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Sample records for brachiaria brizantha pasture

  1. Performance of sheep grazing in pastures of Brachiaria decumbens, Brachiaria brizantha, Panicum maximum, and Andropogon gayanus with different protodioscin concentrations.

    PubMed

    Gracindo, Cristiane Vinhaes; Louvandini, Helder; Riet-Correa, Franklin; Barbosa-Ferreira, Marcos; Castro, Márcio Botelho de

    2014-06-01

    Brachiaria spp. are the most important grasses for ruminants in central-western Brazil. However, the use of these pastures is limited by their toxicity due to steroidal saponins. This experiment was conducted for 60 days to demonstrate the resistance of sheep raised on Brachiaria spp. pastures to steroidal saponin poisoning. The experiment was composed by 48 animals randomly divided into four groups (n = 12). Among them, 32 4- to 5-month-old castrated male crossbred Santa Inês sheep, originating from flocks that had been grazing on Brachiaria spp. for more than three consecutive years, and 16 were non-adapted (naïve) sheep from flocks that never had prior contact with pastures of Brachiaria spp. were randomly divided into four groups. Each of the four experimental groups was composed by eight adapted and four non-adapted animals. The four experimental groups were introduced into paddocks, each of which contained a single grass: either Brachiaria decumbens, Brachiaria brizantha, Panicum maximum, or Andropogon gayanus. The addition of the naïve sheep to the groups was designed to detect pastures' toxicity to naïve sheep and to adjust the stocking rate to optimize the use of forage. The weight gains of sheep grazing on B. decumbens, B. brizantha, and P. maximum were similar; however, the A. gayanus group showed lower weight gains compared with the other groups (P < 0.05). The mean serum activities of γ-glutamyltransferase in the sheep grazing on B. decumbens were higher than those in the sheep from the other groups. No significant differences among the groups were found in aspartate aminotransferase, creatinine, albumin, or total protein serum concentrations. No clinical signs were observed in the adapted sheep in any of the pastures. Of the four non-adapted sheep introduced into the B. decumbens pasture, two showed clinical signs of steroidal saponin poisoning, and one died. No clinical signs were observed in the non-adapted sheep in the other pastures

  2. Ingestive Behavior of Heifers Supplemented with Glycerin in Substitution of Corn on Brachiaria brizantha Pasture

    PubMed Central

    Facuri, L. M. A. M.; Silva, R. R.; da Silva, F. F.; de Carvalho, G. G. P.; Sampaio, C. B.; Mendes, F. B. L.; Lisboa, M. M.; Barroso, D. S.; Carvalho, V. M.; Pereira, M. M. S.

    2014-01-01

    The objective was to evaluate the ingestive behavior of crossbred heifers finished on a Brachiaria brizantha cv. Marandu pasture receiving four levels of glycerin in their supplementation. Thirty-six crossbred heifers with average initial weight of 264.83±3.83 kg and 20 months of age were distributed into a completely randomized design with four treatments and nine replications: control (0%), 4.82%, 10.12%, and 15.56% glycerin in the dry matter. The grazing time reduced linearly (p<0.05), whereas the time spent on activities like rumination, idleness, trough and total chewing time were quadratically affected (p<0.05). Bite rate and number of bites/day were quadratically influenced (p<0.05). The number of bites/swallowed cud and the number of bites/minute, however, increased linearly (p<0.05). Although the time spent on each cud and number of chews per cud were not affected (p>0.05). The number of rumination periods reduced linearly (p<0.05), whereas the number of grazing, idle and trough periods, and the times per grazing, idle, rumination and trough periods were quadratically affected (p<0.05). The feed and rumination efficiencies of the dry matter, non-fibrous carbohydrates, pasture dry matter and concentrate were quadratically affected (p>0.05) whereas the feed efficiency of neutral detergent fiber reduced linearly (p<0.05). Addition of glycerin in substitution of corn in supplements for animals managed on pastures does not influenced feed intake, but reduces the grazing time and increases the idle time. The supplementation also improves feed and rumination efficiencies. PMID:25358318

  3. Somatic Embryogenesis and Plant Regeneration of Brachiaria brizantha.

    PubMed

    Cabral, Glaucia B; Carneiro, Vera T C; Dusi, Diