aid in the design of crop management strategies that aim at improving crop competitiveness with weeds.

Louisiana farm discussion: 8 foot row spacing

USDA-ARS?s Scientific Manuscript database

This year several tests in growers’ fields were used to compare traditional 6-foot row spacing to 8-foot row spacing. Cane is double-drilled in the wider row spacing. The wider row spacing would accommodate John Deere 3522 harvester. Field data indicate the sugarcane yields are very comparable in 8-...

Meteorological and associated data collected over agricultural fields in Pinal County, Arizona, 1989 and 1990

USGS Publications Warehouse

Owen-Joyce, Sandra J.; Brown, Paul W.

1995-01-01

Data were collected at temporary meteorological stations installed in agricultural fields in Pinal County, Arizona, to evaluate the spatial and temporal variability of point data and to examine how station location affects ground-based meteorological data and the resulting values of evapotranspiration calculated using remotely sensed multispectral data from satellites. Time-specific data were collected to correspond with satellite overpasses from April to October 1989, and June 27-28, 1990. Meteorological data consisting of air temperature, relative humidity, wind speed, solar radiation, and net radiation were collected at each station during all periods of the project. Supplementary measurements of soil temperature, soil heat flux density, and surface or canopy temperature were obtained at some locations during certain periods of the project. Additional data include information on data-collection periods, station positions, instrumentation, sensor heights, and field dimensions. Other data, which correspond to the extensive field measurements made in con- junction with satellite overpasses in 1989 and 1990, include crop type, canopy cover, canopy height, irrigation, cultivation, and orientation of rows. Field boundaries and crop types were mapped in a 2- to 3-square-kilometer area surrounding each meteorological station. Field data are presented in tabular and graphic form. Meteorological and supplementary data are available, upon request, in digital form.

The Big Deals in Biofuels

ERIC Educational Resources Information Center

Brainard, Jeffrey

2007-01-01

Plants that bear less familiar names such as switch grass, "Miscanthus," and kenaf, are not much to look at, having weathered Iowa's winter snows. But Iowa State researchers see these crops as seeds of change in alternative fuels. Rows of experimental crops line the test plots at Iowa State University's research farm. Although corn is…

Effects of tillage and broiler litter on crop productions in an eroded soil

USDA-ARS?s Scientific Manuscript database

Soils in the southeastern United States, where the climate is subtropical, are severely eroded from intense row crop agriculture many years ago. This study was initiated in 2005 at the Plant Material Center, NRCS, in Coffeeville MS, on an Loring silt loam (fine-silty, mixed, thermic, Glossic Fragiud...

Iowa Commercial Pesticide Applicator Manual, Category 1A: Agricultural Weed Control.

ERIC Educational Resources Information Center

Jennings, Vivan M.; Ryan, Stephen O.

This manual provides information needed to meet the standards for pesticide applicator certification. Weeds, their effects, and control in relation to crop production are presented. Pre- and post-emergence treatments are discussed for row crops such as corn and soybeans. Problems with herbicide application to grass pastures, small grains, and…

Advances in the two-source energy balance model: Partioning of evaporation and transpiration for row crops for cotton

USDA-ARS?s Scientific Manuscript database

Accurate partitioning of the evaporation (E) and transpiration (T) components of evapotranspiration (ET) in remote sensing models is important for evaluating strategies aimed at increasing crop water productivity. The two-source energy balance (TSEB) model solves the energy balance of the soil-plant...

Soil water infiltration affected by topsoil thickness in row crop and switchgrass production systems

USDA-ARS?s Scientific Manuscript database

Conversion of annual grain crop systems to biofuel production systems can restore soil hydrologic function; however, information on these effects is limited. Hence, the objective of this study was to evaluate the influence of topsoil thickness on water infiltration in claypan soils for grain and swi...

A mowing strategy to convert red clover to annual crops in organic farming

USDA-ARS?s Scientific Manuscript database

Organic producers are interested in no-till cropping systems. In this study, we found that perennial clover can be converted to corn without tillage. Conversion tactics involved fall mowing in the third year of red clover, followed by between-row mowing of weeds and volunteer red clover in corn gr...

Nitrogen supply and demand in short-rotation sweetgum plantations

Treesearch

D. Andrew Scott; James A. Burger; Donald J. Kaczmarek; Michael B. Kane

2004-01-01

Intensive management is crucial for optimizing hardwood plantation success, and nitrogen (N) nutrition management is one of the most important practices in intensive management. Because management of short-rotation woody crop plantations is a mixture of row-crop agriculture and plantation forestry, we tested the usefulness of an agronomic budget modified for deciduous...

Water use efficiency and evapotranspiration in maize-soybean relay strip intercrop systems as affected by planting geometries.

PubMed

Rahman, Tanzeelur; Liu, Xin; Hussain, Sajad; Ahmed, Shoaib; Chen, Guopeng; Yang, Feng; Chen, Lilian; Du, Junbo; Liu, Weiguo; Yang, Wenyu

2017-01-01

Optimum planting geometries have been shown to increase crop yields in maize-soybean intercrop systems. However, little is known about whether changes in planting geometry improve the seasonal water use of maize and soybean intercrops. We conducted two different field experiments in 2013 and 2014 to investigate the effects of changes in planting geometry on water use efficiency (WUE) and evapotranspiration (ETc) of maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] relay strip intercrop systems. Our results showed that the leaf area index of maize for both years where intercropping occurred was notably greater compared to sole maize, thus the soil water content (SWC), soil evaporation (E), and throughfall followed a decreasing trend in the following order: central row of maize strip (CRM) < adjacent row between maize and soybean strip (AR) < central row of soybean strip (CRS). When intercropped, the highest grain yield for maize and total yields were recorded for the 40:120 cm and 40:160 cm planting geometries using 160 cm and 200 cm bandwidth, respectively. By contrast, the highest grain yield of intercropped soybean was appeared for the 20:140 cm and 20:180 cm planting geometries. The largest land equivalent ratios were 1.62 for the 40:120 cm planting geometry and 1.79 for the 40:160 cm planting geometry, indicating that both intercropping strategies were advantageous. Changes in planting geometries did not show any significant effect on the ETc of the maize and soybean intercrops. WUEs in the different planting geometries of intercrop systems were lower compared to sole cropping. However, the highest group WUEs of 23.06 and 26.21 kg ha-1 mm-1 for the 40:120 cm and 40:160 cm planting geometries, respectively, were 39% and 23% higher than those for sole cropping. Moreover, the highest water equivalent ratio values of 1.66 and 1.76 also appeared for the 40:120 cm and 40:160 cm planting geometries. We therefore suggest that an optimum planting geometry of 40:160 cm and bandwidth of 200 cm could be a viable planting pattern management method for attaining high group WUE in maize-soybean intercrop systems.

Effect of pre-planting irrigation, maize planting pattern and nitrogen on weed seed bank population.

PubMed

Hemmati, E; Vazan, S; Oveisi, M

2011-01-01

Pre-planting irrigation and planting patterns are important factors in weed management that effect on seed bank. Additionally, the nitrogen is the most important factor in plant growth that affects weed-crop competition and ultimately, seed rain into the soil. A field experiment was conducted to study the effect of nitrogen application rates, pre-planting irrigation and maize planting patterns on weed seed bank population. Experimental factors were nitrogen rates at 4 levels (200, 300, 400 and 500 kg per hectare) as main plot; and pre-planting irrigation at 2 levels (irrigation before planting plus weeding emerged seedlings and, irrigation after sowing), and maize planting patterns (one-row and two-row planting of maize with same density per square of row length) that were assigned in a factorial arrangement to the sub plots. Soil samples were taken at the beginning of the season (before planting of maize) and at the end of the season (after harvest) at depth of 0-5 cm in the fixed quadrates (60 cm x 60 cm). The weed seeds were extracted from the soil samples and were identified using standard methods. The majority of weed seed bank populations included 6 weed species: Portulaca oleracea, Chenopodium album, Amaranthus retroflexus, Sorghum halepense, Daturea stramonium, Xanthium strumarium. Results showed that population of weed seed bank increased significantly with increasing nitrogen rate. The increasing rate was different between one-row and two-row planting patterns. The parameters indicated that seed bank population was much higher in a one row planting pattern of maize. With two-row planting, seed bank was decreased by 34, 26, 20 and 5% at 200, 300, 400 and 500 kg N/ha, respectively. Pre-planting irrigation was also found an effective implement to reduce the weed seed bank. When pre-planting irrigation was applied, seed bank was decreased by 57, 43, 34 and 9% at 200, 300, 400 and 500 kg N/ha. Increasing nitrogen because of weed's better growth and higher seed production neutralized the decreasing effect of pre-planting irrigation and two-row planting of maize on weed seed bank population.

Monitoring Evaporation/Transpiration in a Vineyard from Two-Source Energy Balance and Radiometric Temperatures

NASA Astrophysics Data System (ADS)

Sánchez, Juan Manuel; Doña, Carolina; Cuxart, Joan; Caselles, Vicente; Niclòs, Raquel

2014-05-01

Water management and understanding of irrigation efficiency could be significantly improved if the components of evapotranspiration (ET) in row-crop systems (plants and soil interrows) could be quantified separately. This evaporation/transpiration (E/T) partition, and its daily and seasonal evolution, depends on a variety of biophysical and environmental factors. In this work we present an operational method to provide continuous E/T results avoiding soil or canopy disturbance. This technique is based on the combination of the surface-atmosphere energy exchange modeling together with an accurate remote thermal characterization of the crop elements. An experiment was carried out in a row-crop vineyard in Mallorca, Spain, from June 2012 to May 2013. A set of 6 thermal-infrared radiometers (IRTs) were mounted in a mast placed in the middle of a vineyard N-S row. Two IRTs pointed to the soil between rows and other two pointed to the plants from a frontal view, measuring both east and west sides of the row. A fifth IRT pointed upward to collect the downwelling sky radiance and the remaining IRT was mounted at 4.5-m height over the canopy measuring the composed soil-canopy temperature. Measurements of the four components of the net radiation over the canopy and soil heat fluxes, as well as air temperature, humidity, wind speed, and soil moisture, were collected and stored in 15-min averages. A two-source energy balance approach was applied to the vineyard from its appropriate thermal characterization. Total and separate soil/canopy components of net radiation, soil, sensible and latent heat fluxes were obtained every 15 minutes and averaged at hourly and daily scales. Comparison between observed and modeled values of available surface energy showed relative errors below 15%. An analysis of the partition E/T was conducted along the vineyard growing season and the different phenological stages. In this experiment, interrow soil evaporation reached as much as 1/3 of the total cumulative evapotranspiration from floration to harvest. This technique can be useful for scientists and land managers interested in improving water use efficiency, not only because it is shown as an alternative to traditional weighing lysimeters, but also because the presented method allows the continuous monitoring of the E/T partition under a variety of meteorological conditions and covering the different stages of the crop development.

Fertilizing cotton with broiler litter is superior to inorganic fertilizers in Mississippi soils

USDA-ARS?s Scientific Manuscript database

Poultry litter, a mixture of mainly manure and bedding material, is well known as a source of mineral plant nutrients and as a soil conditioner. It has been shown to be an effective fertilizer for row crops, forage and pasture crops, and even for forest trees. The effectiveness of litter as a fert...

High residue cover crops alone or with strategic tillage to manage glyphosate-resistant palmer amaranth (amaranthus palmeri) in Southeastern cotton (gossypium hirsutum)

USDA-ARS?s Scientific Manuscript database

Glyphosate-resistant (GR) Palmer amaranth (Amaranthus palmeri S. Wats) is redefining row crop weed management in the Southeast due to its widespread distribution, high competitive ability, copious seed production, and resilience to standard weed management programs. Herbicides alone are failing to p...

Pelletized biochar as a carrier for AM fungi in the on-farm system of inoculum production in compost and vermiculite mixtures

USDA-ARS?s Scientific Manuscript database

On farm production of arbuscular mycorrhizal [AM] fungi is suitable for vegetable and horticultural crop production because the inocula may be efficiently mixed into horticultural potting media for plant production in the greenhouse. These inocula are not amenable for use in row crop production bec...

Separation of man-made and natural patterns in high-altitude imagery of agricultural areas

NASA Technical Reports Server (NTRS)

Samulon, A. S.

1975-01-01

A nonstationary linear digital filter is designed and implemented which extracts the natural features from high-altitude imagery of agricultural areas. Essentially, from an original image a new image is created which displays information related to soil properties, drainage patterns, crop disease, and other natural phenomena, and contains no information about crop type or row spacing. A model is developed to express the recorded brightness in a narrow-band image in terms of man-made and natural contributions and which describes statistically the spatial properties of each. The form of the minimum mean-square error linear filter for estimation of the natural component of the scene is derived and a suboptimal filter is implemented. Nonstationarity of the two-dimensional random processes contained in the model requires a unique technique for deriving the optimum filter. Finally, the filter depends on knowledge of field boundaries. An algorithm for boundary location is proposed, discussed, and implemented.

Effects of dried wastewater-treatment sludge application on ground-water quality in South Dade County, Florida

USGS Publications Warehouse

Howie, Barbara

1992-01-01

Four test fields in the south Dade agricultural area were studied to determine the effects of sludge application on ground-water quality. Two fields had been cultivated for 10 years or more, and two had not been farmed for at least 10 years. The fields were representative of the area's two soil types (Rockdale and Perrine marl) and two major crop types (row crops and groves). Before the application of sludge, wells upgradient of, within, and downgradient of each field were sampled for possible sludge contaminants at the end of wet and dry seasons. Municipal wastewater treatment sludge from the Dade County Water and Sewe Authority Department was then applied to the fields at varying application rates. The wells at each field were sampled over a 2-year period under different hydrologic conditions for possible sludge-related constituents (specific conductance, pH, alkalinity, nitrogen, phosphorus, total organic carbon, copper, iron, magnesium, manganese, potassium, zinc, arsenic, cadmium, chloride, chromium, lead, mercury, nickel, and sodium). Comparisons were made between water quality in the vicinity of the test fields and Florida Department of Environmental Regulation primary and secondary drinking-water regulations, an between water quality upgradient of, beneath, and downgradient of the fields. Comparisons between presludge and postsludge water quality did not indicate any improvement because of retention of agrichemicals by the sludge nor did they indicate any deterioration because of leaching from the sludge. Comparisons of water quality upgradient of the fields to water quality beneath and downgradient of the fields also did not indicate any changes related to sludge. Florida Department of Environmental Regulation primary and secondary drinking-water regulations wer exceeded at the Rockdale maximum-application field by mercury (9.5 ug/L (micrograms per liter)), and the Perrine marl maximum-application field by manganese (60 ug/L) and lead (85 ug/L), and at the Perrine marl row-crop field by mercury (5.2 ug/L). All other exceedances were either in presludge or upgradient samples, or they were for constituents or properties, such as iron and color, which typically exceed standards in native ground water. Acid-extractable and base-neutral compounds, volatile organic compounds, chlorophenoxy herbicides, organophosphorus insecticides, and organochlorine compounds were analyzed for one shallow well at each field twice annually. Those compounds that equaled or exceeded the detection limit after sludge was applied included benzene (0.3 and 1.2 ug/L), chloroform (0.2 and 0.3 ug/L), bis(2-Ethylhexyl)phthalate (29 and 42 ug/L), methylene chloride (14 ug/L), tolulene (0.2, 0.4, 0.5, 1.3, and 4.4 ug/L), 1, 1,1-trichloroethana (0.6 ug/L), trichloroethylene (0.3 ug/L), 2.4-D (0.01 ug/L), and xylene (0.3 ug/L). It ws not possible to ascertain the origin of these compounds becuase they are available from sources other than sludge.

Inheritance and identification of a major quantitative trait locus (QTL) that confers resistance to Meloidogyne incognita and a novel QTL for plant height in sweet sorghum

USDA-ARS?s Scientific Manuscript database

Southern root-knot nematodes (Meloidogyne incognita) are a pest on many economically important row crop and vegetable species and management relies on chemicals, plant resistance, and cultural practices such as crop rotation. Little is known about the inheritance of resistance to M. incognita or the...

Can orchards help connect Mediterranean ecosystems? Animal movement data alter conservation priorities

USGS Publications Warehouse

Nogeire, Theresa M.; Davis, Frank W.; Crooks, Kevin R.; McRae, Brad H.; Lyren, Lisa M.; Boydston, Erin E.

2015-01-01

As natural habitats become fragmented by human activities, animals must increasingly move through human-dominated systems, particularly agricultural landscapes. Mapping areas important for animal movement has therefore become a key part of conservation planning. Models of landscape connectivity are often parameterized using expert opinion and seldom distinguish between the risks and barriers presented by different crop types. Recent research, however, suggests different crop types, such as row crops and orchards, differ in the degree to which they facilitate or impede species movements. Like many mammalian carnivores, bobcats (Lynx rufus) are sensitive to fragmentation and loss of connectivity between habitat patches. We investigated how distinguishing between different agricultural land covers might change conclusions about the relative conservation importance of different land uses in a Mediterranean ecosystem. Bobcats moved relatively quickly in row crops but relatively slowly in orchards, at rates similar to those in natural habitats of woodlands and scrub. We found that parameterizing a connectivity model using empirical data on bobcat movements in agricultural lands and other land covers, instead of parameterizing the model using habitat suitability indices based on expert opinion, altered locations of predicted animal movement routes. These results emphasize that differentiating between types of agriculture can alter conservation planning outcomes.

Weed management practices affect the diversity and relative abundance of physic nut mites.

PubMed

Saraiva, Althiéris de Sousa; Sarmento, Renato A; Erasmo, Eduardo A L; Pedro-Neto, Marçal; de Souza, Danival José; Teodoro, Adenir V; Silva, Daniella G

2015-03-01

Crop management practices determine weed community, which in turn may influence patterns of diversity and abundance of associated arthropods. This study aimed to evaluate whether local weed management practices influence the diversity and relative abundance of phytophagous and predatory mites, as well as mites with undefined feeding habits--of the families Oribatidae and Acaridae--in a physic nut (Jatropha curcas L.) plantation subjected to (1) within-row herbicide spraying and between-row mowing; (2) within-row herbicide spraying and no between-row mowing; (3) within-row weeding and between-row mowing; (4) within-row weeding and no between-row mowing; and (5) unmanaged (control). The herbicide used was glyphosate. Herbicide treatments resulted in higher diversity and relative abundance of predatory mites and mites with undefined feeding habit on physic nut shrubs. This was probably due to the toxic effects of the herbicide on mites or to removal of weeds. Within-row herbicide spraying combined with between-row mowing was the treatment that most contributed to this effect. Our results show that within-row weeds harbor important species of predatory mites and mites with undefined feeding habit. However, the dynamics of such mites in the system can be changed according to the weed management practice applied. Among the predatory mites of the family Phytoseiidae Amblydromalus sp. was the most abundant, whereas Brevipalpus phoenicis was the most frequent phytophagous mite and an unidentified oribatid species was the most frequent mite with undefined feeding habit.

Modeling Pollinator Community Response to Contrasting Bioenergy Scenarios

PubMed Central

Bennett, Ashley B.; Meehan, Timothy D.; Gratton, Claudio; Isaacs, Rufus

2014-01-01

In the United States, policy initiatives aimed at increasing sources of renewable energy are advancing bioenergy production, especially in the Midwest region, where agricultural landscapes dominate. While policy directives are focused on renewable fuel production, biodiversity and ecosystem services will be impacted by the land-use changes required to meet production targets. Using data from field observations, we developed empirical models for predicting abundance, diversity, and community composition of flower-visiting bees based on land cover. We used these models to explore how bees might respond under two contrasting bioenergy scenarios: annual bioenergy crop production and perennial grassland bioenergy production. In the two scenarios, 600,000 ha of marginal annual crop land or marginal grassland were converted to perennial grassland or annual row crop bioenergy production, respectively. Model projections indicate that expansion of annual bioenergy crop production at this scale will reduce bee abundance by 0 to 71%, and bee diversity by 0 to 28%, depending on location. In contrast, converting annual crops on marginal soil to perennial grasslands could increase bee abundance from 0 to 600% and increase bee diversity between 0 and 53%. Our analysis of bee community composition suggested a similar pattern, with bee communities becoming less diverse under annual bioenergy crop production, whereas bee composition transitioned towards a more diverse community dominated by wild bees under perennial bioenergy crop production. Models, like those employed here, suggest that bioenergy policies have important consequences for pollinator conservation. PMID:25365559

Vegetation Water Content Mapping for Agricultural Regions in SMAPVEX16

NASA Astrophysics Data System (ADS)

White, W. A.; Cosh, M. H.; McKee, L.; Berg, A. A.; McNairn, H.; Hornbuckle, B. K.; Colliander, A.; Jackson, T. J.

2017-12-01

Vegetation water content impacts the ability of L-band radiometers to measure surface soil moisture. Therefore it is necessary to quantify the amount of water held in surface vegetation for an accurate soil moisture remote sensing retrieval. A methodology is presented for generating agricultural vegetation water content maps using Landsat 8 scenes for agricultural fields of Iowa and Manitoba for the Soil Moisture Active Passive Validation Experiments in 2016 (SMAPVEX16). Manitoba has a variety of row crops across the region, and the study period encompasses the time frame from emergence to reproduction, as well as a forested region. The Iowa study site is dominated by corn and soybeans, presenting an easier challenge. Ground collection of vegetation biomass and water content were also collected to provide a ground truth data source. Errors for the resulting vegetation water content maps ranged depending upon crop type, but generally were less than 15% of the total plant water content per crop type. Interpolation is done between Landsat overpasses to produce daily vegetation water content maps for the summer of 2016 at a 30 meter resolution.

Characterization of Genome-Wide Variation in Four-Row Wax, a Waxy Maize Landrace with a Reduced Kernel Row Phenotype

PubMed Central

Liu, Hanmei; Wang, Xuewen; Wei, Bin; Wang, Yongbin; Liu, Yinghong; Zhang, Junjie; Hu, Yufeng; Yu, Guowu; Li, Jian; Xu, Zhanbin; Huang, Yubi

2016-01-01

In southwest China, some maize landraces have long been isolated geographically, and have phenotypes that differ from those of widely grown cultivars. These landraces may harbor rich genetic variation responsible for those phenotypes. Four-row Wax is one such landrace, with four rows of kernels on the cob. We resequenced the genome of Four-row Wax, obtaining 50.46 Gb sequence at 21.87× coverage, then identified and characterized 3,252,194 SNPs, 213,181 short InDels (1–5 bp) and 39,631 structural variations (greater than 5 bp). Of those, 312,511 (9.6%) SNPs were novel compared to the most detailed haplotype map (HapMap) SNP database of maize. Characterization of variations in reported kernel row number (KRN) related genes and KRN QTL regions revealed potential causal mutations in fea2, td1, kn1, and te1. Genome-wide comparisons revealed abundant genetic variations in Four-row Wax, which may be associated with environmental adaptation. The sequence and SNP variations described here enrich genetic resources of maize, and provide guidance into study of seed numbers for crop yield improvement. PMID:27242868

Chemical composition and biological activity of essential oils of Origanum vulgare L. subsp. vulgare L. under different growth conditions.

PubMed

De Falco, Enrica; Mancini, Emilia; Roscigno, Graziana; Mignola, Enrico; Taglialatela-Scafati, Orazio; Senatore, Felice

2013-12-04

This research was aimed at investigating the essential oil production, chemical composition and biological activity of a crop of pink flowered oregano (Origanum vulgare L. subsp. vulgare L.) under different spatial distribution of the plants (single and binate rows). This plant factor was shown to affect its growth, soil covering, fresh biomass, essential oil amount and composition. In particular, the essential oil percentage was higher for the binate row treatment at the full bloom. The chemical composition of the oils obtained by hydrodistillation was fully characterized by GC and GC-MS. The oil from plants grown in single rows was rich in sabinene, while plants grown in double rows were richer in ocimenes. The essential oils showed antimicrobial action, mainly against Gram-positive pathogens and particularly Bacillus cereus and B. subtilis.

Micrometeorological measurements and vapour pressure deficit relations under in-field rainwater harvesting

NASA Astrophysics Data System (ADS)

Tesfuhuney, Weldemichael A.; Walker, Sue; Van Rensburg, Leon D.; Steyn, A. Stephan

2016-08-01

In a cropped field, microclimate and thermal stability conditions depend on the canopy structures and the prevailing weather. The main aim of the study therefore was to characterize the vertical profiles of weather variables within and above a maize (Zea mays L.) canopy and to describe the water vapour pressure deficit (VPD) under different atmospheric and soil surface conditions for both wide and narrow runoff strips with the in-field rainwater harvesting (IRWH) system. Micrometeorological measurements of wind, temperature and relative humidity were performed at eight levels, within canopy (1.8 and 2.1 m), and just above the canopy (2.4, 2.7, 3.0, and 3.3 m) up to reference levels (3.9 and 4.5 m) when the maize reached a maximum height of 2.2 m. Under incomplete canopy cover of the IRWH system, two important factors complicated evapotranspiration estimation, namely the local advection and high temperatures of the bare soil between adjacent plant rows. Diurnal variations of water vapour related to turbulence at each locality and its position in the thermal internal boundary layers. Generally, advection was more pronounced in wide runoff strips than narrow strips. On wide runoff strips the wind was more effective in replacing the air between the rows and maintained a higher driving force for evaporation. The maximum VPD over the narrow strips was observed at reference level during a dry day, at about 2.2 kPa in the afternoon, while wet day VPD reached a maximum of 1.8 kPa. The VPD of the wide runoff strips correlated negatively with wind speed, but showed a fairly positive correlation with some scattered values on wet days after rain. Therefore, profile characteristics within and above plant canopies played a key role in determining the VPD and consequently, could help to explain transpiration rates of crops. Hence, VPD relations enhanced the understanding of the heat energy exchange processes under the heterogeneous nature of maize canopy of the IRWH tillage system.

United States Department of Agriculture-Agricultural Research Service research in application technology for pest management.

PubMed

Smith, L A; Thomson, S J

2003-01-01

A research summary is presented that emphasizes ARS achievements in application technology over the past 2-3 years. Research focused on the improvement of agricultural pesticide application is important from the standpoint of crop protection as well as environmental safety. Application technology research is being actively pursued within the ARS, with a primary focus on application system development, drift management, efficacy enhancement and remote sensing. Research on application systems has included sensor-controlled hooded sprayers, new approaches to direct chemical injection, and aerial electrostatic sprayers. For aerial application, great improvements in on-board flow controllers permit accurate field application of chemicals. Aircraft parameters such as boom position and spray release height are being altered to determine their effect on drift. Other drift management research has focused on testing of low-drift nozzles, evaluation of pulsed spray technologies and evaluation of drift control adjuvants. Research on the use of air curtain sprayers in orchards, air-assist sprayers for row crops and vegetables, and air deflectors on aircraft has documented improvements in application efficacy. Research has shown that the fate of applied chemicals is influenced by soil properties, and this has implications for herbicide efficacy and dissipation in the environment. Remote sensing systems are being used to target areas in the field where pests are present so that spray can be directed to only those areas. Soil and crop conditions influence propensity for weeds and insects to proliferate in any given field area. Research has indicated distinct field patterns favorable for weed growth and insect concentration, which can provide further assistance for targeted spraying.

Comparison of species-rich cover crop mixtures in Hungarian vineyards

NASA Astrophysics Data System (ADS)

Donkó, Adam; Miglécz, Tamas; Valkó, Orsolya; Török, Peter; Deák, Balazs; Kelemen, Andras; Zanathy, Gabor; Drexler, Dora

2014-05-01

In case of vine growing, agricultural practices of the past decades - as mechanical cultivation on steep vineyard slopes - can endanger the soil of vineyards. Moreover, climate change scenarios predict heavier rainstorms, which can also promote the degradation of the soil. These are some of the reasons why sustainable floor management plays an increasingly important role in viticulture recently. The use of cover crops in the inter-row has a special importance, especially on steep slopes and in case of organic farming to provide conditions for environmental friendly soil management. Species-rich cover crop seed mixtures may help to prevent erosion and create easier cultivation circumstances. Furthermore they have a positive effect on soil structure, soil fertility and ecosystem functions. However, it is important to find suitable seed mixtures for specific production sites, consisting ideally of native species from local provenance, adapted to the local climate/vine region/vineyard. Requirements for suitable cover crop species are as follows: they should save the soil from erosion and also from compaction caused by the movement of workers and machines, they should not compete significantly with the grapevines, or influence produce quality. We started to develop and apply several species-rich cover crop seed mixtures in spring 2012. During the experiments, three cover crop seed mixtures (Biocont-Ecovin mixture, mixture of legumes, mixture of grasses and herbs) were compared in vineyards of the Tokaj and Szekszárd vine regions of Hungary. Each mixture was sown in three consecutive inter-rows at each experimental site (all together 10 sites). Besides botanical measurements, yield, must quality, and pruning weight was studied in every treatment. The botanical survey showed that the following species of the mixtures established successfully and prospered during the years 2012 and 2013: Coronilla varia, Lotus corniculatus, Medicago lupulina, Onobrychis viciifolia, Plantago lanceolata, Trifolium pratense, Trifolium repens and Vicia sativa. We found that weed cover was lower in every treatment compared to the unsown control plots, thus, cover crops suppressed weeds of the inter-rows effectively. Most examined indices of grapevines were not significantly affected by the applied cover crop. However, the tendency of the results shows that in the drier climate of Hungary every second inter-row sowing is more preferable than consecutive cover-crop application, where erosion control is not essential. The opinion of the growers about the mixtures varied. The Biocont-Ecovin mixture was praised for its early aesthetic qualities, produced by Camelina sativa, Phacelia tanacetifolia and Sinapis alba. However, it was criticized for its non-native species, the foreign provenance of some seeds, and the height of the vegetation. The other two mixtures did not produce a spectacular flowering, but developed a lower canopy, and were praised for their native species content. Due to spring sowing the grass-herb mixture, containing a number of species with autumn germination, produced the lowest coverage among the tested mixtures in the first year. However, as predicted, it performed satisfactorily in the second year of the trial. The interest of the vine-growers underlines the importance of the topic for the Central-Eastern European region, thus further examination will be continued in 2014.

Water saving in chufa cultivation using flat raised beds and drip irrigation

NASA Astrophysics Data System (ADS)

Pascual-Seva, N.; San Bautista, A.; López-Galarza, S.; Maroto, J. V.; Pascual, B.

2012-04-01

Chufa (Cyperus esculentus L. var. sativus), also known as tiger nut, is a typical crop in the Region of Valencia (Spain). Its tubers are used to produce a beverage called horchata. Chufa has been cultivated traditionally in ridges and furrow irrigated. Currently, the quality of water used is acceptable, there are no limitations on supply, and water is not expensive; therefore, large amounts of water are used. The European Water Framework Directive 2000/60 is based on the precautionary principle, considering preventive action for measures to be taken; thus, water use is an issue to improve. Moreover, drought periods are becoming more frequent and extended, and water is being diverted to other uses. In this two year study (2007-2008), we analysed how yield and irrigation water use efficiency (IWUE) are affected by two cultivation factors: planting strategy and irrigation system. Three planting strategies were analysed: ridges (R) and flat raised beds, with two (B2) and three (B3) plant rows along them, while two irrigation systems were compared, furrow (FI) and drip irrigation (DI). Within the beds, the effect of the position of the plant row was considered, differing among plants grown in the north (n), central (c), and south (s) rows. Distances between ridge and bed axes were 60, 80 and 120 cm for R, B2 and B3, respectively. Irrigation was based on the Volumetric Soil Water Content (VSWC), which was continuously monitored with capacitance sensors (ECH2O EC-5 in FI and multidepth capacitance sensors C-Probe in DI). Each irrigation session started when the VSWC in R dropped to 60% and 80% of field capacity in FI and DI, respectively. Each DI session lasted 60 min in 2007; while in 2008 the installation was automated, stopping each session when the sum of the VSWC at 10, 20, and 30 cm soil depth reached its corresponding field capacity value. With both irrigation systems, beds were irrigated simultaneously with ridges and with the same irrigation duration. Plants from the different plant rows were sampled periodically and later fractionated into leaves, roots, and tubers, to examine the evolution of the different plant organs. The results showed that there were no differences among planting strategies in 2007; however, in 2008, R produced lower yields than the two types of beds. The interaction between the experimental years and the irrigation strategy did affect the yield significantly, obtaining higher yields with DI than with FI, which led to higher yields in 2007 than in 2008. Regarding the IWUE, DI gave the highest values, especially in 2008. Ridges led to the highest IWUE with DI, and the lowest IWUE with FI. When comparing the different planting lines, the highest yield was obtained in the southern row. It can be concluded that modifications to the planting strategy and the irrigation system within the traditional cultivation practices of the chufa crop would increase IWUE and lead to major water savings.

Assessment of palladium footprint from road traffic in two highway environments.

PubMed

Clément, N; Muresan, B; Hedde, M; François, D

2015-12-01

Palladium (Pd) is an emerging eco-toxic pollutant from vehicle catalytic converters, emitted worldwide for more than two decades. Nowadays, the spatial extent of Pd fallout is growing along roads, but its subsequent fate in neighboring terrestrial ecosystems has not been extensively addressed yet. Two sites representative of contrasted natural environments (field, forest) but located under similar ambient conditions were selected to isolate and analyze the specific impact of vehicular Pd, along highway A71, France. Pd impregnation was assessed along 200-m-long transects perpendicular to the highway. Contents were measured in soils, earthworms, plant communities of the right of way (ROW), and the neighboring field (crop weeds), as well as in a moss, and bramble and ivy leaves in the forest. The direct impact of Pd fallouts appears to be confined in the grassy verge of the highway: ROW soils ([Pd] = 52-65 ng g(-1)), earthworms ([Pd] = 18-38 ng g(-1)), and plant community ([Pd] = 10-23 ng g(-1)). Pd footprint is pointed out by the accumulation index calculated for earthworms and plant communities even though transfer coefficients indicate the absence of bioaccumulation (TCs < 1). An indirect longer range transfer of Pd is identified, induced by hydric transport of organic matter.

Crop biometric maps: the key to prediction.

PubMed

Rovira-Más, Francisco; Sáiz-Rubio, Verónica

2013-09-23

The sustainability of agricultural production in the twenty-first century, both in industrialized and developing countries, benefits from the integration of farm management with information technology such that individual plants, rows, or subfields may be endowed with a singular "identity." This approach approximates the nature of agricultural processes to the engineering of industrial processes. In order to cope with the vast variability of nature and the uncertainties of agricultural production, the concept of crop biometrics is defined as the scientific analysis of agricultural observations confined to spaces of reduced dimensions and known position with the purpose of building prediction models. This article develops the idea of crop biometrics by setting its principles, discussing the selection and quantization of biometric traits, and analyzing the mathematical relationships among measured and predicted traits. Crop biometric maps were applied to the case of a wine-production vineyard, in which vegetation amount, relative altitude in the field, soil compaction, berry size, grape yield, juice pH, and grape sugar content were selected as biometric traits. The enological potential of grapes was assessed with a quality-index map defined as a combination of titratable acidity, sugar content, and must pH. Prediction models for yield and quality were developed for high and low resolution maps, showing the great potential of crop biometric maps as a strategic tool for vineyard growers as well as for crop managers in general, due to the wide versatility of the methodology proposed.

Crop Biometric Maps: The Key to Prediction

PubMed Central

Rovira-Más, Francisco; Sáiz-Rubio, Verónica

2013-01-01

The sustainability of agricultural production in the twenty-first century, both in industrialized and developing countries, benefits from the integration of farm management with information technology such that individual plants, rows, or subfields may be endowed with a singular “identity.” This approach approximates the nature of agricultural processes to the engineering of industrial processes. In order to cope with the vast variability of nature and the uncertainties of agricultural production, the concept of crop biometrics is defined as the scientific analysis of agricultural observations confined to spaces of reduced dimensions and known position with the purpose of building prediction models. This article develops the idea of crop biometrics by setting its principles, discussing the selection and quantization of biometric traits, and analyzing the mathematical relationships among measured and predicted traits. Crop biometric maps were applied to the case of a wine-production vineyard, in which vegetation amount, relative altitude in the field, soil compaction, berry size, grape yield, juice pH, and grape sugar content were selected as biometric traits. The enological potential of grapes was assessed with a quality-index map defined as a combination of titratable acidity, sugar content, and must pH. Prediction models for yield and quality were developed for high and low resolution maps, showing the great potential of crop biometric maps as a strategic tool for vineyard growers as well as for crop managers in general, due to the wide versatility of the methodology proposed. PMID:24064605

Comprehensive Understanding for Vegetated Scene Radiance Relationships

NASA Technical Reports Server (NTRS)

Kimes, D. S.; Deering, D. W.

1984-01-01

The improvement of our fundamental understanding of the dynamics of directional scattering properties of vegetation canopies through analysis of field data and model simulation data is discussed. Directional reflectance distributions spanning the entire existance hemisphere were measured in two field studies; one using a Mark III 3-band radiometer and one using rapid scanning bidirectional field instrument called PARABOLA. Surfaces measured included corn, soybeans, bare soils, grass lawn, orchard grass, alfalfa, cotton row crops, plowed field, annual grassland, stipa grass, hard wheat, salt plain shrubland, and irrigated wheat. Some structural and optical measurements were taken. Field data show unique reflectance distributions ranging from bare soil to complete vegetation canopies. Physical mechanisms causing these trends are proposed based on scattering properties of soil and vegetation. Soil exhibited a strong backscattering peak toward the Sun. Complete vegetation exhibited a bowl distribution with the minimum reflectance near nadir. Incomplete vegetation canopies show shifting of the minimum reflectance off of nadir in the forward scattering direction because both the scattering properties or the vegetation and soil are observed.

Linking resilience theory and diffusion of innovations theory to understand the potential for perennials in the U.S. Corn Belt

Treesearch

Ryan C. Atwell; Lisa A. Schulte; Lynne M. Westphal

2009-01-01

In the last 200 yr, more than 80% of the land in the U.S. Corn Belt agro-ecosystem has been converted from natural perennial vegetation to intensive agricultural production of row crops. Despite research showing how re-integration of perennial vegetation, e.g., cover crops, pasture, riparian buffers, and restored wetlands, at strategic landscape positions can bolster...

Airborne observed solar elevation and row direction effects on the near-IR/red ratio of cotton

NASA Technical Reports Server (NTRS)

Millard, J. P.; Jackson, R. D.; Goettelman, R. C.; Leroy, M. J. (Principal Investigator)

1981-01-01

An airborne multispectral scanner was used to obtain data over two adjacent cotton fields having rows perpendicular to one another, at three times of day (different solar elevations), and on two dates (different plant size). The near IR/red ratios were displayed in image form, so that within-field variations and differences between fields could be easily assessed. The ratio varied with changing Sun elevation for north-south oriented rows, but no variation was detected for east-west oriented rows.

Mitigation of indirect environmental effects of GM crops

PubMed Central

Pidgeon, J.D; May, M.J; Perry, J.N; Poppy, G.M

2007-01-01

Currently, the UK has no procedure for the approval of novel agricultural practices that is based on environmental risk management principles. Here, we make a first application of the ‘bow-tie’ risk management approach in agriculture, for assessment of land use changes, in a case study of the introduction of genetically modified herbicide tolerant (GMHT) sugar beet. There are agronomic and economic benefits, but indirect environmental harm from increased weed control is a hazard. The Farm Scale Evaluation (FSE) trials demonstrated reduced broad-leaved weed biomass and seed production at the field scale. The simplest mitigation measure is to leave a proportion of rows unsprayed in each GMHT crop field. Our calculations, based on FSE data, show that a maximum of 2% of field area left unsprayed is required to mitigate weed seed production and 4% to mitigate weed biomass production. Tilled margin effects could simply be mitigated by increasing the margin width from 0.5 to 1.5 m. Such changes are cheap and simple to implement in farming practices. This case study demonstrates the usefulness of the bow-tie risk management approach and the transparency with which hazards can be addressed. If adopted generally, it would help to enable agriculture to adopt new practices with due environmental precaution. PMID:17439853

Neonicotinoid insecticide removal by prairie strips in row-cropped watersheds with historical seed coating use

USGS Publications Warehouse

Hladik, Michelle L.; Bradbury, Steven; Schulte, Lisa A.; Helmers, Matthew; Witte, Christopher; Kolpin, Dana W.; Garrett, Jessica D.; Harris, Mary

2017-01-01

Neonicotinoids are a widely used class of insecticides that are commonly applied as seed coatings for agricultural crops. Such neonicotinoid use may pose a risk to non-target insects, including pollinators and natural enemies of crop pests, and ecosystems. This study assessed neonicotinoid residues in groundwater, surface runoff water, soil, and native plants adjacent to corn and soybean crop fields with a history of being planted with neonicotinoid-treated seeds from 2008-2013. Data from six sites with the same crop management history, three with and three without in-field prairie strips, were collected in 2015-2016, 2-3 years after neonicotinoid (clothianidin and imidacloprid) seed treatments were last used. Three of the six neonicotinoids analyzed were detected in at least one environmental matrix: the two applied as seed coatings on the fields (clothianidin and imidacloprid) and another widely used neonicotinoid (thiamethoxam). Sites with prairie strips generally had lower concentrations of neonicotinoids: groundwater and footslope soil neonicotinoid concentrations were significantly lower in the sites with prairie strips than those without; mean concentrations for groundwater were 11 and 20 ng/L (p = 0.048) and <1 and 6 ng/g (p = 0.0004) for soil, respectively. Surface runoff water concentrations were not significantly (p = 0.38) different for control sites (44 ng/L) or sites with prairie strips (140 ng/L). Consistent with the decreased inputs of neonicotinoids, concentrations tended to decrease over the sampling timeframe. Two sites recorded concentration increases, however, potentially due to disturbance of previous applications or influence from nearby fields where use of seed treatments continued. There were no detections (limit of detection: 1 ng/g) of neonicotinoids in the foliage or roots of plants comprising prairie strips, indicating a low likelihood of exposure to pollinators and other insects visiting these plants following the cessation of seed coating use. Offsite transport of neonicotinoids to aquatic systems through the groundwater and surface water were furthermore reduced with prairie strips. This study demonstrates the potential for prairie strips comprising 10% of an agricultural catchment to mitigate the non-target impacts of neonicotinoids.

Indicators: Atrazine

EPA Pesticide Factsheets

Atrazine is an herbicide widely used for control of broadleaf and grassy weeds. It is sprayed on row crops such as corn, sorghum and sugarcane, and in some areas is used on residential lawns. It also been used on highway and railroad rights-of-way.

Soil erosion and sediment connectivity modelling in Burgundy vineyards: case study of Mercurey, France

NASA Astrophysics Data System (ADS)

Fressard, Mathieu; Cossart, Étienne; Lejot, Jêrome; Michel, Kristell; Perret, Franck; Christol, Aurélien; Mathian, Hélène; Navratil, Oldrich

2017-04-01

This research aims at assessing the impact of agricultural landscape structure on soil erosion and sediment connectivity at the catchment scale. The investigations were conducted the vineyards of Mercurey (Burgundy, France), characterized by important issues related to soil loss, flash floods and associated management infrastructures maintenance. The methodology is based on two main steps that include (1) field investigations and (2) modelling. The field investigations consists in DEM acquisition by LiDAR imaging from a drone, soil mapping and human infrastructures impacting runoff classification and mapping (such as crop rows, storm water-basins, drainage network, roads, etc.). These data aims at supplying the models with field observations. The modelling strategy is based on two main steps: First, the modelling of soil sensitivity to erosion, using the spatial application of the RUSLE equation. Secondly, to assess the sediment connectivity in this area, a model based on graph theory developed by Cossart and Fressard (2017) is tested. The results allow defining the influence of different anthropogenic structures on the sediment connectivity and soil erosion at the basin scale. A set of sub-basins influenced by various anthropogenic infrastructures have been identified and show contrasted sensitivities to erosion. The modelling of sediment connectivity show that the runoff pattern is strongly influenced by the vine rows orientation and the drainage network. I has also permitted to identify non collected (by storm water-basins) areas that strongly contribute to the turbid floods sediment supply and to soil loss during high intensity precipitations events.

Georeferenced LiDAR 3D vine plantation map generation.

PubMed

Llorens, Jordi; Gil, Emilio; Llop, Jordi; Queraltó, Meritxell

2011-01-01

The use of electronic devices for canopy characterization has recently been widely discussed. Among such devices, LiDAR sensors appear to be the most accurate and precise. Information obtained with LiDAR sensors during reading while driving a tractor along a crop row can be managed and transformed into canopy density maps by evaluating the frequency of LiDAR returns. This paper describes a proposed methodology to obtain a georeferenced canopy map by combining the information obtained with LiDAR with that generated using a GPS receiver installed on top of a tractor. Data regarding the velocity of LiDAR measurements and UTM coordinates of each measured point on the canopy were obtained by applying the proposed transformation process. The process allows overlap of the canopy density map generated with the image of the intended measured area using Google Earth(®), providing accurate information about the canopy distribution and/or location of damage along the rows. This methodology was applied and tested on different vine varieties and crop stages in two important vine production areas in Spain. The results indicate that the georeferenced information obtained with LiDAR sensors appears to be an interesting tool with the potential to improve crop management processes.

Using satellite vegetation and compound topographic indices to map highly erodible cropland buffers for cellulosic biofuel crop developments in eastern Nebraska, USA

USGS Publications Warehouse

Gu, Yingxin; Wylie, Bruce K.

2015-01-01

Cultivating annual row crops in high topographic relief waterway buffers has negative environmental effects and can be environmentally unsustainable. Growing perennial grasses such as switchgrass (Panicum virgatum L.) for biomass (e.g., cellulosic biofuel feedstocks) instead of annual row crops in these high relief waterway buffers can improve local environmental conditions (e.g., reduce soil erosion and improve water quality through lower use of fertilizers and pesticides) and ecosystem services (e.g., minimize drought and flood impacts on production; improve wildlife habitat, plant vigor, and nitrogen retention due to post-senescence harvest for cellulosic biofuels; and serve as carbon sinks). The main objectives of this study are to: (1) identify cropland areas with high topographic relief (high runoff potentials) and high switchgrass productivity potential in eastern Nebraska that may be suitable for growing switchgrass, and (2) estimate the total switchgrass production gain from the potential biofuel areas. Results indicate that about 140,000 hectares of waterway buffers in eastern Nebraska are suitable for switchgrass development and the total annual estimated switchgrass biomass production for these suitable areas is approximately 1.2 million metric tons. The resulting map delineates high topographic relief croplands and provides useful information to land managers and biofuel plant investors to make optimal land use decisions regarding biofuel crop development and ecosystem service optimization in eastern Nebraska.

Spatial variability of soil carbon and nitrogen in two hybrid poplar-hay crop systems in southern Quebec, Canada

NASA Astrophysics Data System (ADS)

Winans, K. S.

2013-12-01

Canadian agricultural operations contribute approximately 8% of national GHG emissions each year, mainly from fertilizers, enteric fermentation, and manure management (Environment Canada, 2010). With improved management of cropland and forests, it is possible to mitigate GHG emissions through carbon (C) sequestration while enhancing soil and crop productivity. Tree-based intercropped (TBI) systems, consisting of a fast-growing woody species such as poplar (Populus spp.) planted in widely-spaced rows with crops cultivated between tree rows, were one of the technologies prioritized for investigation by the Agreement for the Agricultural Greenhouse Gases Program (AAGGP), because fast growing trees can be a sink for atmospheric carbon-dioxide (CO2) as well as a long-term source of farm income (Montagnini and Nair, 2004). However, there are relatively few estimates of the C sequestration in the trees or due to tree inputs (e.g., fine root turnover, litterfall that gets incorporated into SOC), and hybrid poplars grow exponentially in the first 8-10 years after planting. With the current study, our objectives were (1) to evaluate spatial variation in soil C and nitrogen (N) storage, CO2 and nitrogen oxide (N20), and tree and crop productivity for two hybrid poplar-hay intercrop systems at year 9, comparing TBI vs. non-TBI systems, and (2) to evaluate TBI systems in the current context of C trading markets, which value C sequestration in trees, unharvested crop components, and soils of TBI systems. The study results will provide meaningful measures that indicate changes due to TBI systems in the short-term and in the long-term, in terms of GHG mitigation, enhanced soil and crop productivity, as well as the expected economic returns in TBI systems.

Coordinating management of water, salinity and trace elements for cotton under mulched drip irrigation with brackish water

NASA Astrophysics Data System (ADS)

Jin, M.; Chen, W.; Liang, X.

2016-12-01

Rational irrigation with brackish water can increase crop production, but irrational use may cause soil salinization. In order to understand the relationships among water, salt, and nutrient (including trace elements) and find rational schemes to manage water, salinity and nutrient in cotton fields, field and pot experiments were conducted in an arid area of southern Xinjiang, northwest China. Field experiments were performed from 2008 to 2015, and involved mulched drip irrigation during the growing season and flood irrigation afterwards. The average cotton yield of seven years varied between 3,575 and 5,095 kg/ha, and the irrigation water productivity between 0.91 and 1.16 kg/m3. With the progress of brackish water irrigation, Cu, Fe, Mn, and Na showed strong aggregation in topsoil at the narrow row, whereas the contents of Ca and K decreased in the order of inter-mulch gap, the wide inter row, and the narrow row. The contents of Cu, Fe, Mn, Ca and K in root soil reduced with cotton growth, whereas Na increased. Although mulched drip irrigation during the growing season resulted in an increase in salinity in the root zone, flood irrigation after harvesting leached the accumulated salts below background levels. Based on experiments a scheme for coordinating management of soil water, salt, and nutrient is proposed, that is, under the planting pattern of one mulch, two drip lines and four rows, the alternative irrigation plus a flood irrigation after harvesting or before seeding was the ideal scheme. Numerical simulations using solute transport model coupled with the root solute uptake based on the experiments and extended by another 20 years, suggest that the mulched drip irrigation using alternatively fresh and brackish water during the growing season and flood irrigation with fresh water after harvesting, is a sustainable irrigation practice that should not lead to soil salinization. Pot experiments with trace elements and different saline water showed significantly antagonistic effects on cotton growth and yield between NaCl and Mn or Zn or B. Zn concentration in irrigation water under salinity stress affected the uptake of nutrient elements and caused the different contents of nutrient elements in cotton, and influenced cotton growth and yields.

Contaminant Transport to Shallow Drainage Water in Pothole Topography

USDA-ARS?s Scientific Manuscript database

Nutrient and herbicide losses from row crop agriculture represent potential environmental and human health hazards. In order to determine where nutrient and herbicide mitigation strategies can be targeted for optimum performance, levels of nutrients and herbicides were measured in an agricultural dr...

Stylet Penetration Estimates for a Suite of Phytophagous Hemipteran Pests of Row Crops

USDA-ARS?s Scientific Manuscript database

Members of the Miridae (Lygus lineolaris Palisot de Beauvois and Pseudatomoscelis seriatus Reuter) and Pentatomidae (Acrosternum hilare Say, Euschistus servus (Say), E. tristigmus (Say), E. quadrator Rolston, Oebalus pugnax (Fabricius), Piezodorus guildinii (Westwood), and Thyanta custator accerra M...

Allometric method to estimate leaf area index for row crops

USDA-ARS?s Scientific Manuscript database

Leaf area index (LAI) is critical for predicting plant metabolism, biomass production, evapotranspiration, and greenhouse gas sequestration, but direct LAI measurements are difficult and labor intensive. Several methods are available to measure LAI indirectly or calculate LAI using allometric method...

Keeping soil in the field - runoff and erosion management in asparagus crops

NASA Astrophysics Data System (ADS)

Niziolomski, Joanna; Simmons, Robert; Rickson, Jane; Hann, Mike

2016-04-01

Row crop production (including potatoes, onions, carrots, asparagus, bulbs and lettuce) is regarded as one of the most erosive agricultural cropping systems. This is a result of the many practices involved that increase erosion risk including: fine seedbed preparation, a typically short growing season where adequate ground cover protects the soil, permanent bare soil areas between crops, and often intensive harvesting methods that can damage soil structure and result in soil compaction. Sustained exposure of bare soil coupled with onsite compaction on slightly sloping land results in soil and water issues in asparagus production. Asparagus production is a growing British industry covering > 2000 ha and is worth approximately £30 million yr-1. However, no tried and tested erosion control measurements currently exist to manage associated problems. Research has recently been undertaken investigating the effectiveness of erosion control measures suitable for asparagus production systems. These consisted of surface applied wheat straw mulch and shallow soil disturbance (< 350 mm) using several tine configurations: a currently adopted winged tine, a narrow with two shallow leading tines, and a modified para-plough. These treatments were tested individually and in combination (straw mulch with each shallow soil disturbance tine configuration) using triplicated field plots situated on a working asparagus farm in Herefordshire, UK. Testing was conducted between May and November 2013. Rainfall-event based runoff and erosion measurements were taken including; runoff volume, runoff rate and total soil loss. Runoff and soil erosion was observed from all treatments. However, the surface application of straw mulch alone out performed each shallow soil disturbance practice. This suggests that runoff and erosion from asparagus production can be reduced using the simple surface application of straw.

METHODOLOGY FOR EVALUATING THE EFFECTIVENESS OF NONPOINT SOURCE POLLUTION ABATEMENT PROGRAMS

EPA Science Inventory

The Upper Big Walnut Creek watershed encompasses 190 square miles of predominantly agricultural cropland (65%) in Central Ohio (USA) where agronomic fertilizers and herbicides are used in row crop production. Runoff from the watershed drain to Hoover Reservoir which is Central Oh...

Al Basrah, Iraq

NASA Image and Video Library

2017-12-08

Al Basrah, Iraq Sensor: L7 ETM+ Acquisition Date: April 4, 2003 Path/Row: 166/39 Lat/Long: 30.486/47.811 Smoke drifts south in this image of Al Basrah, located in southeastern Iraq. The green circles from the center to the left of the image represent irrigated crops.

Reconciling opposing soil processes in row-crop agroecosystems via soil functional zone management

USDA-ARS?s Scientific Manuscript database

Sustaining soil productivity in agroecosystems presents a fundamental ecological challenge: nutrient provisioning depends upon aggregate turnover and microbial decomposition of organic matter (SOM); yet to prevent soil depletion these processes must be balanced by those that restore nutrients and SO...

Fate and transport of copper-based crop protectants in plasticulture runoff and the impact of sedimentation as a best management practice.

PubMed

Gallagher, D L; Johnston, K M; Dietrich, A M

2001-08-01

The fate and distribution of copper-based crop protectants, applied to plasticulture tomato fields to protect against disease, were investigated in a greenhouse-scale simulation of farming conditions in a coastal environment. Following rainfall, 99% of the applied copper was found to remain on the fields sorbed to the soil and plants; most of the soil-bound copper was found sorbed to the top 2.5 cm of soil between the plasticulture rows. Of the copper leaving the agricultural fields, 82% was found in the runoff with the majority, 74%. sorbed to the suspended solids. The remaining copper, 18%, leached through the soil and entered the groundwater with 10% in the dissolved phase and 8% sorbed to suspended solids. Although only 1% copper was found to leave the field, this was sufficient to cause high copper concentrations (average 2102+/-433 microg/L total copper and 189+/-139 microg/L dissolved copper) in the runoff. Copper concentrations in groundwater samples were also high (average 312+/-198 microg/L total copper and 216+/-99 microg/L dissolved copper). Sedimentation, a best management practice for reducing copper loadings. was found to reduce the total copper concentrations in runoff by 90% to a concentration of 245+/-127 microg/L; however, dissolved copper concentrations remained stable, averaging 139+/-55 microg/L. Total copper concentrations were significantly reduced by the effective removal of suspended solids with sorbed copper.

Estimating effectiveness of crop management for reduction of soil erosion and runoff

NASA Astrophysics Data System (ADS)

Hlavcova, K.; Studvova, Z.; Kohnova, S.; Szolgay, J.

2017-10-01

The paper focuses on erosion processes in the Svacenický Creek catchment which is a small sub-catchment of the Myjava River basin. To simulate soil loss and sediment transport the USLE/SDR and WaTEM/SEDEM models were applied. The models were validated by comparing the simulated results with the actual bathymetry of a polder at the catchment outlet. Methods of crop management based on rotation and strip cropping were applied for the reduction of soil loss and sediment transport. The comparison shows that the greatest intensities of soil loss were achieved by the bare soil without vegetation and from the planting of maize for corn. The lowest values were achieved from the planting of winter wheat. At the end the effectiveness of row crops and strip cropping for decreasing design floods from the catchment was estimated.

HCMM energy budget data as a model input for assessing regions of high potential groundwater pollution. [South Dakota

NASA Technical Reports Server (NTRS)

Moore, D. G. (Principal Investigator); Heilman, J. L.

1980-01-01

The author has identified the following significant results. Day thermal data were analyzed to assess depth to groundwater in the test site. HCMM apparent temperature was corrected for atmospheric effects using lake temperature of the Oahe Reservoir in central South Dakota. Soil surface temperatures were estimated using an equation developed for ground studies. A significant relationship was found between surface soil temperature and depth to groundwater, as well as between the surface soil-maximum air temperature differential and soil water content (% of field capacity) in the 0 cm and 4 cm layer of the profile. Land use for the data points consisted of row crops, small grains, stubble, and pasture.

Increased soil organic carbon stocks under agroforestry: A survey of six different sites in France

NASA Astrophysics Data System (ADS)

Cardinael, Rémi; Chevallier, Tiphaine; Cambou, Aurélie; Beral, Camille; Barthes, Bernard; Dupraz, Christian; Kouakoua, Ernest; Chenu, Claire

2017-04-01

Introduction: Agroforestry systems are land use management systems in which trees are grown in combination with crops or pasture in the same field. In silvoarable systems, trees are intercropped with arable crops, and in silvopastoral systems trees are combined with pasture for livestock. These systems may produce forage and timber as well as providing ecosystem services such as climate change mitigation. Carbon (C) is stored in the aboveground and belowground biomass of the trees, and the transfer of organic matter from the trees to the soil can increase soil organic carbon (SOC) stocks. Few studies have assessed the impact of agroforestry systems on carbon storage in soils in temperate climates, as most have been undertaken in tropical regions. Methods: This study assessed five silvoarable systems and one silvopastoral system in France. All sites had an agroforestry system with an adjacent, purely agricultural control plot. The land use management in the inter-rows in the agroforestry systems and in the control plots were identical. The age of the study sites ranged from 6 to 41 years after tree planting. Depending on the type of soil, the sampling depth ranged from 20 to 100 cm and SOC stocks were assessed using equivalent soil masses. The aboveground biomass of the trees was also measured at all sites. Results: In the silvoarable systems, the mean organic carbon stock accumulation rate in the soil was 0.24 (0.09-0.46) Mg C ha-1 yr-1 at a depth of 30 cm and 0.65 (0.004-1.85) Mg C ha-1 yr-1 in the tree biomass. Increased SOC stocks were also found in deeper soil layers at two silvoarable sites. Young plantations stored additional SOC but mainly in the soil under the rows of trees, possibly as a result of the herbaceous vegetation growing in the rows. At the silvopastoral site, the SOC stock was significantly greater at a depth of 30-50 cm than in the control. Overall, this study showed the potential of agroforestry systems to store C in both soil and biomass in temperate regions.

Evaluation of Daily Evapotranspiration Over Orchards Using METRIC Approach and Landsat Satellite Observations

NASA Astrophysics Data System (ADS)

He, R.; Jin, Y.; Daniele, Z.; Kandelous, M. M.; Kent, E. R.

2016-12-01

The pistachio and almond acreage in California has been rapidly growing in the past 10 years, raising concerns about competition for limited water resources in California. A robust and cost-effective mapping of crop water use, mostly evapotranspiration (ET), by orchards, is needed for improved farm-level irrigation management and regional water planning. METRIC™, a satellite-based surface energy balance approach, has been widely used to map field-scale crop ET, mostly over row crops. We here aim to apply METRIC with Landsat satellite observations over California's orchards and evaluate the ET estimates by comparing with field measurements in South San Joaquin Valley, California. Reference ET of grass (ETo) from California Irrigation Management Information system (CIMIS) stations was used to estimate daily ET of commercial almond and pistachio orchards. Our comparisons showed that METRIC-Landsat ET daily estimates agreed well with ET measured by the eddy covariance and surface renewal stations, with a RMSE of 1.25 and a correlation coefficient of 0.84 for the pistachio orchard. A slight high bias of satellite based ET estimates was found for both pistachio and almond orchards. We also found time series of NDVI was highly correlated with ET temporal dynamics within each field, but the correlation was reduced to 0.56 when all fields were pooled together. Net radiation, however, remained highly correlated with ET across all the fields. The METRIC ET was able to distinguish the differences in ET among salt- and non-salt affected pistachio orchards, e.g., mean daily ET during growing season in salt-affected orchards was lower than that of non-salt affected one by 0.87 mm/day. The remote sensing based ET estimate will support a variety of state and local interests in water use and management, for both planning and regulatory/compliance purposes, and provide the farmers observation-based guidance for site-specific and time-sensitive irrigation management.

Tree growth and management in Ugandan agroforestry systems: effects of root pruning on tree growth and crop yield.

PubMed

Wajja-Musukwe, Tellie-Nelson; Wilson, Julia; Sprent, Janet I; Ong, Chin K; Deans, J Douglas; Okorio, John

2008-02-01

Tree root pruning is a potential tool for managing belowground competition when trees and crops are grown together in agroforestry systems. We investigated the effects of tree root pruning on shoot growth and root distribution of Alnus acuminata (H.B. & K.), Casuarina equisetifolia L., Grevillea robusta A. Cunn. ex R. Br., Maesopsis eminii Engl. and Markhamia lutea (Benth.) K. Schum. and on yield of adjacent crops in sub-humid Uganda. The trees were 3 years old at the commencement of the study, and most species were competing strongly with crops. Tree roots were pruned 41 months after planting by cutting and back-filling a trench to a depth of 0.3 m, at a distance of 0.3 m from the trees, on one side of the tree row. The trench was reopened and roots recut at 50 and 62 months after planting. We assessed the effects on tree growth and root distribution over a 3 year period, and crop yield after the third root pruning at 62 months. Overall, root pruning had only a slight effect on aboveground tree growth: height growth was unaffected and diameter growth was reduced by only 4%. A substantial amount of root regrowth was observed by 11 months after pruning. Tree species varied in the number and distribution of roots, and C. equisetifolia and M. lutea had considerably more roots per unit of trunk volume than the other species, especially in the surface soil layers. Casuarina equisetifolia and M. eminii were the tree species most competitive with crops and G. robusta and M. lutea the least competitive. Crop yield data provided strong evidence of the redistribution of root activity following root pruning, with competition increasing on the unpruned side of tree rows. Thus, one-sided root pruning will be useful in only a few circumstances.

Remote Sensing of Almond and Walnut Tree Canopy Temperatures Using an Inexpensive Infrared Sensor on a Small Unmanned Aerial Vehicle

NASA Astrophysics Data System (ADS)

Crawford, Kellen Ethan

Improving water use efficiency in agriculture will become increasingly important in the face of decreasing water resources and a growing population. Increasing water use efficiency, or water productivity, has been shown to greatly reduce irrigation water usage in many orchard crops with little to no impact on yield. In some specialty crops, improving water productivity can even lead to a higher value crop. Current irrigation practices depend largely on uniform applications of water over large fields with varying degrees of heterogeneity. As a result, much of the field receives more water than it needs. A system to monitor the needs of each plant or smaller groups of plants within the field would be helpful in distributing irrigation water according to each plant or group of plants' needs. Such a system would help conserve water resources. Stomatal conductance is a good indicator of plant water-based stress, as it is the main response a plant has to limit transpiration-related water losses. The difference between leaf temperature and air temperature, when adjusted for environmental conditions, can give a good indication of stomatal conductance. Recent efforts at UC Davis have employed a handheld sensor suite to measure leaf temperature and other environmental variables like wind speed, air temperature, and humidity in almond and walnut trees. Though effective, this method requires walking or driving through the orchard and measuring several leaves on a given tree, so it is impractical for large-scale monitoring. Satellite and aircraft can measure canopy temperatures remotely, but these applications typically do not have the spatial resolution for precise monitoring or the temporal resolution necessary for irrigation decisions, and they are too expensive and impractical for smaller-scale farms. A smaller unmanned aerial vehicle (UAV) could employ the same methods as satellite and larger aircraft-based systems, but relatively inexpensively and at a scale catered to the needs of a given field for more precise monitoring. The goal of this study was to explore the feasibility of using an inexpensive temperature sensor (Melexis MLX90614; NV Melexis SA, Rozendaalstraat 12, 8900 Ieper, Belgium) on a small UAV (Mikrokopter OktoXL; Hisystems GmbH Flachsmeerstrasse 2, 26802 Moormerland, Germany) to sense the canopy temperatures of almond and walnut trees. To accomplish this goal, we installed an infrared temperature sensor and a digital camera on a small UAV. The camera provided a spatial awareness of the IR temperature measurements which would otherwise require a very expensive thermal imager to obtain. The UAV was flown above almond and walnut trees recording images and temperatures, which were aligned temporally in post-processing. The pixels of each image were classified in to four classes: sunlit leaves, shaded leaves, sunlit soil, and shaded soil. Assuming that the measured temperature could be described as a weighted sum of each class in the field of view of the IR sensor, a linear system of equations was established to estimate the temperature of each class using at least several measurements of the same tree. Results indicated a good correlation between the temperatures estimated from the linear system of equations and the temperatures of those classes sampled on the ground immediately following each flight. With leaf temperatures ranging from about 12 to 40 degrees Celsius between 23 flights over two years, the linear solver was able to estimate the temperature of the sunlit and shaded leaves to within several degrees Celsius of the sampled temperature in most cases, with a coefficient of determination (r2 value) of 0.96 during the first year, and 0.73 during the second year. An additional study was undertaken to detect spatial temperature distribution within the orchard. Ground measurements were taken of every other tree in two walnut rows and one almond row using the handheld sensor, and the UAV was flown over those rows immediately following each ground sampling. An interpolated temperature map of the UAV's temperature measurements indicated a very similar temperature distribution as that measured with the handheld sensor, but the UAV was much faster and, in parts of the rows, it provided a higher spatial resolution than the handheld sensor.

Compatibility of switchgrass as an energy crop in farming systems of the southeastern USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bransby, D.I.; Rodriguez-Kabana, R.; Sladden, S.E.

1993-12-31

The objective of this paper is to examine the compatibility of switchgrass as an energy crop in farming systems in the southeastern USA, relative to other regions. In particular, the issues addressed are (1) competition between switchgrass as an energy crop and existing farm enterprises, based primarily on economic returns, (2) complementarity between switchgrass and existing farm enterprises, and (3) environmental benefits. Because projected economic returns for switchgrass as an energy crop are highest in the Southeast, and returns from forestry and beef pastures (the major existing enterprises) are low, there is a very strong economic incentive in this region.more » In contrast, based on current information, economic viability of switchgrass as an energy crop in other regions appears doubtful. In addition, switchgrass in the southeastern USA would complement forage-livestock production, row crop production and wildlife and would provide several additional environmental benefits. It is concluded that the southeastern USA offers the greatest opportunity for developing switchgrass as an economically viable energy crop.« less

Factors affecting low summer dissolved oxygen concentrations in Mississippi Delta bayous

USDA-ARS?s Scientific Manuscript database

Streams in watersheds supporting intensive row-crop agriculture are vulnerable to ecological degradation due to non-point source pollutants such as nutrients. Low gradient streams such as bayous are especially susceptible to pollutants due to increased water residence time, and they often exhibit po...

Crop circles and organic weed control

USDA-ARS?s Scientific Manuscript database

Organic vegetable production relies on integrated weed control measures to attain satisfactory weed control. An experiment was established in autumn 2010 and 2011 at the North Alabama Horticulture Experiment Station, Cullman, AL. Plot size at both locations was 2.5 by 6 m containing a single row o...

Soil quality indicator responses to row crop, grazed pasture, and agroforestry buffer management

USDA-ARS?s Scientific Manuscript database

Incorporation of trees and establishment of grass buffers within agroecosystems are management practices shown to enhance soil quality. Soil enzyme activities and water stable aggregates (WSA) have been identified as sensitive soil quality indicators to evaluate early responses to soil management. ...

Cropping system diversification for food production in Mindanao rubber plantations: a rice cultivar mixture and rice intercropped with mungbean

PubMed Central

Elazegui, Francisco; Duque, Jo-Anne Lynne Joy E.; Mundt, Christopher C.; Vera Cruz, Casiana M.

2017-01-01

Including food production in non-food systems, such as rubber plantations and biofuel or bioenergy crops, may contribute to household food security. We evaluated the potential for planting rice, mungbean, rice cultivar mixtures, and rice intercropped with mungbean in young rubber plantations in experiments in the Arakan Valley of Mindanao in the Philippines. Rice mixtures consisted of two- or three-row strips of cultivar Dinorado, a cultivar with higher value but lower yield, and high-yielding cultivar UPL Ri-5. Rice and mungbean intercropping treatments consisted of different combinations of two- or three-row strips of rice and mungbean. We used generalized linear mixed models to evaluate the yield of each crop alone and in the mixture or intercropping treatments. We also evaluated a land equivalent ratio for yield, along with weed biomass (where Ageratum conyzoides was particularly abundant), the severity of disease caused by Magnaporthe oryzae and Cochliobolus miyabeanus, and rice bug (Leptocorisa acuta) abundance. We analyzed the yield ranking of each cropping system across site-year combinations to determine mean relative performance and yield stability. When weighted by their relative economic value, UPL Ri-5 had the highest mean performance, but with decreasing performance in low-yielding environments. A rice and mungbean intercropping system had the second highest performance, tied with high-value Dinorado but without decreasing relative performance in low-yielding environments. Rice and mungbean intercropped with rubber have been adopted by farmers in the Arakan Valley. PMID:28194318

Groundwater recharge in irrigated semi-arid areas: quantitative hydrological modelling and sensitivity analysis

NASA Astrophysics Data System (ADS)

Jiménez-Martínez, Joaquín; Candela, Lucila; Molinero, Jorge; Tamoh, Karim

2010-12-01

For semi-arid regions, methods of assessing aquifer recharge usually consider the potential evapotranspiration. Actual evapotranspiration rates can be below potential rates for long periods of time, even in irrigated systems. Accurate estimations of aquifer recharge in semi-arid areas under irrigated agriculture are essential for sustainable water-resources management. A method to estimate aquifer recharge from irrigated farmland has been tested. The water-balance-modelling approach was based on VisualBALAN v. 2.0, a computer code that simulates water balance in the soil, vadose zone and aquifer. The study was carried out in the Campo de Cartagena (SE Spain) in the period 1999-2008 for three different groups of crops: annual row crops (lettuce and melon), perennial vegetables (artichoke) and fruit trees (citrus). Computed mean-annual-recharge values (from irrigation+precipitation) during the study period were 397 mm for annual row crops, 201 mm for perennial vegetables and 194 mm for fruit trees: 31.4, 20.7 and 20.5% of the total applied water, respectively. The effects of rainfall events on the final recharge were clearly observed, due to the continuously high water content in soil which facilitated the infiltration process. A sensitivity analysis to assess the reliability and uncertainty of recharge estimations was carried out.

Growth and yield of valencia, spanish, virginia and runner market type peanuts in various row spacings

USDA-ARS?s Scientific Manuscript database

Currently, the majority of peanuts grown in New Mexico and West Texas are planted in single rows on beds 36 to 40 inches apart. In 2006-2008, several field studies were conducted with Valencia peanuts comparing single row, twin row, and diamond planting patterns in various populations. The basic c...

Nutrients discharged to the Mississippi River from eastern Iowa watersheds, 1996-1997

USGS Publications Warehouse

Becher, Kent D.; Schnoebelen, Douglas J.; Akers, Kimberlee K.

2000-01-01

The introduction of nutrients from chemical fertilizer, animal manure, wastewater, and atmospheric deposition to the eastern Iowa environment creates a large potential for nutrient transport in watersheds. Agriculture constitutes 93 percent of all land use in eastern Iowa. As part of the U.S. Geological Survey National Water Quality Assessment Program, water samples were collected (typically monthly) from six small and six large watersheds in eastern Iowa between March 1996 and September 1997. A Geographic Information System (GIS) was used to determine land use and quantify inputs of nitrogen and phosphorus within the study area. Streamliow from the watersheds is to the Mississippi River. Chemical fertilizer and animal manure account for 92 percent of the estimated total nitrogen and 99.9 percent of the estimated total phosphorus input in the study area. Total nitrogen and total phosphorus loads for 1996 were estimated for nine of the 12 rivers and creeks using a minimum variance unbiased estimator model. A seasonal pattern of concentrations and loads was observed. The greatest concentrations and loads occur in the late spring to early summer in conjunction with row-crop fertilizer applications and spring nmoff and again in the late fall to early winter as vegetation goes into dormancy and additional fertilizer is applied to row-crop fields. The three largest rivers in eastern Iowa transported an estimated total of 79,000 metric tons of total nitrogen and 6,800 metric tons of total phosphorus to the Mississippi River in 1996. The estimated mass of total nitrogen and total phosphorus transported to the Mississippi River represents about 19 percent of all estimated nitrogen and 9 percent of all estimated phosphorus input to the study area.

Factors affecting low summer dissolved oxygen concentrations in Mississippi Delta bayous

USDA-ARS?s Scientific Manuscript database

Streams in watersheds supporting intensive row-crop agriculture are vulnerable to ecological degradation due to non-point source discharge of pollutants such as nutrients. Low gradient streams such as bayous are especially susceptible due to increased water residence time, and often result in poor w...

Soil water retention within an eroded and restored landscape

USDA-ARS?s Scientific Manuscript database

Significant changes in soil properties and productivity have occurred as a result of intensive row crop production. Many of these changes are related to soil loss from water, wind, and tillage erosion. Soil is lost from convex and steeper landscape positions and deposited in concave lower landscape ...

Trace gas flux from container production of woody landscape plants

USDA-ARS?s Scientific Manuscript database

The agriculture industry is a large source of greenhouse gas (GHG) emissions which are widely believed to be causing increased global temperatures. Reduction of these emissions has been heavily researched, with most of the work focusing on row crop and animal production sectors. Little attention has...

Effects of outplanting horticultural species on soil CO2 efflux

USDA-ARS?s Scientific Manuscript database

Increased atmospheric carbon dioxide (CO2) concentration is widely thought to be the main driving factor behind global climate change. Much of the work on reducing greenhouse gas (GHG) emissions and methods of carbon (C) sequestration has been conducted in row crop and forest systems; however, virt...

7 CFR 457.171 - Cabbage crop insurance provisions.

Code of Federal Regulations, 2013 CFR

2013-01-01

.... Commercial or better in accordance with the United States Standards for Grades of Cabbage, or processing.... Commercial for fresh market cabbage; or (b) U.S. No. 2 for processing cabbage. Planted acreage. In addition... initially be planted in rows wide enough to permit mechanical cultivation. Cabbage planted or seeds planted...

Plant growth responses of apple and pear trees to doses of glyphosate

USDA-ARS?s Scientific Manuscript database

Glyphosate is commonly used for intra-row weed management in perennial plantations, where unintended crop exposure to this herbicide can cause growth reduction. The objective of this research was to analyze the initial plant growth behavior of young apple and pear plants exposed to glyphosate. Glyph...

Runoff and sediment reduction from integration of native prairie filter strips into row-crop agriculture

USDA-ARS?s Scientific Manuscript database

Agroecosystems provide multiple benefits including food, fiber, fuel, clean water and air, habitat, carbon sequestration, recreation, and aesthetics. But most agricultural landscapes are managed for only a few of these benefits. This project aimed to evaluate how the integration of diverse perennial...

Calcium Content of Hardwood Litter Four Times that from Pine; Nitrogen Double

Treesearch

Louis J. Metz

1952-01-01

Most Piedmont forests, growing on land worn out by row cropping and abandoned, are low in site quality. They contribute appreciable flood runoff and sediment. Soil structure is poor and nutrient content low. Such improvement as takes place comes generally from litter fall, particularly hsrdwood leaves.

Simulating woodchip bioreactor performance using a dual-porosity model

USDA-ARS?s Scientific Manuscript database

Nitrate in the Nation's surface waters has been a persistent health and ecological problem. The major source of nitrate is tile drainage from agricultural row crops. Denitrification bioreactors have been shown to be effective in removing much of the nitrate from tile drains. While we understand i...

Influences of spatial scale and soil permeability on relationships between land cover and baseflow stream nutrient concentrations

EPA Science Inventory

The Little Miami River (LMR) basin, dominated by agriculture, contains two geologically-distinct regions; a glaciated northern till plain with soils three times more permeable than a southern, pre-Wisconsinan drift plain. The influences of two landscape measures, percent row crop...

In Vivo Production of Agrotis ipsilon Nucleopolyhedrovirus for Quantity and Quality

USDA-ARS?s Scientific Manuscript database

The black cutworm, Agrotis ipsilon (Hüfnagel), is a pest causing damage to a variety plants from urban turf environments to farming row crops. A recently discovered baculovirus has the potential to be developed as a microbial-based biological pesticide to provide targeted control of this insect pest...

Impact of ground speed and varying seeding rates on meter performance

USDA-ARS?s Scientific Manuscript database

Achieving optimum planter performance is an important requirement for obtaining higher crop yields. Planter performance depends on several factors but meter speed is an important one which is a function of ground speed, seeding rate and row spacing. A study was conducted to evaluate the influence of...

Soil health for improved food securities: natural ecosystems, row crop, and livestock production

USDA-ARS?s Scientific Manuscript database

Recent environmental and ecological awareness has resulted in consideration of soil as more than just a medium for root growth and livestock production. In order to meet the expected growing world population and subsequent food production demands, producers are reevaluating traditional management sy...

Spatially-Explicit Estimates of Greenhouse Gas Emissions from Fire and Land-Use Change in the Brazilian Cerrado

NASA Astrophysics Data System (ADS)

Galford, G. L.; Spera, S. A.; Coe, M. T.; Costa, C., Jr.

2014-12-01

Understanding the multiple types of land-use changes that can occur within an ecosystem provides a comprehensive picture of the human's impact on natural systems. We use the Cerrado (savanna) of Brazil to examine the primary and secondary impacts of land-use change on greenhouse gas emissions. The primary land-use changes include fires for land-clearing, conversions to pasture and row-crop agriculture, and shifting management practices of agricultural lands. Secondary land-use changes include savanna degradation due to fires that escape from intended burn areas. These escape fires typically have a lower combustion completion coefficient than clearing fires, so it is important to distinguish them to correctly estimate the regional greenhouse gas budget. We have created a first-order spatio-temporal model of greenhouse gas emissions that can be easily modified for other savanna regions using globally available data products as inputs. Our data inputs are derived from publically available remote sensing imagery. Initial biomass is estimated by Baccini et al. 2012, which is derived from LiDAR and MODIS imagery. All other input data sets give annual estimates. Clearing of the savanna is documented by LAPIG of Universidade Federal de Goias using MODIS (MOD13Q1), LANDSAT and CBERS images. MODIS burned area products delineate annual fires; in combination with the savanna clearing database we determine primary and escape fires. Pastures and row-crop agriculture are documented by LAPIG and Spera et al. 2014, respectively. The row-crop agriculture dataset enables us to estimate greenhouse gas emissions associated with specific crops (e.g., soy or maize) and management (e.g., fertilizer use). Recent contributions to the literature have provided many in situ measurements from the land-use changes of interest needed to estimate a regional greenhouse gas budget, including combustion coefficients of savanna sub-types, carbon emission soil stocks, nitrogen emissions from fertilizer, and carbon storage in pastures. With this wealth of information, we present a complete greenhouse gas portfolio including a sensitivity analysis for this dynamic region with an eye to applications for other savanna regions.

Pixel-By Estimation of Scene Motion in Video

NASA Astrophysics Data System (ADS)

Tashlinskii, A. G.; Smirnov, P. V.; Tsaryov, M. G.

2017-05-01

The paper considers the effectiveness of motion estimation in video using pixel-by-pixel recurrent algorithms. The algorithms use stochastic gradient decent to find inter-frame shifts of all pixels of a frame. These vectors form shift vectors' field. As estimated parameters of the vectors the paper studies their projections and polar parameters. It considers two methods for estimating shift vectors' field. The first method uses stochastic gradient descent algorithm to sequentially process all nodes of the image row-by-row. It processes each row bidirectionally i.e. from the left to the right and from the right to the left. Subsequent joint processing of the results allows compensating inertia of the recursive estimation. The second method uses correlation between rows to increase processing efficiency. It processes rows one after the other with the change in direction after each row and uses obtained values to form resulting estimate. The paper studies two criteria of its formation: gradient estimation minimum and correlation coefficient maximum. The paper gives examples of experimental results of pixel-by-pixel estimation for a video with a moving object and estimation of a moving object trajectory using shift vectors' field.

Forest River Basin, North Dakota. Feasibility Report for Flood Control and Related Purposes. Phase I.

DTIC Science & Technology

1975-06-01

grown on 69.1 percent, row crops on 4.2 percent, and tame hay crops on 3.6 percent. About 23.1 percent of the culti- vated land Is in summer fallow. The ...17. DISTRIBUTION STATEMENT (of the abettact entered In Block 20, If different from Report) D T C I .’. ,ow IS. SUPPLEMENTARY NOTES 19. KEY WORDS...re"ve, eie f necearty amd identify by block number) The Forest River subbasin is located in northeastern North Dakota and is a tributary to the Red

Crop Yields and Climate Change to the Year 2000. Volume 2: Climate Model and Technical Appendixes.

DTIC Science & Technology

1988-01-01

drawn for an even chance assumes that technology will allow for man- agement of the soil to maintain fertility through crop rotation , etc. I would expect... rotations , or it may be barley/fallow or some other combination, and often the cereal is grown several years in a row. Wheat seeded on stubble, i.e... rotations , and that there might be a gradual conversion to this system, to be completed by the year 2000. Then, taking the value of 31.9 for the year 2000

Reconnecting tile drainage to riparian buffer hydrology for enhanced nitrate removal.

PubMed

Jaynes, D B; Isenhart, T M

2014-03-01

Riparian buffers are a proven practice for removing NO from overland flow and shallow groundwater. However, in landscapes with artificial subsurface (tile) drainage, most of the subsurface flow leaving fields is passed through the buffers in drainage pipes, leaving little opportunity for NO removal. We investigated the feasibility of re-routing a fraction of field tile drainage as subsurface flow through a riparian buffer for increasing NO removal. We intercepted an existing field tile outlet draining a 10.1-ha area of a row-cropped field in central Iowa and re-routed a fraction of the discharge as subsurface flow along 335 m of an existing riparian buffer. Tile drainage from the field was infiltrated through a perforated pipe installed 75 cm below the surface by maintaining a constant head in the pipe at a control box installed in-line with the existing field outlet. During 2 yr, >18,000 m (55%) of the total flow from the tile outlet was redirected as infiltration within the riparian buffer. The redirected water seeped through the 60-m-wide buffer, raising the water table approximately 35 cm. The redirected tile flow contained 228 kg of NO. On the basis of the strong decrease in NO concentrations within the shallow groundwater across the buffer, we hypothesize that the NO did not enter the stream but was removed within the buffer by plant uptake, microbial immobilization, or denitrification. Redirecting tile drainage as subsurface flow through a riparian buffer increased its NO removal benefit and is a promising management practice to improve surface water quality within tile-drained landscapes. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

A method for mapping corn using the US Geological Survey 1992 National Land Cover Dataset

USGS Publications Warehouse

Maxwell, S.K.; Nuckols, J.R.; Ward, M.H.

2006-01-01

Long-term exposure to elevated nitrate levels in community drinking water supplies has been associated with an elevated risk of several cancers including non-Hodgkin's lymphoma, colon cancer, and bladder cancer. To estimate human exposure to nitrate, specific crop type information is needed as fertilizer application rates vary widely by crop type. Corn requires the highest application of nitrogen fertilizer of crops grown in the Midwest US. We developed a method to refine the US Geological Survey National Land Cover Dataset (NLCD) (including map and original Landsat images) to distinguish corn from other crops. Overall average agreement between the resulting corn and other row crops class and ground reference data was 0.79 kappa coefficient with individual Landsat images ranging from 0.46 to 0.93 kappa. The highest accuracies occurred in Regions where corn was the single dominant crop (greater than 80.0%) and the crop vegetation conditions at the time of image acquisition were optimum for separation of corn from all other crops. Factors that resulted in lower accuracies included the accuracy of the NLCD map, accuracy of corn areal estimates, crop mixture, crop condition at the time of Landsat overpass, and Landsat scene anomalies.

The century experiment: the first twenty years of UC Davis' Mediterranean agroecological experiment.

PubMed

Wolf, Kristina M; Torbert, Emma E; Bryant, Dennis; Burger, Martin; Denison, R Ford; Herrera, Israel; Hopmans, Jan; Horwath, Will; Kaffka, Stephen; Kong, Angela Y Y; Norris, R F; Six, Johan; Tomich, Thomas P; Scow, Kate M

2018-02-01

The Century Experiment at the Russell Ranch Sustainable Agriculture Facility at the University of California, Davis provides long-term agroecological data from row crop systems in California's Central Valley starting in 1993. The Century Experiment was initially designed to study the effects of a gradient of water and nitrogen availability on soil properties and crop performance in ten different cropping systems to measure tradeoffs and synergies between agricultural productivity and sustainability. Currently systems include 11 different cropping systems-consisting of four different crops and a cover crop mixture-and one native grass system. This paper describes the long-term core data from the Century Experiment from 1993-2014, including crop yields and biomass, crop elemental contents, aerial-photo-based Normalized Difference Vegetation Index data, soil properties, weather, chemical constituents in irrigation water, winter weed populations, and operational data including fertilizer and pesticide application amounts and dates, planting dates, planting quantity and crop variety, and harvest dates. This data set represents the only known long-term set of data characterizing food production and sustainability in irrigated and rainfed Mediterranean annual cropping systems. There are no copyright restrictions associated with the use of this dataset. © 2018 by the Ecological Society of America.

Relationship of land use to water quality in the Chesapeake Bay region. [water sampling and photomapping river basins

NASA Technical Reports Server (NTRS)

Correll, D. L.

1978-01-01

Both the proportions of the various land use categories present on each watershed and the specific management practices in use in each category affect the quality of runoff waters, and the water quality of the Bay. Several permanent and portable stations on various Maryland Rivers collect volume-integrated water samples. All samples are analyzed for a series of nutrient, particulate, bacterial, herbicide, and heavy metal parameters. Each basin is mapped with respect to land use by the analysis of low-elevation aerial photos. Analyses are verified and adjusted by ground truth surveys. Data are processed and stored in the Smithsonian Institution data bank. Land use categories being investigated include forests/old fields, pastureland, row crops, residential areas, upland swamps, and tidal marshes.

[Water-saving mechanisms of intercropping system in improving cropland water use efficiency].

PubMed

Zhang, Feng-Yun; Wu, Pu-Te; Zhao, Xi-Ning; Cheng, Xue-Feng

2012-05-01

Based on the multi-disciplinary researches, and in terms of the transformation efficiency of surface water to soil water, availability of cropland soil water, crop canopy structure, total irrigation volume needed on a given area, and crop yield, this paper discussed the water-saving mechanisms of intercropping system in improving cropland water use efficiency. Intercropping system could promote the full use of cropland water by plant roots, increase the water storage in root zone, reduce the inter-row evaporation and control excessive transpiration, and create a special microclimate advantageous to the plant growth and development. In addition, intercropping system could optimize source-sink relationship, provide a sound foundation for intensively utilizing resources temporally and spatially, and increase the crop yield per unit area greatly without increase of water consumption, so as to promote the crop water use efficiency effectively.

Evaluation of the APEX Model to Simulate Runoff Quality from Agricultural Fields in the Southern Region of the United States.

PubMed

Ramirez-Avila, John J; Radcliffe, David E; Osmond, Deanna; Bolster, Carl; Sharpley, Andrew; Ortega-Achury, Sandra L; Forsberg, Adam; Oldham, J Larry

2017-11-01

The Agricultural Policy Environmental eXtender (APEX) model has been widely applied to assess phosphorus (P) loss in runoff water and has been proposed as a model to support practical decisions regarding agricultural P management, as well as a model to evaluate tools such as the P Index. The aim of this study is to evaluate the performance of APEX to simulate P losses from agricultural systems to determine its potential use for refinement or replacement of the P Index in the southern region of the United States. Uncalibrated and calibrated APEX model predictions were compared against measured water quality data from row crop fields in North Carolina and Mississippi and pasture fields in Arkansas and Georgia. Calibrated models satisfactorily predicted event-based surface runoff volumes at all sites (Nash-Sutcliffe efficiency [NSE] > 0.47, |percent bias [PBIAS]| < 34) except Arkansas (NSE < 0.11, |PBIAS| < 50) but did not satisfactory simulate sediment, dissolved P, or total P losses in runoff water. The APEX model tended to underestimate dissolved and total P losses from fields where manure was surface applied. The model also overestimated sediments and total P loads during irrigation events. We conclude that the capability of APEX to predict sediment and P losses is limited, and consequently so is the potential for using APEX to make P management recommendations to improve P Indices in the southern United States. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Comparisons of evening and morning SMOS passes over the Midwest United States

USDA-ARS?s Scientific Manuscript database

This study investigates differences in the soil moisture product and brightness temperatures between 6 pm and 6 am local solar time, when the SMOS passes for a region in north-central Iowa. This region consists of 69 SMOS pixels and has uniform land-cover, consisting of maize and soybean row crops. ...

Soil with a short history of poultry litter fertilization remains superior to normally fertilized soil for cotton

USDA-ARS?s Scientific Manuscript database

Research has shown poultry litter is a superior fertilizer for cotton and other row crops. The productivity of soil that had received poultry litter as a fertilizer is not known after cessation of litter application and returning to conventional fertilization with inorganic fertilizers. This study ...

The impact of tillage on Pinto bean cultivar response to drought induced by deficit irrigation

USDA-ARS?s Scientific Manuscript database

Drought stress is a major factor limiting yield of dry bean (Phaseolus vulgaris) and drought tolerant cultivars are being developed. Reducing tillage in row crops has advantages of conserving moisture and increasing water infiltration, and may alter the response of dry bean cultivars to drought stre...

Soil functional zone management: a vehicle for enhancing production and soil ecosystem services in row-crop agroecosystems

USDA-ARS?s Scientific Manuscript database

There is increasing demand for food, bioenergy feedstocks and a wide variety of bio-based products. In response, agriculture has made great gains in production, but is increasingly depleting soil regulating and supporting ecosystem services. New production systems have emerged, such as Conservation ...

MEASUREMENT OF NITROGEN OXIDE EMISSIONS FROM AN AGRICULTURAL SOIL WITH A DYNAMIC CHAMBER SYSTEM

EPA Science Inventory

Biogenic soil emissions of nitric oxide (NO) were measured from an intensively managed agricultural row crop (corn, Zea mays) during a 4 week period May 15 through June 9, 1995). The site was located in Washington County, near the town of Plymouth, which is in the Lower Coastal P...

Carbon sequestration potential of grazed pasture depends on prior management history

USDA-ARS?s Scientific Manuscript database

Grazed pastures are often assumed to be net sinks for removing carbon dioxide from the atmosphere and thus, are promoted as a management practice that can help mitigate climate change. The ability to serve as a C sink is especially pronounced following a history of tillage and row crop production. I...

Row and plant spacing effects on growth and yield of dryland cotton where growing season duration is limited

USDA-ARS?s Scientific Manuscript database

Irrigation water availability is decreasing in the Southern Great Plains due to continued pumping from the Ogallala aquifer. Cotton (Gossypium hirsutum L.) is a profitable alternative crop suited to sustainable dryland production. However, the growing season of the Texas Panhandle and southwestern...

Nezara viridula (L.) in Central Texas: II. Seasonal occurrence of black spotted condition in adult females

USDA-ARS?s Scientific Manuscript database

Nezara viridula (L.) continues to plague cotton and row crop producers annually after successfully overwintering in a production region. A physiological marker in the female reproductive system – known as a black spot condition – alluding to overwintering status was previously reported and a simila...

Effects of poultry litter placement on seedling and early-stage growth of corn and cotton

USDA-ARS?s Scientific Manuscript database

Interest in using poultry litter (PL) as a nutrient source for row crop production within the Southeastern U.S. has increased. Poultry litter is generally broadcast on the soil surface. This practice exposes the litter’s N to volatilization and P to surface water runoff, potentially negatively impac...

Poultry litter placement effects on cotton seedling emergence and early growth stage

USDA-ARS?s Scientific Manuscript database

Interest in using poultry litter (PL) as a nutrient source for row crop production has increased in the Southeastern U.S. Poultry litter is generally broadcasted on the soil surface. This practice exposes litter N to volatilization and litter P to loss with surface water runoff, which potentially ne...

Soil aggregates and their associated carbon and nitrogen content in winter annual pastures using different tillage management options

USDA-ARS?s Scientific Manuscript database

Traditionally, winter annual pastures are established on grazing areas that are steeply sloping and not regarded as suitable for row-crop production. Using conventional (CT) tillage methods to prepare these fragile lands for winter annual pastures leads to increased erosion and rapid soil degradatio...

Sunn hemp as a ground cover to manage fall armyworm populations

USDA-ARS?s Scientific Manuscript database

Fall armyworm (FAW), Spodoptera frugiperda, is a serious pest of sweet corn in south Florida and a pest of other vegetable, row, and forage crops in the southeastern, mid-Atlantic, and central U.S. It is a migratory pest, moving north each season from overwintering areas in southern Texas and south...

History of Piedmont Forests: Implications For Current Pine Management

Treesearch

D.H. Van Lear; R.A. Harper; P.R. Kapeluck; W.D. Carroll

2004-01-01

Piedmont forests were maintained for millennia in an open condition by anthropogenic- and lightning-ignited fires. After European settlement, row-crop agriculture caused serious soil erosion, making Piedmont soils less capable of supplying moisture and nutrients during drought periods. Dense stands of pine, both naturally and artificially regenerated over the past 70...

7 CFR 457.139 - Fresh market tomato (dollar plan) crop insurance provisions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... adjacent row of plants. Tropical depression. A system identified by the U.S. Weather Service as a tropical depression, and for the period of time so designated, including tropical storms, gales, and hurricanes. 2...; (2) Fire; (3) Freeze; (4) Hail; (5) Tornado; (6) Tropical depression; or (7) Failure of the...

ASSESSING THE QUANTITY AND QUALITY OF DEPRESSIONAL WETLANDS IN THE REDWOOD RIVER WATERSHED UTILIZING A PROBABILISTIC SURVEY DESIGN

EPA Science Inventory

Located in southwestern Minnesota, the Redwood River watershed lies within an area of the Prairie Pothole Region where land use is predominantly a mixture of row crop and livestock agriculture. In 2003 the condition of emergent depressional wetlands in this watershed was assesse...

New modes of use and opportunities for research in forage plants

USDA-ARS?s Scientific Manuscript database

Forages play an important role in the production of meat and dairy throughout the world. Forages are not only an integral part of human protein production, but they can also improve row crop production management systems, play a role in reducing the dependence on fossil fuels and mitigate environme...

Management implications of cowbird parasitism on neotropical migrant songbirds

Treesearch

Scott K. Robinson; Joseph A. Grzybowski; Stephen I. Rothstein; Margaret C. Brittingham; Lisa J. Petit; Frank R. Thompson

1993-01-01

Populations of brood parasitic Brown-headed Cowbirds (Molofhrus afer) have increased to the point where they pose a potential threat to populations of many neotropical migrant songbirds. Because cowbirds mostly feed in short grass (e.g., pastures and lawns) or on bare ground (e.g., row crops), they benefit directly from human activities. Cowbirds...

Genetic algorithm optimized rainfall-runoff fuzzy inference system for row crop watersheds with claypan soils

USDA-ARS?s Scientific Manuscript database

The fuzzy logic algorithm has the ability to describe knowledge in a descriptive human-like manner in the form of simple rules using linguistic variables, and provides a new way of modeling uncertain or naturally fuzzy hydrological processes like non-linear rainfall-runoff relationships. Fuzzy infe...

Multi-scale measurements show limited soil greenhouse gas emissions in Kenyan smallholder coffee-dairy systems.

PubMed

Ortiz-Gonzalo, Daniel; de Neergaard, Andreas; Vaast, Philippe; Suárez-Villanueva, Víctor; Oelofse, Myles; Rosenstock, Todd S

2018-06-01

Efforts have been made in recent years to improve knowledge about soil greenhouse gas (GHG) fluxes from sub-Saharan Africa. However, data on soil GHG emissions from smallholder coffee-dairy systems have not hitherto been measured experimentally. This study aimed to quantify soil GHG emissions at different spatial and temporal scales in smallholder coffee-dairy farms in Murang'a County, Central Kenya. GHG measurements were carried out for one year, comprising two cropping seasons, using vented static chambers and gas chromatography. Sixty rectangular frames were installed on two farms comprising the three main cropping systems found in the area: 1) coffee (Coffea arabica L.); 2) Napier grass (Pennisetum purpureum); and 3) maize intercropped with beans (Zea mays and Phaseolus vulgaris). Within these fields, chambers were allocated on fertilised and unfertilised locations to capture spatial variability. Cumulative annual fluxes in coffee plots ranged from 1 to 1.9kgN 2 O-Nha -1 , 6.5 to 7.6MgCO 2 -Cha -1 and - 3.4 to -2.2kgCH 4 -Cha -1 , with 66% to 94% of annual GHG fluxes occurring during rainy seasons. Across the farm plots, coffee received most of the N inputs and had 56% to 89% higher emissions of N 2 O than Napier grass, maize and beans. Within farm plots, two to six times higher emissions were found in fertilised hotspots - around the perimeter of coffee trees or within planted maize rows - than in unfertilised locations between trees, rows and planting holes. Background and induced soil N 2 O emissions from fertiliser and manure applications in the three cropping systems were lower than hypothesized from previous studies and empirical models. This study supplements methods and underlying data for the quantification of GHG emissions at multiple spatial and temporal scales in tropical, smallholder farming systems. Advances towards overcoming the dearth of data will facilitate the understanding of synergies and tradeoffs of climate-smart approaches for low emissions development. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

SU-E-T-458: Determining Threshold-Of-Failure for Dead Pixel Rows in EPID-Based Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gersh, J; Wiant, D

Purpose: A pixel correction map is applied to all EPID-based applications on the TrueBeam (Varian Medical Systems, Palo Alto, CA). When dead pixels are detected, an interpolative smoothing algorithm is applied using neighboring-pixel information to supplement missing-pixel information. The vendor suggests that when the number of dead pixels exceeds 70,000, the panel should be replaced. It is common for entire detector rows to be dead, as well as their neighboring rows. Approximately 70 rows can be dead before the panel reaches this threshold. This study determines the number of neighboring dead-pixel rows that would create a large enough deviation inmore » measured fluence to cause failures in portal dosimetry (PD). Methods: Four clinical two-arc VMAT plans were generated using Eclipse's AXB algorithm and PD plans were created using the PDIP algorithm. These plans were chosen to represent those commonly encountered in the clinic: prostate, lung, abdomen, and neck treatments. During each iteration of this study, an increasing number of dead-pixel rows are artificially applied to the correction map and a fluence QA is performed using the EPID (corrected with this map). To provide a worst-case-scenario, the dead-pixel rows are chosen so that they present artifacts in the highfluence region of the field. Results: For all eight arc-fields deemed acceptable via a 3%/3mm gamma analysis (pass rate greater than 99%), VMAT QA yielded identical results with a 5 pixel-width dead zone. When 10 dead lines were present, half of the fields had pass rates below the 99% pass rate. With increasing dead rows, the pass rates were reduced substantially. Conclusion: While the vendor still suggests to request service at the point where 70,000 dead rows are measured (as recommended by the vendor), the authors suggest that service should be requested when there are greater than 5 consecutive dead rows.« less

Spatial distribution pattern of termite in Endau Rompin Plantation

NASA Astrophysics Data System (ADS)

Jalaludin, Nur-Atiqah; Rahim, Faszly

2015-09-01

We censused 18 field blocks approximately 190 ha with total of 28,604 palms in a grid of 2×4 palms from July 2011 to March 2013. The field blocks comprise of rows of palm trees, harvesting paths, field drains and stacking rows with maximum of 30 palms per row, planted about 9 m apart, alternately in maximum of 80 rows. SADIE analysis generating index of aggregation, Ia, local clustering value, Vi and local gap value, Vj is adopted to estimate spatial pattern. The patterns were then presented in contour map using Surfer 12 software. The patterns produced associated with factors i.e. habitat disturbance, habitat fragmentation and resources affecting nesting and foraging activities. Result shows that field blocks with great habitat disturbance recorded highest dead palms and termites hits. Blocks located far from the main access road recorded less than 2% palms with termite hits. This research may provide ecological data on termite spatial pattern in oil palm ecosystem.

Separability of agricultural crops with airborne scatterometry

NASA Technical Reports Server (NTRS)

Mehta, N. C.

1983-01-01

Backscattering measurements were acquired with airborne scatterometers over a site in Cass County, North Dakota on four days in the 1981 crop growing season. Data were acquired at three frequencies (L-, C- and Ku-bands), two polarizations (like and cross) and ten incidence angles (5 degrees to 50 degrees in 5 degree steps). Crop separability is studied in an hierarchical fashion. A two-class separability measure is defined, which compares within-class to between-class variability, to determine crop separability. The scatterometer channels with the best potential for crop separability are determined, based on this separability measure. Higher frequencies are more useful for discriminating small grains, while lower frequencies tend to separate non-small grains better. Some crops are more separable when row direction is taken into account. The effect of pixel purity is to increase the separability between all crops while not changing the order of useful scatterometer channels. Crude estimates of separability errors are calculated based on these analyses. These results are useful in selecting the parameters of active microwave systems in agricultural remote sensing.

Evaluation of initial collector field performance at the Langley Solar Building Test Facility

NASA Technical Reports Server (NTRS)

Boyle, R. J.; Jensen, R. N.; Knoll, R. H.

1977-01-01

The thermal performance of the solar collector field for the NASA Langley Solar Building Test Facility is given for October 1976 through January 1977. A 1,180 square meter solar collector field with seven collector designs helped to provide hot water for the building heating system and absorption air conditioner. The collectors were arranged in 12 rows with nominally 51 collectors per row. Heat transfer rates for each row were calculated and recorded along with sensor, insolation, and weather data every five minutes using a minicomputer. The agreement between the experimental and predicted collector efficiencies was generally within five percentage points.

Evaluation of initial collector field performance at the Langley Solar Building Test Facility

NASA Technical Reports Server (NTRS)

Boyle, R. J.; Knoll, R. H.; Jensen, R. N.

1977-01-01

The thermal performance of the solar collector field for the NASA Langley Solar Building Test Facility is given for October 1976 through January 1977. An 1180 square meter solar collector field with seven collector designs helped to provide hot water for the building heating system and absorption air conditioner. The collectors were arranged in 12 rows with nominally 51 collectors per row. Heat transfer rates for each row are calculated and recorded along with sensor, insolation, and weather data every 5 minutes using a mini-computer. The agreement between the experimental and predicted collector efficiencies was generally within five percentage points.

Runoff quality from no-till cotton fertilized with broiler litter in subsurface bands.

PubMed

Adeli, A; Tewolde, H; Shankle, M W; Way, T R; Brooks, J P; McLaughlin, M R

2013-01-01

Surface broadcast of broiler litter to no-till row crops exposes the litter and its nutrients to risks of loss in runoff water and volatilization and may limit the potential benefit of litter to the crops. Subsurface banding of litter could alleviate these risks. A field study was conducted in 2008 and 2009 on an upland Falkner silt loam soil to determine the effect of broiler litter placement on runoff nutrient losses from no-till cotton ( L.). Treatments included surface broadcast broiler litter applied manually, subsurface-banded litter applied by tractor-drawn equipment, and no broiler litter, all in combination with or without winter wheat ( L.) cover crop residue. Broiler litter rate was 5.6 Mg ha. The experimental design was a randomized complete block with a split-plot arrangement of treatments replicated three times. In 2008, simulated rainfall was used to generate runoff 27 d after litter application. Subsurface-banded litter reduced runoff total C, N, P, NH, NO, Cu, Zn and water-soluble P (WP) concentrations by 72, 64, 51, 49, 70, 36, 65, and 77%, respectively, compared with surface broadcast. The reductions were greater in 2009 where runoff occurred 1 d after litter application. Bacterial runoff was decreased by one log with subsurface-banded litter compared to surface broadcast. Except for C, NH, N, and WP, the presence of winter cover crop residue did not affect the load or runoff nutrient concentrations in either year. The results indicate that subsurface banding litter to no-till cotton substantially reduces nutrient and bacterial losses in runoff compared with surface broadcasting. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Automated thinning increases uniformity of in-row spacing and plant size in romaine lettuce

USDA-ARS?s Scientific Manuscript database

Low availability and high cost of farm hand labor make automated thinners a faster and cheaper alternative to hand thinning in lettuce (Lactuca sativa L.). However, the effects of this new technology on uniformity of plant spacing and size as well as crop yield are not proven. Three experiments wer...

Foliar spray banding characteristics

Treesearch

A.R. Womac; C.W. Smith; Joseph E. Mulrooney

2004-01-01

Foliar spray banding was explored as a means of reducing peticide use compared to broadcast applications. Barious geometric spray patterns and delivery angles of foliar spray bands were investigated to increase spray deposits in a crop row at a constant spray rate of 94 L/ha. Wind-free laboratory results indicated that a banded application using three 65° hollow-cone...

Gypsum's influence on corn yield and p loss from an eroded southern piedmont soil

USDA-ARS?s Scientific Manuscript database

Gypsum (CaSO4) has been shown to reduce dissolved P in surface water runoff from pastures fertilized with poultry litter (PL). However, limited research has evaluated gypsum’s influence on P loss under row crops. Moreover, can gypsum effectively reduce P loss when applied only to grass buffer strips...

Applying Poultry Litter in the Fall to Fertilize Corn May not be Advisable Under Warm Climate

USDA-ARS?s Scientific Manuscript database

Row crop farmers prefer to apply poultry litter in the fall or winter but whether this practice is safe environmentally and effective for production in regions with warm fall and winter months is not well researched and documented. Research in Mississippi tested the effectiveness of fall- versus spr...

Groundwater flow, variability, and transport pathways in the Mar Negro of the Jobos Bay National Estuarine Research Reserve, Puerto Rico

USDA-ARS?s Scientific Manuscript database

The Jobos Bay National Estuarine Research Reserve (JBNERR) is a semi-enclosed ecosystem along the southeast coast of Puerto Rico. Agriculture, including vegetable, row crop, tree fruit, pasture, and poultry, is an important land use within the watershed. To better understand the potential impact of ...

Water quality effects of switchgrass intercropping on pine forest in Coastal North Carolina.

Treesearch

Augustine Muwamba; Devendra Amatya; George M Chescheir; Jamie Nettles; Timothy Appelboom; Herbert Ssegane; Ernest Tollner; Mohamed Youssef; Francois Birgand; R. Wayne Skaggs; Shiying Tian

2017-01-01

Interplanting a cellulosic bioenergy crop (switchgrass, Panicum virgatum L.) between loblolly pine (Pinus taeda L.) rows could potentially provide a sustainable source of bio-feedstock without competing for land currently in food production. The objectives of this study were to: (1) quantify the concentrations and loads of drainage water nitrogen (N) and phosphorus (...

Migratory patterns of the fall armyworm (Spodoptera frugiperda) in the western hemisphere

USDA-ARS?s Scientific Manuscript database

Fall armyworm (FAW) is a serious pest of sweet corn in south Florida and a pest of other vegetable, row, and forage crops in the southeastern, mid-Atlantic, and central U.S. It is a migratory pest, moving north each season from overwintering areas in southern Texas and southern Florida. For the la...

Using Hydrus 2-D to assess the emitters optimal position for Eggplants under surface and subsurface drip irrigation

NASA Astrophysics Data System (ADS)

Ghazouani, Hiba; Autovino, Dario; Douh, Boutheina; Boujelben, Abdel Hamid; Provenznao, Giuseppe; Rallo, Giovanni

2014-05-01

The main objective of the work is to assess the emitters optimal position for Eggplant crop (Solanum melongena L.) in a sandy loam soil irrigated with surface or subsurface drip irrigation systems, by means of field measurements and simulations carried out with Hydrus-2D model. Initially, the performance of the model is evaluated on the basis of the comparison between simulated soil water contents (SWC) and the corresponding measured in two plots, in which laterals with coextruded emitters are laid on the soil surface (T0) and at 20 cm depth (T20), respectively. In order to choose the best position of the lateral, the results of different simulation runs, carried out by changing the installation depth of the lateral (5 cm, 15 cm and 45 cm) were compared in terms of ratio between actual transpiration and total amount of water provided during the entire growing season (WUE). Experiments were carried out, from April to June 2007, at Institut Supérieur Agronomique de Chott Mériem (Sousse, Tunisia). In the two plots, plants were spaced 0.40 m along the row and 1.2 m between the rows. Each plot was irrigated by means of laterals with coextruded emitters spaced 0.40 m and discharging a flow rate equal to 4.0 l h-1 at a nominal pressure of 100 kPa. In each plot, spatial and temporal variability of SWCs were acquired with a Time Domain Reflectometry probe (Trime-FM3), on a total of four 70 cm long access tubes, installed along the direction perpendicular to the plant row, at distances of 0, 20, 40 and 60 cm from the emitter. Irrigation water was supplied, accounting for the rainfall, every 7-10 days at the beginning of the crop cycle (March-April) and approximately once a week during the following stages till the harvesting (May-June), for a total of 15 one-hour watering. To run the model, soil evaporation, Ep, and crop transpiration, Tp were determined according to the modified FAO Penman-Monteith equation and the dual crop coefficient approach, whereas soil hydraulics and rooting system parameters were experimentally determined. Simulated SWCs resulted fairly close to the corresponding measured at different distances from the emitter and therefore the model was able to predict SWCs in the root zone with values of the Root Mean Square Error generally lower than 4%. This result is consequent to the appropriate schematization of the root distribution, as well as of the root water uptake. Simulations also evidenced the contribute of soil evaporation losses when laterals are installed from the soil surface to a 20 cm depth, whereas significant water losses by deep percolation occured at the highest installation depth. The values of WUE associated to the different examined installation depths tend to a very slight increase when the position of the lateral rises from 0 to 15 cm and start to decrease for the higher depths.

Micropole undulator

DOEpatents

Tatchyn, Roman O.; Csonka, Paul L.; Cremer, Jay T.

1990-12-11

Micropole undulators for use in the generation of x-rays from moving charged particles are disclosed. Two rows of spaced apart poles are arranged so that each pole produces a magnetic field aligned with all other similar fields. The poles are the ends of "C"-shaped magnets. In each row, adjacent poles are separated by spacers made of a superconducting material.

Yield Response of Spring Maize to Inter-Row Subsoiling and Soil Water Deficit in Northern China.

PubMed

Liu, Zhandong; Qin, Anzhen; Zhao, Ben; Ata-Ul-Karim, Syed Tahir; Xiao, Junfu; Sun, Jingsheng; Ning, Dongfeng; Liu, Zugui; Nan, Jiqin; Duan, Aiwang

2016-01-01

Long-term tillage has been shown to induce water stress episode during crop growth period due to low water retention capacity. It is unclear whether integrated water conservation tillage systems, such asspringdeepinter-row subsoiling with annual or biennial repetitions, can be developed to alleviate this issue while improve crop productivity. Experimentswere carried out in a spring maize cropping system on Calcaric-fluvicCambisolsatJiaozuoexperimentstation, northern China, in 2009 to 2014. Effects of threesubsoiling depths (i.e., 30 cm, 40 cm, and 50 cm) in combination with annual and biennial repetitionswasdetermined in two single-years (i.e., 2012 and 2014)againstthe conventional tillage. The objectives were to investigateyield response to subsoiling depths and soil water deficit(SWD), and to identify the most effective subsoiling treatment using a systematic assessment. Annualsubsoiling to 50 cm (AS-50) increased soil water storage (SWS, mm) by an average of8% in 0-20 cm soil depth, 19% in 20-80 cm depth, and 10% in 80-120 cm depth, followed by AS-40 and BS-50, whereas AS-30 and BS-30 showed much less effects in increasing SWS across the 0-120 cm soil profile, compared to the CK. AS-50 significantly reduced soil water deficit (SWD, mm) by an average of123% during sowing to jointing, 318% during jointing to filling, and 221% during filling to maturity, compared to the CK, followed by AS-40 and BS-50. An integrated effect on increasing SWS and reducing SWD helped AS-50 boost grain yield by an average of 31% and biomass yield by 30%, compared to the CK. A power function for subsoiling depth and a negative linear function for SWD were used to fit the measured yields, showing the deepest subsoiling depth (50 cm) with the lowest SWD contributed to the highest yield. Systematic assessment showed that AS-50 received the highest evaluation index (0.69 out of 1.0) among all treatments. Deepinter-row subsoilingwith annual repetition significantly boosts yield by alleviating SWD in critical growth period and increasing SWS in 20-80 cm soil depth. The results allow us to conclude that AS-50 can be adopted as an effective approach to increase crop productivity, alleviate water stress, and improve soil water availability for spring maize in northern China.

Long-term soil organic carbon changes in cereal and ley rotations: model testing

NASA Astrophysics Data System (ADS)

Kynding Borgen, Signe; Dörsch, Peter; Krogstad, Tore; Azzaroli Bleken, Marina

2015-04-01

Reliable modeling of soil organic carbon (SOC) dynamics in agroecosystems is crucial to define mitigation strategies related to crop management on the farm scale as well as the regional scale. International climate agreements and national political decisions rely to a large extent on the National Greenhouse gas Inventory Reports that are submitted annually to the UNFCCC. However, lower tier methods are used to estimate SOC changes on cropland in most country reports. The application of mechanistic models in national greenhouse gas inventory estimation requires proper model testing against measurements in order to verify the estimated emissions. Few long-term field experiments measuring SOC stock changes have been conducted in Norway. We evaluate the performance of the Introductory Carbon Balance Model (ICBM) in simulating SOC changes over 60 years in a field experiment conducted in Ås from 1953-2013. The site is located in south-eastern Norway, on the boarder of the boreal and temperate climate zone, where the majority of the country's grain production occurs. The field trial consisted of four rotations: I) continuous cereal, II) cereal + row crops, III) 2 years of ley + 4 years of cereal, IV) 4 years of ley + 2 years of cereal, and four treatments per rotation: a) low NPK, b) high NPK, c) low NPK + FYM, and d) straw (on rotations I and II) or high NPK + FYM (on rotations III and IV). The annual external modifying factor of the decomposition rate was calculated based on daily minimum and maximum temperature, precipitation, relative humidity, wind speed, and net radiation, and adjusted for soil type and crop management according to default ICBM calibration. We present results of simulated C changes for the long term plots and explore options to improve parameter calibration. Finally, we provide suggestions for how problems regarding model verification can be handled with when applying the model on a national scale for inventory reporting.

The role of the whitefly, Bemisia tabaci (Gennadius), and farmer practices in the spread of cassava brown streak ipomoviruses.

PubMed

Maruthi, Midatharahally N; Jeremiah, Simon C; Mohammed, Ibrahim U; Legg, James P

2017-12-01

Cassava brown streak disease (CBSD) is arguably the most dangerous current threat to cassava, which is Africa's most important food security crop. CBSD is caused by two RNA viruses: Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). The roles of the whitefly Bemisia tabaci (Gennadius) and farmer practices in the spread of CBSD were investigated in a set of field and laboratory experiments. The virus was acquired and transmitted by B. tabaci within a short time (5-10 min each for virus acquisition and inoculation), and was retained for up to 48 hr. Highest virus transmission (60%) was achieved using 20-25 suspected viruliferous whiteflies per plant that were given acquisition and inoculation periods of 24 and 48 hr, respectively. Experiments mimicking the agronomic practices of cassava leaf picking or the use of contaminated tools for making cassava stem cuttings did not show the transmission of CBSV or UCBSV. Screenhouse and field experiments in Tanzania showed that the spread of CBSD next to spreader rows was high, and that the rate of spread decreased with increasing distance from the source of inoculum. The disease spread in the field up to a maximum of 17 m in a cropping season. These results collectively confirm that CBSV and UCBSV are transmitted by B. tabaci semipersistently, but for only short distances in the field. This implies that spread over longer distances is due to movements of infected stem cuttings used for planting material. These findings have important implications for developing appropriate management strategies for CBSD.

Identifying Spatiotemporal Changes In Irrigated Area Across Southwestern Michigan, USA, Using Remote Sensing and Climate Data

NASA Astrophysics Data System (ADS)

Xu, T.; Deines, J. M.; Kendall, A. D.; Hyndman, D. W.

2017-12-01

Irrigation, which has become more common in humid regions, is the largest consumptive water use across the US and the globe. In southwestern Michigan, there has been a dramatic expansion in irrigation water use for row crops (primarily corn and soybean) in the past decade, mostly from groundwater pumping. The rapid expansion of irrigated row crops has potentially profound implications for terrestrial water balances, food production, and local to regional climate. Detailed maps of spatio-temporal changes in irrigation are essential to better understand irrigation impacts. However, accurate monitoring of irrigation area can be difficult in humid regions using remotely sensed methods due to the similarity in greenness between non-irrigated and irrigated areas in most years. Here, we use remote sensing to create annual, 30m-resolution maps of irrigated cropland by integrating Landsat and MODIS satellite products along with the PRISM climate dataset. From these data we developed spatial time series of vegetation and extreme weather indices, including novel indices we developed specifically to maximize detection of irrigation. Using these input data, machine learning classification was then performed over the region to identify irrigated crop area for each year. The resulting annual irrigation maps suggest that total irrigated area in southwestern Michigan increased by 160% from 2000 to 2017. The accuracy of the maps is assessed relative to maps created for an arid region using the same method. The maps can be integrated into hydrologic models to quantify irrigation impacts and support water resources management.

Micropole undulator

DOEpatents

Tatchyn, R.O.; Csonka, P.L.; Cremer, J.T.

1990-12-11

Micropole undulators for use in the generation of x-rays from moving charged particles are disclosed. Two rows of spaced apart poles are arranged so that each pole produces a magnetic field aligned with all other similar fields. The poles are the ends of C''-shaped magnets. In each row, adjacent poles are separated by spacers made of a superconducting material. 11 figs.

An Old-Growth Definition for Southwestern Subtropical Upland Forests

Treesearch

David D. Diamond

1998-01-01

Mainly evergreen, broad-leaved forests in the Southwestern United States are restricted to the Lower Rio Grande Valley of Texas. The soils and long growing season make this region valuable cropland, and, thus, almost all of the area once occupied by this forest type has been converted to row crops. Remaining old-growth forests are usually dominated by some combination...

Informing rangeland stewardship with research: lessons learned from Yolo County, California

Treesearch

Vance Russell; Chris Rose; Miles DaPrato

2008-01-01

Approximately 70 percent of the contiguous United States is in private lands with half of this total in row crop or rangelands. Audubon California’s Landowner Stewardship Program engages with farmers and ranchers on conservation and restoration projects in a manner compatible with existing agricultural operations. To assess the success of these efforts, Audubon,...

Sediment removal by prairie filter strips in row-cropped ephemeral watersheds

Treesearch

Matthew J. Helmers; Xiaobo Zhou; Heidi Asbjornsen; Randy Kolka; Mark D. Tomer; Richard M. Cruse

2012-01-01

Twelve small watersheds in central Iowa were used to evaluate the eff ectiveness of prairie filter strips (PFS) in trapping sediment from agricultural runoff. Four treatments with PFS of different size and location (100% rowcrop, 10% PFS of total watershed area at footslope, 10% PFS at footslope and in contour strips, 20% PFS at footslope and in contour strips)...

Ultraviolet-B radiation in a row-crop canopy: an extended 1-D model

Treesearch

Wei Gao; Richard H. Grant; Gordon M. Heisler; James R. Slusser

2003-01-01

A decrease in stratospheric ozone may result in a serious threat to plants, since biologically active short-wavelength ultraviolet-B (UV-B 280-320 nm) radiation will increase even with a relatively small decrease in ozone. Numerous investigations have demonstrated that the effect of UV-B enhancements on plants includes reduction in grain yield, alteration in species...

The culture of indian tobacco (Lobelia inflata L.)

Treesearch

Arnold Krochmal; Leon Wilken; Leon Wilken

1970-01-01

Indian tobacco (Lobelia inflata L.) is the source of an alkaloid (lobeline) that is used in anti-smoking preparations. Because of a brisk market demand for lobelia-and a decline in the harvesting of wild plants-we have studied how to grow this wild Appalachian annual as a row crop under cultivation. Our studies, begun in 1967, have continued through 1970. We have...

Compensated Row-Column Ultrasound Imaging System Using Fisher Tippett Multilayered Conditional Random Field Model

PubMed Central

Ben Daya, Ibrahim; Chen, Albert I. H.; Shafiee, Mohammad Javad; Wong, Alexander; Yeow, John T. W.

2015-01-01

3-D ultrasound imaging offers unique opportunities in the field of non destructive testing that cannot be easily found in A-mode and B-mode images. To acquire a 3-D ultrasound image without a mechanically moving transducer, a 2-D array can be used. The row column technique is preferred over a fully addressed 2-D array as it requires a significantly lower number of interconnections. Recent advances in 3-D row-column ultrasound imaging systems were largely focused on sensor design. However, these imaging systems face three intrinsic challenges that cannot be addressed by improving sensor design alone: speckle noise, sparsity of data in the imaged volume, and the spatially dependent point spread function of the imaging system. In this paper, we propose a compensated row-column ultrasound image reconstruction system using Fisher-Tippett multilayered conditional random field model. Tests carried out on both simulated and real row-column ultrasound images show the effectiveness of our proposed system as opposed to other published systems. Visual assessment of the results show our proposed system’s potential at preserving detail and reducing speckle. Quantitative analysis shows that our proposed system outperforms previously published systems when evaluated with metrics such as Peak Signal to Noise Ratio, Coefficient of Correlation, and Effective Number of Looks. These results show the potential of our proposed system as an effective tool for enhancing 3-D row-column imaging. PMID:26658577

Accumulation of Zn, Cd, Cu, and Pb in Chinese cabbage as influenced by climatic conditions under protected cultivation.

PubMed

Moreno, Diego A; Víllora, Gemma; Hernández, Joaquín; Castilla, Nicolás; Romero, Luis

2002-03-27

Accumulation of heavy metals from agricultural soils contaminated by low levels heavy metals has important implications in the understanding of heavy metal contamination in the food chain. Through field experiments (1994-1996), the influence of thermal regime under different treatments on the accumulation of zinc, cadmium, copper, and lead in Chinese cabbage [Brassica pekinensis (Lour) Rupr. cv. Nagaoka 50] grown in a Calcareous Fluvisol (Xerofluvent) in Granada (southern Spain) was examined. Two floating row covers were used: T(1) (perforated polyethylene, 50 microm thick) and T(2) (17 g m(-2) polypropylene nonwoven fleece). An uncovered cultivation (T(0)) served as control. Zn, Cd, Cu, and Pb levels in the whole tops of experimental plants were analyzed. Treatments T(1) and T(2) gave rise to differences in environmental conditions with respect to T(0). The influence of environmental factors manipulated by floating row covers (particularly under T(1)) increased total heavy metal accumulation in the above ground plant biomass with respect to the open-air crop. The total contents of Zn, Cd, Cu, and Pb were 30, 50, 90, and 40% higher in T(1), respectively, than in T(0). This technique could be used in contaminated zones for different plant species because the thermal effect favors the process of phytoextraction and thus reduces the contamination.

Profiling agricultural land cover change in the North Central U.S. using ten years of the Cropland Data Layer

NASA Astrophysics Data System (ADS)

Sandborn, A.; Ebinger, L.

2016-12-01

The Cropland Data Layer (CDL), produced by the USDA/National Agricultural Statistics Service, provides annual, georeferenced crop specific land cover data over the contiguous United States. Several analyses were performed on ten years (2007-2016) of CDL data in order to visualize and quantify agricultural change over the North Central region (North Dakota, South Dakota, and Minnesota). Crop masks were derived from the CDL and layered to produce a ten-year time stack of corn, soybeans, and spring wheat at 30m spatial resolution. Through numerous image analyses, a temporal profile of each crop type was compiled and portrayed cartographically. For each crop, analyses included calculating the mean center of crop area over the ten year sequence, identifying the first and latest year the crop was grown on each pixel, and distinguishing crop rotation patterns and replacement statistics. Results show a clear north-western expansion trend for corn and soybeans, and a western migration trend for spring wheat. While some change may be due to commonly practiced crop rotation, this analysis shows that crop footprints have extended into areas that were previously other crops, idle cropland, and pasture/rangeland. Possible factors contributing to this crop migration pattern include profit advantages of row crops over small grains, improved crop genetics, climate change, and farm management program changes. Identifying and mapping these crop planting differences will better inform agricultural best practices, help to monitor the latest crop migration patterns, and present researchers with a way to quantitatively measure and forecast future agricultural trends.

Effect of feeding strategies and cropping systems on greenhouse gas emission from Wisconsin certified organic dairy farms.

PubMed

Liang, D; Sun, F; Wattiaux, M A; Cabrera, V E; Hedtcke, J L; Silva, E M

2017-07-01

Organic agriculture continues to expand in the United States, both in total hectares and market share. However, management practices used by dairy organic producers, and their resulting environmental impacts, vary across farms. This study used a partial life cycle assessment approach to estimate the effect of different feeding strategies and associated crop production on greenhouse gas emissions (GHG) from Wisconsin certified organic dairy farms. Field and livestock-driven emissions were calculated using 2 data sets. One was a 20-yr data set from the Wisconsin Integrated Cropping System Trial documenting management inputs, crop and pasture yields, and soil characteristics, used to estimate field-level emissions from land associated with feed production (row crop and pasture), including N 2 O and soil carbon sequestration. The other was a data set summarizing organic farm management in Wisconsin, which was used to estimate replacement heifer emission (CO 2 equivalents), enteric methane (CH 4 ), and manure management (N 2 O and CH 4 ). Three combinations of corn grain (CG) and soybean (SB) as concentrate (all corn = 100% CG; baseline = 75% CG + 25% SB; half corn = 50% CG + 50% SB) were assigned to each of 4 representative management strategies as determined by survey data. Overall, GHG emissions associated with crop production was 1,297 ± 136 kg of CO 2 equivalents/t of ECM without accounting for soil carbon changes (ΔSC), and GHG emission with ΔSC was 1,457 ± 111 kg of CO 2 equivalents/t of ECM, with greater reliance on pasture resulting in less ΔSC. Higher levels of milk production were a major driver associated with reduction in GHG emission per metric tonne of ECM. Emissions per metric tonne of ECM increased with increasing proportion of SB in the ration; however, including SB in the crop rotation decreased N 2 O emission per metric tonne of ECM from cropland due to lower applications of organically approved N fertility inputs. More SB at the expense of CG in the ration reduced enteric CH 4 emission per metric tonne of ECM (because of greater dietary fat content) but increased N 2 O emission per metric tonne of ECM from manure (because of greater N content). An increased reliance on pasture for feed at the expense of grain resulted in decreased in milk production, subsequently leading to substantially higher emissions per metric tonne of ECM. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Agricultural Policy Environmental eXtender Simulation of Three Adjacent Row-Crop Watersheds in the Claypan Region.

PubMed

Anomaa Senaviratne, G M M M; Udawatta, Ranjith P; Baffaut, Claire; Anderson, Stephen H

2013-01-01

The Agricultural Policy Environmental Extender (APEX) model is used to evaluate best management practices on pollutant loading in whole farms or small watersheds. The objectives of this study were to conduct a sensitivity analysis to determine the effect of model parameters on APEX output and use the parameterized, calibrated, and validated model to evaluate long-term benefits of grass waterways. The APEX model was used to model three (East, Center, and West) adjacent field-size watersheds with claypan soils under a no-till corn ( L.)/soybean [ (L.) Merr.] rotation. Twenty-seven parameters were sensitive for crop yield, runoff, sediment, nitrogen (dissolved and total), and phosphorous (dissolved and total) simulations. The model was calibrated using measured event-based data from the Center watershed from 1993 to 1997 and validated with data from the West and East watersheds. Simulated crop yields were within ±13% of the measured yield. The model performance for event-based runoff was excellent, with calibration and validation > 0.9 and Nash-Sutcliffe coefficients (NSC) > 0.8, respectively. Sediment and total nitrogen calibration results were satisfactory for larger rainfall events (>50 mm), with > 0.5 and NSC > 0.4, but validation results remained poor, with NSC between 0.18 and 0.3. Total phosphorous was well calibrated and validated, with > 0.8 and NSC > 0.7, respectively. The presence of grass waterways reduced annual total phosphorus loadings by 13 to 25%. The replicated study indicates that APEX provides a convenient and efficient tool to evaluate long-term benefits of conservation practices. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Effect of land use change for bioenergy on greenhouse gas emissions from a wet marginal soil in New York State, USA.

NASA Astrophysics Data System (ADS)

Stoof, Cathelijne; Mason, Cedric; Steenhuis, Tammo; Richards, Brian

2013-04-01

Millions of hectares of marginal lands in the Northeast USA no longer used for agriculture are suitable for production of second-generation cellulosic bioenergy crops, offering the potential for regional bioenergy production without inducing food vs. fuel competition for prime farmland. Abundant water resources, close proximity between production and markets, and compatibility with existing agricultural systems all favor development in the region. Yet, little is known about how sustainable bioenergy crop production on marginal lands is regarding greenhouse gas emissions. In a 10-ha field trial on wet marginal soils in upstate New York, we are assessing the effect of land use change (from fallow land to perennial grass stands) on N2O and CH4 emissions. The deep clay loam is unsuited for row-crop agriculture because it is too dry in summer and too wet in winter. Monthly chamber campaigns were performed from April to November 2012 to monitor large scale (10-20 m resolution) differences caused by land cover type (n=4 for both switchgrass, reed-canary grass and a 50-yr unplowed control) across soil moisture gradients (n=5 soil moisture levels per replicate). Additional weekly campaigns assessed the smaller scale spatial and temporal variability in emissions at meter-scale. Here we present results of both the large and small-scale patterns in greenhouse gas emissions from this marginal soil, and discuss effects of soil properties and hydrologic conditions as potential drivers. Insight gained about the environmental impact of bioenergy crops can be used to assess the sustainability of using this region's underutilized land base for energy production.

Effect of non-crop vegetation types on conservation biological control of pests in olive groves

PubMed Central

Cayuela, Luis; Gurr, Geoff M.; Campos, Mercedes

2013-01-01

Conservation biological control (CBC) is an environmentally sound potential alternative to the use of chemical insecticides. It involves modifications of the environment to promote natural enemy activity on pests. Despite many CBC studies increasing abundance of natural enemies, there are far fewer demonstrations of reduced pest density and very little work has been conducted in olive crops. In this study we investigated the effects of four forms of non-crop vegetation on the abundance of two important pests: the olive psyllid (Euphyllura olivina) and the olive moth (Prays oleae). Areas of herbaceous vegetation and areas of woody vegetation near olive crops, and smaller patches of woody vegetation within olive groves, decreased pest abundance in the crop. Inter-row ground covers that are known to increase the abundance of some predators and parasitoids had no effect on the pests, possibly as a result of lack of synchrony between pests and natural enemies, lack of specificity or intra-guild predation. This study identifies examples of the right types of diversity for use in conservation biological control in olive production systems. PMID:23904994

Cost of areal reduction of gulf hypoxia through agricultural practice.

PubMed

Whittaker, Gerald; Barnhart, Bradley L; Srinivasan, Raghavan; Arnold, Jeffrey G

2015-02-01

A major share of the area of hypoxic growth in the Northern Gulf of Mexico has been attributed to nutrient run-off from agricultural fields, but no estimate is available for the cost of reducing Gulf hypoxic area using agricultural conservation practices. We apply the Soil and Water Assessment Tool using observed daily weather to simulate the reduction in nitrogen loading in the Upper Mississippi River Basin (UMRB) that would result from enrolling all row crop acreage in the Conservation Reserve Program (CRP). Nitrogen loadings at the outlet of the UMRB are used to predict Gulf hypoxic area, and net cash farm rent is used as the price for participation in the CRP. Over the course of the 42 year simulation, direct CRP costs total more than $388 billion, and the Inter-Governmental Task Force goal of hypoxic area less than 5000 square kilometers is met in only two years. Published by Elsevier B.V.

Rainwater deficit and irrigation demand for row crops in Mississippi Blackland Prairie

Treesearch

Gary Feng; Ying Ouyang; Ardeshir Adeli; John Read; Johnie Jenkins

2018-01-01

Irrigation research in the mid-south United States has not kept pace with a steady increase in irrigated area in recent years. This study used rainfall records from 1895 to 2016 to determine rainwater deficit and irrigation demand for soybean [Glycine max (L.) Merr.], corn (Zea mays L.), and cotton (Gossypium hirsutum L.) in the Blackland Prairie region of Mississippi...

Active control of turbomachine discrete tones

NASA Technical Reports Server (NTRS)

Fleeter, Sanford

1994-01-01

This paper was directed at active control of discrete frequency noise generated by subsonic blade rows through cancellation of the blade row interaction generated propagating acoustic waves. First discrete frequency noise generated by a rotor and stator in a duct was analyzed to determine the propagating acoustic pressure waves. Then a mathematical model was developed to analyze and predict the active control of discrete frequency noise generated by subsonic blade rows through cancellation of the propagating acoustic waves, accomplished by utilizing oscillating airfoil surfaces to generate additional control propagating pressure waves. These control waves interact with the propagating acoustic waves, thereby, in principle, canceling the acoustic waves and thus, the far field discrete frequency tones. This model was then applied to a fan exit guide vane to investigate active airfoil surface techniques for control of the propagating acoustic waves, and thus the far field discrete frequency tones, generated by blade row interactions.

Active control of turbomachine discrete tones

NASA Astrophysics Data System (ADS)

Fleeter, Sanford

This paper was directed at active control of discrete frequency noise generated by subsonic blade rows through cancellation of the blade row interaction generated propagating acoustic waves. First discrete frequency noise generated by a rotor and stator in a duct was analyzed to determine the propagating acoustic pressure waves. Then a mathematical model was developed to analyze and predict the active control of discrete frequency noise generated by subsonic blade rows through cancellation of the propagating acoustic waves, accomplished by utilizing oscillating airfoil surfaces to generate additional control propagating pressure waves. These control waves interact with the propagating acoustic waves, thereby, in principle, canceling the acoustic waves and thus, the far field discrete frequency tones. This model was then applied to a fan exit guide vane to investigate active airfoil surface techniques for control of the propagating acoustic waves, and thus the far field discrete frequency tones, generated by blade row interactions.

Ground-Based Robotic Sensing of an Agricultural Sub-Canopy Environment

NASA Astrophysics Data System (ADS)

Burns, A.; Peschel, J.

2015-12-01

Airborne remote sensing is a useful method for measuring agricultural crop parameters over large areas; however, the approach becomes limited to above-canopy characterization as a crop matures due to reduced visual access of the sub-canopy environment. During the growth cycle of an agricultural crop, such as soybeans, the micrometeorology of the sub-canopy environment can significantly impact pod development and reduced yields may result. Larger-scale environmental conditions aside, the physical structure and configuration of the sub-canopy matrix will logically influence local climate conditions for a single plant; understanding the state and development of the sub-canopy could inform crop models and improve best practices but there are currently no low-cost methods to quantify the sub-canopy environment at a high spatial and temporal resolution over an entire growth cycle. This work describes the modification of a small tactical and semi-autonomous, ground-based robotic platform with sensors capable of mapping the physical structure of an agricultural row crop sub-canopy; a soybean crop is used as a case study. Point cloud data representing the sub-canopy structure are stored in LAS format and can be used for modeling and visualization in standard GIS software packages.

Results 18 years after planting loblolly pines at different spacings

Treesearch

S. Little; H. A. Somes

1958-01-01

In 1939 a test of four spacings in planting loblolly pine seedlings was begun in an abandoned field on Maryland's Eastern Shore. The spacings were 4, 5.7, 8, and 11.3 feet between trees; each spacing was replicated on four 100-footsquare plots. In the 4- and 8-foot spacings, rows and trees within rows were 4 or 8 feet apart, with trees opposite in adjoining rows....

L-Band H Polarized Microwave Emission During the Corn Growth Cycle

NASA Technical Reports Server (NTRS)

Joseph, A. T.; va der Velde, R.; O'Neill, P. E.; Kim, E.; Lang, R. H.; Gish, T.

2012-01-01

Hourly L-band (1.4 GHz) horizontally (H) polarized brightness temperatures (T(sub B))'s measured during five episodes (more than two days of continuous measurements) of the 2002 corn growth cycle are analyzed. These T(sub B)'s measurements were acquired as a part of a combined active/passive microwave field campaign, and were obtained at five incidence and three azimuth angles relative to the row direction. In support of this microwave data collection, intensive ground sampling took place once a week. Moreover, the interpretation of the hourly T(sub B)'s could also rely on the data obtained using the various automated instruments installed in the same field. In this paper, the soil moisture and temperature measured at fixed time intervals have been employed as input for the tau-omega model to reproduce the hourly T(sub B). Through the calibration of the vegetation and surface roughness parameterizations, the impact of the vegetation morphological changes on the microwave emission and the dependence of the soil surface roughness parameter, h(sub r), on soil moisture are investigated. This analysis demonstrates that the b parameter, appearing in the representation of the canopy opacity, has an angular dependence that varies throughout the growing period and also that the parameter hr increases as the soil dries in a portion of the dry-down cycle. The angular dependence of the b parameter imposes the largest uncertainty on T(sub B) simulations near senescence as the response of b to the incidence is also affected by the crop row orientation. On the other hand, the incorporation of a soil moisture dependent h(sub r) parameterization was responsible for the largest error reduction of T(sub B) simulations in the early growth cycle.

Agricultural irrigated land-use inventory for Polk County, Florida, 2016

USGS Publications Warehouse

Marella, Richard L.; Berry, Darbi; Dixon, Joann F.

2017-08-16

An accurate inventory of irrigated crop acreage is not available at the level of resolution needed to better estimate agricultural water use or to project future water demands in many Florida counties. A detailed digital map and summary of irrigated acreage was developed for Polk County, Florida, during the 2016 growing season. This cooperative project between the U.S. Geological Survey and the Office of Agricultural Water Policy of the Florida Department of Agriculture and Consumer Services is part of an effort to improve estimates of water use and projections of future demands across all counties in the State. The irrigated areas were delineated by using land-use data provided by the Florida Department of Agriculture and Consumer Services, along with information obtained from the South and Southwest Florida Water Management Districts consumptive water-use permits. Delineations were field verified between April and December 2016. Attribute data such as crop type, primary water source, and type of irrigation system were assigned to the irrigated areas.The results of this inventory and field verification indicate that during the 2016 growing seasons (spring, summer, fall, and winter), an estimated 88,652 acres were irrigated within Polk County. Of the total field-verified crops, 83,995 acres were in citrus; 2,893 acres were in other non-citrus fruit crops (blueberries, grapes, peaches, and strawberries); 621 acres were in row crops (primarily beans and watermelons); 1,117 acres were in nursery (container and tree farms) and sod production; and 26 acres were in field crops including hay and pasture. Of the total inventoried irrigated acreage within Polk County, 98 percent (86,566 acres) was in the Southwest Florida Water Management District, and the remaining 2 percent (2,086 acres) was in the South Florida Water Management District.About 85,788 acres (96.8 percent of the acreage inventoried) were irrigated by a microirrigation system, including drip, bubblers, and spray emitters. The remaining 3.2 percent of the irrigated acreage was irrigated by a sprinkler system (2,360 acres) or subsurface flood systems (504 acres). Groundwater was the primary source of water used on irrigated acreage (88 percent, or 78,050 acres); the remaining 10,602 acres (12 percent) used groundwater combined with surface water as the irrigation source.The irrigated acreage estimated by the U.S. Geological Survey (USGS) for this 2016 inventory (88,652 acres) is about 11 percent higher than the 79,869 acres estimated by the U.S. Department of Agriculture (USDA) for 2012. Citrus and pasture in Polk County show the biggest difference in irrigated acreage between the USGS and USDA totals. Irrigated citrus acreage inventoried in 2016 by the USGS totaled 83,996 acres, whereas the USDA reported 78,305 acres of citrus in 2012. The USGS identified 6 acres of irrigated pasture and 20 acres of hay, whereas the USDA reported 6,631 acres of irrigated pasture and 1,349 acres of hay for 2012. In general, differences between the 2016 USGS field-verified acreage totals and acreage published by the USDA for 2012 could be due to (1) irrigated acreage for some specific crops increased or decreased substantially during the 4-year interval between 2012 and 2016 because of production or economic changes, (2) the assumption that if an irrigation system was present, it was used in 2016, when in fact some landowners may not have used their irrigation systems during this growing period even if they had a crop in the field, or (3) the amount of irrigated acreage published by the USDA for selected crops may be underestimated as a result of how information is obtained and formulated by the agency during census compilations.

Delta-Flux: An eddy covariance network for a climate-smart Lower Mississippi Basin

USGS Publications Warehouse

Runkle, Benjamin R. K.; Rigby, James R.; Reba, Michele L.; Anapalli, Saseendran S.; Bhattacharjee, Joydeep; Krauss, Ken W.; Liang, Lu; Locke, Martin A.; Novick, Kimberly A.; Sui, Ruixiu; Suvočarev, Kosana; White, Paul M.

2017-01-01

Networks of remotely monitored research sites are increasingly the tool used to study regional agricultural impacts on carbon and water fluxes. However, key national networks such as the National Ecological Observatory Network and AmeriFlux lack contributions from the Lower Mississippi River Basin (LMRB), a highly productive agricultural area with opportunities for soil carbon sequestration through conservation practices. The authors describe the rationale to create the new Delta-Flux network, which will coordinate efforts to quantify carbon and water budgets at seventeen eddy covariance flux tower sites in the LMRB. The network structure will facilitate climate-smart management strategies based on production-scale and continuous measurements of carbon and water fluxes from the landscape to the atmosphere under different soil and water management conditions. The seventeen instrumented field sites are expected to monitor fluxes within the most characteristic landscapes of the target area: row-crop fields, pasture, grasslands, forests, and marshes. The network participants are committed to open collaboration and efficient regionalization of site-level findings to support sustainable agricultural and forestry management and conservation of natural resources.

Changes in soil carbon cycling accompanying conversion of row-crop fields to grazing dairy pastures

NASA Astrophysics Data System (ADS)

Thompson, A.; Kramer, M. G.; Hill, N.; Machmuller, M. B.; Cyle, K.

2011-12-01

Increasingly, the dairy industry in the eastern US is transitioning from total confinement dairy systems (TCD) toward pasture-based, management intensive grazing dairy (MiGD) systems. This transition is driven by the fact that MiGDs require substantially less operating capital and are more economically efficient than TCD systems. Consequently, the impact of this transition and shift in land-use practice on carbon dynamics may be considerable. Land-use in a Management intensive Grazing Dairy (MiGD) system is fundamentally different than conventional confinement dairies and conventional no-till pastures. The forage system involves rotational grazing at optimal digestibility, when the plants are immature (~20-days) and consequently protein-rich. MiGD cows spend >90% of their time in the field and deposit > 90% of their waste directly to the soil surface. Thus, little above ground plant residues are directly returned to the soil, but rather substantial C inputs derive from bovine manure. We sampled a MiGD-chronosequence of row-crop to MiGD conversion established in 2007 in eastern Georgia. All soils across the MiGD-chronosequence, all occur in relative (40 km) close proximity to one another, are deep, well-drained, fine and fine sandy loam Ultisols formed on Coastal Plain sediments. Prior to MiGD established, the soils were farmed for > 50 yrs using conventional tillage techniques. Our current sampling to 1m depths captures fields at 0, 2, 3, and 5 yrs since conversion. Total soil carbon (C) and the carbon concentration of the clay fraction increased following conversion, with the greatest increases occurring between 3 and 5 yrs since conversion. These C increases were limited to the upper 40cm of the soil, with minimal change occurring at depth. Characterization of the protein and ligand content of these soils via 13C NMR and chemolytic techniques as a function of soil particle density and size is in progress and will be presented along with estimates of carbon dioxide and methane fluxes across the MiGD chronosequence. Our broad goal is to quantify ruminal methane emissions and changes to soil C-stocks and stability associated with this land-use shift. Our preliminary data suggest such a land-use change will likely improve soil health and increase C-stocks. Balancing this against potential increases in methane emissions is a key knowledge gap for future southeastern U.S. C-cycling estimates.

Leaf primordium size specifies leaf width and vein number among row-type classes in barley.

PubMed

Thirulogachandar, Venkatasubbu; Alqudah, Ahmad M; Koppolu, Ravi; Rutten, Twan; Graner, Andreas; Hensel, Goetz; Kumlehn, Jochen; Bräutigam, Andrea; Sreenivasulu, Nese; Schnurbusch, Thorsten; Kuhlmann, Markus

2017-08-01

Exploring genes with impact on yield-related phenotypes is the preceding step to accomplishing crop improvements while facing a growing world population. A genome-wide association scan on leaf blade area (LA) in a worldwide spring barley collection (Hordeum vulgare L.), including 125 two- and 93 six-rowed accessions, identified a gene encoding the homeobox transcription factor, Six-rowed spike 1 (VRS1). VRS1 was previously described as a key domestication gene affecting spike development. Its mutation converts two-rowed (wild-type VRS1, only central fertile spikelets) into six-rowed spikes (mutant vrs1, fully developed fertile central and lateral spikelets). Phenotypic analyses of mutant and wild-type leaves revealed that mutants had an increased leaf width with more longitudinal veins. The observed significant increase of LA and leaf nitrogen (%) during pre-anthesis development in vrs1 mutants also implies a link between wider leaf and grain number, which was validated from the association of vrs1 locus with wider leaf and grain number. Histological and gene expression analyses indicated that VRS1 might influence the size of leaf primordia by affecting cell proliferation of leaf primordial cells. This finding was supported by the transcriptome analysis of mutant and wild-type leaf primordia where in the mutant transcriptional activation of genes related to cell proliferation was detectable. Here we show that VRS1 has an independent role on barley leaf development which might influence the grain number. © 2017 The Authors. The Plant Journal published by John Wiley & Sons Ltd and Society for Experimental Biology.

Alfalfa (Medicago sativa L.)/maize (Zea mays L.) intercropping provides a feasible way to improve yield and economic incomes in farming and pastoral areas of northeast China.

PubMed

Sun, Baoru; Peng, Yi; Yang, Hongyu; Li, Zhijian; Gao, Yingzhi; Wang, Chao; Yan, Yuli; Liu, Yanmei

2014-01-01

Given the growing challenges to food and eco-environmental security as well as sustainable development of animal husbandry in the farming and pastoral areas of northeast China, it is crucial to identify advantageous intercropping modes and some constraints limiting its popularization. In order to assess the performance of various intercropping modes of maize and alfalfa, a field experiment was conducted in a completely randomized block design with five treatments: maize monoculture in even rows, maize monoculture in alternating wide and narrow rows, alfalfa monoculture, maize intercropped with one row of alfalfa in wide rows and maize intercropped with two rows of alfalfa in wide rows. Results demonstrate that maize monoculture in alternating wide and narrow rows performed best for light transmission, grain yield and output value, compared to in even rows. When intercropped, maize intercropped with one row of alfalfa in wide rows was identified as the optimal strategy and the largely complementary ecological niches of alfalfa and maize were shown to account for the intercropping advantages, optimizing resource utilization and improving yield and economic incomes. These findings suggest that alfalfa/maize intercropping has obvious advantages over monoculture and is applicable to the farming and pastoral areas of northeast China.

Alfalfa (Medicago sativa L.)/Maize (Zea mays L.) Intercropping Provides a Feasible Way to Improve Yield and Economic Incomes in Farming and Pastoral Areas of Northeast China

PubMed Central

Sun, Baoru; Peng, Yi; Yang, Hongyu; Li, Zhijian; Gao, Yingzhi; Wang, Chao; Yan, Yuli; Liu, Yanmei

2014-01-01

Given the growing challenges to food and eco-environmental security as well as sustainable development of animal husbandry in the farming and pastoral areas of northeast China, it is crucial to identify advantageous intercropping modes and some constraints limiting its popularization. In order to assess the performance of various intercropping modes of maize and alfalfa, a field experiment was conducted in a completely randomized block design with five treatments: maize monoculture in even rows, maize monoculture in alternating wide and narrow rows, alfalfa monoculture, maize intercropped with one row of alfalfa in wide rows and maize intercropped with two rows of alfalfa in wide rows. Results demonstrate that maize monoculture in alternating wide and narrow rows performed best for light transmission, grain yield and output value, compared to in even rows. When intercropped, maize intercropped with one row of alfalfa in wide rows was identified as the optimal strategy and the largely complementary ecological niches of alfalfa and maize were shown to account for the intercropping advantages, optimizing resource utilization and improving yield and economic incomes. These findings suggest that alfalfa/maize intercropping has obvious advantages over monoculture and is applicable to the farming and pastoral areas of northeast China. PMID:25329376

ARGUS/LLNL IR Camera Calibration and Characterization

DTIC Science & Technology

1989-11-01

122 of the 244 rows, once every 1/60 second. The even-numbered detector rows, beginning with row zero , are read out in one field; the odd-numbered...Radiometrically, a very cold reference scene is desirable because the absolute signal level of the reference scene is subtracted from all subsequent...to have effectively zero radiant energy within the spectral passband of the sensor, and so may be ignored. 1.3 LABORATORY EQUIPMENT CONFIGURATION The

Control of wilt disease of lentil through bio control agents and organic amendments in Tarai region of Uttarakhand, India.

PubMed

Garkoti, Ankita; Kumar, Vijay; Tripathi, H S

2014-11-01

The present work aimed at evaluating the efficacy of bioagents and organic amendments against lentil wilt pathogen. Field trials were carried out consecutively during Rabi 2010-11 and 2011-12 crop seasons in Randomized Block Design (RBD) with three replications, using 'Pant L-639' a popular cultivar. The plot size was 3.0 x 1.5 m2 with row spacing of 30 cm. Effect of selected bioagents and organic amendments on disease incidence, 1000 grain weight and yield kg ha' of lentil was recorded. It was observed that seed treatment with Trichoderma harizanum + Pseudomonas fluorescens significant by reduced 1.73% (2010-11) and 1.93% (2011-12) in Fusarium wilt disease incidence and increase in grain yield 507.6 kg ha(-1) and 496.0 kg ha(-1) respectively during both crop seasons. Among organic amendments, minimum wilt disease incidence of 1.69% (2010-11) and 1.81% (2011-12) and maximum grain yield 496.3 kg ha(-1) (2010-11) and 484.0 kg ha(-1) (2011-12) were observed in farm yard manure + spent compost treated plots. This indicates that these treatments have important roles in biologically based management strategies for controling Fusarium wilt disease under organic mode of lentil cultivation in Uttarakhand State.

Crop resources. [18 papers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seigler, D.S.

Eighteen papers originally presented as a symposium on Crop Resources at the 17th annual meeting of the Society for Economic Botany in Urbana, Illinois, June 13 to 17, 1976 comprise this book. The papers are: Potential Wealth in New Crops: Research and Development, L. H. Princen; Plant Introductions--A Source of New Crops, George A. White; Nonfood Uses for Commercial Vegetable Oil Crops, E. H. Pryde; New Industrial Potentials for Carbohydrates, F. H. Otey; The Current Importance of Plants as a Source of Drugs, Norman R. Farnsworth; Potentials for Development of Wild Plants as Row Crops for Use by Man, Arnoldmore » Krochmal and Connie Krochmal; Recent Evidence in Support of the Tropical Origin of New World Crops, C. Earle Smith, Jr.; Requirements for a Green Revolution, G. F. Sprague; How Green Can a Revolution Be, Jack R. Harlan; Increasing Cereal Yields: Evolution under Domestication, J. M. J. de Wet; Hevea Rubber: Past and Future, Ernest P. Imle; Horseradish--Problems and Research in Illinois, A. M. Rhodes; Dioscorea--The Pill Crop, Norman Applezweig; Plant Derivatives for Insect Control, Robert L. Metcalf; Evolutionary Dynamics of Sorghum Domestication, J. M. J. de Wet and Y. Shecter; The Origin and Future of Wheat, E. R. Sears; Current Thoughts on Origins, Present Status, and Future of Soybeans, T. Hymowitz and C. A. Newell; and The Origin of Corn--Studies of the Last Hundred Years, Garrison Wilkes. (MCW)« less

Estimation of streamflow, base flow, and nitrate-nitrogen loads in Iowa using multiple linear regression models

USGS Publications Warehouse

Schilling, K.E.; Wolter, C.F.

2005-01-01

Nineteen variables, including precipitation, soils and geology, land use, and basin morphologic characteristics, were evaluated to develop Iowa regression models to predict total streamflow (Q), base flow (Qb), storm flow (Qs) and base flow percentage (%Qb) in gauged and ungauged watersheds in the state. Discharge records from a set of 33 watersheds across the state for the 1980 to 2000 period were separated into Qb and Qs. Multiple linear regression found that 75.5 percent of long term average Q was explained by rainfall, sand content, and row crop percentage variables, whereas 88.5 percent of Qb was explained by these three variables plus permeability and floodplain area variables. Qs was explained by average rainfall and %Qb was a function of row crop percentage, permeability, and basin slope variables. Regional regression models developed for long term average Q and Qb were adapted to annual rainfall and showed good correlation between measured and predicted values. Combining the regression model for Q with an estimate of mean annual nitrate concentration, a map of potential nitrate loads in the state was produced. Results from this study have important implications for understanding geomorphic and land use controls on streamflow and base flow in Iowa watersheds and similar agriculture dominated watersheds in the glaciated Midwest. (JAWRA) (Copyright ?? 2005).

Increase globe artichoke cropping sustainability using sub-surface drip-irrigation systems in a Mediterranean coastal area for reducing groundwater withdrawal

NASA Astrophysics Data System (ADS)

Mantino, Alberto; Marchina, Chiara; Bonari, Enrico; Fabbrizzi, Alessandro; Rossetto, Rudy

2017-04-01

During the last decades in coastal areas of the Mediterranean basin, human growth posed severe stresses on freshwater resources due to increasing demand by agricultural, industrial and civil activities, in particular on groundwater. This in turn led to worsening of water quality, loss/reduction of wetlands, up to soil salinization and abandonment of agricultural areas. Within the EU LIFE REWAT project a number of demonstration measures will take place in the lower Cornia valley (Livorno, Italy), both structural (pilot) and non-structural (education, dissemination and capacity building), aiming at achieving sustainable and participated water management. In particular, the five demonstration actions are related to: (1) set up of a managed aquifer recharge facility, (2) restoration of a Cornia river reach, (3) water saving in the civil water supply sector, (4) water saving in agriculture, (5) reuse of treated wastewater for irrigation purposes. Thus, the REWAT project general objective is to develop a new model of governance for sustainable development of the lower Cornia valley based on the water asset at its core. As per water use in agriculture, the lower Cornia valley is well known for the horticultural production. In this regard, globe artichoke (Cynara cardunculus L. var. scolymus L. (Fiori)) crops, a perennial cool-season vegetable, cover a surface of about 600 ha. In order to increase stability and productivity of the crop, about 2000 - 4000 m3 ha-1 yr-1 of irrigation water is required. Recent studies demonstrated that yield of different crops increases using Sub-surface Drip-Irrigation (SDI) system under high frequency irrigation management enhancing water use efficiency. In the SDI systems, the irrigation water is delivered to the plant root zone, below the soil surface by buried plastic tubes containing embedded emitters located at regular spacing. Within the LIFE REWAT, the specific objectives of the pilot on irrigation efficiency is to (i) demonstrate the suitability of SDI for globe artichoke cultivation, reducing the water consumption, while maintaining (or even increasing) crop production and (ii) assess the crop water use efficiency respect to surface drip-irrigation. The field test is located in Venturina (Italy) and it covers a surface of 4 ha. The soil is characterized by sandy-loam texture, 1.72% of organic matter at 7.81 pH. Groundwater is the main source of supply for irrigation. By the chemical point of view, a monitoring campaign in spring 2016 showed a neutral pH of 7.2, electrical conductivity of 1363 μS/cm, 373 and 243 mg/l of total sulphate and carbonate, respectively, thus demonstrating the suitability of groundwater for SDI application. The SDI system was implemented at the beginning of September 2016. The sub-surface buried pipelines, were placed at 0.25 m depth, with emitters spaced 0.5 m. The distance between pipelines was 1.5 m, according to globe artichoke layout (1.5 m between rows, 1 m in-row spacing). Surface-buried tubes were placed in an area about 0.75 ha wide for the comparison with SDI. Artichoke var. Terom were transplanted after the SDI operation test. In the next 3 years, both crop productivity and water use will be assessed. Results will be presented and discussed with the whole farmer's community. Acknowledgement This paper is presented within the framework of the project LIFE REWAT, which has received funding from the LIFE Programme of the European Union Grant Agreement LIFE14 ENV/IT/001290.

Native prairie filter strips reduce runoff from hillslopes under annual row-crop systems in Iowa, USA

NASA Astrophysics Data System (ADS)

Hernandez-Santana, V.; Zhou, X.; Helmers, M. J.; Asbjornsen, H.; Kolka, R.; Tomer, M.

2013-01-01

SummaryIntensively managed annual cropping systems have produced high crop yields but have often produced significant ecosystem services alteration, in particular hydrologic regulation loss. Reconversion of annual agricultural systems to perennial vegetation can lead to hydrologic function restoration, but its effect is still not well understood. Therefore, our objective was to assess the effects of strategic introduction of different amounts and location of native prairie vegetation (NPV) within agricultural landscapes on hydrological regulation. The study was conducted in Iowa (USA), and consisted of a fully balanced, replicated, incomplete block design whereby 12 zero-order ephemeral flow watersheds received four treatments consisting of varying proportions (0%, 10%, and 20%) of prairie vegetation located in different watershed positions (footslope vs. contour strips). Runoff volume and rate were measured from 2008 to 2010 (April-October) with an H-Flume installed in each catchment, and automated ISCO samplers. Over the entire study period, we observed a total of 129 runoff events with an average runoff volume reduction of 37% based on the three treatments with NPV compared to watersheds with row crops. We observed a progressively greater reduction across the 3 years of the study as the perennial strips became established with the greatest differences among treatments occurring in 2010. The differences among the watersheds were attributed mainly to NPV amount and position, with the 10% NPV at footslope treatment having the greatest runoff reduction probably because the portion of NPV filter strip that actually contacted watershed runoff was greater with the 10% NPV at footslope. We observed greater reductions in runoff in spring and fall likely because perennial prairie plants were active and crops were absent or not fully established. High antecedent soil moisture sometimes led to little benefit of the NPV treatments but in general the NPV treatments were effective during both small and large events. We conclude that, small amounts of NPV strategically incorporated into corn-soybean watersheds in the Midwest US can be used to effectively reduce runoff.

Fluid-flow of a row of jets in crossflow - A numerical study

NASA Technical Reports Server (NTRS)

Kim, S.-W.; Benson, T. J.

1992-01-01

A detailed computer-visualized flow field of a row of jets in a confined crossflow is presented. The Reynolds averaged Navier-Stokes equations are solved using a finite volume method that incorporates a partial differential equation for incremental pressure to obtain a divergence-free flow field. The turbulence is described by a multiple-time-scale turbulence model. The computational domain includes the upstream region of the circular jet so that the interaction between the jet and the crossflow is simulated accurately. It is shown that the row of jets in the crossflow is characterized by a highly complex flow field that includes a horse-shoe vortex and two helical vortices whose secondary velocity components are co-rotating in space. It is also shown that the horse-shoe vortex is a ring of reversed flows located along the circumference of the jet exit.

Distribution of E/N and N/e/ in a cross-flow electric discharge laser. [electric field to neutral gas density and electron number density

NASA Technical Reports Server (NTRS)

Dunning, J. W., Jr.; Lancashire, R. B.; Manista, E. J.

1976-01-01

Measurements have been conducted of the effect of the convection of ions and electrons on the discharge characteristics in a large scale laser. The results are presented for one particular distribution of ballast resistance. Values of electric field, current density, input power density, ratio of electric field to neutral gas density (E/N), and electron number density were calculated on the basis of measurements of the discharge properties. In a number of graphs, the E/N ratio, current density, power density, and electron density are plotted as a function of row number (downstream position) with total discharge current and gas velocity as parameters. From the dependence of the current distribution on the total current, it appears that the electron production in the first two rows significantly affects the current flowing in the succeeding rows.

Energy crop mapping with enhanced TM/MODIS time series in the BCAP agricultural lands

NASA Astrophysics Data System (ADS)

Wang, Cuizhen; Fan, Qian; Li, Qingting; SooHoo, William M.; Lu, Linlin

2017-02-01

Since the mid-2000s, agricultural lands in the United States have been undergoing rapid change to meet the increasing bioenergy demand. In 2009 the USDA Biomass Crop Assistance Program (BCAP) was established. In its Project Area 1, land owners are financially supported to grow perennial prairie grasses (switchgrass) in their row-crop lands. To promote the program, this study tested the feasibility of biomass crop mapping based on unique timings of crop development. With a previously published data fusion algorithm - the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM), a 10-day normalized difference vegetation index (NDVI) time series in 2007 was established by fusing MODIS reflectance into TM image series. Two critical dates - peak growing (PG) and peak drying (PD) - were extracted and a unique "PG-0-PD" timing sequence was defined for each crop. With a knowledge-based decision tree approach, the classification of enhanced TM/MODIS time series reached an overall accuracy of 76% against the USDA Crop Data layer (CDL). Especially, our results showed that winter wheat single cropping and wheat-soybean double cropping were much better classified, which may provide additional information for the CDL product. More importantly, this study extracted the first spatial layer of warm-season prairie grasses that have not been published in any national land cover products, which could serve as a base map for decision making of bioenergy land use in BCAP land.

Forcing function modeling for flow induced vibration

NASA Technical Reports Server (NTRS)

Fleeter, Sanford

1993-01-01

The fundamental forcing function unsteady aerodynamics for application to turbomachine blade row forced response are considered, accomplished through a series of experiments performed in a rotating annular cascade and a research axial flow turbine. In particular, the unsteady periodic flowfields downstream of rotating rows of perforated plates, airfoils and turbine blade rows are measured with a cross hot-wire and an unsteady total pressure probe. The unsteady velocity and static pressure fields were then analyzed harmonically and split into vortical and potential gusts, accomplished by developing a gust splitting analysis which includes both gust unsteady static pressure and velocity data. The perforated plate gusts closely were found to be linear theory vortical gusts, satisfying the vortical gust constraints. The airfoil and turbine blade row generated velocity perturbations did not satisfy the vortical gust constraints. However, the decomposition of the unsteady flow field separated the data into a propagating vortical component which satisfied these vortical gust constraints and a decaying potential component.

Receptors signaling gravity orientation in an insect

NASA Technical Reports Server (NTRS)

Hartman, H. B.

1982-01-01

Displacement in any direction from primary orientation is found to evoke tonic activity from at least one of the four interneurons of a certain type of burrowing cockroach; the receptive field for each interneuron is slightly more than a quadrant. The receptive field of each interneuron is found to be the same as the row of receptors providing the input. Displacement about the least stable axis (0-180 deg) or roll, on the one hand, and the most stable axis (90-270 deg) or pitch, on the other, is found to be unambiguously signaled by pairs of interneurons. Indications are obtained that receptors in the lateral row drive a giant interneuron in a contralateral connective and those in the medial row drive one in an ipsilateral connective.

Cover cropping to reduce nitrate loss through subsurface drainage in the northern U.S. corn belt.

PubMed

Strock, J S; Porter, P M; Russelle, M P

2004-01-01

Despite the use of best management practices for nitrogen (N) application rate and timing, significant losses of nitrate nitrogen (NO3(-)-N) in drainage discharge continue to occur from row crop cropping systems. Our objective was to determine whether a autumn-seeded winter rye (Secale cereale L.) cover crop following corn (Zea mays L.) would reduce NO3(-)-N losses through subsurface tile drainage in a corn-soybean [Glycine mar (L.) Merr.] cropping system in the northern Corn Belt (USA) in a moderately well-drained soil. Both phases of the corn-soybean rotation, with and without the winter rye cover crop following corn, were established in 1998 in a Normania clay loam (fine-loamy, mixed, mesic Aquic Haplustoll) soil at Lamberton, MN. Cover cropping did not affect subsequent soybean yield, but reduced drainage discharge, flow-weighted mean nitrate concentration (FWMNC), and NO3(-)-N loss relative to winter fallow, although the magnitude of the effect varied considerably with annual precipitation. Three-year average drainage discharge was lower with a winter rye cover crop than without (p = 0.06). Over three years, subsurface tile-drainage discharge was reduced 11% and NO3(-)-N loss was reduced 13% for a corn-soybean cropping system with a rye cover crop following corn than with no rye cover crop. We estimate that establishment of a winter rye cover crop after corn will be successful in one of four years in southwestern Minnesota. Cover cropping with rye has the potential to be an effective management tool for reducing NO3(-)-N loss from subsurface drainage discharge despite challenges to establishment and spring growth in the north-central USA.

Drip irrigation management in different chufa planting strategies: yield and irrigation water use efficiency

NASA Astrophysics Data System (ADS)

Pascual-Seva, Nuria; San Bautista, Alberto; López-Galarza, Salvador; Maroto, José Vicente; Pascual, Bernardo

2013-04-01

In a study presented in the EGU assembly 2012, it was analysed how yield and irrigation water use efficiency (IWUE) in chufa (Cyperus esculentus L. var. sativus), crop, were affected by planting strategy (ridges and flat raised beds, with two and three plant rows along them) and irrigation system [furrow (FI) and drip irrigation (DI)]. Each irrigation session started when the Volumetric Soil Water Content (VSWC) in ridges dropped to 80% of field capacity; beds were irrigated simultaneously with ridges and with the same irrigation duration. R produced lower yield than the two types of beds, and yields in DI were higher than those FI. Ridges led to the highest IWUE with DI, and to the lowest with FI. Then, it was decided to analyse, in DI, how yield and IWUE responded to start each irrigation session when the VSWC in the central point of different planting strategies [ridges (R), and flat raised beds with two (b) and three (B) plant rows along them] dropped to 80% of field capacity. In R and b, plants were irrigated by a single dripline per plant row, while in B two irrigation layouts were assayed: a single dripline per plant row (B3) and two driplines per bed (B2), placing each dripline between two planting rows. Irrigation session stop was also automated as a function of the VSWC. Results show that yield was affected (P˜0.01) by planting strategy; the greatest yield was obtained in b (2.4 kgm-2), differing (P˜0.05) from that obtained in R (2.1 kgm-2), with intermediate yields in B2 (2.3 kgm-2) and B3 (2.3 kgm-2). Yield was not affected (P˜0.05) by the utilisation of two or three driplines in B. Considerably less irrigation water was applied (IWA) in R (376 mm) than in B3 (465 mm), B2 (475 mm) and b (502 mm). This automatic irrigation management, as a function of the VSWC in each planting strategy, lead to adjust the IWA to the plant water requirements, which were similar in all three flat raised beds, since they correspond to the same planting density, that was, in turn, higher than in R. IWUE was affected (P˜0.01) by the planting strategy, obtaining greater (P˜0.05) values in R (5.54 kgm-3) than in B3 (4.84 kgm-3), B2 (4.76 kgm-3), and b (4.73 kgm-3). With the herein presented irrigation management, IWUE in flat raised beds considerably increased in relation to the previous experiments (automated as a function of the VSWC in R), although they resulted in lower values (P˜0.05) than in R. When comparing the different planting rows, neither the yield nor the average tuber weight was affected by their position. b leaded to the highest yield, while R resulted in the lowest yield, but with the highest IWUE. Considering the current prices of both tubers and irrigation water, the profit obtained by the increase in yield reached with b is greater than the cost that supposes its greater IWA. Nevertheless, if there were water delivery restrictions or price increases, R would represent a recommendable strategy.

Aerial Photography: Use in Detecting Simulated Insect Defoliation in Corn

NASA Technical Reports Server (NTRS)

Chiang, H. C.; Latham, R.; Meyer, M. P.

1973-01-01

Artificial defoliation in corn was used to explore the usefulness of aerial photography in detecting crop insect infestations. Defoliation on the top of plants was easily detected, while that on the base was less so. Aero infrared film with Wratten 89B filter gave the best results, and morning flights at the scale of 1:15840 are recommended. Row direction, plant growth stage, and time elapse since defoliation were not important factors.

Lake Nutrient Responses to Integrated Conservation Practices in an Agricultural Watershed.

PubMed

Lizotte, Richard E; Yasarer, Lindsey M W; Locke, Martin A; Bingner, Ronald L; Knight, Scott S

2017-03-01

Watershed-scale management efforts to reduce nutrient loads and improve the conservation of lakes in agricultural watersheds require effective integration of a variety of agricultural conservation best management practices (BMPs). This paper documents watershed-scale assessments of the influence of multiple integrated BMPs on oxbow lake nutrient concentrations in a 625-ha watershed of intensive row-crop agricultural activity during a 14-yr monitoring period (1996-2009). A suite of BMPs within fields and at field edges throughout the watershed and enrollment of 87 ha into the Conservation Reserve Program (CRP) were implemented from 1995 to 2006. Total phosphorus (TP), soluble reactive phosphorus (SRP), ammonium, and nitrate were measured approximately biweekly from 1996 to 2009, and total nitrogen (TN) was measured from 2001 to 2009. Decreases in several lake nutrient concentrations occurred after BMP implementation. Reductions in TP lake concentrations were associated with vegetative buffers and rainfall. No consistent patterns of changes in TN or SRP lake concentrations were observed. Reductions in ammonium lake concentrations were associated with conservation tillage and CRP. Reductions in nitrate lake concentrations were associated with vegetative buffers. Watershed simulations conducted with the AnnAGNPS (Annualized Agricultural Non-Point Source) model with and without BMPs also show a clear reduction in TN and TP loads to the lake after the implementation of BMPs. These results provide direct evidence of how watershed-wide BMPs assist in reducing nutrient loading in aquatic ecosystems and promote a more viable and sustainable lake ecosystem. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Potential of global croplands and bioenergy crops for climate change mitigation through deployment for enhanced weathering.

PubMed

Kantola, Ilsa B; Masters, Michael D; Beerling, David J; Long, Stephen P; DeLucia, Evan H

2017-04-01

Conventional row crop agriculture for both food and fuel is a source of carbon dioxide (CO 2 ) and nitrous oxide (N 2 O) to the atmosphere, and intensifying production on agricultural land increases the potential for soil C loss and soil acidification due to fertilizer use. Enhanced weathering (EW) in agricultural soils-applying crushed silicate rock as a soil amendment-is a method for combating global climate change while increasing nutrient availability to plants. EW uses land that is already producing food and fuel to sequester carbon (C), and reduces N 2 O loss through pH buffering. As biofuel use increases, EW in bioenergy crops offers the opportunity to sequester CO 2 while reducing fossil fuel combustion. Uncertainties remain in the long-term effects and global implications of large-scale efforts to directly manipulate Earth's atmospheric CO 2 composition, but EW in agricultural lands is an opportunity to employ these soils to sequester atmospheric C while benefitting crop production and the global climate. © 2017 The Author(s).

Variability in Time and Space of Meloidogyne incognita Fall Population Density in Cotton Fields

PubMed Central

Wheeler, Terry A.; Baugh, Brant; Kaufman, Harold; Schuster, Greta; Siders, Kerry

2000-01-01

Three cotton fields infested with Meloidogyne incognita were intensively sampled in the fall for 3 years (1996 to 1998) to determine if intensive sampling for M. incognita, for which spatial location is important, was necessary every year in a continuous cotton system. Two composite soil samples (20 cores each), taken over an area covering one-third of the field length and two rows wide, were averaged to represent that area (row-location combination). Each field (except one) had 24 areas assayed for changes in M. incognita population density (Pf) over a 3-year period. At all three sites, Pf was higher during fall 1998 than fall 1996. There were no differences in Pf between rows within a year or between years (no. row × year interaction) at any of the sites. At all three sites, there was a consistent difference each year in Pf among locations in a field (no. year × location interaction). At each area, M. incognital/500 cm³ was labeled for one of four Pf classes: <250, 250 to 999, 1,000 to 2,499, and ≥ 2,500. Management of root-knot nematode would likely be altered as classification changed. The areas that were reclassified by two classes or more after 1 and 2 years ranged from 0 to 29% and 25 to 54%, respectively. The risk of underestimating Pf of M. incognita was higher in one site 2 years after the initial intensive sampling procedure, whereas in another site there was little change in Pf 2 years after initial sampling. Sampling frequency will need to be decided on a field-by-field basis. PMID:19270975

Trends of pesticides and nitrate in ground water of the Central Columbia Plateau, Washington, 1993-2003

USGS Publications Warehouse

Frans, L.

2008-01-01

Pesticide and nitrate data for ground water sampled in the Central Columbia Plateau, Washington, between 1993 and 2003 by the U.S. Geological Survey National Water-Quality Assessment Program were evaluated for trends in concentration. A total of 72 wells were sampled in 1993-1995 and again in 2002-2003 in three well networks that targeted row crop and orchard land use settings as well as the regional basalt aquifer. The Regional Kendall trend test indicated that only deethylatrazine (DEA) concentrations showed a significant trend. Deethylatrazine concentrations were found to increase beneath the row crop land use well network, the regional aquifer well network, and for the dataset as a whole. No other pesticides showed a significant trend (nor did nitrate) in the 72-well dataset. Despite the lack of a trend in nitrate concentrations within the National Water-Quality Assessment dataset, previous work has found a statistically significant decrease in nitrate concentrations from 1998-2002 for wells with nitrate concentrations above 10 mg L-1 within the Columbia Basin ground water management area, which is located within the National Water-Quality Assessment study unit boundary. The increasing trend in DEA concentrations was found to negatively correlate with soil hydrologic group using logistic regression and with soil hydrologic group and drainage class using Spearman's correlation. The decreasing trend in high nitrate concentrations was found to positively correlate with the depth to which the well was cased using logistic regression, to positively correlate with nitrate application rates and sand content of the soil, and to negatively correlate with soil hydrologic group using Spearman's correlation. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

School Transformation + Development Map

ERIC Educational Resources Information Center

Locker, Frank M.

2010-01-01

The field of education has highly varied educational practices and facilities needs. Still, much of education continues to be delivered in the recognizable tradition of teachers working alone in isolated classrooms and buildings planned based on rows and rows of those classrooms. But there is no longer one single, universal view of how education…

Multispectral determination of soil moisture. [Guymon, Oklahoma

NASA Technical Reports Server (NTRS)

Estes, J. E.; Simonett, D. S. (Principal Investigator); Hajic, E. J.; Blanchard, B. J.

1980-01-01

The edited Guymon soil moisture data collected on August 2, 5, 14, 17, 1978 were grouped into four field cover types for statistical analysis. These are the bare, milo with rows parallel to field of view, milo with rows perpendicular to field of view and alfalfa cover groups. There are 37, 22, 24 and 14 observations respectively in each group for each sensor channel and each soil moisture layer. A subset of these data called the 'five cover set' (VEG5) limited the scatterometer data to the 15 deg look angle and was used to determine discriminant functions and combined group regressions.

Prediction of the far field noise from wind energy farms

NASA Technical Reports Server (NTRS)

Shepherd, K. P.; Hubbard, H. H.

1986-01-01

The basic physical factors involved in making predictions of wind turbine noise and an approach which allows for differences in the machines, the wind energy farm configurations and propagation conditions are reviewed. Example calculations to illustrate the sensitivity of the radiated noise to such variables as machine size, spacing and numbers, and such atmosphere variables as absorption and wind direction are presented. It is found that calculated far field distances to particular sound level contours are greater for lower values of atmospheric absorption, for a larger total number of machines, for additional rows of machines and for more powerful machines. At short and intermediate distances, higher sound pressure levels are calculated for closer machine spacings, for more powerful machines, for longer row lengths and for closer row spacings.

China Macroeconomic: Summary Data Banks (China Macroeconomic: Documentation Data Banks. Volume 1. Population Gross Value Output of Agriculture and Industry).

DTIC Science & Technology

1984-11-15

3) IL- R 0 104 em fm r4. N V @f 4 . * N P - 3 a U N I 11 111Bala ---w4f ft ’D " & W. f4p r... ;;W 6.C 4’ 0 4.-49 A B C D EF G H AF25:FH/CNTG3.3GJ...A Sources, see below Load from row 12 to row 54 * - 104 - A B C D E F G H AF09:FK/PCICi.3FD revision 001 6/13/83 17:45 Prices of Industrial Crops Prices...Val Brig Ind Brig Ind Brig Ind (80 pr) (70 pr) (80 pr) (bil RMB)(bil RHB ) (bil RMB) XOBI XOBILK XOBI 1949 N/A N/A N/A 1950 N/A N/A N/A 1951 N/A N/A N/A

The effect of row structure on soil moisture retrieval accuracy from passive microwave data.

PubMed

Xingming, Zheng; Kai, Zhao; Yangyang, Li; Jianhua, Ren; Yanling, Ding

2014-01-01

Row structure causes the anisotropy of microwave brightness temperature (TB) of soil surface, and it also can affect soil moisture retrieval accuracy when its influence is ignored in the inversion model. To study the effect of typical row structure on the retrieved soil moisture and evaluate if there is a need to introduce this effect into the inversion model, two ground-based experiments were carried out in 2011. Based on the observed C-band TB, field soil and vegetation parameters, row structure rough surface assumption (Q p model and discrete model), including the effect of row structure, and flat rough surface assumption (Q p model), ignoring the effect of row structure, are used to model microwave TB of soil surface. Then, soil moisture can be retrieved, respectively, by minimizing the difference of the measured and modeled TB. The results show that soil moisture retrieval accuracy based on the row structure rough surface assumption is approximately 0.02 cm(3)/cm(3) better than the flat rough surface assumption for vegetated soil, as well as 0.015 cm(3)/cm(3) better for bare and wet soil. This result indicates that the effect of row structure cannot be ignored for accurately retrieving soil moisture of farmland surface when C-band is used.

Blade Row Interaction Effects on the Performance of a Moderately Loaded NASA Transonic Compressor Stage

NASA Technical Reports Server (NTRS)

VanZante, Dale E.; To, Wai-Ming; Chen, Jen-Ping

2003-01-01

Blade row interaction effects on loss generation in compressors have received increased attention as compressor work-per-stage and blade loading have increased. Two dimensional Laser Doppler Velocimeter measurements of the velocity field in a NASA transonic compressor stage show the magnitude of interactions in the velocity field at the peak efficiency and near stall operating conditions. The experimental data are presented along with an assessment of the velocity field interactions. In the present study the experimental data are used to confirm the fidelity of a three-dimensional, time-accurate, Navier Stokes calculation of the stage using the MSU-TURBO code at the peak efficiency and near stall operating conditions. The simulations are used to quantify the loss generation associated with interaction phenomena. At the design point the stator pressure field has minimal effect on the rotor performance. The rotor wakes do have an impact on loss production in the stator passage at both operating conditions. A method for determining the potential importance of blade row interactions on performance is presented.

The HMONG Diaspora and the Struggle for an Identity

DTIC Science & Technology

2012-12-01

land. 11 Additionally, the Spanish introduced low maintenance crops such as maize , sweet potatoes, and peanuts from the Americas. 12 The Han...Thomas Lum, “Laos: Background and U.S. Relations, “ Congressional Research Service (January 4, 2010) http://www.fas.org/sgp/crs/row/RL34320. pdf , accessed...downloads/367. pdf , (accessed September 27, 2012), 6. 117 Bradley Klapper, “Clinton Reaches Out to Laos in Historic Visit,” The Salt Lake Tribune, (July 11

Sampling Design and Procedures for Fixed Surface-Water Sites in the Georgia-Florida Coastal Plain Study Unit, 1993

DTIC Science & Technology

1995-01-01

Station number Station drainage area (km2) Land resource province Land-use description Fixed-site type Altamaha River near Everett City, Ga . 02226160...Creek near Tallahassee, Fla. 02326838 27 SCP suburban indicator Little River near Ty Ty, Ga . 02317797 334 SCP agriculture (mixed row crops) indicator...Middle Prong St. Marys River near Taylor, Fla. 02229000 324 CFW silviculture indicator Tucsawhatchee Creek near Hawkinsville, Ga . 02215100 422 SCP

Skip-row Planting Patterns Stabilize Corn Grain Yields in the Central Great Plains

USDA-ARS?s Scientific Manuscript database

The highly variable climate of the Central Great Plains makes dryland corn (Zea mays) production a risky enterprise. Twenty-three field trials were conducted across the Central Great Plains from 2004 through 2006 to quantify the effect of various skip-row planting patterns and plant populations on g...

Linearized Unsteady Aerodynamic Analysis of the Acoustic Response to Wake/Blade-Row Interaction

NASA Technical Reports Server (NTRS)

Verdon, Joseph M.; Huff, Dennis L. (Technical Monitor)

2001-01-01

The three-dimensional, linearized Euler analysis, LINFLUX, is being developed to provide a comprehensive and efficient unsteady aerodynamic scheme for predicting the aeroacoustic and aeroelastic responses of axial-flow turbomachinery blading. LINFLUX couples a near-field, implicit, wave-split, finite-volume solution to far-field acoustic eigensolutions, to predict the aerodynamic responses of a blade row to prescribed structural and aerodynamic excitations. It is applied herein to predict the acoustic responses of a fan exit guide vane (FEGV) to rotor wake excitations. The intent is to demonstrate and assess the LINFLUX analysis via application to realistic wake/blade-row interactions. Numerical results are given for the unsteady pressure responses of the FEGV, including the modal pressure responses at inlet and exit. In addition, predictions for the modal and total acoustic power levels at the FEGV exit are compared with measurements. The present results indicate that the LINFLUX analysis should be useful in the aeroacoustic design process, and for understanding the three-dimensional flow physics relevant to blade-row noise generation and propagation.

Genetic Diversity and Population Structure in a Legacy Collection of Spring Barley Landraces Adapted to a Wide Range of Climates

PubMed Central

Walther, Alexander; Özkan, Hakan; Graner, Andreas; Kilian, Benjamin

2014-01-01

Global environmental change and increasing human population emphasize the urgent need for higher yielding and better adapted crop plants. One strategy to achieve this aim is to exploit the wealth of so called landraces of crop species, representing diverse traditional domesticated populations of locally adapted genotypes. In this study, we investigated a comprehensive set of 1485 spring barley landraces (Lrc1485) adapted to a wide range of climates, which were selected from one of the largest genebanks worldwide. The landraces originated from 5° to 62.5° N and 16° to 71° E. The whole collection was genotyped using 42 SSR markers to assess the genetic diversity and population structure. With an average allelic richness of 5.74 and 372 alleles, Lrc1485 harbours considerably more genetic diversity than the most polymorphic current GWAS panel for barley. Ten major clusters defined most of the population structure based on geographical origin, row type of the ear and caryopsis type – and were assigned to specific climate zones. The legacy core reference set Lrc648 established in this study will provide a long-lasting resource and a very valuable tool for the scientific community. Lrc648 is best suited for multi-environmental field testing to identify candidate genes underlying quantitative traits but also for allele mining approaches. PMID:25541702

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horton, David Scott

Petroleum prices have made alternative fuel crops a viable option for ethanol production. Sweet sorghum [Sorghum bicolor] is a non-food crop that may produce large quantities of ethanol with minimal inputs. Eleven cultivars were planted in 2008 and 2009 as a half-season crop. Four-row plots 6.9 m by 0.5 m, were monitored bimonthly for °Brix, height, and sugar accumulation. Yield and extractable sap were taken at the end of season. Stalk yield was greatest for the cultivar Sugar Top (4945 kg ha-1) and lowest for Simon (1054 kg ha-1). Dale ranked highest ethanol output (807 L ha-1) while Simon (123more » L ha-1) is the lowest. All cultivars peak Brix accumulation occurs in early October. Individual sugar concentrations indicated sucrose is the predominant sugar with glucose and fructose levels dependent on cultivar. Supplemental ethanol in fermented wort was the best preservative tested to halt degradation of sorghum wort.« less

Vegetation effects on soil water erosion rates and nutrient losses at Santa Catarina highlands, south Brazil

NASA Astrophysics Data System (ADS)

Bertol, I.; Barbosa, F. T.; Vidal Vázquez, E.; Paz Ferreiro, J.

2009-04-01

Water erosion involves three main processes: detachment, transport and deposition of soil particles. The main factors affecting water erosion are rainfall, soil, topography, soil management and land cover and use. Soil erosion potential is increased if the soil has no or very little vegetative cover of plants and/or crop residues, whereas plant and residue cover substantially decrease rates of soil erosion. Plant and residue cover protects the soil from raindrop impact and splash, tends to slow down the movement of surface runoff and allows excess surface water to infiltrate. Moreover, plant and residue cover improve soil physical, chemical and biological properties. Soils with improved structure have a greater resistance to erosion. By contrast, accelerated soil erosion is accentuated by deforestation, biomass burning, plowing and disking, cultivation of open-row crops, etc. The erosion-reducing effectiveness of plant and/or residue covers depends on the type, extent and quantity of cover. Vegetation and residue combinations that completely cover the soil are the most efficient in controlling soil. Partially incorporated residues and residual roots are also important, as these provide channels that allow surface water to move into the soil. The effectiveness of any crop, management system or protective cover also depends on how much protection is available at various periods during the year, relative to the amount of erosive rainfall that falls during these periods. Most of the erosion on annual row crop land can be reduced by leaving a residue cover greater after harvest and over the winter months, or by inter-seeding a forage crop. Soil erosion potential is also affected by tillage operations and tillage system. Conservation tillage reduces water erosion in relation to conventional tillage by increasing soil cover and soil surface roughness. Here, we review the effect of vegetation on soil erosion in the Santa Catarina highlands, south of Brazil, under subtropical climatic conditions. The area cropped under no tillage in Brazil has increased rapidly since 1990, especially in the southern region. This practice was first introduced in the 1970s as a strategy to control soil erosion and continuous declines in land productivity under conventional tillage systems. No tillage almost entirely keeps the previous crop residue on the surface. In the last 15 years soil and water losses by water erosion have been quantified for different soil tillage systems, diverse crop rotations and successive crop stages under simulated and natural rain conditions. Plot experiments showed that soil losses under no tillage systems with a vegetative cover were 98% lower when compared with conventionally tilled bare soil. Moreover water losses were 60% lower for these conditions. Conventional tillage (plowing + harrowing) in the presence of vegetative cover reduced soil losses and water losses by 80% and 50%, respectively, taken the uncultivated bare soil as a reference. The review includes the effect of vegetative cover on nutrient losses at the studied sites in the Santa Catarina highlands.

Soybean canopy reflectance as a function of view and illumination geometry

NASA Technical Reports Server (NTRS)

Ranson, K. J.; Vanderbilt, V. C.; Biehl, L. L.; Robinson, B. F.; Bauer, M. E.

1981-01-01

Reflectances were calculated from measurements at four wavelength bands through eight view azimuth and seven view zenith directions, for various solar zenith and azimuth angles over portions of three days, in an experimental characterization of a soybean field by means of its reflectances and physical and agronomic attributes. Results indicate that the distribution of reflectance from a soybean field is a function of the solar illumination and viewing geometry, wavelength, and row direction, as well as the state of canopy development. Shadows between rows were found to affect visible wavelength band reflectance to a greater extent than near-IR reflectance. A model describing reflectance variation as a function of projected solar and viewing angles is proposed, which approximates the visible wavelength band reflectance variations of a canopy with a well-defined row structure.

Effect of the different cover crops on the soil moisture in a Hungarian vineyard

NASA Astrophysics Data System (ADS)

Donkó, Ádám; Miglécz, Tamás; Valkó, Orsolya; Deák, Balázs; Kelemen, András; Török, Péter; Tóthmérész, Béla; Drexler, Dóra

2017-04-01

Since many years it is well known that the one-sided mechanical soil cultivation of vineyard inter-rows has many disadvantages. Growers can choose from alternative tillage technologies, such as the usage of green manure, or covering the inter-rows with straw mulch. Another possible technology is tto cover the inter-rows with species-rich seed mixtures. However, selection of the most suitable species is crucial; we have to take into consideration the age of the vines, and the specific characteristics of the vineyards involved. Species rich cover crop technology has many advantages: 1) it helps to prevent erosion and creates easier cultivation circumstances, 2) it has a positive effect on soil structure, soil fertility and ecosystem services, 3) we can create native mixtures from local provenance, adapted to the local climate/vine region/vineyard which enhances the nature conservation value of our site. But, they should not compete significantly with the grapevines, or negatively influence produce quality. In the year of 2012 we created, and started to study three different cover-crop mixtures in Hungarian wine regions under on-farm conditions: Biocont-Ecovin mixture, Mixture of Legumes, Mixture of Grass and Herbs. The results of the botanical surveys, yield and pruning weight were published in many papers and presentations before (e.g. Miglécz et al. 2015, Donkó et al. 2016). Besides the above measures, one key point of the effectiveness and sustainability of the living mulch vegetation is the level of soil moisture. That is why we started to investigate the soil moisture (vol %) of different treatments (Biocont-Ecovin mixture, Mixture of Legumes, Mixture of Grass and Herbs, coverage with Lolium perenne, and Control (spontaneous weed flora)) in at the Feind Winery in Balatonfőkajár (Hungary). The investigated variety is Welschriesling on loamy soil (Tihany Formation), planted in 2010. The seed mixtures were sown in the spring of 2013. We measured soil moisture in 2015, at two sampling dates (April and June). During sampling the soil moisture content was measured in seven different depths per sampling point in five replicates: 10 cm, 20 cm, 30 cm, 40 cm, 50 cm, 60 cm, and 70 cm. We found significantly lower indices in case of the Lolium perenne treatment compared to the Grass-forb, and Control treatments in 40-70 cm depth. The results are in accordance with the results of previous research, that state that the use of Lolium perenne in the inter-rows can be sustainable in case of at least 7-800 mm precipitation/year, or under irrigated conditions. Among the three species-rich mixtures we have not found significant differences, but the results show that the Grass-forb mixture (with Plantago lanceolata domination) utilized the least moisture from the soil. Literature Donkó Á, Miglécz T, Valkó O, Tóthmérész B, Deák B, Kelemen A, Török P, Zanathy G, Zsigrai Gy, Drexler D (2015): Intercropping experiments in Hungarian vineyards. HUNGARIAN AGRICULTURE RESEARCH. 24 (4): pp. 31-34. (2015) Miglécz T, Valkó O, Török P, Deák B, Kelemen A, Donkó Á, Drexler D, Tóthmérész B: Establishment of three cover crop mixtures in vineyards. SCIENTIA HORTICULTURAE 197: pp. 117-123. (2015)

Estimation of runoff mitigation by morphologically different cover crop root systems

NASA Astrophysics Data System (ADS)

Yu, Yang; Loiskandl, Willibald; Kaul, Hans-Peter; Himmelbauer, Margarita; Wei, Wei; Chen, Liding; Bodner, Gernot

2016-07-01

Hydrology is a major driver of biogeochemical processes underlying the distinct productivity of different biomes, including agricultural plantations. Understanding factors governing water fluxes in soil is therefore a key target for hydrological management. Our aim was to investigate changes in soil hydraulic conductivity driven by morphologically different root systems of cover crops and their impact on surface runoff. Root systems of twelve cover crop species were characterized and the corresponding hydraulic conductivity was measured by tension infiltrometry. Relations of root traits to Gardner's hydraulic conductivity function were determined and the impact on surface runoff was estimated using HYDRUS 2D. The species differed in both rooting density and root axes thickness, with legumes distinguished by coarser axes. Soil hydraulic conductivity was changed particularly in the plant row where roots are concentrated. Specific root length and median root radius were the best predictors for hydraulic conductivity changes. For an intensive rainfall simulation scenario up to 17% less rainfall was lost by surface runoff in case of the coarsely rooted legumes Melilotus officinalis and Lathyrus sativus, and the densely rooted Linum usitatissimum. Cover crops with coarse root axes and high rooting density enhance soil hydraulic conductivity and effectively reduce surface runoff. An appropriate functional root description can contribute to targeted cover crop selection for efficient runoff mitigation.

Biology and management of Avena fatua and Avena ludoviciana: two noxious weed species of agro-ecosystems.

PubMed

Bajwa, Ali Ahsan; Akhter, Muhammad Javaid; Iqbal, Nadeem; Peerzada, Arslan Masood; Hanif, Zarka; Manalil, Sudheesh; Hashim, Saima; Ali, Hafiz Haider; Kebaso, Lynda; Frimpong, David; Namubiru, Halima; Chauhan, Bhagirath Singh

2017-08-01

Avena fatua and Avena ludoviciana are closely related grass weed species infesting a large number of crops around the world. These species are widely distributed in diverse agro-ecosystems from temperate to sub-tropical regions due to their unique seed traits, successful germination ecology, high competitive ability, and allelopathic potential. A. fatua is more widespread, adaptable, and problematic than A. ludoviciana. Both these species infest major winter and spring crops, including wheat, oat, barley, canola, maize, alfalfa, and sunflower, causing up to 70% yield losses depending on crop species and weed density. Chemical control has been challenged by large-scale herbicide resistance evolution in these weed species. A. fatua is the most widespread herbicide-resistant weed in the world, infesting about 5 million hectares in 13 countries. The use of alternative herbicides with different modes of action has proved effective. Several cultural practices, including diverse crop rotations, cover crops, improved crop competition (using competitive cultivars, high seed rates, narrow row spacing, altered crop geometry), and allelopathic suppression, have shown promise for controlling A. fatua and A. ludoviciana. The integrated use of these cultural methods can reduce the herbicide dose required, and lower dependency on herbicides to control these grasses. Moreover, integrated management may successfully control herbicide-resistant populations of these weed species. The use of integrated approaches based on the knowledge of biology and ecology of A. fatua and A. ludoviciana may help to manage them sustainably in the future.

The effects of more extreme rainfall patterns on nitrogen leaching from a field crop system in the upper Midwest, USA

NASA Astrophysics Data System (ADS)

Hess, L.; Hinckley, E. L. S.; Robertson, G. P.; Matson, P. A.

2016-12-01

As global surface temperatures rise, the proportion of total rainfall that falls in heavy storm events is increasing in many areas, in particular the US Midwest, a major agricultural region. These changes in rainfall patterns may have consequences for ecosystem nutrient losses, especially from agricultural ecosystems. We conducted a multi-year rainfall manipulation experiment to examine how more extreme rainfall patterns affect nitrogen (N) leaching from row-crop ecosystems in the upper Midwest, and to what extent tillage may moderate these effects. 5x5m rainout shelters were installed in April 2015 to impose control and extreme rainfall patterns in replicated plots under conventional tillage and no-till management at the Kellogg Biological Station LTER site. Plots exposed to the control rainfall treatment received ambient rainfall, and those exposed to the extreme rainfall treatment received the same total amount of water but applied once every 2 weeks, to simulate larger, less frequent storms. N leaching was calculated as the product of measured soil water N concentrations and modeled soil water drainage at 1.2m depth using HYDRUS-1D. Based on data to date, more N has been leached from both tilled and no-till soils exposed to the extreme rainfall treatment compared to the control rainfall treatment. Results thus far suggest that greater soil water drainage is a primary driver of this increase, and changes in within-system nitrogen cycling - such as net N mineralization and crop N uptake - may also play a role. The experiment is ongoing, and our results so far suggest that intensifying precipitation patterns may exacerbate N leaching from agricultural soils, with potentially negative consequences for receiving ground- and surface waters, as well as for farmers.

Management of sheath blight and narrow brown leaf spot with biocontrol agents in organic rice, 2010

USDA-ARS?s Scientific Manuscript database

The experiment was established in a field of League-type soil (3% sand, 32% silt, and 64% clay) under organic management for many years at the Texas A&M University System's Agrilife Research and Extension Center, Beaumont. Plots consisted of seven 18-ft rows, and spaced 7 inches between rows. There ...

Optimal design of wind barriers using 3D computational fluid dynamics simulations

NASA Astrophysics Data System (ADS)

Fang, H.; Wu, X.; Yang, X.

2017-12-01

Desertification is a significant global environmental and ecological problem that requires human-regulated control and management. Wind barriers are commonly used to reduce wind velocity or trap drifting sand in arid or semi-arid areas. Therefore, optimal design of wind barriers becomes critical in Aeolian engineering. In the current study, we perform 3D computational fluid dynamics (CFD) simulations for flow passing through wind barriers with different structural parameters. To validate the simulation results, we first inter-compare the simulated flow field results with those from both wind-tunnel experiments and field measurements. Quantitative analyses of the shelter effect are then conducted based on a series of simulations with different structural parameters (such as wind barrier porosity, row numbers, inter-row spacing and belt schemes). The results show that wind barriers with porosity of 0.35 could provide the longest shelter distance (i.e., where the wind velocity reduction is more than 50%) thus are recommended in engineering designs. To determine the optimal row number and belt scheme, we introduce a cost function that takes both wind-velocity reduction effects and economical expense into account. The calculated cost function show that a 3-row-belt scheme with inter-row spacing of 6h (h as the height of wind barriers) and inter-belt spacing of 12h is the most effective.

Soil greenhouse gas (GHG) emissions from smallholder crop-livestock systems in Central Kenya

NASA Astrophysics Data System (ADS)

Ortiz Gonzalo, Daniel; Vaast, Philippe; de Neergaard, Andreas; Oelofse, Myles; Albrecht, Alain; Rosenstock, Todd S.

2017-04-01

Few studies measured empirically greenhouse gas (GHG) emissions in sub-Saharan Africa. More specifically, there is no experimental data on GHG emissions from coffee systems in East Africa and estimations with GHG calculators have shown some limitations. The objectives of our study are to: 1) Quantify soil GHG fluxes in smallholder coffee-dairy farms in Central Kenya and; 2) Compare results with the GHG emissions estimated with GHG calculators. The study area is situated in Murang'a County at 1700 m.a.s.l. on the Eastern slopes of the Aberdares Range, where coffee (Coffee arabica) is cultivated within integrated crop-livestock-agroforestry systems. We carried out GHG measurements along two cropping seasons using non-flow through non-steady static chambers. Sixty rectangular frames (0.355m x 0.255m) were installed at two representative farms, including the three main cropping systems found in the area: 1) Coffee (Coffee arabica); 2) Napier grass (Pennisetum purpureum); 3) Maize intercropped with beans (Zea mays and Phaseolus vulgaris). We used the gas pooling technique to overcome spatial variability and obtain a composite sample from the two treatment chambers: fertilized and non-fertilized. The sampling was performed twice per week during the rainy season and once per week during the dry season. Fertilizer and manure applications were followed by daily measurements during seven days after application. Annual fluxes (cumulative) in coffee plots ranged from 0.8 to 2.1 kg N2O-N ha-1, 6.3 to 8.2 Mg CO2-C ha-1 and -1.3 to -0.8 kg CH4-C ha-1, with higher fluxes during the rainy seasons. Emissions of N2O and CO2 from coffee plots were 20 to 80% higher than those in maize and napier grass. We found significant higher emissions in fertilized hot-spots (45 -190 % higher around coffee bushes perimeter, within maize rows and in napier holes) than in non-fertilized locations (between trees, between rows and between holes). Though this aspect is crucial for upscaling the emissions to farm scale, it is not always accounted in empirical models. GHG calculators overestimated both background and induced soil N2O emissions from fertilizer and manure applications in the three cropping systems. Our study contributes to the generation of underlying data and emission factors (EFs) for quantifying GHG emissions in tropical farming systems.

Delineation of major soil associations using ERTS-1 imagery

NASA Technical Reports Server (NTRS)

Parks, W. L.; Bodenheimer, R. E.

1973-01-01

The delineation of a major soil association in the loess region of Obion County has been accomplished using ERTS-1 imagery. Channel 7 provides the clearest differentiation. The separation of other smaller soil associations in an intensive row crop agricultural area is somewhat more difficult. Soil differentiation has been accomplished visually as well as electronically using a scanning microdensitometer. Lower altitude aircraft imagery permits a more refined soil association identification and where imagery is of sufficient scale, even individual soils may be identified.

Finding of No Significant Impact for the Missouri River Recovery Program Lower Little Sioux Bend Shallow Water Habitat Construction Project

DTIC Science & Technology

2011-07-01

A relatively small portion of this accreted land would be removed by the proposed project and returned to the River. U.S. Army Corps of Engineers... Planting a portion of the site currently utilized for row-crop agriculture to native hardwood tree species. • Gradual sloping of the new River...the change would be localized and so small that it would not be of any measurable or perceptible consequence. Minor: Impact could result in a

Soil Science as a Field Discipline - Experiences in Iowa, USA

NASA Astrophysics Data System (ADS)

Burras, C. Lee

2015-04-01

Effective field understanding of soils is crucial. This is true everywhere but especially so in Iowa, a 15 million hectare state in the central USA's "corn belt." Iowa is intensely farmed and almost exclusively privately owned. Many regions of Iowa have had over 90% of their land area in row crops for the past 60 years. In these regions two very common land management strategies are tile drainage (1.5 million km total) and high rates of fertilization (e.g., 200 kg N/ha-yr for cropland) Iowa also has problematic environmental issues including high rates of erosion, excessive sediment and nutrient pollution in water bodies and episodic catastrophic floods. Given the preceding the Agronomy, Environmental Science and Sustainable Agriculture programs at Iowa State University (ISU) offer a strong suite of soil science classes - undergraduate through graduate. The objective of this presentation is to review selected field based soil science courses offered by those programs. This review includes contrasting and comparing campus-based and immersion classes. Immersion classes include ones offered at Iowa Lakeside Laboratory, as "soil judging" and internationally. Findings over the past 20 years are consistent. Students at all levels gain soil science knowledge, competency and confidence proportional to the amount of time spent in field activities. Furthermore their professional skepticism is sharpened. They are also preferentially hired even in career postings that do not require fieldwork. In other words, field learning results in better soil science professionals who have highly functional and sought after knowledge.

Momentum and particle transport in a nonhomogenous canopy

NASA Astrophysics Data System (ADS)

Gould, Andrew W.

Turbulent particle transport through the air plays an important role in the life cycle of many plant pathogens. In this study, data from a field experiment was analyzed to explore momentum and particle transport within a grape vineyard. The overall goal of these experiments was to understand how the architecture of a sparse agricultural canopy interacts with turbulent flow and ultimately determines the dispersion of airborne fungal plant pathogens. Turbulence in the vineyard canopy was measured using an array of four sonic anemometers deployed at heights z/H 0.4, 0.9, 1.45, and 1.95 where z is the height of the each sonic and H is the canopy height. In addition to turbulence measurements from the sonic anemometers, particle dispersion was measured using inert particles with the approximate size and density of powdery mildew spores and a roto-rod impaction trap array. Measurements from the sonic anemometers demonstrate that first and second order statistics of the wind field are dependent on wind direction orientation with respect to vineyard row direction. This dependence is a result of wind channeling which transfers energy between the velocity components when the wind direction is not aligned with the rows. Although the winds have a strong directional dependence, spectra analysis indicates that the structure of the turbulent flow is not fundamentally altered by the interaction between wind direction and row direction. Examination of a limited number of particle release events indicates that the wind turning and channeling observed in the momentum field impacts particle dispersion. For row-aligned flow, particle dispersion in the direction normal to the flow is decreased relative to the plume spread predicted by a standard Gaussian plume model. For flow that is not aligned with the row direction, the plume is found to rotate in the same manner as the momentum field.

Population Structure of Barley Landrace Populations and Gene-Flow with Modern Varieties

PubMed Central

Bellucci, Elisa; Bitocchi, Elena; Rau, Domenico; Nanni, Laura; Ferradini, Nicoletta; Giardini, Alessandro; Rodriguez, Monica; Attene, Giovanna; Papa, Roberto

2013-01-01

Landraces are heterogeneous plant varieties that are reproduced by farmers as populations that are subject to both artificial and natural selection. Landraces are distinguished by farmers due to their specific traits, and different farmers often grow different populations of the same landrace. We used simple sequence repeats (SSRs) to analyse 12 barley landrace populations from Sardinia from two collections spanning 10 years. We analysed the population structure, and compared the population diversity of the landraces that were collected at field level (population). We used a representative pool of barley varieties for diversity comparisons and to analyse the effects of gene flow from modern varieties. We found that the Sardinian landraces are a distinct gene pool from those of both two-row and six-row barley varieties. There is also a low, but significant, mean level and population-dependent level of introgression from the modern varieties into the Sardinian landraces. Moreover, we show that the Sardinian landraces have the same level of gene diversity as the representative sample of modern commercial varieties grown in Italy in the last decades, even within population level. Thus, these populations represent crucial sources of germplasm that will be useful for crop improvement and for population genomics studies and association mapping, to identify genes, loci and genome regions responsible for adaptive variations. Our data also suggest that landraces are a source of valuable germplasm for sustainable agriculture in the context of future climate change, and that in-situ conservation strategies based on farmer use can preserve the genetic identity of landraces while allowing adaptation to local environments. PMID:24386303

Hydrological and sedimentation implications of landscape changes in a Himalayan catchment due to bioenergy cropping

NASA Astrophysics Data System (ADS)

Remesan, Renji; Holman, Ian; Janes, Victoria

2015-04-01

There is a global effort to focus on the development of bioenergy and energy cropping, due to the generally increasing demand for crude oil, high oil price volatility and climate change mitigation challenges. Second generation energy cropping is expected to increase greatly in India as the Government of India has recently approved a national policy of 20 % biofuel blending by 2017; furthermore, the country's biomass based power generation potential is estimated as around ~24GW and large investments are expected in coming years to increase installed capacity. In this study, we have modelled the environmental influences (e.g.: hydrology and sediment) of scenarios of increased biodiesel cropping (Jatropha curcas) using the Soil and Water Assessment Tool (SWAT) in a northern Indian river basin. SWAT has been applied to the River Beas basin, using daily Tropical Rainfall Measuring Mission (TRMM) precipitation and NCEP Climate Forecast System Reanalysis (CFSR) meteorological data to simulate the river regime and crop yields. We have applied Sequential Uncertainty Fitting Ver. 2 (SUFI-2) to quantify the parameter uncertainty of the stream flow modelling. The model evaluation statistics for daily river flows at the Jwalamukhi and Pong gauges show good agreement with measured flows (Nash Sutcliffe efficiency of 0.70 and PBIAS of 7.54 %). The study has applied two land use change scenarios of (1) increased bioenergy cropping in marginal (grazing) lands in the lower and middle regions of catchment (2) increased bioenergy cropping in low yielding areas of row crops in the lower and middle regions of the catchment. The presentation will describe the improved understanding of the hydrological, erosion and sediment delivery and food production impacts arising from the introduction of a new cropping variety to a marginal area; and illustrate the potential prospects of bioenergy production in Himalayan valleys.

Computation of flow in radial- and mixed-flow cascades by an inviscid-viscous interaction method

NASA Technical Reports Server (NTRS)

Serovy, G. K.; Hansen, E. C.

1980-01-01

The use of inviscid-viscous interaction methods for the case of radial or mixed-flow cascade diffusers is discussed. A literature review of investigations considering cascade flow-field prediction by inviscid-viscous iterative computation is given. Cascade aerodynamics in the third blade row of a multiple-row radial cascade diffuser are specifically investigated.

Weed management and cotton yield under two row spacings, conventional and conservation tillage systems utilizing conventional, glufosinate-, and glyphosate-based weed management systems

USDA-ARS?s Scientific Manuscript database

A field experiment was conducted in 2005 and 2006, to evaluate weed control in conventional, Liberty Link® (LL), and Roundup Ready® (RR) herbicide systems under standard [102 cm (40 inch)] and narrow [38 cm (15 inch)] row-spacings utilizing conventional and high-residue conservation tillage systems....

Polarization signatures for abandoned agricultural fields in the Manix Basin area of the Mojave Desert - Can polarimetric SAR detect desertification?

NASA Technical Reports Server (NTRS)

Ray, Terrill W.; Farr, Tom G.; Van Zyl, Jakob J.

1992-01-01

Radar backscatter from abandoned circular alfalfa fields in the Manix Basin area of the Mojave desert shows systematic changes with length of abandonment. The obliteration of circular planting rows by surface processes could account for the disappearance of bright spokes, which seem to be reflection patterns from remnants of the planting rows, with increasing length of abandonment. An observed shift in the location of the maximum L-band copolarization return away from VV, as well as an increase in surface roughness, both occurring with increasing age of abandonment, seems to be attributable to the formation of wind ripples on the relatively vegetationless fields.

Discriminating crop, weeds and soil surface with a terrestrial LIDAR sensor.

PubMed

Andújar, Dionisio; Rueda-Ayala, Victor; Moreno, Hugo; Rosell-Polo, Joan Ramón; Escolá, Alexandre; Valero, Constantino; Gerhards, Roland; Fernández-Quintanilla, César; Dorado, José; Griepentrog, Hans-Werner

2013-10-29

In this study, the evaluation of the accuracy and performance of a light detection and ranging (LIDAR) sensor for vegetation using distance and reflection measurements aiming to detect and discriminate maize plants and weeds from soil surface was done. The study continues a previous work carried out in a maize field in Spain with a LIDAR sensor using exclusively one index, the height profile. The current system uses a combination of the two mentioned indexes. The experiment was carried out in a maize field at growth stage 12-14, at 16 different locations selected to represent the widest possible density of three weeds: Echinochloa crus-galli (L.) P.Beauv., Lamium purpureum L., Galium aparine L.and Veronica persica Poir.. A terrestrial LIDAR sensor was mounted on a tripod pointing to the inter-row area, with its horizontal axis and the field of view pointing vertically downwards to the ground, scanning a vertical plane with the potential presence of vegetation. Immediately after the LIDAR data acquisition (distances and reflection measurements), actual heights of plants were estimated using an appropriate methodology. For that purpose, digital images were taken of each sampled area. Data showed a high correlation between LIDAR measured height and actual plant heights (R2 = 0.75). Binary logistic regression between weed presence/absence and the sensor readings (LIDAR height and reflection values) was used to validate the accuracy of the sensor. This permitted the discrimination of vegetation from the ground with an accuracy of up to 95%. In addition, a Canonical Discrimination Analysis (CDA) was able to discriminate mostly between soil and vegetation and, to a far lesser extent, between crop and weeds. The studied methodology arises as a good system for weed detection, which in combination with other principles, such as vision-based technologies, could improve the efficiency and accuracy of herbicide spraying.

Discriminating Crop, Weeds and Soil Surface with a Terrestrial LIDAR Sensor

PubMed Central

Andújar, Dionisio; Rueda-Ayala, Victor; Moreno, Hugo; Rosell-Polo, Joan Ramón; Escolà, Alexandre; Valero, Constantino; Gerhards, Roland; Fernández-Quintanilla, César; Dorado, José; Griepentrog, Hans-Werner

2013-01-01

In this study, the evaluation of the accuracy and performance of a light detection and ranging (LIDAR) sensor for vegetation using distance and reflection measurements aiming to detect and discriminate maize plants and weeds from soil surface was done. The study continues a previous work carried out in a maize field in Spain with a LIDAR sensor using exclusively one index, the height profile. The current system uses a combination of the two mentioned indexes. The experiment was carried out in a maize field at growth stage 12–14, at 16 different locations selected to represent the widest possible density of three weeds: Echinochloa crus-galli (L.) P.Beauv., Lamium purpureum L., Galium aparine L.and Veronica persica Poir.. A terrestrial LIDAR sensor was mounted on a tripod pointing to the inter-row area, with its horizontal axis and the field of view pointing vertically downwards to the ground, scanning a vertical plane with the potential presence of vegetation. Immediately after the LIDAR data acquisition (distances and reflection measurements), actual heights of plants were estimated using an appropriate methodology. For that purpose, digital images were taken of each sampled area. Data showed a high correlation between LIDAR measured height and actual plant heights (R2 = 0.75). Binary logistic regression between weed presence/absence and the sensor readings (LIDAR height and reflection values) was used to validate the accuracy of the sensor. This permitted the discrimination of vegetation from the ground with an accuracy of up to 95%. In addition, a Canonical Discrimination Analysis (CDA) was able to discriminate mostly between soil and vegetation and, to a far lesser extent, between crop and weeds. The studied methodology arises as a good system for weed detection, which in combination with other principles, such as vision-based technologies, could improve the efficiency and accuracy of herbicide spraying. PMID:24172283

Soybean canopy reflectance as a function of view and illumination geometry

NASA Technical Reports Server (NTRS)

Bauer, M. E. (Principal Investigator); Ranson, K. J.; Vanderbilt, V. C.; Biehl, L. L.; Robinson, B. F.

1982-01-01

The results of an experiment designed to characterize a soybean field by its reflectance at various view and illumination angles and by its physical and agronomic attributes are presented. Reflectances were calculated from measurements at four wavelength bands through eight view azimuth and seven view zenith directions for various solar zenith and azimuth angles during portions of three days. An ancillary data set consisting of the agronomic and physical characteristics of the soybean field is described. The results indicate that the distribution of reflectance from a soybean field is a function of the solar illumination and viewing geometry, wavelength and row direction, as well as the state of development of the canopy. Shadows between rows greatly affected the reflectance in the visible wavelength bands and to a lesser extent in the near infrared wavelengths. A model is proposed that describes the reflectance variation as a function of projected solar and projected viewing angles. The model appears to approximate the reflectance variations in the visible wavelength bands from a canopy with well defined row structure.

Effects of vegetation, corridor width and regional land use on early successional birds on powerline corridors.

PubMed

Askins, Robert A; Folsom-O'Keefe, Corrine M; Hardy, Margaret C

2012-01-01

Powerline rights-of-way (ROWs) often provide habitat for early successional bird species that have suffered long-term population declines in eastern North America. To determine how the abundance of shrubland birds varies with habitat within ROW corridors and with land use patterns surrounding corridors, we ran Poisson regression models on data from 93 plots on ROWs and compared regression coefficients. We also determined nest success rates on a 1-km stretch of ROW. Seven species of shrubland birds were common in powerline corridors. However, the nest success rates for prairie warbler (Dendroica discolor) and field sparrow (Spizella pusilla) were <21%, which is too low to compensate for estimated annual mortality. Some shrubland bird species were more abundant on narrower ROWs or at sites with lower vegetation or particular types of vegetation, indicating that vegetation management could be refined to favor species of high conservation priority. Also, several species were more abundant in ROWs traversing unfragmented forest than those near residential areas or farmland, indicating that corridors in heavily forested regions may provide better habitat for these species. In the area where we monitored nests, brood parasitism by brown-headed cowbirds (Molothrus ater) occurred more frequently close to a residential area. Although ROWs support dense populations of shrubland birds, those in more heavily developed landscapes may constitute sink habitat. ROWs in extensive forests may contribute more to sustaining populations of early successional birds, and thus may be the best targets for habitat management.

Effects of Vegetation, Corridor Width and Regional Land Use on Early Successional Birds on Powerline Corridors

PubMed Central

Askins, Robert A.; Folsom-O'Keefe, Corrine M.; Hardy, Margaret C.

2012-01-01

Powerline rights-of-way (ROWs) often provide habitat for early successional bird species that have suffered long-term population declines in eastern North America. To determine how the abundance of shrubland birds varies with habitat within ROW corridors and with land use patterns surrounding corridors, we ran Poisson regression models on data from 93 plots on ROWs and compared regression coefficients. We also determined nest success rates on a 1-km stretch of ROW. Seven species of shrubland birds were common in powerline corridors. However, the nest success rates for prairie warbler (Dendroica discolor) and field sparrow (Spizella pusilla) were <21%, which is too low to compensate for estimated annual mortality. Some shrubland bird species were more abundant on narrower ROWs or at sites with lower vegetation or particular types of vegetation, indicating that vegetation management could be refined to favor species of high conservation priority. Also, several species were more abundant in ROWs traversing unfragmented forest than those near residential areas or farmland, indicating that corridors in heavily forested regions may provide better habitat for these species. In the area where we monitored nests, brood parasitism by brown-headed cowbirds (Molothrus ater) occurred more frequently close to a residential area. Although ROWs support dense populations of shrubland birds, those in more heavily developed landscapes may constitute sink habitat. ROWs in extensive forests may contribute more to sustaining populations of early successional birds, and thus may be the best targets for habitat management. PMID:22363660

Experiments and modeling of dilution jet flow fields

NASA Technical Reports Server (NTRS)

Holdeman, James D.

1986-01-01

Experimental and analytical results of the mixing of single, double, and opposed rows of jets with an isothermal or variable-temperature main stream in a straight duct are presented. This study was performed to investigate flow and geometric variations typical of the complex, three-dimensional flow field in the dilution zone of gas-turbine-engine combustion chambers. The principal results, shown experimentally and analytically, were the following: (1) variations in orifice size and spacing can have a significant effect on the temperature profiles; (2) similar distributions can be obtained, independent of orifice diameter, if momentum-flux ratio and orifice spacing are coupled; (3) a first-order approximation of the mixing of jets with a variable-temperature main stream can be obtained by superimposing the main-stream and jets-in-an-isothermal-crossflow profiles; (4) the penetration of jets issuing mixing is slower and is asymmetric with respect to the jet centerplanes, which shift laterally with increasing downstream distance; (5) double rows of jets give temperature distributions similar to those from a single row of equally spaced, equal-area circular holes; (6) for opposed rows of jets, with the orifice centerlines in line, the optimum ratio of orifice spacing to duct height is one-half the optimum value for single-side injection at the same momentum-flux ratiol and (7) for opposed rows of jets, with the orifice centerlines staggered, the optimum ratio of orifice spacing to duct height is twice the optimum value for single-side injection at the same momentum-flux ratio.

Intercropping Competition between Apple Trees and Crops in Agroforestry Systems on the Loess Plateau of China

PubMed Central

Gao, Lubo; Xu, Huasen; Bi, Huaxing; Xi, Weimin; Bao, Biao; Wang, Xiaoyan; Bi, Chao; Chang, Yifang

2013-01-01

Agroforestry has been widely practiced in the Loess Plateau region of China because of its prominent effects in reducing soil and water losses, improving land-use efficiency and increasing economic returns. However, the agroforestry practices may lead to competition between crops and trees for underground soil moisture and nutrients, and the trees on the canopy layer may also lead to shortage of light for crops. In order to minimize interspecific competition and maximize the benefits of tree-based intercropping systems, we studied photosynthesis, growth and yield of soybean (Glycine max L. Merr.) and peanut (Arachis hypogaea L.) by measuring photosynthetically active radiation, net photosynthetic rate, soil moisture and soil nutrients in a plantation of apple (Malus pumila M.) at a spacing of 4 m × 5 m on the Loess Plateau of China. The results showed that for both intercropping systems in the study region, soil moisture was the primary factor affecting the crop yields followed by light. Deficiency of the soil nutrients also had a significant impact on crop yields. Compared with soybean, peanut was more suitable for intercropping with apple trees to obtain economic benefits in the region. We concluded that apple-soybean and apple-peanut intercropping systems can be practical and beneficial in the region. However, the distance between crops and tree rows should be adjusted to minimize interspecies competition. Agronomic measures such as regular canopy pruning, root barriers, additional irrigation and fertilization also should be applied in the intercropping systems. PMID:23936246

Intercropping competition between apple trees and crops in agroforestry systems on the Loess Plateau of China.

PubMed

Gao, Lubo; Xu, Huasen; Bi, Huaxing; Xi, Weimin; Bao, Biao; Wang, Xiaoyan; Bi, Chao; Chang, Yifang

2013-01-01

Agroforestry has been widely practiced in the Loess Plateau region of China because of its prominent effects in reducing soil and water losses, improving land-use efficiency and increasing economic returns. However, the agroforestry practices may lead to competition between crops and trees for underground soil moisture and nutrients, and the trees on the canopy layer may also lead to shortage of light for crops. In order to minimize interspecific competition and maximize the benefits of tree-based intercropping systems, we studied photosynthesis, growth and yield of soybean (Glycine max L. Merr.) and peanut (Arachis hypogaea L.) by measuring photosynthetically active radiation, net photosynthetic rate, soil moisture and soil nutrients in a plantation of apple (Malus pumila M.) at a spacing of 4 m × 5 m on the Loess Plateau of China. The results showed that for both intercropping systems in the study region, soil moisture was the primary factor affecting the crop yields followed by light. Deficiency of the soil nutrients also had a significant impact on crop yields. Compared with soybean, peanut was more suitable for intercropping with apple trees to obtain economic benefits in the region. We concluded that apple-soybean and apple-peanut intercropping systems can be practical and beneficial in the region. However, the distance between crops and tree rows should be adjusted to minimize interspecies competition. Agronomic measures such as regular canopy pruning, root barriers, additional irrigation and fertilization also should be applied in the intercropping systems.

Response of Main Maize Varieties to Water Stress and Comprehensive Evaluation in Hebei Province

NASA Astrophysics Data System (ADS)

Yue, Haiwang; Chen, Shuping; Bu, Junzhou; Wei, Jianwei; Peng, Haicheng; Li, Yuan; Li, Chunjie; Xie, Junliang

2018-01-01

Drought is a serious threat to maize production in Hebei province. Planting drought resistant maize varieties is an effective measure to solve drought in arid and less rain areas. Drought resistance in maize is controlled by many genes, and multiple indexes should be used for comprehensive evaluation (Campos H et al.2004). In the arid rain shed, using 34 maize varieties to promote crop production compared to the drought resistance test. The experiment was conducted with two treatments of drought stress (irrigation only at seedling stage) and normal irrigation, and 12 agronomic traits related to drought resistance of maize were determined. The results showed that drought had significant effects on maize yield and main agronomic characters. Under drought stress, plant height, ear length, bare tip, ear row number, row grains, 1000-kernel weight, ASI index can be used as identification index of drought resistance of maize in different period. The results indicated that the variety with strong drought resistance is Zhongdi175, the worst drought resistance is Woyu964.

Variable rainfall intensity and tillage effects on runoff, sediment, and carbon losses from a loamy sand under simulated rainfall.

PubMed

Truman, C C; Strickland, T C; Potter, T L; Franklin, D H; Bosch, D D; Bednarz, C W

2007-01-01

The low-carbon, intensively cropped Coastal Plain soils of Georgia are susceptible to runoff, soil loss, and drought. Reduced tillage systems offer the best management tool for sustained row crop production. Understanding runoff, sediment, and chemical losses from conventional and reduced tillage systems is expected to improve if the effect of a variable rainfall intensity storm was quantified. Our objective was to quantify and compare effects of a constant (Ic) intensity pattern and a more realistic, observed, variable (Iv) rainfall intensity pattern on runoff (R), sediment (E), and carbon losses (C) from a Tifton loamy sand cropped to conventional-till (CT) and strip-till (ST) cotton (Gossypium hirsutum L.). Four treatments were evaluated: CT-Ic, CT-Iv, ST-Ic, and ST-Iv, each replicated three times. Field plots (n=12), each 2 by 3 m, were established on each treatment. Each 6-m2 field plot received simulated rainfall at a constant (57 mm h(-1)) or variable rainfall intensity pattern for 70 min (12-run ave.=1402 mL; CV=3%). The Iv pattern represented the most frequent occurring intensity pattern for spring storms in the region. Compared with CT, ST decreased R by 2.5-fold, E by 3.5-fold, and C by 7-fold. Maximum runoff values for Iv events were 1.6-fold higher than those for Ic events and occurred 38 min earlier. Values for Etot and Ctot for Iv events were 19-36% and 1.5-fold higher than corresponding values for Ic events. Values for Emax and Cmax for Iv events were 3-fold and 4-fold higher than corresponding values for Ic events. Carbon enrichment ratios (CER) were or=1.0 for CT plots (except for first 20 min). Maximum CER for CT-Ic, CT-Iv, ST-Ic, and ST-Iv were 2.0, 2.2, 1.0, and 1.2, respectively. Transport of sediment, carbon, and agrichemicals would be better understood if variable rainfall intensity patterns derived from natural rainfall were used in rainfall simulations to evaluate their fate and transport from CT and ST systems.

Use of Landsat imagery to estimate ground-water pumpage for irrigation on the Columbia Plateau in eastern Washington, 1985

USGS Publications Warehouse

Van Metre, P.C.; Seevers, Paul

1991-01-01

A method for estimating ground-water pumpage for irrigation was developed for the Columbia Plateau in eastern Washington. The method combines water-application rates estimated from pumpage data with acreage of irrigated crops that was mapped by using Landsat imagery. The study area consisted of Grant, Lincoln, Adams, and Franklin Counties, an area of approximately 8,900 square miles, and accounts for approximately three-fourths of the ground-water pumpage in the Columbia Plateau in eastern Washington. Data from two passes of Landsat's multispectral scanner were analyzed by using a spectral band ratioing procedure to map irrigated crops for the study area. Data from one pass of Landsat's thematic mapper, covering approximately two-thirds of the study area, also were analyzed for determining irrigated crops in the area resulting in a 6-percent improvement in accuracy over the multispectral scanner analysis. A total of 576 annual water-application rates associated with particular crops, for the 1982 through 1985 seasons, were calculated. A regression equation was developed for estimating annual water-application rates as a function of crop type, annual precipitation, irrigation system type, and available water capacity of the soil. Crops were grouped into three water-use categories: (1) small grains, primarily wheat and barley; (2) high water-use crops consisting of corn, alfalfa, and potatoes; and (3) miscellaneous vegetable and row crops. Annual water-application rates, expressed as a depth of water, then were multiplied by irrigated area determined by Landsat to estimate a volume of water pumped for irrigation for 1985-620,000 acre-feet. An assessment of accuracy for estimating pumpage for 28 of the sites showed that total predicted pumpage was within 4 percent of the total observed pumpage.

[Light competition and productivity of agroforestry system in loess area of Weibei in Shaanxi].

PubMed

Peng, Xiao-bang; Cai, Jing; Jiang, Zai-min; Zhang, Yuan-ying; Zhang, Shuo-xin

2008-11-01

Agroforestry is the most effective way for the restoration of disturbed land on Loess Plateau and the development of poorly local economy. Taking the tree-based intercropping systems of walnut or plum with soybean or pepper in the loess area of Weibei as test objects, the photosynthesis, growth, and yield of soybean (Qindou 8) and pepper (Shanjiao 981) in the systems were studied. The results showed that the photosynthetic active radiation (PAR), net photosynthetic rate (Pn), growth, and yield of individual soybean or pepper plants were significantly decreased, with the effects increased with decreasing distance from tree rows. Leaf water potential was not significantly or poorly correlated with the Pn, growth, and yield of the two crops. However, there were significant positive correlations between the soil moisture content in 10-20 cm layer and the biomass and yield of soybean, and the above-ground biomass of pepper. PAR was highly correlated with the yield of both crops, which indicated that light competition was one of the key factors leading to the decrease of crop yield.

Automated Mobile System for Accurate Outdoor Tree Crop Enumeration Using an Uncalibrated Camera.

PubMed

Nguyen, Thuy Tuong; Slaughter, David C; Hanson, Bradley D; Barber, Andrew; Freitas, Amy; Robles, Daniel; Whelan, Erin

2015-07-28

This paper demonstrates an automated computer vision system for outdoor tree crop enumeration in a seedling nursery. The complete system incorporates both hardware components (including an embedded microcontroller, an odometry encoder, and an uncalibrated digital color camera) and software algorithms (including microcontroller algorithms and the proposed algorithm for tree crop enumeration) required to obtain robust performance in a natural outdoor environment. The enumeration system uses a three-step image analysis process based upon: (1) an orthographic plant projection method integrating a perspective transform with automatic parameter estimation; (2) a plant counting method based on projection histograms; and (3) a double-counting avoidance method based on a homography transform. Experimental results demonstrate the ability to count large numbers of plants automatically with no human effort. Results show that, for tree seedlings having a height up to 40 cm and a within-row tree spacing of approximately 10 cm, the algorithms successfully estimated the number of plants with an average accuracy of 95.2% for trees within a single image and 98% for counting of the whole plant population in a large sequence of images.

Automated Mobile System for Accurate Outdoor Tree Crop Enumeration Using an Uncalibrated Camera

PubMed Central

Nguyen, Thuy Tuong; Slaughter, David C.; Hanson, Bradley D.; Barber, Andrew; Freitas, Amy; Robles, Daniel; Whelan, Erin

2015-01-01

This paper demonstrates an automated computer vision system for outdoor tree crop enumeration in a seedling nursery. The complete system incorporates both hardware components (including an embedded microcontroller, an odometry encoder, and an uncalibrated digital color camera) and software algorithms (including microcontroller algorithms and the proposed algorithm for tree crop enumeration) required to obtain robust performance in a natural outdoor environment. The enumeration system uses a three-step image analysis process based upon: (1) an orthographic plant projection method integrating a perspective transform with automatic parameter estimation; (2) a plant counting method based on projection histograms; and (3) a double-counting avoidance method based on a homography transform. Experimental results demonstrate the ability to count large numbers of plants automatically with no human effort. Results show that, for tree seedlings having a height up to 40 cm and a within-row tree spacing of approximately 10 cm, the algorithms successfully estimated the number of plants with an average accuracy of 95.2% for trees within a single image and 98% for counting of the whole plant population in a large sequence of images. PMID:26225982

The Use of Cover Crops as Climate-Smart Management in Midwest Cropping Systems

NASA Astrophysics Data System (ADS)

Basche, A.; Miguez, F.; Archontoulis, S.; Kaspar, T.

2014-12-01

The observed trends in the Midwestern United States of increasing rainfall variability will likely continue into the future. Events such as individual days of heavy rain as well as seasons of floods and droughts have large impacts on agricultural productivity and the natural resource base that underpins it. Such events lead to increased soil erosion, decreased water quality and reduced corn and soybean yields. Winter cover crops offer the potential to buffer many of these impacts because they essentially double the time for a living plant to protect and improve the soil. However, at present, cover crops are infrequently utilized in the Midwest (representing 1-2% of row cropped land cover) in particular due to producer concerns over higher costs and management, limited time and winter growing conditions as well as the potential harm to corn yields. In order to expand their use, there is a need to quantify how cover crops impact Midwest cropping systems in the long term and namely to understand how to optimize the benefits of cover crops while minimizing their impacts on cash crops. We are working with APSIM, a cropping systems platform, to specifically quantify the long term future impacts of cover crop incorporation in corn-based cropping systems. In general, our regional analysis showed only minor changes to corn and soybean yields (<1% differences) when a cover crop was or was not included in the simulation. Further, a "bad spring" scenario (where every third year had an abnormally wet/cold spring and cover crop termination and planting cash crop were within one day) did not result in any major changes to cash crop yields. Through simulations we estimate an average increase of 4-9% organic matter improvement in the topsoil and an average decrease in soil erosion of 14-32% depending on cover crop planting date and growth. Our work is part of the Climate and Corn-based Cropping Systems Coordinated Agriculture Project (CSCAP), a collaboration of eleven Midwestern institutions established to evaluate how conservation practices, including cover crops, improve the resilience of Midwest agriculture to future change. Such collaborations can help better quantify long term impacts of conservation practices on the landscape that ultimately lead to more climate-smart management of such agricultural systems.

Computer systems and methods for the query and visualization of multidimensional databases

DOEpatents

Stolte, Chris; Tang, Diane L.; Hanrahan, Patrick

2015-11-10

A computer displays a graphical user interface on its display. The graphical user interface includes a schema information region and a data visualization region. The schema information region includes a plurality of fields of a multi-dimensional database that includes at least one data hierarchy. The data visualization region includes a columns shelf and a rows shelf. The computer detects user actions to associate one or more first fields with the columns shelf and to associate one or more second fields with the rows shelf. The computer generates a visual table in the data visualization region in accordance with the user actions. The visual table includes one or more panes. Each pane has an x-axis defined based on data for the one or more first fields, and each pane has a y-axis defined based on data for the one or more second fields.

Planting pattern and weed control method influence on yield production of corn (Zea mays L.)

NASA Astrophysics Data System (ADS)

Purba, E.; Nasution, D. P.

2018-02-01

Field experiment was carried out to evaluate the influence of planting patterns and weed control methods on the growth and yield of corn. The effect of the planting pattern and weed control method was studied in a split plot design. The main plots were that of planting pattern single row (25cm x 60cm), double row (25cm x 25cm x 60cm) and triangle row ( 25cm x 25cm x 25cm). Subplot was that of weed control method consisted five methods namely weed free throughout the growing season, hand weeding, sprayed with glyphosate, sprayed with paraquat, and no weeding.. Result showed that both planting pattern and weed control method did not affect the growth of corn. However, planting pattern and weed control method significantly affected yield production. Yield resulted from double row and triangle planting pattern was 14% and 41% higher, consecutively, than that of single row pattern. The triangle planting pattern combined with any weed control method produced the highest yield production of corn.

Development of a Linearized Unsteady Euler Analysis with Application to Wake/Blade-Row Interactions

NASA Technical Reports Server (NTRS)

Verdon, Joseph M.; Montgomery, Matthew D.; Chuang, H. Andrew

1999-01-01

A three-dimensional, linearized, Euler analysis is being developed to provide a comprehensive and efficient unsteady aerodynamic analysis for predicting the aeroacoustic and aeroelastic responses of axial-flow turbomachinery blading. The mathematical models needed to describe nonlinear and linearized, inviscid, unsteady flows through a blade row operating within a cylindrical annular duct are presented in this report. A numerical model for linearized inviscid unsteady flows, which couples a near-field, implicit, wave-split, finite volume analysis to far-field eigen analyses, is also described. The linearized aerodynamic and numerical models have been implemented into the three-dimensional unsteady flow code, LINFLUX. This code is applied herein to predict unsteady subsonic flows driven by wake or vortical excitations. The intent is to validate the LINFLUX analysis via numerical results for simple benchmark unsteady flows and to demonstrate this analysis via application to a realistic wake/blade-row interaction. Detailed numerical results for a three-dimensional version of the 10th Standard Cascade and a fan exit guide vane indicate that LINFLUX is becoming a reliable and useful unsteady aerodynamic prediction capability that can be applied, in the future, to assess the three-dimensional flow physics important to blade-row, aeroacoustic and aeroelastic responses.

A CFD analysis of blade row interactions within a high-speed axial compressor

NASA Astrophysics Data System (ADS)

Richman, Michael Scott

Aircraft engine design provides many technical and financial hurdles. In an effort to streamline the design process, save money, and improve reliability and performance, many manufacturers are relying on computational fluid dynamic simulations. An overarching goal of the design process for military aircraft engines is to reduce size and weight while maintaining (or improving) reliability. Designers often turn to the compression system to accomplish this goal. As pressure ratios increase and the number of compression stages decrease, many problems arise, for example stability and high cycle fatigue (HCF) become significant as individual stage loading is increased. CFD simulations have recently been employed to assist in the understanding of the aeroelastic problems. For accurate multistage blade row HCF prediction, it is imperative that advanced three-dimensional blade row unsteady aerodynamic interaction codes be validated with appropriate benchmark data. This research addresses this required validation process for TURBO, an advanced three-dimensional multi-blade row turbomachinery CFD code. The solution/prediction accuracy is characterized, identifying key flow field parameters driving the inlet guide vane (IGV) and stator response to the rotor generated forcing functions. The result is a quantified evaluation of the ability of TURBO to predict not only the fundamental flow field characteristics but the three dimensional blade loading.

Cotton Production Practices Change Soil Properties

NASA Astrophysics Data System (ADS)

Blaise, D.; Singh, J. V.

2012-04-01

Historically, indigenous Asiatic cottons (Gossypium arboreum) were cultivated with minimal inputs in India. The introduction of the Upland cottons (G. hirsutum) and later the hybrid (H-4) triggered a whole set of intensified agronomic management with reliance on high doses of fertilisers and pesticide usage. In 2002, the transgenic Bt cotton hybrids were introduced and released for commercial cultivation. Presently, more than 95% of the nearly 12.2 million hectares of cotton area is under the Bt transgenic hybrids. These hybrids are not only high yielding but have reduced the dependence on pesticide because of an effective control of the lepidopteran pests. Thus, a change in the management practices is evident over the years. In this paper, we discuss the impact of two major agronomic management practices namely, nutrient management and tillage besides organic cotton cultivation in the rainfed cotton growing regions of central India characterized by sub-humid to semi-arid climate and dominated by Vertisols. Long-term studies at Nagpur, Maharashtra indicated the importance of integrated nutrient management (INM) wherein a part of the nutrient needs through fertiliser was substituted with organic manures such as farmyard manure (FYM). With the application of mineral fertilisers alone, soils became deficient in micronutrients. This was not observed with the FYM amended plots. Further, the manure amended plots had a better soil physical properties and the water holding capacity of the soil improved due to improvements in soil organic matter (SOM). Similarly, in a separate experiment, an improvement in SOM was observed in the organically managed fields because of continuous addition of organic residues. Further, it resulted in greater biological activity compared to the conventionally managed fields. Conservation tillage systems such as reduced tillage (RT) are a means to improve soil health and crop productivity. Long-term studies on tillage practices such as conventional tillage {CT}, RT with two inter-row cultivations {RT1} and RT with no inter-row cultivation {RT2} were conducted for 11 years. At the end of the study, an improvement in the soil physical properties such as water stable aggregates and mean weight diameter were observed in the RT system and the plots amended with green manure (GM) cover crop compared to those without. Further, available soil moisture content was greater in the GM mulched plots up to 0.60 m depth compared to the without GM treatment. The RT systems, too, had a higher SOM content than the CT probably due to less soil disturbance and greater retention of crop residues. INM and conservation tillage are strategies to sequester C and reduce emissions. It can also mitigate green house gas emissions because less of fertiliser would be used in the INM treatments. Studies conducted, thus far, have not indicated any adverse effect of Bt cotton cultivation. However, there could be a possibility, of nutrient depletion with the cultivation of Bt transgenic hybrids because of higher biomass and nutrient removal increasing the nutrient demand. Studies on these aspects are needed to understand how long-term cultivation of Bt cotton hybrids will alter the soil properties.

The potential of climate change adjustment in crops: A synthesis

USDA-ARS?s Scientific Manuscript database

This chapter covers a study on various field crops like cereals, legumes, oil seeds, vegetables, cash crops, underutilized crops, and energy crops and their genetic adjustment to changing climates. More than 30 major field crops have been covered in different chapters of this book, which highlight h...

Application of holography to flow visualization within rotating compressor blade row. [to determine three dimensional shock patterns

NASA Technical Reports Server (NTRS)

Wuerker, R. F.; Kobayashi, R. J.; Heflinger, L. O.; Ware, T. C.

1974-01-01

Two holographic interblade row flow visualization systems were designed to determine the three-dimensional shock patterns and velocity distributions within the rotating blade row of a transonic fan rotor, utilizing the techniques of pulsed laser transmission holography. Both single- and double-exposure bright field holograms and dark field scattered-light holograms were successfully recorded. Two plastic windows were installed in the rotor tip casing and outer casing forward of the rotor to view the rotor blade passage. The viewing angle allowed detailed investigation of the leading edge shocks and shocks in the midspan damper area; limited details of the trailing edge shocks also were visible. A technique was devised for interpreting the reconstructed holograms by constructing three dimensional models that allowed identification of the major shock systems. The models compared favorably with theoretical predictions and results of the overall and blade element data. Most of the holograms were made using the rapid double-pulse technique.

Effects of alternative cropping systems on globe artichoke qualitative traits.

PubMed

Spanu, Emanuela; Deligios, Paola A; Azara, Emanuela; Delogu, Giovanna; Ledda, Luigi

2018-02-01

Traditionally, globe artichoke cultivation in the Mediterranean basin is based on monoculture and on use of high amounts of nitrogen fertiliser. This raises issues regarding its compatibility with sustainable agriculture. We studied the effect of one typical conventional (CONV) and two alternative cropping systems [globe artichoke in sequence with French bean (NCV1), or in biannual rotation (NCV2) with cauliflower and with a leguminous cover crop in inter-row spaces] on yield, polyphenol and mineral content of globe artichoke heads over two consecutive growing seasons. NCV2 showed statistical differences in terms of fresh product yield with respect to the monoculture systems. In addition, the dihydroxycinnamic acids and dicaffeoylquinic acids of non-conventional samples were one-fold significantly higher than the conventional one. All the samples reported good mineral content, although NCV2 achieved a higher Fe content than conventional throughout the two seasons. After two and three dates of sampling, the CONV samples showed the highest levels of K content. In our study, an acceptable commercial yield and quality of 'Spinoso sardo' were achieved by shifting the common conventional agronomic management to more sustainable ones, by means of an accurate choice of cover crop species and rotations introduced in the systems. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Organically fertilized onions (Allium cepa L.): effects of the fertilizer placement method on quercetin content and soil nitrogen dynamics.

PubMed

Mogren, Lars M; Caspersen, Siri; Olsson, Marie E; Gertsson, Ulla E

2008-01-23

Field-cured onions cv. Hyskin ( Allium cepa L.) supplied with organic nitrogen fertilizer were studied. The fertilizer was applied by broadcasting and harrowing, broadcasting and rotary cultivation, or placement between rows. Nitrogen dynamics were monitored throughout the growing season by soil sampling. Variation in quercetin content in the onion scales was analyzed by HPLC. The organically fertilized onions were compared with inorganically fertilized onions grown in the same field. Inoculation with arbuscular mycorrhizal fungi (AMF) in the row at sowing or during commercial transplant production was tested but did not significantly affect mycorrhizal root colonization levels in the field. Onions that received no fertilizer at all or that had fertilizer placed between rows had better establishment, probably due to more favorable soil nitrogen concentrations for seedling emergence. Broadcast application led to higher nitrogen concentration in the root zone, resulting in fewer but larger individual onions. Quercetin levels were not significantly altered as a result of nitrogen fertilizer source (inorganic or organic), application method, or mycorrhizal inoculation. However, variation between years was significant, with quercetin levels in 2004 almost twice as high as those in 2005.

Assessing HYDRUS-2D model to estimate soil water contents and olive tree transpiration fluxes under different water distribution systems

NASA Astrophysics Data System (ADS)

Autovino, Dario; Negm, Amro; Rallo, Giovanni; Provenzano, Giuseppe

2016-04-01

In Mediterranean countries characterized by limited water resources for agricultural and societal sectors, irrigation management plays a major role to improve water use efficiency at farm scale, mainly where irrigation systems are correctly designed to guarantee a suitable application efficiency and the uniform water distribution throughout the field. In the last two decades, physically-based agro-hydrological models have been developed to simulate mass and energy exchange processes in the soil-plant-atmosphere (SPA) system. Mechanistic models like HYDRUS 2D/3D (Šimunek et al., 2011) have been proposed to simulate all the components of water balance, including actual crop transpiration fluxes estimated according to a soil potential-dependent sink term. Even though the suitability of these models to simulate the temporal dynamics of soil and crop water status has been reported in the literature for different horticultural crops, a few researches have been considering arboreal crops where the higher gradients of root water uptake are the combination between the localized irrigation supply and the three dimensional root system distribution. The main objective of the paper was to assess the performance of HYDRUS-2D model to evaluate soil water contents and transpiration fluxes of an olive orchard irrigated with two different water distribution systems. Experiments were carried out in Castelvetrano (Sicily) during irrigation seasons 2011 and 2012, in a commercial farm specialized in the production of table olives (Olea europaea L., var. Nocellara del Belice), representing the typical variety of the surrounding area. During the first season, irrigation water was provided by a single lateral placed along the plant row with four emitters per plant (ordinary irrigation), whereas during the second season a grid of emitters laid on the soil was installed in order to irrigate the whole soil surface around the selected trees. The model performance was assessed based on the comparison between measured and simulated soil water content and actual transpiration fluxes, under the hypothesis to neglect the contribute of the tree capacitance. Moreover, two different crop water stress functions and in particular the linear model proposed by Feddes et al. (1978) and the S-shape model suggested by van Genuchten et al. (1987), were considered. The result of the study evidenced that for the investigated crop and under the examined conditions, HYDRUS-2D model reproduces fairly well the dynamic of soil water contents at different distances from the emitters (RMSE<0.09 cm3 cm-3) and actual crop transpiration fluxes (RMSE<0.11 mm d-1), whose estimations can be slightly improved by assuming a S-shape crop water stress function. Key-words: Olive tree, HYDRUS-2D, Soil water content, Actual transpiration fluxes

Initial nitrous oxide, carbon dioxide, and methane costs of converting conservation reserve program grassland to row crops under no-till vs. conventional tillage.

PubMed

Ruan, Leilei; Philip Robertson, G

2013-08-01

Around 4.4 million ha of land in USDA Conservation Reserve Program (CRP) contracts will expire between 2013 and 2018 and some will likely return to crop production. No-till (NT) management offers the potential to reduce the global warming costs of CO2 , CH4 , and N2 O emissions during CRP conversion, but to date there have been no CRP conversion tillage comparisons. In 2009, we converted portions of three 9-21 ha CRP fields in Michigan to conventional tillage (CT) or NT soybean production and reserved a fourth field for reference. Both CO2 and N2 O fluxes increased following herbicide application in all converted fields, but in the CT treatment substantial and immediate N2 O and CO2 fluxes occurred after tillage. For the initial 201-day conversion period, average daily N2 O fluxes (g N2 O-N ha(-1)  d(-1) ) were significantly different in the order: CT (47.5 ± 6.31, n = 6) ≫ NT (16.7 ± 2.45, n = 6) ≫ reference (2.51 ± 0.73, n = 4). Similarly, soil CO2 fluxes in CT were 1.2 times those in NT and 3.1 times those in the unconverted CRP reference field. All treatments were minor sinks for CH4 (-0.69 ± 0.42 to -1.86 ± 0.37 g CH4 -C ha(-1)  d(-1) ) with no significant differences among treatments. The positive global warming impact (GWI) of converted soybean fields under both CT (11.5 Mg CO2 e ha(-1) ) and NT (2.87 Mg CO2 e ha(-1) ) was in contrast to the negative GWI of the unconverted reference field (-3.5 Mg CO2 e ha(-1) ) with on-going greenhouse gas (GHG) mitigation. N2 O contributed 39.3% and 55.0% of the GWI under CT and NT systems with the remainder contributed by CO2 (60.7% and 45.0%, respectively). Including foregone mitigation, we conclude that NT management can reduce GHG costs by ~60% compared to CT during initial CRP conversion. © 2013 John Wiley & Sons Ltd.

Remote sensing of perennial crop stand duration and pre-crop identification

USDA-ARS?s Scientific Manuscript database

Field to field variability in soil erosion and off-site transport of nutrients and pesticides in western Oregon in any single year is primarily driven by the question of whether individual fields were disturbed for planting of new crop stands or remained in production of established perennial crops...

The importance of pH and sand substrate in the revegetation of saline non-waterlogged peat fields.

PubMed

Montemayor, Marilou B; Price, Jonathan; Rochefort, Line

2015-11-01

A partially peat-extracted coastal bog contaminated by seawater was barren and required revegetation as a wetland. Peat fields were rectangular in shape, cambered in cross-section profile, and separated by drainage ditches. Common to all peat fields were symmetrical patterns in micro-topography with slopes between differences in elevation. Saline non-waterlogged slopes of ∼5% occurred as a symmetrical pair on each side of the crest of the cambered profile, at one end of each peat field. Three rows were laid across this slope (Top, Middle, and Bottom rows) and transplanted with naturally-growing plant species with their sand substrate, in three experiments, and grown for a year. In the Spartina pectinata experiment, bare root stem sections were also planted. Another experiment was conducted to determine changes in the characteristics of a volume of sand when incubated in saline peat fields. We found the salinity of peat increased with moisture downslope, and pH decreased with increase in salinity. S. pectinata grew best when planted with its sand substrate compared with bare root stem section, and when planted in Bottom rows. Juncus balticus had excellent growth in all rows. Unexpectedly, Festuca rubra that was inconspicuous beneath the J. balticus canopy in the natural donor site grew densely within the J. balticus sods. Agrostis stolonifera grew well but seemed to show intolerance to the surrounding acidic peat by curling up its stolons. The pH of the incubated sand volume was much higher than the surrounding peat. These studies suggest that recognition of plant niches and pH manipulation are important in the revegetation of disturbed Sphagnum peatlands that are found abundantly in the northern hemisphere. Results are also relevant to the reclamation of other disturbed lands. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of a telemetry and yield-mapping system of olive harvester.

PubMed

Castillo-Ruiz, Francisco J; Pérez-Ruiz, Manuel; Blanco-Roldán, Gregorio L; Gil-Ribes, Jesús A; Agüera, Juan

2015-02-10

Sensors, communication systems and geo-reference units are required to achieve an optimized management of agricultural inputs with respect to the economic and environmental aspects of olive groves. In this study, three commercial olive harvesters were tracked during two harvesting seasons in Spain and Chile using remote and autonomous equipment that was developed to determine their time efficiency and effective based on canopy shaking for fruit detachment. These harvesters work in intensive/high-density (HD) and super-high-density (SHD) olive orchards. A GNSS (Global Navigation Satellite System) and GSM (Global System for Mobile Communications) device was installed to track these harvesters. The GNSS receiver did not affect the driver's work schedule. Time elements methodology was adapted to the remote data acquisition system. The effective field capacity and field efficiency were investigated. In addition, the field shape, row length, angle between headland alley and row, and row alley width were measured to determinate the optimum orchard design parameters value. The SHD olive harvester showed significant lower effective field capacity values when alley width was less than 4 m. In addition, a yield monitor was developed and installed on a traditional olive harvester to obtain a yield map from the harvested area. The hedge straddle harvester stood out for its highly effective field capacity; nevertheless, a higher field efficiency was provided by a non-integral lateral canopy shaker. All of the measured orchard parameters have influenced machinery yields, whether effective field capacity or field efficiency. A saving of 40% in effective field capacity was achieved with a reduction from 4 m or higher to 3.5 m in alley width for SHD olive harvester. A yield map was plotted using data that were acquired by a yield monitor, reflecting the yield gradient in spite of the larger differences between tree yields.

Sampling design for groundwater solute transport: Tests of methods and analysis of Cape Cod tracer test data

USGS Publications Warehouse

Knopman, Debra S.; Voss, Clifford I.; Garabedian, Stephen P.

1991-01-01

Tests of a one-dimensional sampling design methodology on measurements of bromide concentration collected during the natural gradient tracer test conducted by the U.S. Geological Survey on Cape Cod, Massachusetts, demonstrate its efficacy for field studies of solute transport in groundwater and the utility of one-dimensional analysis. The methodology was applied to design of sparse two-dimensional networks of fully screened wells typical of those often used in engineering practice. In one-dimensional analysis, designs consist of the downstream distances to rows of wells oriented perpendicular to the groundwater flow direction and the timing of sampling to be carried out on each row. The power of a sampling design is measured by its effectiveness in simultaneously meeting objectives of model discrimination, parameter estimation, and cost minimization. One-dimensional models of solute transport, differing in processes affecting the solute and assumptions about the structure of the flow field, were considered for description of tracer cloud migration. When fitting each model using nonlinear regression, additive and multiplicative error forms were allowed for the residuals which consist of both random and model errors. The one-dimensional single-layer model of a nonreactive solute with multiplicative error was judged to be the best of those tested. Results show the efficacy of the methodology in designing sparse but powerful sampling networks. Designs that sample five rows of wells at five or fewer times in any given row performed as well for model discrimination as the full set of samples taken up to eight times in a given row from as many as 89 rows. Also, designs for parameter estimation judged to be good by the methodology were as effective in reducing the variance of parameter estimates as arbitrary designs with many more samples. Results further showed that estimates of velocity and longitudinal dispersivity in one-dimensional models based on data from only five rows of fully screened wells each sampled five or fewer times were practically equivalent to values determined from moments analysis of the complete three-dimensional set of 29,285 samples taken during 16 sampling times.

Straw management and greenhouse gas emissions in sugarcane cropping in São Paulo State, Brazil

NASA Astrophysics Data System (ADS)

Pitombo, L.; Cantarella, H.; Packer, A.; Ramos, N.; de Lima, M.; Carmo, J.

2012-04-01

Greenhouse gas emissions during the cropping would consolidate or derail the biofuels as an environmental commodity, mainly due to N2O emissions from fertilizers. It occurs because the Greenhouse Gas Potential of N2O is 298 times greater than CO2; thus, the range among the balance favorable or not is very close. Since in São Paulo State the sugarcane harvest has been changed from burned to no-burned form due to environmental and social factors, the straw is maintained in the field. However, primarily because straw changes carbon, nitrogen and water availability, we hypothesized that straw influences N2O emissions from soil. At this work, our aim is to determine the amount of applied fertilizer emitted as N2O in sugarcane crop with different levels of straw maintained in the field. The experiment was installed in October 2011 in a commercial area in São Paulo State, which is the principal producer in Brazil (22°22' S, 47°30'W). It is conducted in four blocks with four plots (12x15m) each with the treatments 0; 50; 75; 100% of produced straw by the crop maintained in the field. Nitrogen fertilizer was applied at line as ammonium nitrate (100 kg N ha-1) in all plots. Subplots were included with no nitrogen fertilizer for determination of background emissions. For gas efflux determination is adopted the chamber-based method, where is used the linear regression based on the curve generated from the four gas values measured along the 30 min intervals. The gas measurements are taken at fertilizer line and in between-row position. Inside the chambers (30 cm diameter) were placed the respective amount of straw (by area) and fertilizer (by length). We adopt high frequency of gas samplings to avoid quantification errors from seasonality. Among October and December the samplings are done in alternated days because we are waiting the peak emissions in this period as well as verify in other works. After December, the samplings interval will decrease progressively until once by month. Key periods as isolated rainy events in dry season will be comprise with more intensity of samplings. Concomitant with gas measurements we determine soil moisture, temperature and mineral nitrogen content in soil for subsidize models of emission and support gas emission. If more straw coincides with more N2O emissions, it will incentives activities which aims turn enable the use of part of sugarcane straw as a byproduct for energetic use. In addition, because frequency of sampling is considered a lack in greenhouse gas emissions determination, we expect that this work would be a tool for regional and national greenhouse gas emissions inventories.

Upper midwest climate variations: farmer responses to excess water risks.

PubMed

Morton, Lois Wright; Hobbs, Jonathan; Arbuckle, J Gordon; Loy, Adam

2015-05-01

Persistent above average precipitation and runoff and associated increased sediment transfers from cultivated ecosystems to rivers and oceans are due to changes in climate and human action. The US Upper Midwest has experienced a 37% increase in precipitation (1958-2012), leading to increased crop damage from excess water and off-farm loss of soil and nutrients. Farmer adaptive management responses to changing weather patterns have potential to reduce crop losses and address degrading soil and water resources. This research used farmer survey ( = 4778) and climate data (1971-2011) to model influences of geophysical context, past weather, on-farm flood and saturated soils experiences, and risk and vulnerability perceptions on management practices. Seasonal precipitation varied across six Upper Midwest subregions and was significantly associated with variations in management. Increased warm-season precipitation (2007-2011) relative to the past 40 yr was positively associated with no-till, drainage, and increased planting on highly erodible land (HEL). Experience with saturated soils was significantly associated with increased use of drainage and less use of no-till, cover crops, and planting on HEL. Farmers in counties with a higher percentage of soils considered marginal for row crops were more likely to use no-till, cover crops, and plant on HEL. Respondents who sell corn through multiple markets were more likely to have planted cover crops and planted on HEL in 2011.This suggests that regional climate conditions may not well represent individual farmers' actual and perceived experiences with changing climate conditions. Accurate climate information downscaled to localized conditions has potential to influence specific adaptation strategies. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Profiling crop pollinators: life history traits predict habitat use and crop visitation by Mediterranean wild bees.

PubMed

Pisanty, Gideon; Mandelik, Yael

2015-04-01

Wild pollinators, bees in particular, may greatly contribute to crop pollination and provide a safety net against declines in commercial pollinators. However, the identity, life history traits, and environmental sensitivities of main crop pollinator species.have received limited attention. These are crucial for predicting pollination services of different communities and for developing management practices that enhance crop pollinators. We sampled wild bees in three crop systems (almond, confection sunflower, and seed watermelon) in a mosaic Israeli Mediterranean landscape. Bees were sampled in field/orchard edges and interiors, and in seminatural scrub surrounding the fields/orchards. We also analyzed land cover at 50-2500 m radii around fields/orchards. We used this data to distinguish crop from non-crop pollinators based on a set of life history traits (nesting, lecty, sociality, body size) linked to habitat preference and crop visitation. Bee abundance and species richness decreased from the surrounding seminatural habitat to the field/orchard interior, especially across the seminatural habitat-field edge ecotone. Thus, although rich bee communities were found near fields, only small fractions crossed the ecotone and visited crop flowers in substantial numbers. The bee assemblage in agricultural fields/orchards and on crop flowers was dominated by ground-nesting bees of the tribe Halictini, which tend to nest within fields. Bees' habitat preferences were determined mainly by nesting guild, whereas crop visitation was determined mainly by sociality. Lecty and body size also affected both measures. The percentage of surrounding seminatural habitat at 250-2500 m radii had a positive effect on wild bee diversity in field edges, for all bee guilds, while at 50-100 m radii, only aboveground nesters were positively affected. In sum, we found that crop and non-crop pollinators are distinguished by behavioral and morphological traits. Hence, analysis of life-history traits of bee communities can help assess the pollination services they are likely to provide (when taking into account single-visit pollination efficiency). The ecotone between agricultural fields and surrounding habitats is a major barrier that filters many bee species, particularly with regard to their nesting requirements. Thus, greater attention should be given to management practices that encourage pollinators to live and nest, and not only forage, within fields.

Landscape composition creates a threshold influencing Lesser Prairie-Chicken population resilience to extreme drought

USGS Publications Warehouse

Ross, Beth E.; Haukos, David A.; Hagen, Christian A.; Pitman, James C.

2016-01-01

Habitat loss and degradation compound the effects of climate change on wildlife, yet responses to climate and land cover change are often quantified independently. The interaction between climate and land cover change could be intensified in the Great Plains region where grasslands are being converted to row-crop agriculture concurrent with increased frequency of extreme drought events. We quantified the combined effects of land cover and climate change on a species of conservation concern in the Great Plains, the Lesser Prairie-Chicken (Tympanuchus pallidicinctus  ). We combined extreme drought events and land cover change with lek count surveys in a Bayesian hierarchical model to quantify changes in abundance of male Lesser Prairie-Chickens from 1978 to 2014 in Kansas, the core of their species range. Our estimates of abundance indicate a gradually decreasing population through 2010 corresponding to drought events and reduced grassland areas. Decreases in Lesser Prairie-Chicken abundance were greatest in areas with increasing row-crop to grassland land cover ratio during extreme drought events, and decreased grassland reduces the resilience of Lesser Prairie-Chicken populations to extreme drought events. A threshold exists for Lesser Prairie-Chickens in response to the gradient of cropland:grassland land cover. When moving across the gradient of grassland to cropland, abundance initially increased in response to more cropland on the landscape, but declined in response to more cropland after the threshold (δ=0.096, or 9.6% cropland). Preservation of intact grasslands and continued implementation of initiatives to revert cropland to grassland should increase Lesser Prairie-Chicken resilience to extreme drought events due to climate change.

Time Series Analysis of Remote Sensing Observations for Citrus Crop Growth Stage and Evapotranspiration Estimation

NASA Astrophysics Data System (ADS)

Sawant, S. A.; Chakraborty, M.; Suradhaniwar, S.; Adinarayana, J.; Durbha, S. S.

2016-06-01

Satellite based earth observation (EO) platforms have proved capability to spatio-temporally monitor changes on the earth's surface. Long term satellite missions have provided huge repository of optical remote sensing datasets, and United States Geological Survey (USGS) Landsat program is one of the oldest sources of optical EO datasets. This historical and near real time EO archive is a rich source of information to understand the seasonal changes in the horticultural crops. Citrus (Mandarin / Nagpur Orange) is one of the major horticultural crops cultivated in central India. Erratic behaviour of rainfall and dependency on groundwater for irrigation has wide impact on the citrus crop yield. Also, wide variations are reported in temperature and relative humidity causing early fruit onset and increase in crop water requirement. Therefore, there is need to study the crop growth stages and crop evapotranspiration at spatio-temporal scale for managing the scarce resources. In this study, an attempt has been made to understand the citrus crop growth stages using Normalized Difference Time Series (NDVI) time series data obtained from Landsat archives (http://earthexplorer.usgs.gov/). Total 388 Landsat 4, 5, 7 and 8 scenes (from year 1990 to Aug. 2015) for Worldwide Reference System (WRS) 2, path 145 and row 45 were selected to understand seasonal variations in citrus crop growth. Considering Landsat 30 meter spatial resolution to obtain homogeneous pixels with crop cover orchards larger than 2 hectare area was selected. To consider change in wavelength bandwidth (radiometric resolution) with Landsat sensors (i.e. 4, 5, 7 and 8) NDVI has been selected to obtain continuous sensor independent time series. The obtained crop growth stage information has been used to estimate citrus basal crop coefficient information (Kcb). Satellite based Kcb estimates were used with proximal agrometeorological sensing system observed relevant weather parameters for crop ET estimation. The results show that time series EO based crop growth stage estimates provide better information about geographically separated citrus orchards. Attempts are being made to estimate regional variations in citrus crop water requirement for effective irrigation planning. In future high resolution Sentinel 2 observations from European Space Agency (ESA) will be used to fill the time gaps and to get better understanding about citrus crop canopy parameters.

Spreadsheet Calculations for Jets in Crossflow: Opposed Rows of Inline and Staggered Holes and Single and Opposed Rows with Alternating Hole Sizes

NASA Technical Reports Server (NTRS)

Holdeman, James D.; Clisset, James R.; Moder, Jeffrey P.

2010-01-01

The primary purpose of this jet-in-crossflow study was to calculate expected results for two configurations for which limited or no experimental results have been published: (1) cases of opposed rows of closely-spaced jets from inline and staggered round holes and (2) rows of jets from alternating large and small round holes. Simulations of these configurations were performed using an Excel (Microsoft Corporation) spreadsheet implementation of a NASA-developed empirical model which had been shown in previous publications to give excellent representations of mean experimental scalar results suggesting that the NASA empirical model for the scalar field could confidently be used to investigate these configurations. The supplemental Excel spreadsheet is posted with the current report on the NASA Glenn Technical Reports Server (http://gltrs.grc.nasa.gov) and can be accessed from the Supplementary Notes section as TM-2010-216100-SUPPL1.xls. Calculations for cases of opposed rows of jets with the orifices on one side shifted show that staggering can improve the mixing, particularly for cases where jets would overpenetrate slightly if the orifices were in an aligned configuration. The jets from the larger holes dominate the mixture fraction for configurations with a row of large holes opposite a row of smaller ones although the jet penetration was about the same. For single and opposed rows with mixed hole sizes, jets from the larger holes penetrated farther. For all cases investigated, the dimensionless variance of the mixture fraction decreased significantly with increasing downstream distance. However, at a given downstream distance, the variation between cases was small.

Crop improvement using life cycle datasets acquired under field conditions.

PubMed

Mochida, Keiichi; Saisho, Daisuke; Hirayama, Takashi

2015-01-01

Crops are exposed to various environmental stresses in the field throughout their life cycle. Modern plant science has provided remarkable insights into the molecular networks of plant stress responses in laboratory conditions, but the responses of different crops to environmental stresses in the field need to be elucidated. Recent advances in omics analytical techniques and information technology have enabled us to integrate data from a spectrum of physiological metrics of field crops. The interdisciplinary efforts of plant science and data science enable us to explore factors that affect crop productivity and identify stress tolerance-related genes and alleles. Here, we describe recent advances in technologies that are key components for data driven crop design, such as population genomics, chronological omics analyses, and computer-aided molecular network prediction. Integration of the outcomes from these technologies will accelerate our understanding of crop phenology under practical field situations and identify key characteristics to represent crop stress status. These elements would help us to genetically engineer "designed crops" to prevent yield shortfalls because of environmental fluctuations due to future climate change.

Polarization signatures for abandoned agricultural fields in the Manix Basin area of the Mojave Desert

NASA Technical Reports Server (NTRS)

Ray, Terrill W.; Farr, Tom G.; Vanzyl, Jakob J.

1991-01-01

Polarimetric signatures from abandoned circular alfalfa fields in the Manix Basin area of the Mojave desert show systematic changes with length of abandonment. The obliteration of circular planting rows by surface processes could account for the disappearance of bright 'spokes', which seems to be reflection patterns from remnants of the planting rows, with increasing length of abandonment. An observed shift in the location of the maximum L-band copolarization return away from VV, as well as an increase in surface roughness, both occurring with increasing age of abandonment, seems to be attributable to the formation of wind ripple on the relatively vegetationless fields. A Late Pleistocene/Holocene sand bar deposit, which can be identified in the radar images, is probably responsible for the failure of three fields to match the age sequence patterns in roughness and peak shift.

Evaluating regional water scarcity: Irrigated crop water budgets for groundwater management in the Wisconsin Central Sands

NASA Astrophysics Data System (ADS)

Nocco, M. A.; Kucharik, C. J.; Kraft, G.

2013-12-01

Regional water scarcity dilemmas between agricultural and aquatic land users pervade the humid northern lake states of Wisconsin, Minnesota, and Michigan, where agricultural irrigation relies on groundwater drawn from shallow aquifers. As these aquifers have strong connectivity to surface waters, irrigation lowers water levels in lakes and wetlands and reduces stream discharges. Irrigation expansion has cultivated a 60-year water scarcity dilemma in The Wisconsin Central Sands, the largest irrigated region in the humid northern lake states, dedicated to potato, maize, and processing vegetable production. Irrigation has depleted Wisconsin Central Sands surface waters, lowering levels in some lakes by over 2 m and drying some coldwater trout streams. Aquatic ecosystems, property values, and recreational uses in some surface waters have been devastated. While the causal link between pumping and surface water stress is established, understanding crop-mediated processes, such as the timing and magnitude of groundwater consumption by evapotranspiration (ET) and groundwater recharge, will be useful in management of groundwater, irrigated cropping systems, and surface water health. Previous modeling and field efforts have compared irrigated crop water use to a natural reference condition on a net annual basis. As a result, we presently understand that for irrigated potatoes and maize, the average annual ET is greater and therefore, the average annual recharge is less than rainfed row crops, grasslands, and both coniferous and deciduous forests. However, we have a limited understanding of the magnitude and timing of ET and recharge from irrigated cropping systems on shorter time scales that proceed with the annual cropping cycle (i.e. planting, full canopy, harvest, residue cover). We seek to understand the spatiotemporal variability of crop water budgets and associated water scarcity in the Wisconsin Central Sands through detailed measurements of drainage (potential recharge) and by inferring ET through difference, modeling, and gas exchange. In April 2013 prior to planting, we installed 10 passive capillary wick lysimeters below the effective rooting zone (z=100 cm) in potato (n=6) and maize (n=4) cropping systems to collect drainage at a 10-minute time-step under cultivation on Isherwood Farms, a sixth-generation family farm in the Wisconsin Central Sands region. Lysimeters were also instrumented to measure soil moisture and temperature at depth (z=10, 20, 40, 80 cm). Farm operators initiated center-pivot irrigation when soil moisture dropped to approximately 50% of plant available water content. Results show that drainage for May-July 2013 was 43 × 53 mm and 48 × 41 mm in irrigated potato and maize cropping systems, respectively, despite 320 mm of precipitation received during the experimental period, which was 15% above average for this region. Soil moisture consistently fluctuated in response to precipitation/irrigation events at the 10 and 20 cm soil depths, but rarely fluctuated in response to precipitation/irrigation events at the 40 and 80 cm soil depths, supporting the low drainage observed during the growing season. Future work will couple these drainage data to ongoing phenological, micrometeorological, and gas exchange observations in order to infer ET and calculate crop water budgets on a seasonal basis.

A Model for Backscattering from Quasi Periodic Corn Canopies at L-Band

NASA Technical Reports Server (NTRS)

Lang, R.; Utku, C.; Zhao, Q.; O'Neill, P.

2010-01-01

In this study, a model for backscattering at L-band from a corn canopy is proposed. The canopy consists of a quasi-periodic distribution of stalks and a random distribution of leaves. The Distorted Born Approximation (DBA) is employed to calculate the single scattered return from the corn field. The new feature of the method is that the coherence of the stalks in the row direction is incorporated in the model in a systematic fashion. Since the wavelength is on the order of the distance between corn stalks in a row, grating lobe behavior is observed at certain azimuth angles of incidence. The results are compared with experimental values measured in Huntsville, Alabama in 1998. The mean field and the effective dielectric constant of the canopy are obtained by using the Foldy approximation. The stalks are placed in the effective medium in a two dimensional lattice to simulate the row structure of a corn field. In order to mimic a real corn field, a quasi-periodic stalk distribution is assumed where the stalks are given small random perturbations about their lattice locations. Corn leaves are also embedded in the effective medium and the backscattered field from the stalks and the leaves is computed. The backscattering coefficient is calculated and averaged over successive stalk position perturbations. It is assumed that soil erosion has smoothed the soil sufficiently so that it can be assumed flat. Corn field backscatter data was collected from cornfields during the Huntsville 98 experimental campaign held at Alabama A&M University Research Station, Huntsville, Alabama in 1998 using the NASA/GW truck mounted radar. Extensive ground truth data was collected. This included soil moisture measurements and corn plant architectural data to be used in the model. In particular, the distances between the stalks in a single row have been measured. The L-band radar backscatter data was collected for both H and V polarizations and for look angles of 15o and 45o over a two week period under varying soil moisture conditions. These measured backscattering values will be compared with the model backscattering values and a discussion of the results will be presented.

Microwave backscattering from an anisotropic soybean canopy

NASA Technical Reports Server (NTRS)

Lang, R. H.; Saatchi, S.; Levine, D. M.

1986-01-01

Electromagnetic backscattering from a soybean canopy is modeled in the L band region of the spectrum. Mature soybean plants are taken as an ensemble of leaves and stems which are represented by lossy dielectric disks and rods respectively. Field data indicated that leaves and stems are not distributed uniformly in the azimuth coordinate. The plant has a tendency to grow out into the area between the rows. The effects on backscattered radar waves was computed by the distorted Born approximation. Results for look directions along the rows and perpendicular to the rows show that only a modest difference occurs in the L band frequency range. The use of another nonuniform distribution, different from those observed experimentally, results in a significant effect due to vegetation asymmetry.

Impact of climate change on water balance components in Mediterranean rainfed olive orchards under tillage or cover crop soil management

NASA Astrophysics Data System (ADS)

Rodríguez-Carretero, María Teresa; Lorite, Ignacio J.; Ruiz-Ramos, Margarita; Dosio, Alessandro; Gómez, José A.

2013-04-01

The rainfed olive orchards in Southern Spain constitute the main socioeconomic system of the Mediterranean Spanish agriculture. These systems have an elevated level of complexity and require the accurate characterization of crop, climate and soil components for a correct management. It is common the inclusion of cover crops (usually winter cereals or natural cover) intercalated between the olive rows in order to reduce water erosion. Saving limited available water requires specific management, mowing or killing these cover crops in early spring. Thus, under the semi-arid conditions in Southern Spain the management of the cover crops in rainfed olive orchards is essential to avoid a severe impact to the olive orchards yield through depletion of soil water. In order to characterize this agricultural system, a complete water balance model has been developed, calibrated and validated for the semi-arid conditions of Southern Spain, called WABOL (Abazi et al., 2013). In this complex and fragile system, the climate change constitutes a huge threat for its sustainability, currently limited by the availability of water resources, and its forecasted reduction for Mediterranean environments in Southern Spain. The objective of this study was to simulate the impact of climate change on the different components of the water balance in these representative double cropping systems: transpiration of the olive orchard and cover crop, runoff, deep percolation and soil water content. Four climatic scenarios from the FP6 European Project ENSEMBLES were first bias corrected for temperatures and precipitation (Dosio and Paruolo, 2011; Dosio et al., 2012) and, subsequently, used as inputs for the WABOL model for five olive orchard fields located in Southern Spain under different conditions of crop, climate, soils and management, in order to consider as much as possible of the variability detected in the Spanish olive orchards. The first results indicate the significant effect of the cover crop on the transpiration of the olive orchard, indicating that a correct water and soil management is crucial for these systems especially under climate change conditions. Thus, a significant reduction of transpiration was detected when the cover crops were implanted. When the climatic conditions were more limited (reductions of around 21% for the annual precipitation and increases around 13% for reference evapotranspiration), the impact on olive orchards were critical, affecting seriously the profitability of the olive orchards. In this context, cover crops can be considered as part of adaptation strategies. Further studies will be required for the determination of optimal species and varieties to be used as cover crops to reduce the impact of climate change on olive orchards under semi-arid conditions. References Abazi U, Lorite IJ, Cárceles B, Martínez-Raya A, Durán VH, Francia JR, Gómez JA (2013) WABOL: A conceptual water balance model for analyzing rainfall water use in olive orchards under different soil and cover crop Management strategies. Computers and Electronics in Agriculture 91:35-48 Dosio A, Paruolo P (2011) Bias correction of the ENSEMBLES high-resolution climate change projections for use by impact models: Evaluation on the present climate. Journal of Geophysical Research, V 116, D16106, doi:10.1029/2011JD015934 Dosio A, Paruolo P, Rojas R (2012) Bias correction of the ENSEMBLES high resolution climate change projections for use by impact models: Analysis of the climate change signal. Journal of Geophysical Research, V 117, D17, doi: 10.1029/2012JD017968

A review of turbomachinery blade-row interaction research

NASA Technical Reports Server (NTRS)

Smith, Todd E.

1988-01-01

Analytical and experimental research in the area of unsteady aerodynamics of turbomachinery has conventionally been applied to blading which oscillates when placed in a uniformly flowing fluid. Comparatively less effort has been offered for the study of blading which is subjected to nonuniformities within the flow field. The fluid dynamic environment of a blade-row embedded within multi-stage turbomachines is dominated by such highly unsteady fluid flow conditions. The production of wakes and circumferential pressure variations from adjacent blade-rows causes large unsteady energy transfers between the fluid and the blades. Determination of the forced response of a blade requires the ability to predict the unsteady loads which are induced by these aerodynamic sources. A review of research publications was done to determine recent investigations of the response of turbomachinery blading subjected to aerodynamic excitations. Such excitations are a direct result of the blade-row aerodynamic interaction which occurs between adjacent cascades of blades. The reports and papers reviewed have been organized into areas emphasizing experimental or analytical efforts.

Comparative cervical profiles of adult and under-18 front-row rugby players: implications for playing policy

PubMed Central

Hamilton, D F; Gatherer, D; Robson, J; Graham, N; Rennie, N; MacLean, J G B; Simpson, A H R W

2014-01-01

Objective To compare the cervical isometric strength, fatigue endurance and range of motion of adult and under-18 age-grade front-row rugby players to inform the development of a safe age group policy with particular reference to scrummaging. Design Cross-sectional cohort study. Setting ‘Field testing’ at Murrayfield stadium. Participants 30 high-performance under-18 players and 22 adult front-row rugby players. Outcome measures Isometric neck strength, height, weight and grip strength. Results Youth players demonstrated the same height and grip strength as the adult players; however, the adults were significantly heavier and demonstrated substantially greater isometric strength (p<0.001). Only two of the ‘elite’ younger players could match the adult mean cervical isometric strength value. In contrast to school age players in general, grip strength was poorly associated with neck strength (r=0.2) in front-row players; instead, player weight (r=0.4) and the number of years’ experience of playing in the front row (r=0.5) were the only relevant factors in multivariate modelling of cervical strength (R2=0.3). Conclusions Extreme forces are generated between opposing front rows in the scrum and avoidance of mismatch is important if the risk of injury is to be minimised. Although elite youth front-row rugby players demonstrate the same peripheral strength as their adult counterparts on grip testing, the adults demonstrate significantly greater cervical strength. If older youths and adults are to play together, such findings have to be noted in the development of age group policies with particular reference to the scrum. PMID:24797427

Comparative cervical profiles of adult and under-18 front-row rugby players: implications for playing policy.

PubMed

Hamilton, D F; Gatherer, D; Robson, J; Graham, N; Rennie, N; Maclean, J G B; Simpson, A H R W

2014-05-05

To compare the cervical isometric strength, fatigue endurance and range of motion of adult and under-18 age-grade front-row rugby players to inform the development of a safe age group policy with particular reference to scrummaging. Cross-sectional cohort study. 'Field testing' at Murrayfield stadium. 30 high-performance under-18 players and 22 adult front-row rugby players. Isometric neck strength, height, weight and grip strength. Youth players demonstrated the same height and grip strength as the adult players; however, the adults were significantly heavier and demonstrated substantially greater isometric strength (p<0.001). Only two of the 'elite' younger players could match the adult mean cervical isometric strength value. In contrast to school age players in general, grip strength was poorly associated with neck strength (r=0.2) in front-row players; instead, player weight (r=0.4) and the number of years' experience of playing in the front row (r=0.5) were the only relevant factors in multivariate modelling of cervical strength (R(2)=0.3). Extreme forces are generated between opposing front rows in the scrum and avoidance of mismatch is important if the risk of injury is to be minimised. Although elite youth front-row rugby players demonstrate the same peripheral strength as their adult counterparts on grip testing, the adults demonstrate significantly greater cervical strength. If older youths and adults are to play together, such findings have to be noted in the development of age group policies with particular reference to the scrum.

Identification of downy mildew resistance gene candidates by positional cloning in maize (Zea mays subsp. mays; Poaceae)1

PubMed Central

Kim, Jae Yoon; Moon, Jun-Cheol; Kim, Hyo Chul; Shin, Seungho; Song, Kitae; Kim, Kyung-Hee; Lee, Byung-Moo

2017-01-01

Premise of the study: Positional cloning in combination with phenotyping is a general approach to identify disease-resistance gene candidates in plants; however, it requires several time-consuming steps including population or fine mapping. Therefore, in the present study, we suggest a new combined strategy to improve the identification of disease-resistance gene candidates. Methods and Results: Downy mildew (DM)–resistant maize was selected from five cultivars using a spreader row technique. Positional cloning and bioinformatics tools were used to identify the DM-resistance quantitative trait locus marker (bnlg1702) and 47 protein-coding gene annotations. Eventually, five DM-resistance gene candidates, including bZIP34, Bak1, and Ppr, were identified by quantitative reverse-transcription PCR (RT-PCR) without fine mapping of the bnlg1702 locus. Conclusions: The combined protocol with the spreader row technique, quantitative trait locus positional cloning, and quantitative RT-PCR was effective for identifying DM-resistance candidate genes. This cloning approach may be applied to other whole-genome-sequenced crops or resistance to other diseases. PMID:28224059

Occurrence of pesticides in groundwater underlying areas of high-density row-crop production in Alabama, 2009-2013

USGS Publications Warehouse

Welch, Heather L.

2015-01-01

Concentrations of metolachlor and atrazine have substantially decreased in the northern Alabama wells since 2000. A decline in use of metolachlor and atrazine from a high in the late-1990s and a high in 2004, respectively, in northern Alabama could account for the lower concentrations. Fluometuron use has also declined since 1998, but the relation between time and concentrations differed in the five northern Alabama wells. Fluometuron concentrations in three of the five wells have been decreasing over time, while concentrations in the remaining two wells have been increasing.

Fifth symposium on surface mining and reclamation. NCA/BCR coal conference and Expo IV

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1977-01-01

The Fifth Symposium on Surface Mining and Reclamation, sponsored by the National Coal Association and Bituminous Coal Research, Inc., was held at the Kentucky Fair and Exposition Center, Louisville, Kentucky, October 18-20, 1977. Twenty-six papers from the proceedings have been entered individually into EDB and ERA. Topics covered include spoil bank revegetation, use of aerial photography, reclamation for row crop production, hydrology, computer programs related to this work, subirrigated alluvial valley floors, reclamation on steep slopes, mountain top removal, surface mine road design, successional processes involved in reclamation, land use planning, etc. (LTN)

Estimation of Nitrogen Pools in Irrigated Potato Production on Sandy Soil Using the Model SUBSTOR

PubMed Central

Prasad, Rishi; Hochmuth, George J.; Boote, Kenneth J.

2015-01-01

Recent increases in nitrate concentrations in the Suwannee River and associated springs in northern Florida have raised concerns over the contributions of non-point sources. The Middle Suwannee River Basin (MSRB) is of special concern because of prevalent karst topography, unconfined aquifers and sandy soils which increase vulnerability of the ground water contamination from agricultural operations- a billion dollar industry in this region. Potato (Solanum tuberosum L.) production poses a challenge in the area due to the shallow root system of potato plants, and low water and nutrient holding capacity of the sandy soils. A four-year monitoring study for potato production on sandy soil was conducted on a commercial farm located in the MSRB to identify major nitrogen (N) loss pathways and determine their contribution to the total environmental N load, using a partial N budget approach and the potato model SUBSTOR. Model simulated environmental N loading rates were found to lie within one standard deviation of the observed values and identified leaching loss of N as the major sink representing 25 to 38% (or 85 to 138 kg ha-1 N) of the total input N (310 to 349 kg ha-1 N). The crop residues left in the field after tuber harvest represented a significant amount of N (64 to 110 kg ha-1N) and posed potential for indirect leaching loss of N upon their mineralization and the absence of subsequent cover crops. Typically, two months of fallow period exits between harvest of tubers and planting of the fall row crop (silage corn). The fallow period is characterized by summer rains which pose a threat to N released from rapidly mineralizing potato vines. Strategies to reduce N loading into the groundwater from potato production must focus on development and adoption of best management practices aimed on reducing direct as well as indirect N leaching losses. PMID:25635904

The Impacts of Various Environments Factors and Adaptive Management Strategies on Food Crops in the 21st Century Based on a Land Surface Model

NASA Astrophysics Data System (ADS)

Jain, A. K.; Lin, T. S.; Lawrence, P.; Kheshgi, H. S.

2017-12-01

Environmental factors - characterized by increasing levels of CO2, and changes in temperature and precipitation patterns - present potential risks to global food supply. To date, understanding of environmental factors' effects on crop production remains uncertain due to (1) uncertainties in projected trends of these factors and their spatial and temporal variability; (2) uncertainties in the physiological, genetic and molecular basis of crop adaptation to adaptive management practices (e.g. change in planting time, irrigation and N fertilization etc.) and (3) uncertainties in current land surface models to estimate the response of crop production to changes in environmental factors and management strategies. In this study we apply a process-based land surface model, the Integrated Science Assessment model (ISAM), to assess the impact of various environmental factors and management strategies on the production of row crops (corn, soybean and wheat) at regional and global scales. Results are compared to corresponding simulations performed with the crop model in the Community Land Model (CLM4.5). Each model is driven with historical atmospheric forcing data (1901-2005), and projected atmospheric forcing data under RCP 4.5 or RCP 8.5 (2006-2100) from CESM CMIP5 simulations to estimate the effects of different climate change projections on potential productivity of food crops at a global scale. For each set of atmospheric forcing data, production of each crop is simulated with and without inclusion of adaptive management practices (e.g. application of irrigation, N fertilization, change in planting time and crop cultivars etc.) to assess the effect of adaptation on projected crop production over the 21st century. In detail, three questions are addressed: (1) what is the impact of different climate change projections on global crop production; (2) what is the effect of adaptive management practices on projected crop production; and (3) how do differences in model mechanisms in ISAM and CLM4.5 impact projected global crop production and adaptive management practices (irrigation and N fertilizer) over the 21st century. The major outcomes of this study will help to understand the uncertainties in potential productivity of food crops under different environmental conditions and management practices.

Spatial and spectral simulation of LANDSAT images of agricultural areas

NASA Technical Reports Server (NTRS)

Pont, W. F., Jr. (Principal Investigator)

1982-01-01

A LANDSAT scene simulation capability was developed to study the effects of small fields and misregistration on LANDSAT-based crop proportion estimation procedures. The simulation employs a pattern of ground polygons each with a crop ID, planting date, and scale factor. Historical greenness/brightness crop development profiles generate the mean signal values for each polygon. Historical within-field covariances add texture to pixels in each polygon. The planting dates and scale factors create between-field/within-crop variation. Between field and crop variation is achieved by the above and crop profile differences. The LANDSAT point spread function is used to add correlation between nearby pixels. The next effect of the point spread function is to blur the image. Mixed pixels and misregistration are also simulated.

Nature of magnetization and lateral spin-orbit interaction in gated semiconductor nanowires.

PubMed

Karlsson, H; Yakimenko, I I; Berggren, K-F

2018-05-31

Semiconductor nanowires are interesting candidates for realization of spintronics devices. In this paper we study electronic states and effects of lateral spin-orbit coupling (LSOC) in a one-dimensional asymmetrically biased nanowire using the Hartree-Fock method with Dirac interaction. We have shown that spin polarization can be triggered by LSOC at finite source-drain bias,as a result of numerical noise representing a random magnetic field due to wiring or a random background magnetic field by Earth magnetic field, for instance. The electrons spontaneously arrange into spin rows in the wire due to electron interactions leading to a finite spin polarization. The direction of polarization is, however, random at zero source-drain bias. We have found that LSOC has an effect on orientation of spin rows only in the case when source-drain bias is applied.

Nature of magnetization and lateral spin–orbit interaction in gated semiconductor nanowires

NASA Astrophysics Data System (ADS)

Karlsson, H.; Yakimenko, I. I.; Berggren, K.-F.

2018-05-01

Semiconductor nanowires are interesting candidates for realization of spintronics devices. In this paper we study electronic states and effects of lateral spin–orbit coupling (LSOC) in a one-dimensional asymmetrically biased nanowire using the Hartree–Fock method with Dirac interaction. We have shown that spin polarization can be triggered by LSOC at finite source-drain bias,as a result of numerical noise representing a random magnetic field due to wiring or a random background magnetic field by Earth magnetic field, for instance. The electrons spontaneously arrange into spin rows in the wire due to electron interactions leading to a finite spin polarization. The direction of polarization is, however, random at zero source-drain bias. We have found that LSOC has an effect on orientation of spin rows only in the case when source-drain bias is applied.

Experimental strategies in carrying out VCU for tobacco crop I: plot design and size.

PubMed

Toledo, F H R B; Ramalho, M A P; Pulcinelli, C E; Bruzi, A T

2013-09-19

We aimed to establish standards for tobacco Valor de Cultivo e Uso (VCU) in Brazil. We obtained information regarding the size and design of plots of two varietal groups of tobacco (Virginia and Burley). Ten inbred lines of each varietal group were evaluated in a randomized complete block design with four replications. The plot contained 42 plants with six rows of seven columns each. For each experiment plant, considering the position of the respective plant in the plot (row and column) as a reference, cured leaf weight (g/plant), total sugar content (%), and total alkaloid content (%) were determined. The maximum curvature of the variations in coefficients was estimated. Trials with the number of plants per plot ranging from 2 to 41 were simulated. The use of a border was not justified because the interactions between inbred lines x position in the plots were never significant, showing that the behavior of the inbred lines coincided with the different positions. The plant performance varied according to the column position in the plot. To lessen the effect of this factor, the use of plots with more than one row is recommended. Experimental precision, evaluated by the CV%, increased with an increase in plot size; nevertheless, the maximum curvature of the variation coefficient method showed no expressive increase in precision if the number of plants was greater than seven. The result in identification of the best inbred line, in terms of the size of each plot, coincided with the maximum curvature method.

Stability and adaptability of soybean cultivars in Minas Gerais.

PubMed

Soares, I O; Bruzi, A T; Zambiazzi, E V; Guilherme, S R; Bianchi, M C; Silva, K B; Fronza, V; Teixeira, C M

2017-08-17

Genotypes x environment (G x E) interaction consists of different behavior of genotypes cultivated in different environments. This interaction occurs due to the performance variation of each genotype in different environments. To reduce the effect of the interaction in soybean crops, some studies have been reported in the literature to study their adaptability and stability. However, these studies are still scarce in Minas Gerais State. Thus, the aim of this study was to verify the adaptability and stability of soybean cultivars and identify the cultivars that contribute least to the G x E interaction in Minas Gerais. Six soybean cultivars were evaluated in 9 different environments. The plots were composed of 4 rows of 5 m with a spacing of 0.5 m between rows, and only the two central rows were harvested. The inoculation with Bradyrhizobium japonicum was performed through sowing furrow. The fertilization followed the recommendations of the Soil Fertility Commission of Minas Gerais. Grain yield was evaluated in kg/ha after conversion to 13% moisture. After individual analysis, the joint analysis was performed by grouping the phenotypic means by the Scott and Knott (1974) test. Wricke's ecovalence methodologies and the Annicchiarico confidence index were applied for the adaptability and stability analysis. The interaction was decomposed into a simple and a complex part. The cultivars BRSMG 820RR and BRSMG 760SRR have wide adaptability and stability. The first one presents a better index of confidence and a small contribution to the interaction.

Contribution of wetlands to nitrate removal at the watershed scale

NASA Astrophysics Data System (ADS)

Hansen, Amy T.; Dolph, Christine L.; Foufoula-Georgiou, Efi; Finlay, Jacques C.

2018-02-01

Intensively managed row crop agriculture has fundamentally changed Earth surface processes within the Mississippi River basin through large-scale alterations of land cover, hydrology and reactive nitrogen availability. These changes have created leaky landscapes where excess agriculturally derived nitrate degrades riverine water quality at local, regional and continental scales. Individually, wetlands are known to remove nitrate but the conditions under which multiple wetlands meaningfully reduce riverine nitrate concentration have not been established. Only one region of the Mississippi River basin—the 44,000 km2 Minnesota River basin—still contains enough wetland cover within its intensively agriculturally managed watersheds to empirically address this question. Here we combine high-resolution land cover data for the Minnesota River basin with spatially extensive repeat water sampling data. By clearly isolating the effect of wetlands from crop cover, we show that, under moderate-high streamflow, wetlands are five times more efficient per unit area at reducing riverine nitrate concentration than the most effective land-based nitrogen mitigation strategies, which include cover crops and land retirement. Our results suggest that wetland restorations that account for the effects of spatial position in stream networks could provide a much greater benefit to water quality then previously assumed.

Landscape configurational heterogeneity by small-scale agriculture, not crop diversity, maintains pollinators and plant reproduction in western Europe.

PubMed

Hass, Annika L; Kormann, Urs G; Tscharntke, Teja; Clough, Yann; Baillod, Aliette Bosem; Sirami, Clélia; Fahrig, Lenore; Martin, Jean-Louis; Baudry, Jacques; Bertrand, Colette; Bosch, Jordi; Brotons, Lluís; Burel, Françoise; Georges, Romain; Giralt, David; Marcos-García, María Á; Ricarte, Antonio; Siriwardena, Gavin; Batáry, Péter

2018-02-14

Agricultural intensification is one of the main causes for the current biodiversity crisis. While reversing habitat loss on agricultural land is challenging, increasing the farmland configurational heterogeneity (higher field border density) and farmland compositional heterogeneity (higher crop diversity) has been proposed to counteract some habitat loss. Here, we tested whether increased farmland configurational and compositional heterogeneity promote wild pollinators and plant reproduction in 229 landscapes located in four major western European agricultural regions. High-field border density consistently increased wild bee abundance and seed set of radish ( Raphanus sativus ), probably through enhanced connectivity. In particular, we demonstrate the importance of crop-crop borders for pollinator movement as an additional experiment showed higher transfer of a pollen analogue along crop-crop borders than across fields or along semi-natural crop borders. By contrast, high crop diversity reduced bee abundance, probably due to an increase of crop types with particularly intensive management. This highlights the importance of crop identity when higher crop diversity is promoted. Our results show that small-scale agricultural systems can boost pollinators and plant reproduction. Agri-environmental policies should therefore aim to halt and reverse the current trend of increasing field sizes and to reduce the amount of crop types with particularly intensive management. © 2018 The Author(s).

Estimation of land surface evapotranspiration with A satellite remote sensing procedure

USGS Publications Warehouse

Irmak, A.; Ratcliffe, I.; Ranade, P.; Hubbard, K.G.; Singh, Ramesh K.; Kamble, B.; Kjaersgaard, J.

2011-01-01

There are various methods available for estimating magnitude and trends of evapotranspiration. Bowen ratio energy balance system and eddy correlation techniques offer powerful alternatives for measuring land surface evapotranspiration. In spite of the elegance, high accuracy, and theoretical attractions of these techniques for measuring evapotranspiration, their practical use over large areas can be limited due to the number of sites needed and the related expense. Application of evapotranspiration mapping from satellite measurements can overcome the limitations. The objective of this study was to utilize the METRICTM (Mapping Evapotranspiration at High Resolution using Internalized Calibration) model in Great Plains environmental settings to understand water use in managed ecosystems on a regional scale. We investigated spatiotemporal distribution of a fraction of reference evapotranspiration (ETrF) using eight Landsat 5 images during the 2005 and 2006 growing season for path 29, row 32. The ETrF maps generated by METRICTM allowed us to follow the magnitude and trend in ETrF for major land-use classes during the growing season. The ETrF was lower early in the growing season for agricultural crops and gradually increased as the normalized difference vegetation index of crops increased, thus presenting more surface area over which water could transpire toward the midseason. Comparison of predictions with Bowen ratio energy balance system measurements at Clay Center, NE, showed that METRICTM performed well at the field scale for predicting evapotranspiration from a cornfield. If calibrated properly, the model could be a viable tool to estimate water use in managed ecosystems in subhumid climates at a large scale.

Multisite Evaluation of APEX for Water Quality: I. Best Professional Judgment Parameterization.

PubMed

Baffaut, Claire; Nelson, Nathan O; Lory, John A; Senaviratne, G M M M Anomaa; Bhandari, Ammar B; Udawatta, Ranjith P; Sweeney, Daniel W; Helmers, Matt J; Van Liew, Mike W; Mallarino, Antonio P; Wortmann, Charles S

2017-11-01

The Agricultural Policy Environmental eXtender (APEX) model is capable of estimating edge-of-field water, nutrient, and sediment transport and is used to assess the environmental impacts of management practices. The current practice is to fully calibrate the model for each site simulation, a task that requires resources and data not always available. The objective of this study was to compare model performance for flow, sediment, and phosphorus transport under two parameterization schemes: a best professional judgment (BPJ) parameterization based on readily available data and a fully calibrated parameterization based on site-specific soil, weather, event flow, and water quality data. The analysis was conducted using 12 datasets at four locations representing poorly drained soils and row-crop production under different tillage systems. Model performance was based on the Nash-Sutcliffe efficiency (NSE), the coefficient of determination () and the regression slope between simulated and measured annualized loads across all site years. Although the BPJ model performance for flow was acceptable (NSE = 0.7) at the annual time step, calibration improved it (NSE = 0.9). Acceptable simulation of sediment and total phosphorus transport (NSE = 0.5 and 0.9, respectively) was obtained only after full calibration at each site. Given the unacceptable performance of the BPJ approach, uncalibrated use of APEX for planning or management purposes may be misleading. Model calibration with water quality data prior to using APEX for simulating sediment and total phosphorus loss is essential. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Geochemical and isotopic tracing of water in nested southern Minnesota corn-belt watersheds.

PubMed

Magner, J A; Alexander, S C

2002-01-01

Land-use changes over the last century in southern Minnesota have influenced riverine water chemistry. A nested watershed approach was used to examine hydrologic pathways of water movement in this now agriculturally intensive region. From field scale subsurface tile-drains of the Beauford ditch to the respective outlets of the Cobb River and Blue Earth River, more than 125 samples were collected for major dissolved ions and isotopes between March 1994 and June 1996 over a range of climatic conditions that included snowmelt and storm-flows. Results indicate that riverine water chemistry is dominated by subsurface tile-drained row crop agriculture. In the mid-1990s, regional ground water discharge into the Cobb and Blue Earth Rivers comprised less than 10% of the total flow based on ionic mixing calculations. Ammonia, present in manure or as anhydrous, is readily exchanged in the soil. This ion exchange releases increasing ratios of magnesium, sodium and strontium relative to calcium, the dominant cation. Soil thaw and snowmelt recharge influenced March-April tile-drain and ditch water isotopic values. Light deltaD values increased as spring infiltration-derived water was displaced from the soil zone by heavier summer precipitation. Delta15N followed a similar but opposite pattern with relatively heavy March-April tile-drain and ditch values trending to lighter delta15N through the growing season. The future of southern Minnesota riverine water quality is closely linked to the management of the landscape. To improve the riverine environment, land owners and managers will need to address cropping systems, fertilization practices and drainage.

Seeing is believing I: The use of thermal sensing from satellite imagery to predict crop yield

NASA Astrophysics Data System (ADS)

B, Potgieter A.; D, Rodriguez; B, Power; J, Mclean; P, Davis

2014-02-01

Volatility in crop production has been part of the Australian environment since cropping began with the arrival of the first European settlers. Climate variability is the main factor affecting crop production at national, state and local scales. At field level spatial patterns on yield production are also determined by spatially changing soil properties in interaction with seasonal climate conditions and weather patterns at critical stages in the crop development. Here we used a combination of field level weather records, canopy characteristics, and satellite information to determine the spatial performance of a large field of wheat. The main objective of this research is to determine the ability of remote sensing technologies to capture yield losses due to water stress at the canopy level. The yield, canopy characteristics (i.e. canopy temperature and ground cover) and seasonal conditions of a field of wheat (~1400ha) (-29.402° South and 149.508°, New South Wales, Australia) were continuously monitored during the winter of 2011. Weather and crop variables were continuously monitored by installing three automatic weather stations in a transect covering different positions and soils in the landscape. Weather variables included rainfall, minimum and maximum temperatures and relative humidity, and crop characteristics included ground cover and canopy temperature. Satellite imagery Landsat TM 5 and 7 was collected at five different stages in the crop cycle. Weather variables and crop characteristics were used to calculate a crop stress index (CSI) at point and field scale (39 fields). Field data was used to validate a spatial satellite image derived index. Spatial yield data was downloaded from the harvester at the different locations in the field. We used the thermal band (land surface temperature, LST) and enhanced vegetation index (EVI) bands from the MODIS (250 m for visible bands and 1km for thermal band) and a derived EVI from Landsat TM 7 (25 m for visible and 90m for thermal) satellite platforms. Results showed that spatial variations in crop yield were related to a satellite derived canopy stress index (CSIsat) and a moisture stress index (MSIsat). A weather station level canopy stress index (CSIws) calculated at midday was correlated to the CSIsat at late morning. In addition, a strong linear relationship was observed between EVI and LST at point scale throughout the crop growth period. Differences were smallest at anthesis when the canopy closure was highest. This suggests that LST imagery data around flowering could be used to calculate crop stress over large areas of the crop. The harvested yield was related (R2 = 0.67) to CSIsat using a fix date across all fields. This relationship improved (R2 = 0.92) using both indices from all five dates across all fields during the crop growth period. Here we successfully showed that satellite derived crop attributes (CSIsat and MSIsat) can account for most of the variability in final crop yield and that they can be used to predict crop yield at field scales. Applications of these results could enhance the ability of producers to hedge their financial on -farm crop production losses due to in-season water stress by taking crop insurance. This is likely to further improve their adaptive capacity and thus strengthening the long-term viability of the industry domestically and elsewhere.

Herbaceous or Salix miyabeana 'SX64' narrow buffer strips as a means to minimize glyphosate and aminomethylphosphonic acid leaching from row crop fields.

PubMed

Hénault-Ethier, Louise; Lucotte, Marc; Moingt, Matthieu; Paquet, Serge; Maccario, Sophie; Smedbol, Élise; Gomes, Marcelo Pedrosa; Lepage, Laurent; Juneau, Philippe; Labrecque, Michel

2017-11-15

Glyphosate is the most widely used herbicide worldwide and is now frequently detected in surface waters of agricultural regions, notably in Quebec (Canada). Numerous legislations require vegetated riparian buffer strips (RBS) along agricultural streams. Quebec policy requires 3-meter-wide RBS. The present study evaluates the efficiency of narrow herbaceous and low- or high-density (33,333 and 55,556stumps/ha) willow, Salix miyabeana 'SX64', RBS, to minimize leaching of glyphosate and its main degradation product (AMPA) from agricultural fields to streams. Our study compared triplicate treatments of herbaceous and willow-planted RBS located in an organic-rich soil at Boisbriand (BB) and in a mineral soil at Saint-Roch-de-l'Achigan (SR). Runoff water was sampled with surface collectors and interstitial water was collected with 35cm or 70cm tension lysimeters. Potential efficiency of the RBS is reported as the percent reduction between edge-of-field and edge-of-stream concentrations in runoff and interstitial waters. Neither glyphosate nor AMPA in runoff were significantly intercepted by the RBS. After field herbicide spraying, glyphosate measured in SR surface soils (0-20cm) was on average 210μg·kg -1 dw (range from undetected to ≤317μg·kg -1 dw). Glyphosate was found to be persistent and its infiltration towards groundwater may be enhanced by the RBS. Contrary to runoff trends, soil glyphosate was significantly less concentrated on the SR edge-of-stream compared to edge-of-field (27-54% potential efficiency). The potential efficiency of herbaceous, low- and high-density willow RBS were undifferentiated. Copyright © 2017 Elsevier B.V. All rights reserved.

Field size, length, and width distributions based on LACIE ground truth data. [large area crop inventory experiment

NASA Technical Reports Server (NTRS)

Pitts, D. E.; Badhwar, G.

1980-01-01

The development of agricultural remote sensing systems requires knowledge of agricultural field size distributions so that the sensors, sampling frames, image interpretation schemes, registration systems, and classification systems can be properly designed. Malila et al. (1976) studied the field size distribution for wheat and all other crops in two Kansas LACIE (Large Area Crop Inventory Experiment) intensive test sites using ground observations of the crops and measurements of their field areas based on current year rectified aerial photomaps. The field area and size distributions reported in the present investigation are derived from a representative subset of a stratified random sample of LACIE sample segments. In contrast to previous work, the obtained results indicate that most field-size distributions are not log-normally distributed. The most common field size observed in this study was 10 acres for most crops studied.

Double row loop-coil configuration for high-speed electrodynamic maglev suspension, guidance, propulsion and guideway directional switching

DOEpatents

He, Jianliang; Rote, Donald M.

1996-01-01

A stabilization and propulsion system comprising a series of loop-coils arranged in parallel rows wherein two rows combine to form one of two magnetic rails. Levitation and lateral stability are provided when the induced field in the magnetic rails interacts with the superconducting magnets mounted on the magnetic levitation vehicle. The loop-coils forming the magnetic rails have specified dimensions and a specified number of turns and by constructing differently these specifications, for one rail with respect to the other, the angle of tilt of the vehicle can be controlled during directional switching. Propulsion is provided by the interaction of a traveling magnetic wave associated with the coils forming the rails and the super conducting magnets on the vehicle.

Double row loop-coil configuration for high-speed electrodynamic maglev suspension, guidance, propulsion and guideway directional switching

DOEpatents

He, J.; Rote, D.M.

1996-05-21

A stabilization and propulsion system are disclosed comprising a series of loop-coils arranged in parallel rows wherein two rows combine to form one of two magnetic rails. Levitation and lateral stability are provided when the induced field in the magnetic rails interacts with the superconducting magnets mounted on the magnetic levitation vehicle. The loop-coils forming the magnetic rails have specified dimensions and a specified number of turns and by constructing differently these specifications, for one rail with respect to the other, the angle of tilt of the vehicle can be controlled during directional switching. Propulsion is provided by the interaction of a traveling magnetic wave associated with the coils forming the rails and the superconducting magnets on the vehicle. 12 figs.

Mapping paddy rice planting area in northeastern Asia with Landsat 8 images, phenology-based algorithm and Google Earth Engine

PubMed Central

Dong, Jinwei; Xiao, Xiangming; Menarguez, Michael A.; Zhang, Geli; Qin, Yuanwei; Thau, David; Biradar, Chandrashekhar; Moore, Berrien

2016-01-01

Area and spatial distribution information of paddy rice are important for understanding of food security, water use, greenhouse gas emission, and disease transmission. Due to climatic warming and increasing food demand, paddy rice has been expanding rapidly in high latitude areas in the last decade, particularly in northeastern (NE) Asia. Current knowledge about paddy rice fields in these cold regions is limited. The phenology- and pixel-based paddy rice mapping (PPPM) algorithm, which identifies the flooding signals in the rice transplanting phase, has been effectively applied in tropical areas, but has not been tested at large scale of cold regions yet. Despite the effects from more snow/ice, paddy rice mapping in high latitude areas is assumed to be more encouraging due to less clouds, lower cropping intensity, and more observations from Landsat sidelaps. Moreover, the enhanced temporal and geographic coverage from Landsat 8 provides an opportunity to acquire phenology information and map paddy rice. This study evaluated the potential of Landsat 8 images on annual paddy rice mapping in NE Asia which was dominated by single cropping system, including Japan, North Korea, South Korea, and NE China. The cloud computing approach was used to process all the available Landsat 8 imagery in 2014 (143 path/rows, ~3290 scenes) with the Google Earth Engine (GEE) platform. The results indicated that the Landsat 8, GEE, and improved PPPM algorithm can effectively support the yearly mapping of paddy rice in NE Asia. The resultant paddy rice map has a high accuracy with the producer (user) accuracy of 73% (92%), based on the validation using very high resolution images and intensive field photos. Geographic characteristics of paddy rice distribution were analyzed from aspects of country, elevation, latitude, and climate. The resultant 30-m paddy rice map is expected to provide unprecedented details about the area, spatial distribution, and landscape pattern of paddy rice fields in NE Asia, which will contribute to food security assessment, water resource management, estimation of greenhouse gas emissions, and disease control. PMID:28025586

Mapping paddy rice planting area in northeastern Asia with Landsat 8 images, phenology-based algorithm and Google Earth Engine.

PubMed

Dong, Jinwei; Xiao, Xiangming; Menarguez, Michael A; Zhang, Geli; Qin, Yuanwei; Thau, David; Biradar, Chandrashekhar; Moore, Berrien

2016-11-01

Area and spatial distribution information of paddy rice are important for understanding of food security, water use, greenhouse gas emission, and disease transmission. Due to climatic warming and increasing food demand, paddy rice has been expanding rapidly in high latitude areas in the last decade, particularly in northeastern (NE) Asia. Current knowledge about paddy rice fields in these cold regions is limited. The phenology- and pixel-based paddy rice mapping (PPPM) algorithm, which identifies the flooding signals in the rice transplanting phase, has been effectively applied in tropical areas, but has not been tested at large scale of cold regions yet. Despite the effects from more snow/ice, paddy rice mapping in high latitude areas is assumed to be more encouraging due to less clouds, lower cropping intensity, and more observations from Landsat sidelaps. Moreover, the enhanced temporal and geographic coverage from Landsat 8 provides an opportunity to acquire phenology information and map paddy rice. This study evaluated the potential of Landsat 8 images on annual paddy rice mapping in NE Asia which was dominated by single cropping system, including Japan, North Korea, South Korea, and NE China. The cloud computing approach was used to process all the available Landsat 8 imagery in 2014 (143 path/rows, ~3290 scenes) with the Google Earth Engine (GEE) platform. The results indicated that the Landsat 8, GEE, and improved PPPM algorithm can effectively support the yearly mapping of paddy rice in NE Asia. The resultant paddy rice map has a high accuracy with the producer (user) accuracy of 73% (92%), based on the validation using very high resolution images and intensive field photos. Geographic characteristics of paddy rice distribution were analyzed from aspects of country, elevation, latitude, and climate. The resultant 30-m paddy rice map is expected to provide unprecedented details about the area, spatial distribution, and landscape pattern of paddy rice fields in NE Asia, which will contribute to food security assessment, water resource management, estimation of greenhouse gas emissions, and disease control.

Persistence of triclopyr in Alaska subarctic environments

USDA-ARS?s Scientific Manuscript database

Field dissipation and vertical mobility of the butoxyethyl ester of triclopyr was assessed in two distinct geographic locations within the state of Alaska. Interior sites near Delta Junction included vegetated plots within highway rights-of-way (ROW) and Conservation Reserve Program (CRP) fields and...

Micropole undulator

DOEpatents

Csonka, P.L.; Tatchyn, R.O.

1989-01-24

Micropole undulators for use in the generation of x-rays from moving charged particles and methods for manufacturing such undulators are disclosed. One type of micropole undulator has two jaws containing rows of spaced apart poles arranged so that each pole produces a magnetic field aligned with all other similar fields. An external biasing field extends through the jaws so that an overall undulator field of substantially sinusoidal shape and substantially zero average value extends along the undulator axis. Preferably, the poles are bars formed of a magnetizable, but unmagnetized, material so that, after the jaws are assembled, all of the bars can be magnetized simultaneously in a uniform magnetic field of suitable strength. Another type of micropole undulator incorporates two parallel layers which have been magnetized to provide rows of alternating magnetic fields extending in opposite directions, the layers being positioned between the pole faces of a highly magnetically permeable material with the south poles of one layer opposite the north poles of the other. Poles in the layers are formed by subjecting successive regions of each layer to oppositely directed and suitably varied magnetizing forces. 16 figs.

Micropole undulator

DOEpatents

Csonka, Paul L.; Tatchyn, Roman O.

1989-01-24

Micropole undulators for use in the generation of x-rays from moving charged particles and methods for manufacturing such undulators are disclosed. One type of micropole undulator has two jaws containing rows of spaced apart poles arranged so that each pole produces a magnetic field aligned with all other similar fields. An external biasing field extends through the jaws so that an overall undulator field of substantially sinusoidal shape and substantially zero average value extends along the undulator axis. Preferably, the poles are bars formed of a magnetizable, but unmagnetized, material so that, after the jaws are assembled, all of the bars can be magnetized simultaneously in a uniform magnetic field of suitable strength. Another type of micropole undulator incorporates two parallel layers which have been magnetized to provide rows of alternating magnetic fields extending in opposite directions, the layers being positioned between the pole faces of a highly magnetically permeable material with the south poles of one layer opposite the north poles of the other. Poles in the layers are formed by subjecting successive regions of each layer to oppositely directed and suitably varied magnetizing forces.

Enrichment Ratio and Aggregate Stability Dynamics in Intensely Managed Landscapes

NASA Astrophysics Data System (ADS)

Wacha, K.; Papanicolaou, T.; Filley, T. R.; Hou, T.; Abban, B. K.; Wilson, C. G.; Boys, J.

2015-12-01

Challenges in understanding the soil carbon dynamics within intensely managed landscapes (IMLs), found throughout much the US Midwest, is highly complex due to the presence of heterogeneous landscape features and properties, as well as a mosaic of physical and biogeochemical processes occurring at different time scales. In addition, rainfall events exacerbate the effects of tillage by the impact of raindrops, which break down aggregates that encase carbon and dislodge and entrain soil particles and aggregates along the downslope. The redistribution of soil and carbon can have huge implications on biogeochemical cycling and overall carbon budgeting. In this study, we provide some rare field data on the mechanisms impacting aggregate stability, enrichment ratio values to estimate fluxes of carbon, as well as lignin chemistry to see influences on oxidation/mineralization rates. Rainfall simulation experiments were conducted within agricultural fields. Experiments were performed on the midslope (eroding) and toeslope (depositional) sections of representative hillslopes, under a variety of land managements, including row crop (conventional and conservation) and restored grasslands. Sensors were utilized to capture the evolution of soil moisture, temperature, microbial respiration pulses, and discharge rates to identify pseudo-steady state conditions. Samples collected at the weir outlet were tested for sediment concentrations and size fractions, as well as carbon and lignin fluxes. Preliminary findings show that conservation management practices have higher aggregate stability and decreased mass fluxes of carbon in the downslope than conventional tillage techniques.

Active-Optical Sensors Using Red NDVI Compared to Red Edge NDVI for Prediction of Corn Grain Yield in North Dakota, U.S.A.

PubMed Central

Sharma, Lakesh K.; Bu, Honggang; Denton, Anne; Franzen, David W.

2015-01-01

Active-optical sensor readings from an N non-limiting area standard established within a farm field are used to predict yield in the standard. Lower yield predictions from sensor readings obtained from other parts of the field outside of the N non-limiting standard area indicate a need for supplemental N. Active-optical sensor algorithms for predicting corn (Zea mays, L.) yield to direct in-season nitrogen (N) fertilization in corn utilize red NDVI (normalized differential vegetative index). Use of red edge NDVI might improve corn yield prediction at later growth stages when corn leaves cover the inter-row space resulting in “saturation” of red NDVI readings. The purpose of this study was to determine whether the use of red edge NDVI in two active-optical sensors (GreenSeeker™ and Holland Scientific Crop Circle™) improved corn yield prediction. Nitrogen rate experiments were established at 15 sites in North Dakota (ND). Sensor readings were conducted at V6 and V12 corn. Red NDVI and red edge NDVI were similar in the relationship of readings with yield at V6. At V12, the red edge NDVI was superior to the red NDVI in most comparisons, indicating that it would be most useful in developing late-season N application algorithms. PMID:26540057

Active-Optical Sensors Using Red NDVI Compared to Red Edge NDVI for Prediction of Corn Grain Yield in North Dakota, U.S.A.

PubMed

Sharma, Lakesh K; Bu, Honggang; Denton, Anne; Franzen, David W

2015-11-02

Active-optical sensor readings from an N non-limiting area standard established within a farm field are used to predict yield in the standard. Lower yield predictions from sensor readings obtained from other parts of the field outside of the N non-limiting standard area indicate a need for supplemental N. Active-optical sensor algorithms for predicting corn (Zea mays, L.) yield to direct in-season nitrogen (N) fertilization in corn utilize red NDVI (normalized differential vegetative index). Use of red edge NDVI might improve corn yield prediction at later growth stages when corn leaves cover the inter-row space resulting in "saturation" of red NDVI readings. The purpose of this study was to determine whether the use of red edge NDVI in two active-optical sensors (GreenSeeker™ and Holland Scientific Crop Circle™) improved corn yield prediction. Nitrogen rate experiments were established at 15 sites in North Dakota (ND). Sensor readings were conducted at V6 and V12 corn. Red NDVI and red edge NDVI were similar in the relationship of readings with yield at V6. At V12, the red edge NDVI was superior to the red NDVI in most comparisons, indicating that it would be most useful in developing late-season N application algorithms.

Solid particle dynamic behavior through twisted blade rows

NASA Technical Reports Server (NTRS)

Hamed, A.

1982-01-01

The particle trajectory calculations provide the essential information which is required for predicting the pattern and intensity of turbomachinery erosion. Consequently, the evaluation of the machine performance deterioration due to erosion is extremely sensitive to the accuracy of the flow field and blade geometry representation in the trajectory computational model. A model is presented that is simple and efficient yet versatile and general to be applicable to axial, radial and mixed flow machines, and to inlets, nozzles, return passages and separators. The results of the computations are presented for the particle trajectories through a row of twisted vanes in the inlet flow field. The effect of the particle size on their trajectories, blade impacts, and on their redistribution and separation are discussed.

Topography and crop management are key factors for the development of american leaf spot epidemics on coffee in costa rica.

PubMed

Avelino, Jacques; Cabut, Sandrine; Barboza, Bernardo; Barquero, Miguel; Alfaro, Ronny; Esquivel, César; Durand, Jean-François; Cilas, Christian

2007-12-01

ABSTRACT We monitored the development of American leaf spot of coffee, a disease caused by the gemmiferous fungus Mycena citricolor, in 57 plots in Costa Rica for 1 or 2 years in order to gain a clearer understanding of conditions conducive to the disease and improve its control. During the investigation, characteristics of the coffee trees, crop management, and the environment were recorded. For the analyses, we used partial least-squares regression via the spline functions (PLSS), which is a nonlinear extension to partial least-squares regression (PLS). The fungus developed well in areas located between approximately 1,100 and 1,550 m above sea level. Slopes were conducive to its development, but eastern-facing slopes were less affected than the others, probably because they were more exposed to sunlight, especially in the rainy season. The distance between planting rows, the shade percentage, coffee tree height, the type of shade, and the pruning system explained disease intensity due to their effects on coffee tree shading and, possibly, on the humidity conditions in the plot. Forest trees and fruit trees intercropped with coffee provided particularly propitious conditions. Apparently, fertilization was unfavorable for the disease, probably due to dilution phenomena associated with faster coffee tree growth. Finally, series of wet spells interspersed with dry spells, which were frequent in the middle of the rainy season, were critical for the disease, probably because they affected the production and release of gemmae and their viability. These results could be used to draw up a map of epidemic risks taking topographical factors into account. To reduce those risks and improve chemical control, our results suggested that farmers should space planting rows further apart, maintain light shading in the plantation, and prune their coffee trees.

Extreme-phenotype genome-wide association study (XP-GWAS): a method for identifying trait-associated variants by sequencing pools of individuals selected from a diversity panel.

PubMed

Yang, Jinliang; Jiang, Haiying; Yeh, Cheng-Ting; Yu, Jianming; Jeddeloh, Jeffrey A; Nettleton, Dan; Schnable, Patrick S

2015-11-01

Although approaches for performing genome-wide association studies (GWAS) are well developed, conventional GWAS requires high-density genotyping of large numbers of individuals from a diversity panel. Here we report a method for performing GWAS that does not require genotyping of large numbers of individuals. Instead XP-GWAS (extreme-phenotype GWAS) relies on genotyping pools of individuals from a diversity panel that have extreme phenotypes. This analysis measures allele frequencies in the extreme pools, enabling discovery of associations between genetic variants and traits of interest. This method was evaluated in maize (Zea mays) using the well-characterized kernel row number trait, which was selected to enable comparisons between the results of XP-GWAS and conventional GWAS. An exome-sequencing strategy was used to focus sequencing resources on genes and their flanking regions. A total of 0.94 million variants were identified and served as evaluation markers; comparisons among pools showed that 145 of these variants were statistically associated with the kernel row number phenotype. These trait-associated variants were significantly enriched in regions identified by conventional GWAS. XP-GWAS was able to resolve several linked QTL and detect trait-associated variants within a single gene under a QTL peak. XP-GWAS is expected to be particularly valuable for detecting genes or alleles responsible for quantitative variation in species for which extensive genotyping resources are not available, such as wild progenitors of crops, orphan crops, and other poorly characterized species such as those of ecological interest. © 2015 The Authors The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.

INTEGRATED WEED CONTROL IN MAIZE.

PubMed

Latré, J; Dewitte, K; Derycke, V; De Roo, B; Haesaert, G

2015-01-01

Integrated pest management has been implemented as a general practice by EU legislation. As weed control actually is the most important crop protection measure in maize for Western Europe, the new legislation will have its impact. The question is of course which systems can be successfully implemented in practice with respect to labour efficiency and economical parameters. During 3 successive growing seasons (2007, 2008, 2009) weed control in maize was evaluated, the main focus was put on different techniques of integrated weed control and was compared with chemical weed control. Additionally, during 4 successive growing seasons (2011, 2012, 2013 and 2014) two objects based on integrated weed control and two objects based on mechanical weed control were compared to about twenty different objects of conventional chemical weed control. One of the objects based on mechanical weed control consisted of treatment with the flex-tine harrow before and after emergence in combination with chemical weed control at a reduced rate in 3-4 leave stage. The second one consisted of broadcast mechanical treatments before and after emergence followed by a final in-row application of herbicides and an inter-row cultivation at 6-7(8) leave stage. All trials were conducted on the Experimental farm of Bottelare HoGent-UGent on a sandy loam soil. Maize was growing in 1/3 crop rotation. The effect on weed growth as well as the economic impact of the different applications was evaluated. Combining chemical and mechanical weed control is a possible option in conventional farming but the disadvantages must be taken into account. A better planned weed control based on the real present weed-population in combination with a carefully thought-out choice of herbicides should also be considered as an IPM--approach.

Anthropogenic disturbance and landscape patterns affect diversity patterns of aquatic benthic macroinvertebrates

USGS Publications Warehouse

Maloney, K.O.; Munguia, P.; Mitchell, R.M.

2011-01-01

Measures of species diversity are valuable tools for assessing ecosystem health. However, most assessments have addressed individual sites or regional taxon pools, with few comparisons of differences in assemblage composition within or among regions. We examined the effects of anthropogenic disturbance on local richness (?? diversity) and species turnover (?? diversity) of benthic macroinvertebrates in small streams within and between 2 ecoregions (Northern Piedmont vs Southeastern Plains ecoregions) of the Patuxent River basin (Maryland, USA). Regional species pools did not differ between ecoregions (Piedmont = 166 taxa, Plains = 162 taxa); however, local richness was lower in the Plains (mean = 17.4 taxa/stream) compared to the Piedmont (mean = 22.2 taxa/stream). When streams were categorized into disturbance classes (low, medium, high), local richness did not differ among categories for either region. However, at the entire Patuxent scale, local richness tended to decrease with % impervious cover in a watershed. Variation in species composition, analyzed with nonmetric multidimensional scaling (nMDS), differed significantly between Piedmont and Plains streams, and Plains streams had higher ?? diversity than Piedmont streams. When partitioned by disturbance category and region, ?? diversity differed only between the low-disturbance sites (Plains > Piedmont). Relationships between ?? diversity and environmental variables varied by region. ?? diversity was weakly negatively related to % row-crop cover in a watershed at the entire Patuxent scale. For the Piedmont region, ?? diversity tended to decrease with % forest, % pasture, and % row-crop cover in a watershed. Such negative relationships between ?? diversity and landuse variables indicate a possible homogenization of the assemblage. The incongruence between diversity measures and composition measures, together with differing effects of anthropogenic land use on ?? diversity in the 2 regions, emphasizes the need to incorporate both ?? and ?? diversity and regional environmental factors in conservation/land management studies. ?? 2011 The North American Benthological Society.

Developments in Time-Division Multiplexing of X-ray Transition-Edge Sensors

NASA Astrophysics Data System (ADS)

Doriese, W. B.; Morgan, K. M.; Bennett, D. A.; Denison, E. V.; Fitzgerald, C. P.; Fowler, J. W.; Gard, J. D.; Hays-Wehle, J. P.; Hilton, G. C.; Irwin, K. D.; Joe, Y. I.; Mates, J. A. B.; O'Neil, G. C.; Reintsema, C. D.; Robbins, N. O.; Schmidt, D. R.; Swetz, D. S.; Tatsuno, H.; Vale, L. R.; Ullom, J. N.

2016-07-01

Time-division multiplexing (TDM) is a mature scheme for the readout of arrays of transition-edge sensors (TESs). TDM is based on superconducting-quantum-interference-device (SQUID) current amplifiers. Multiple spectrometers based on gamma-ray and X-ray microcalorimeters have been operated with TDM readout, each at the scale of 200 sensors per spectrometer, as have several astronomical cameras with thousands of sub-mm or microwave bolometers. Here we present the details of two different versions of our TDM system designed to read out X-ray TESs. The first has been field-deployed in two 160-sensor (8 columns × 20 rows) spectrometers and four 240-sensor (8 columns × 30 rows) spectrometers. It has a three-SQUID-stage architecture, switches rows every 320 ns, and has total readout noise of 0.41 μ Φ 0 / surd Hz. The second, which is presently under development, has a two-SQUID-stage architecture, switches rows every 160 ns, and has total readout noise of 0.19 μ Φ 0 / surd Hz. Both quoted noise values are non-multiplexed and referred to the first-stage SQUID. In a demonstration of this new architecture, a multiplexed 1-column × 32-row array of NIST TESs achieved average energy resolution of 2.55± 0.01 eV at 6 keV.

Development of a Telemetry and Yield-Mapping System of Olive Harvester

PubMed Central

Castillo-Ruiz, Francisco J.; Pérez-Ruiz, Manuel; Blanco-Roldán, Gregorio L.; Gil-Ribes, Jesús A.; Agüera, Juan

2015-01-01

Sensors, communication systems and geo-reference units are required to achieve an optimized management of agricultural inputs with respect to the economic and environmental aspects of olive groves. In this study, three commercial olive harvesters were tracked during two harvesting seasons in Spain and Chile using remote and autonomous equipment that was developed to determine their time efficiency and effective based on canopy shaking for fruit detachment. These harvesters work in intensive/high-density (HD) and super-high-density (SHD) olive orchards. A GNSS (Global Navigation Satellite System) and GSM (Global System for Mobile Communications) device was installed to track these harvesters. The GNSS receiver did not affect the driver’s work schedule. Time elements methodology was adapted to the remote data acquisition system. The effective field capacity and field efficiency were investigated. In addition, the field shape, row length, angle between headland alley and row, and row alley width were measured to determinate the optimum orchard design parameters value. The SHD olive harvester showed significant lower effective field capacity values when alley width was less than 4 m. In addition, a yield monitor was developed and installed on a traditional olive harvester to obtain a yield map from the harvested area. The hedge straddle harvester stood out for its highly effective field capacity; nevertheless, a higher field efficiency was provided by a non-integral lateral canopy shaker. All of the measured orchard parameters have influenced machinery yields, whether effective field capacity or field efficiency. A saving of 40% in effective field capacity was achieved with a reduction from 4 m or higher to 3.5 m in alley width for SHD olive harvester. A yield map was plotted using data that were acquired by a yield monitor, reflecting the yield gradient in spite of the larger differences between tree yields. PMID:25675283

Field Crop Nutrition--Applied Science Concepts. Student Manual.

ERIC Educational Resources Information Center

Miller, Charles R.

This manual is designed to help agricultural education students to determine and provide the proper kinds and amounts of nutrients for the field crops they produce. The manual provides many learning situations regarding field crops--for example, determining nutrient needs, diagnosing nutrient shortages, and selecting and applying fertilizer and…

Modeling the status, trends, and impacts of wild bee abundance in the United States

PubMed Central

Koh, Insu; Lonsdorf, Eric V.; Williams, Neal M.; Brittain, Claire; Isaacs, Rufus; Gibbs, Jason; Ricketts, Taylor H.

2016-01-01

Wild bees are highly valuable pollinators. Along with managed honey bees, they provide a critical ecosystem service by ensuring stable pollination to agriculture and wild plant communities. Increasing concern about the welfare of both wild and managed pollinators, however, has prompted recent calls for national evaluation and action. Here, for the first time to our knowledge, we assess the status and trends of wild bees and their potential impacts on pollination services across the coterminous United States. We use a spatial habitat model, national land-cover data, and carefully quantified expert knowledge to estimate wild bee abundance and associated uncertainty. Between 2008 and 2013, modeled bee abundance declined across 23% of US land area. This decline was generally associated with conversion of natural habitats to row crops. We identify 139 counties where low bee abundances correspond to large areas of pollinator-dependent crops. These areas of mismatch between supply (wild bee abundance) and demand (cultivated area) for pollination comprise 39% of the pollinator-dependent crop area in the United States. Further, we find that the crops most highly dependent on pollinators tend to experience more severe mismatches between declining supply and increasing demand. These trends, should they continue, may increase costs for US farmers and may even destabilize crop production over time. National assessments such as this can help focus both scientific and political efforts to understand and sustain wild bees. As new information becomes available, repeated assessments can update findings, revise priorities, and track progress toward sustainable management of our nation’s pollinators. PMID:26699460

Modeling the status, trends, and impacts of wild bee abundance in the United States.

PubMed

Koh, Insu; Lonsdorf, Eric V; Williams, Neal M; Brittain, Claire; Isaacs, Rufus; Gibbs, Jason; Ricketts, Taylor H

2016-01-05

Wild bees are highly valuable pollinators. Along with managed honey bees, they provide a critical ecosystem service by ensuring stable pollination to agriculture and wild plant communities. Increasing concern about the welfare of both wild and managed pollinators, however, has prompted recent calls for national evaluation and action. Here, for the first time to our knowledge, we assess the status and trends of wild bees and their potential impacts on pollination services across the coterminous United States. We use a spatial habitat model, national land-cover data, and carefully quantified expert knowledge to estimate wild bee abundance and associated uncertainty. Between 2008 and 2013, modeled bee abundance declined across 23% of US land area. This decline was generally associated with conversion of natural habitats to row crops. We identify 139 counties where low bee abundances correspond to large areas of pollinator-dependent crops. These areas of mismatch between supply (wild bee abundance) and demand (cultivated area) for pollination comprise 39% of the pollinator-dependent crop area in the United States. Further, we find that the crops most highly dependent on pollinators tend to experience more severe mismatches between declining supply and increasing demand. These trends, should they continue, may increase costs for US farmers and may even destabilize crop production over time. National assessments such as this can help focus both scientific and political efforts to understand and sustain wild bees. As new information becomes available, repeated assessments can update findings, revise priorities, and track progress toward sustainable management of our nation's pollinators.

Model-based coefficient method for calculation of N leaching from agricultural fields applied to small catchments and the effects of leaching reducing measures

NASA Astrophysics Data System (ADS)

Kyllmar, K.; Mårtensson, K.; Johnsson, H.

2005-03-01

A method to calculate N leaching from arable fields using model-calculated N leaching coefficients (NLCs) was developed. Using the process-based modelling system SOILNDB, leaching of N was simulated for four leaching regions in southern Sweden with 20-year climate series and a large number of randomised crop sequences based on regional agricultural statistics. To obtain N leaching coefficients, mean values of annual N leaching were calculated for each combination of main crop, following crop and fertilisation regime for each leaching region and soil type. The field-NLC method developed could be useful for following up water quality goals in e.g. small monitoring catchments, since it allows normal leaching from actual crop rotations and fertilisation to be determined regardless of the weather. The method was tested using field data from nine small intensively monitored agricultural catchments. The agreement between calculated field N leaching and measured N transport in catchment stream outlets, 19-47 and 8-38 kg ha -1 yr -1, respectively, was satisfactory in most catchments when contributions from land uses other than arable land and uncertainties in groundwater flows were considered. The possibility of calculating effects of crop combinations (crop and following crop) is of considerable value since changes in crop rotation constitute a large potential for reducing N leaching. When the effect of a number of potential measures to reduce N leaching (i.e. applying manure in spring instead of autumn; postponing ploughing-in of ley and green fallow in autumn; undersowing a catch crop in cereals and oilseeds; and increasing the area of catch crops by substituting winter cereals and winter oilseeds with corresponding spring crops) was calculated for the arable fields in the catchments using field-NLCs, N leaching was reduced by between 34 and 54% for the separate catchments when the best possible effect on the entire potential area was assumed.

Occurrence of dichloroacetamide herbicide safeners and co-applied herbicides in midwestern U.S. streams

USGS Publications Warehouse

Woodward, Emily; Hladik, Michelle; Kolpin, Dana W.

2018-01-01

Dichloroacetamide safeners (e.g., AD-67, benoxacor, dichlormid, and furilazole) are co-applied with chloroacetanilide herbicides to protect crops from herbicide toxicity. While such safeners have been used since the early 1970s, there are minimal data about safener usage, occurrence in streams, or potential ecological effects. This study focused on one of these research gaps, occurrence in streams. Seven Midwestern U.S. streams (five in Iowa and two in Illinois), with extensive row-crop agriculture, were sampled at varying frequencies from spring 2016 through summer 2017. All four safeners were detected at least once; furilazole was the most frequently detected (31%), followed by benoxacor (29%), dichlormid (15%), and AD-67 (2%). The maximum concentrations ranged from 42 to 190 ng/L. Stream detections and concentrations of safeners appear to be driven by a combination of timing of application (spring following herbicide application) and precipitation events. Detected concentrations were below known toxicity levels for aquatic organisms.

Soil conservation in Central America and Panama: current problems.

PubMed

Popenoe, H

1976-06-01

Soil conservation measures in Central America go back to the Maya civilization, in which terracing was employed. After the Spanish conquest, plowing, livestock raising, and the succession of social and political changes all contributed to accelerate erosion. Through the past few decades, awareness of the need for soil conservation has again increased; El Salvador and Costa Rica began efforts in that direction in 1943. For sometime, the use of machinery and chemical fertilizers has masked the loss of topsoil, but under recent increases in population pressures, soil conservation measures are gaining in importance. Important agents of erosion in the tropics are heavy seasonal rains at high elevations, alternating with long dry seasons; wind erosion; and landslides after saturation of the soil during prolonged rains. Modern machinery often hastens soil removal, as do also overgrazing, deforestation and vertical crop rows. Under the present energy crisis, human labor is becoming again a significant element in crop production, and soil conservation becomes thereby more feasible and more important.

Unsteady Flows in a Single-Stage Transonic Axial-Flow Fan Stator Row. Ph.D. Thesis - Iowa State Univ.

NASA Technical Reports Server (NTRS)

Hathaway, Michael D.

1986-01-01

Measurements of the unsteady velocity field within the stator row of a transonic axial-flow fan were acquired using a laser anemometer. Measurements were obtained on axisymmetric surfaces located at 10 and 50 percent span from the shroud, with the fan operating at maximum efficiency at design speed. The ensemble-average and variance of the measured velocities are used to identify rotor-wake-generated (deterministic) unsteadiness and turbulence, respectively. Correlations of both deterministic and turbulent velocity fluctuations provide information on the characteristics of unsteady interactions within the stator row. These correlations are derived from the Navier-Stokes equation in a manner similar to deriving the Reynolds stress terms, whereby various averaging operators are used to average the aperiodic, deterministic, and turbulent velocity fluctuations which are known to be present in multistage turbomachines. The correlations of deterministic and turbulent velocity fluctuations throughout the axial fan stator row are presented. In particular, amplification and attenuation of both types of unsteadiness are shown to occur within the stator blade passage.

[Spatio-temporal distribution of carabids and spiders between semi-natural field margin and the adjacent crop fields in agricultural landscape].

PubMed

Zhang, Xu Zhu; Han, Yin; Yu, Zhen Rong; Liu, Yun Hui

2017-06-18

This study was conducted before and after harvesting of wheat and maize in a typical agricultural landscape of the North China Plain. We investigated the diversity of two important natural enemy groups, carabids and spiders, using pitfall traps at crop field margin with different vegetation structures and their neighboring crop field. Throughout the comparison of the spatial and temporal distribution of the diversity of carabids and spiders in field margin and neighboring field, and the investigation of the relationship between arthropod communities and vegetation structure, this study aimed to understand the role of semi-natural field margin in biodiversity conservation of different natural enemy taxa. Results showed that the abundance of spiders was significantly higher in field margin than in neighboring fields over the entire period. No significant difference of the diversity of carabids in field margin and crop field was observed, but the community composition was different. Number of spider families increased in field margin but deceased in crop field after harvesting, indicating a migration activity between field and field margin. Vegetation structure in the field margin had different association with carabids than with spiders, with diversity of dominant carabid species positively associated with herb coverage and negatively with wood coverage, while the diversity of spider family Linyphiidae was positively associated with herb coverage only. Semi-natural habitat benefited the conservation of the diversity of arthropod natural enemies in crop field via promoting their dispersal to crop field, while such impacts differed from different vegetation structures and varied from target beneficial natural enemy communities. Future studies should focus on in-depth understanding of the food and habitat source requirement of different natural enemy taxa, and hence to design suitable semi-natural habitats to maintain a high diversity of natural enemy communities.

A survey of silage management practices on California dairies.

PubMed

Heguy, J M; Meyer, D; Silva-Del-Río, N

2016-02-01

The aim of the present study was to gather baseline information on corn silage-management practices to develop an outreach curriculum for dairy producers and growers. In spring 2013, dairy producers in the San Joaquin Valley (California) were surveyed on their silage-management practices. Response rate was 14.5% (n=160) and herd size averaged 1,512 milking cows. Harvest date was set solely by the dairy producer (53.4%) or with the assistance of the crop manager, custom chopper, or nutritionist (23.3%). On some dairies (23.3%), the dairy producer delegated the harvest date decision. Most dairies (75.0%) estimated crop dry matter before harvest, and the preferred method was milk line evaluation. Dairy producers were mostly unfamiliar with harvest rate but the number [1 (35.9%), 2 (50.3%), or 3 to 5 (13.8%)] and size [6-row (17.7%), 8-row (67.3%), or 10-row (15.0%)] of choppers working simultaneously was reported. Most dairies used a single packing tractor (68.8%) and weighed every load of fresh chopped corn delivered to the silage pit (62%). During harvest, dry matter (66.9%), particle length (80.4%), and kernel processing (92.5%) were monitored. Most dairies completed filling their largest silage structure in less than 3 d (48.5%) or in 4 to 7 d (30.9%). Silage covering was completed no later than 7 2h after structure completion in all dairies, and was often completed within 24 h (68.8%). Packed forage was covered as filled in 19.6% of dairies. Temporary covers were used on some dairies (51.0%), with filling durations of 1 to 60 d. When temporary covers were not used, structures were filled in no more than 15 d. After structure closure, silage feedout started in 1 to 3 wk (44.4%), 4 to 5 wk (31.4%), or 8 or more wk (24.2%). Future considerations included increasing the silage storage area (55.9%), increasing the number of packing tractors (37.0%), planting brown mid-rib varieties (34.4%), buying a defacer to remove silage (33.1%), and creating drive-over piles (32.6%). Survey results will serve to develop and disseminate targeted information on silage management practices at harvest, packing, covering, and feedout on California's San Joaquin Valley dairies. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Active optical sensors for tree stem detection and classification in nurseries.

PubMed

Garrido, Miguel; Perez-Ruiz, Manuel; Valero, Constantino; Gliever, Chris J; Hanson, Bradley D; Slaughter, David C

2014-06-19

Active optical sensing (LIDAR and light curtain transmission) devices mounted on a mobile platform can correctly detect, localize, and classify trees. To conduct an evaluation and comparison of the different sensors, an optical encoder wheel was used for vehicle odometry and provided a measurement of the linear displacement of the prototype vehicle along a row of tree seedlings as a reference for each recorded sensor measurement. The field trials were conducted in a juvenile tree nursery with one-year-old grafted almond trees at Sierra Gold Nurseries, Yuba City, CA, United States. Through these tests and subsequent data processing, each sensor was individually evaluated to characterize their reliability, as well as their advantages and disadvantages for the proposed task. Test results indicated that 95.7% and 99.48% of the trees were successfully detected with the LIDAR and light curtain sensors, respectively. LIDAR correctly classified, between alive or dead tree states at a 93.75% success rate compared to 94.16% for the light curtain sensor. These results can help system designers select the most reliable sensor for the accurate detection and localization of each tree in a nursery, which might allow labor-intensive tasks, such as weeding, to be automated without damaging crops.

Channel flow analysis. [velocity distribution throughout blade flow field

NASA Technical Reports Server (NTRS)

Katsanis, T.

1973-01-01

The design of a proper blade profile requires calculation of the blade row flow field in order to determine the velocities on the blade surfaces. An analysis theory is presented for several methods used for this calculation and associated computer programs that were developed are discussed.

Nonvolatile random access memory

NASA Technical Reports Server (NTRS)

Wu, Jiin-Chuan (Inventor); Stadler, Henry L. (Inventor); Katti, Romney R. (Inventor)

1994-01-01

A nonvolatile magnetic random access memory can be achieved by an array of magnet-Hall effect (M-H) elements. The storage function is realized with a rectangular thin-film ferromagnetic material having an in-plane, uniaxial anisotropy and inplane bipolar remanent magnetization states. The thin-film magnetic element is magnetized by a local applied field, whose direction is used to form either a 0 or 1 state. The element remains in the 0 or 1 state until a switching field is applied to change its state. The stored information is detcted by a Hall-effect sensor which senses the fringing field from the magnetic storage element. The circuit design for addressing each cell includes transistor switches for providing a current of selected polarity to store a binary digit through a separate conductor overlying the magnetic element of the cell. To read out a stored binary digit, transistor switches are employed to provide a current through a row of Hall-effect sensors connected in series and enabling a differential voltage amplifier connected to all Hall-effect sensors of a column in series. To avoid read-out voltage errors due to shunt currents through resistive loads of the Hall-effect sensors of other cells in the same column, at least one transistor switch is provided between every pair of adjacent cells in every row which are not turned on except in the row of the selected cell.

Simulation of crop yield variability by improved root-soil-interaction modelling

NASA Astrophysics Data System (ADS)

Duan, X.; Gayler, S.; Priesack, E.

2009-04-01

Understanding the processes and factors that govern the within-field variability in crop yield has attached great importance due to applications in precision agriculture. Crop response to environment at field scale is a complex dynamic process involving the interactions of soil characteristics, weather conditions and crop management. The numerous static factors combined with temporal variations make it very difficult to identify and manage the variability pattern. Therefore, crop simulation models are considered to be useful tools in analyzing separately the effects of change in soil or weather conditions on the spatial variability, in order to identify the cause of yield variability and to quantify the spatial and temporal variation. However, tests showed that usual crop models such as CERES-Wheat and CERES-Maize were not able to quantify the observed within-field yield variability, while their performance on crop growth simulation under more homogeneous and mainly non-limiting conditions was sufficent to simulate average yields at the field-scale. On a study site in South Germany, within-field variability in crop growth has been documented since years. After detailed analysis and classification of the soil patterns, two site specific factors, the plant-available-water and the O2 deficiency, were considered as the main causes of the crop growth variability in this field. Based on our measurement of root distribution in the soil profile, we hypothesize that in our case the insufficiency of the applied crop models to simulate the yield variability can be due to the oversimplification of the involved root models which fail to be sensitive to different soil conditions. In this study, the root growth model described by Jones et al. (1991) was adapted by using data of root distributions in the field and linking the adapted root model to the CERES crop model. The ability of the new root model to increase the sensitivity of the CERES crop models to different enviromental conditions was then evaluated by means of comparison of the simualtion results with measured data and by scenario calculations.

The 1981 Argentina ground data collection

NASA Technical Reports Server (NTRS)

Horvath, R.; Colwell, R. N. (Principal Investigator); Hicks, D.; Sellman, B.; Sheffner, E.; Thomas, G.; Wood, B.

1981-01-01

Over 600 fields in the corn, soybean and wheat growing regions of the Argentine pampa were categorized by crop or cover type and ancillary data including crop calendars, historical crop production statistics and certain cropping practices were also gathered. A summary of the field work undertaken is included along with a country overview, a chronology of field trip planning and field work events, and the field work inventory of selected sample segments. LANDSAT images were annotated and used as the field work base and several hundred ground and aerial photographs were taken. These items along with segment descriptions are presented. Meetings were held with officials of the State Secretariat of Agriculture (SEAG) and the National Commission on Space Investigations (CNIE), and their support to the program are described.

Effects on aquatic and human health due to large scale bioenergy crop expansion.

PubMed

Love, Bradley J; Einheuser, Matthew D; Nejadhashemi, A Pouyan

2011-08-01

In this study, the environmental impacts of large scale bioenergy crops were evaluated using the Soil and Water Assessment Tool (SWAT). Daily pesticide concentration data for a study area consisting of four large watersheds located in Michigan (totaling 53,358 km²) was estimated over a six year period (2000-2005). Model outputs for atrazine, bromoxynil, glyphosate, metolachlor, pendimethalin, sethoxydim, triflualin, and 2,4-D model output were used to predict the possible long-term implications that large-scale bioenergy crop expansion may have on the bluegill (Lepomis macrochirus) and humans. Threshold toxicity levels were obtained for the bluegill and for human consumption for all pesticides being evaluated through an extensive literature review. Model output was compared to each toxicity level for the suggested exposure time (96-hour for bluegill and 24-hour for humans). The results suggest that traditional intensive row crops such as canola, corn and sorghum may negatively impact aquatic life, and in most cases affect the safe drinking water availability. The continuous corn rotation, the most representative rotation for current agricultural practices for a starch-based ethanol economy, delivers the highest concentrations of glyphosate to the stream. In addition, continuous canola contributed to a concentration of 1.11 ppm of trifluralin, a highly toxic herbicide, which is 8.7 times the 96-hour ecotoxicity of bluegills and 21 times the safe drinking water level. Also during the period of study, continuous corn resulted in the impairment of 541,152 km of stream. However, there is promise with second-generation lignocellulosic bioenergy crops such as switchgrass, which resulted in a 171,667 km reduction in total stream length that exceeds the human threshold criteria, as compared to the base scenario. Results of this study may be useful in determining the suitability of bioenergy crop rotations and aid in decision making regarding the adaptation of large-scale bioenergy cropping systems. Published by Elsevier B.V.

Effects of agricultural practices of three crops on the soil communities under Mediterranean conditions: field evaluation.

NASA Astrophysics Data System (ADS)

Leitão, Sara; José Cerejeira, Maria; Abreu, Manuela; Sousa, José Paulo

2014-05-01

Sustainable agricultural production relies on soil communities as the main actors in key soil processes necessary to maintain sustainable soil functioning. Soil biodiversity influences soil physical and chemical characteristics and thus the sustainability of crop and agro-ecosystems functioning. Agricultural practices (e.g.: soil tillage, pesticides and fertilizer applications, irrigation) may affects negatively or positively soil biodiversity and abundances by modifying the relationships between organisms in the soil ecosystem. The present study aimed to study the influence of agricultural practices of three crops (potato, onion and maize) under Mediterranean climate conditions on soil macro- and mesofauna during their entire crop cycles. Effects on soil communities were assessed at a higher tier of environmental risk assessment comprising field testing of indigenous edaphic communities in a selected study-site located in a major agriculture region of Central Portugal, Ribatejo e Oeste, neighbouring protected wetlands. A reference site near the agricultural field site was selected as a Control site to compare the terrestrial communities' composition and variation along the crop cycle. The field soil and Control site soil are sandy loam soils. Crops irrigation was performed by center-pivot (automated sprinkler that rotates in a half a circle area) and by sprinklers. Soil macro- and mesofauna were collected at both sites (field and Control) using two methodologies through pitfall trapping and soil sampling. The community of soil macro- and mesofauna of the three crops field varied versus control site along the crops cycles. Main differences were due to arachnids, coleopterans, ants and adult Diptera presence and abundance. The feeding activity of soil fauna between control site and crop areas varied only for potato and onion crops vs. control site but not among crops. Concentration of pesticides residues in soil did not cause apparent negative effects on the soil communities. Significant differences of soil communities from potato and onion crops with the one from control site were observed at the beginning and during the crop cycle, but similarities were observed at the last sampling date after harvesting. The same was observed for the maize crop, indicating that soil communities recovered from the agricultural disturbances associated with crops management. An integrated approach such as the one adopted in present study, taking into consideration soil community's abundances, feeding activity and time variations along entire crop cycles of several crops under Mediterranean conditions, as well as soil exposure to pesticides residues, may contribute to decision making towards a sustainability of crop areas, including pesticide use and management practices.

Genetic engineering applied to agriculture has a long row to hoe.

PubMed

Miller, Henry I

2018-01-02

In spite of the lack of scientific justification for skepticism about crops modified with molecular techniques of genetic engineering, they have been the most scrutinized agricultural products in human history. The assumption that "genetically engineered" or "genetically modified" is a meaningful - and dangerous - classification has led to excessive and dilatory regulation. The modern molecular techniques are an extension, or refinement, of older, less precise, less predictable methods of genetic modification, but as long as today's activists and regulators remain convinced that so called "GMOs" represent a distinct and dangerous category of research and products, genetic engineering will fall short of its potential.

Control of Larval Northern Corn Rootworm. (Diabrotica barberi) with Two Steinernematid Nematode Species

PubMed Central

Thurston, G. S.; Yule, W. N.

1990-01-01

The entomogenous nematodes Steinerema feltiae and S. bibionis did not penetrate the roots of corn, Zea mays, to infect larval northern corn rootworm (NCR), Diabrotica barberi, feeding within. Laboratory bioassays against first instar NCR indicated that S. feltiae, Mexican strain (LD₅₀ = 49 nematodes/insect) is more virulent than S. bibionis (LD₅₀ = 100). Numbers of NCR larvae in a grain corn crop were reduced by both nematode species applied at corn seeding time at the rate of 10,000 infective-stage juveniles per linear meter of corn row. The chemical insecticide fonofos provided significantly better control than either nematode species. PMID:19287699

Predicting Flutter and Forced Response in Turbomachinery

NASA Technical Reports Server (NTRS)

VanZante, Dale E.; Adamczyk, John J.; Srivastava, Rakesh; Bakhle, Milind A.; Shabbir, Aamir; Chen, Jen-Ping; Janus, J. Mark; To, Wai-Ming; Barter, John

2005-01-01

TURBO-AE is a computer code that enables detailed, high-fidelity modeling of aeroelastic and unsteady aerodynamic characteristics for prediction of flutter, forced response, and blade-row interaction effects in turbomachinery. Flow regimes that can be modeled include subsonic, transonic, and supersonic, with attached and/or separated flow fields. The three-dimensional Reynolds-averaged Navier-Stokes equations are solved numerically to obtain extremely accurate descriptions of unsteady flow fields in multistage turbomachinery configurations. Blade vibration is simulated by use of a dynamic-grid-deformation technique to calculate the energy exchange for determining the aerodynamic damping of vibrations of blades. The aerodynamic damping can be used to assess the stability of a blade row. TURBO-AE also calculates the unsteady blade loading attributable to such external sources of excitation as incoming gusts and blade-row interactions. These blade loadings, along with aerodynamic damping, are used to calculate the forced responses of blades to predict their fatigue lives. Phase-lagged boundary conditions based on the direct-store method are used to calculate nonzero interblade phase-angle oscillations; this practice eliminates the need to model multiple blade passages, and, hence, enables large savings in computational resources.

All-atom force field for molecular dynamics simulations on organotransition metal solids and liquids. Application to M(CO)(n) (M = Cr, Fe, Ni, Mo, Ru, or W) compounds.

PubMed

Bernardes, Carlos E S; Canongia Lopes, José N; Minas da Piedade, Manuel E

2013-10-31

A previously developed OPLS-based all-atom force field for organometallic compounds was extended to a series of first-, second-, and third-row transition metals based on the study of M(CO)(n) (M = Cr, Fe, Ni, Mo, Ru, or W) complexes. For materials that are solid at ambient temperature and pressure (M = Cr, Mo, W) the validation of the force field was based on reported structural data and on the standard molar enthalpies of sublimation at 298.15 K, experimentally determined by Calvet-drop microcalorimetry using samples corresponding to a specific and well-characterized crystalline phase: Δ(sub)H(m)° = 72.6 ± 0.3 kJ·mol(–1) for Cr(CO)(6), 73.4 ± 0.3 kJ·mol(–1) for Mo(CO)(6), and 77.8 ± 0.3 kJ·mol(–1) for W(CO)(6). For liquids, where problems of polymorphism or phase mixtures are absent, critically analyzed literature data were used. The force field was able to reproduce the volumetric properties of the test set (density and unit cell volume) with an average deviations smaller than 2% and the experimentally determined enthalpies of sublimation and vaporization with an accuracy better than 2.3 kJ·mol(–1). The Lennard-Jones (12-6) potential function parameters used to calculate the repulsive and dispersion contributions of the metals within the framework of the force field were found to be transferable between chromium, iron, and nickel (first row) and between molybdenum and ruthenium (second row).

Comprehensive Forced Response Analysis of J2X Turbine Bladed-Discs with 360 Degree Variation in CFD Loading

NASA Technical Reports Server (NTRS)

Elrod, David; Christensen, Eric; Brown, Andrew

2011-01-01

The temporal frequency content of the dynamic pressure predicted by a 360 degree computational fluid dynamics (CFD) analysis of a turbine flow field provides indicators of forcing function excitation frequencies (e.g., multiples of blade pass frequency) for turbine components. For the Pratt and Whitney Rocketdyne J-2X engine turbopumps, Campbell diagrams generated using these forcing function frequencies and the results of NASTRAN modal analyses show a number of components with modes in the engine operating range. As a consequence, forced response and static analyses are required for the prediction of combined stress, high cycle fatigue safety factors (HCFSF). Cyclically symmetric structural models have been used to analyze turbine vane and blade rows, not only in modal analyses, but also in forced response and static analyses. Due to the tortuous flow pattern in the turbine, dynamic pressure loading is not cyclically symmetric. Furthermore, CFD analyses predict dynamic pressure waves caused by adjacent and non-adjacent blade/vane rows upstream and downstream of the row analyzed. A MATLAB script has been written to calculate displacements due to the complex cyclically asymmetric dynamic pressure components predicted by CFD analysis, for all grids in a blade/vane row, at a chosen turbopump running speed. The MATLAB displacements are then read into NASTRAN, and dynamic stresses are calculated, including an adjustment for possible mistuning. In a cyclically symmetric NASTRAN static analysis, static stresses due to centrifugal, thermal, and pressure loading at the mode running speed are calculated. MATLAB is used to generate the HCFSF at each grid in the blade/vane row. When compared to an approach assuming cyclic symmetry in the dynamic flow field, the current approach provides better assurance that the worst case safety factor has been identified. An extended example for a J-2X turbopump component is provided.

Use of Fuzzy rainfall-runoff predictions for claypan watersheds with conservation buffers in Northeast Missouri

NASA Astrophysics Data System (ADS)

Anomaa Senaviratne, G. M. M. M.; Udawatta, Ranjith P.; Anderson, Stephen H.; Baffaut, Claire; Thompson, Allen

2014-09-01

Fuzzy rainfall-runoff models are often used to forecast flood or water supply in large catchments and applications at small/field scale agricultural watersheds are limited. The study objectives were to develop, calibrate, and validate a fuzzy rainfall-runoff model using long-term data of three adjacent field scale row crop watersheds (1.65-4.44 ha) with intermittent discharge in the claypan soils of Northeast Missouri. The watersheds were monitored for a six-year calibration period starting 1991 (pre-buffer period). Thereafter, two of them were treated with upland contour grass and agroforestry (tree + grass) buffers (4.5 m wide, 36.5 m apart) to study water quality benefits. The fuzzy system was based on Mamdani method using MATLAB 7.10.0. The model predicted event-based runoff with model performance coefficients of r2 and Nash-Sutcliffe Coefficient (NSC) values greater than 0.65 for calibration and validation. The pre-buffer fuzzy system predicted event-based runoff for 30-50 times larger corn/soybean watersheds with r2 values of 0.82 and 0.68 and NSC values of 0.77 and 0.53, respectively. The runoff predicted by the fuzzy system closely agreed with values predicted by physically-based Agricultural Policy Environmental eXtender model (APEX) for the pre-buffer watersheds. The fuzzy rainfall-runoff model has the potential for runoff predictions at field-scale watersheds with minimum input. It also could up-scale the predictions for large-scale watersheds to evaluate the benefits of conservation practices.

Monitoring cover crops using radar remote sensing in southern Ontario, Canada

NASA Astrophysics Data System (ADS)

Shang, J.; Huang, X.; Liu, J.; Wang, J.

2016-12-01

Information on agricultural land surface conditions is important for developing best land management practices to maintain the overall health of the fields. The climate condition supports one harvest per year for the majority of the field crops in Canada, with a relative short growing season between May and September. During the non-growing-season months (October to the following April), many fields are traditionally left bare. In more recent year, there has been an increased interest in planting cover crops. Benefits of cover crops include boosting soil organic matters, preventing soil from erosion, retaining soil moisture, and reducing surface runoff hence protecting water quality. Optical remote sensing technology has been exploited for monitoring cover crops. However limitations inherent to optical sensors such as cloud interference and signal saturation (when leaf area index is above 2.5) impeded its operational application. Radar remote sensing on the other hand is not hindered by unfavorable weather conditions, and the signal continues to be sensitive to crop growth beyond the saturation point of optical sensors. It offers a viable means for capturing timely information on field surface conditions (with or without crop cover) or crop development status. This research investigated the potential of using multi-temporal RADARSAT-2 C-band synthetic aperture radar (SAR) data collected in 2015 over multiple fields of winter wheat, corn and soybean crops in southern Ontario, Canada, to retrieve information on the presence of cover crops and their growth status. Encouraging results have been obtained. This presentation will report the methodology developed and the results obtained.

Important Insect Pests of Fruit - Important Insect Pests of Nuts - Field Crop Insect Pests - Insect Pests of Vegetable Crops.

ERIC Educational Resources Information Center

Gesell, Stanley G.; And Others

This document consists of four agriculture extension service publications from Pennsylvania State University. The titles are: (1) Important Insect Pests of Fruit; (2) Important Insect Pests of Nuts; (3) Field Crop Insect Pests; and (4) Insect Pests of Vegetable Crops. The first publication gives the hosts, injury, and description of 22 insect…

The Potential for Cereal Rye Cover Crops to Host Corn Seedling Pathogens.

PubMed

Bakker, Matthew G; Acharya, Jyotsna; Moorman, Thomas B; Robertson, Alison E; Kaspar, Thomas C

2016-06-01

Cover cropping is a prevalent conservation practice that offers substantial benefits to soil and water quality. However, winter cereal cover crops preceding corn may diminish beneficial rotation effects because two grass species are grown in succession. Here, we show that rye cover crops host pathogens capable of causing corn seedling disease. We isolated Fusarium graminearum, F. oxysporum, Pythium sylvaticum, and P. torulosum from roots of rye and demonstrate their pathogenicity on corn seedlings. Over 2 years, we quantified the densities of these organisms in rye roots from several field experiments and at various intervals of time after rye cover crops were terminated. Pathogen load in rye roots differed among fields and among years for particular fields. Each of the four pathogen species increased in density over time on roots of herbicide-terminated rye in at least one field site, suggesting the broad potential for rye cover crops to elevate corn seedling pathogen densities. The radicles of corn seedlings planted following a rye cover crop had higher pathogen densities compared with seedlings following a winter fallow. Management practices that limit seedling disease may be required to allow corn yields to respond positively to improvements in soil quality brought about by cover cropping.

Land Husbandry: Biochar application to reduce land degradation and erosion on cassava production

NASA Astrophysics Data System (ADS)

Yuniwati, E. D.

2017-12-01

This field experiment was carried out to examine the effect of increasing crop yield on land degradation and erosion in cassava-based cropping systems. The experiment was also aimed at showing that with proper crop management, the planting of cassava does not result in land degradation, and therefore, a sustainable production system can be obtained. The experiment was done in a farmer's fields in Batu, about 15 km south east of Malang, East Java, Indonesia. The soils are Alfisols with a surface slope of about 8%. There were 8 experimental treatments with two replications. The experiment results show that biochar applications reduce of soil erosion rate of the cassava field were not necessarily higher than those of maize in terms of crop yield and crop management. At low-to-medium yield, also observed the nutrient uptake of cassava was lower than that of maize. At high yield, only the K uptake of cassava was higher than that of maize, whereas the N and P uptake was more or less similar. Soil erosion on the cassava field was significantly higher than that on the maize field; however, this only occurred when there was no suitable crop management. Simple crop managements, such as ridging, biochar application, or manure application could significantly reduce soil erosion. The results also revealed that proper management could prevent land degradation and increase crop yield. In turn, the increase in crop yield could decrease soil erosion and plant nutrient depletion.

Managing oriental fruit fly (Diptera: Tephritidae), with spinosad-based protein bait sprays and sanitation in papaya orchards in Hawaii.

PubMed

Piñero, Jaime C; Mau, Ronald F L; Vargas, Roger I

2009-06-01

The efficacy of GF-120 NF Naturalyte Fruit Fly Bait in combination with field sanitation was assessed as a control for female oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), in papaya (Carica papaya L.) orchards in Hawaii. Three different bait spray regimes were evaluated: every row (high use of the bait), every fifth row (moderate use), and every 10th row (low use). Orchard plots in which no bait was applied served as controls. For five of the seven biweekly periods that followed the first bait spray, trapping data revealed significantly fewer female B. dorsalis captured in plots subject to high and moderate bait use than in control plots. Differences in incidence of infestation among treatments were detected only by the third (12 wk after first spray) fruit sampling with significantly fewer infested one-fourth to one-half ripe papaya fruit in plots subject to high and moderate bait use than in control plots. Parasitism rates by Fopius arisanus (Sonan) (Hymenoptera: Braconidae) were not negatively affected by bait application. Results indicate that foliar applications of GF-120 NF Naturalyte Fruit Fly Bait either to all rows (every other tree), or to every fifth row (every tree) in combination with good sanitation can effectively reduce infestation by B. dorsalis in papaya orchards in Hawaii.

Market for ethanol feed joint products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hertzmark, D.; Gould, B.

1979-10-01

This report presents results of econometric estimations and mathematical simulations of markets for joint feed products of motor ethanol. The major issues considered are the nature of current market price relationships, effects on prices, including feed substitutes prices, and effects of demands for increased use of distillers' grains and gluten meal. The econometric section shows that soybean meal was by far the dominant force in the pricing of the two products. However, neither one could be adequately explained without the inclusion of corn in the estimating equations. Later research shows that this was due to the importance of both feedsmore » for metabolizable energy as well as for protein in livestock diets. Current ration formulations would require some discounting of the value of the protein content of the two feeds. Careful siting of the ethanol facilities, and flexible design of the plants so that a maximum number of products may be extracted from the feedstock, seem necessary. Finally, the analysis indicates that substitution in animal diets of these joint products for the corn or milo used originally requires that additional energy be supplied to the animal by some type of forage crop. This implies that additional land may be required for energy production, for such marginal crops as hay and alfalfa, rather than for row crops.« less

Thermography and Sonic Anemometry to Analyze Air Heaters in Mediterranean Greenhouses

PubMed Central

López, Alejandro; Valera, Diego L.; Molina-Aiz, Francisco; Peña, Araceli

2012-01-01

The present work has developed a methodology based on thermography and sonic anemometry for studying the microclimate in Mediterranean greenhouses equipped with air heaters and polyethylene distribution ducts to distribute the warm air. Sonic anemometry allows us to identify the airflow pattern generated by the heaters and to analyze the temperature distribution inside the greenhouse, while thermography provides accurate crop temperature data. Air distribution by means of perforated polyethylene ducts at ground level, widely used in Mediterranean-type greenhouses, can generate heterogeneous temperature distributions inside the greenhouse when the system is not correctly designed. The system analyzed in this work used a polyethylene duct with a row of hot air outlet holes (all of equal diameter) that expel warm air toward the ground to avoid plant damage. We have observed that this design (the most widely used in Almería's greenhouses) produces stagnation of hot air in the highest part of the structure, reducing the heating of the crop zone. Using 88 kW heating power (146.7 W·m−2) the temperature inside the greenhouse is maintained 7.2 to 11.2 °C above the outside temperature. The crop temperature (17.6 to 19.9 °C) was maintained above the minimum recommended value of 10 °C. PMID:23202025

[Growth and development of plants in a row of generations under the conditions of space flight (experiment Greenhouse-5)

NASA Technical Reports Server (NTRS)

Levinskikh, M. A.; Sychev, V. N.; Derendiaeva, T. A.; Signalova, O. B.; Podol'skii, I. G.; Avdeev, S. V.; Bingheim, G. E.; Campbell, W. F. (Principal Investigator)

2001-01-01

Results of the experiment aimed at harvesting a second space generation of wheat var. Apogee in Mir greenhouse Svet (experiment GREENHOUSE-5) are presented. In space flight, germination rate of space seeds from the first crop made up 89% against 100% of the ground seeds. The full biological ripeness was observed in 20 plants grown from the ground seeds and one plant grown from the space seeds following 80- to 90-d vegetation. The plant of the second space generation was morphologically different neither from the species in the first space crop nor from the ground controls. To study the biological characteristics of Apogee seeds gathered in the first and second crops in spaceflight experiment GREENHOUSE-5, the seeds were planted on their return to the laboratory. Morphometric analysis showed that they were essentially similar to the controls. Hence, the space experiments in Mir greenhouse Svet performed during 1998-1999 gave proof that plants cultivated in microgravity can pass the ontogenetic cycle more than once. However, initial results of the investigations into growth and development of plants through several generations are still in-sufficient to speak of possible delayed effects of the spaceflight factors (microgravity, multicomponent radiation, harmful trace contaminants etc.).

Thermography and sonic anemometry to analyze air heaters in Mediterranean greenhouses.

PubMed

López, Alejandro; Valera, Diego L; Molina-Aiz, Francisco; Peña, Araceli

2012-10-16

The present work has developed a methodology based on thermography and sonic anemometry for studying the microclimate in Mediterranean greenhouses equipped with air heaters and polyethylene distribution ducts to distribute the warm air. Sonic anemometry allows us to identify the airflow pattern generated by the heaters and to analyze the temperature distribution inside the greenhouse, while thermography provides accurate crop temperature data. Air distribution by means of perforated polyethylene ducts at ground level, widely used in Mediterranean-type greenhouses, can generate heterogeneous temperature distributions inside the greenhouse when the system is not correctly designed. The system analyzed in this work used a polyethylene duct with a row of hot air outlet holes (all of equal diameter) that expel warm air toward the ground to avoid plant damage. We have observed that this design (the most widely used in Almería's greenhouses) produces stagnation of hot air in the highest part of the structure, reducing the heating of the crop zone. Using 88 kW heating power (146.7 W ∙ m(-2)) the temperature inside the greenhouse is maintained 7.2 to 11.2 °C above the outside temperature. The crop temperature (17.6 to 19.9 °C) was maintained above the minimum recommended value of 10 °C.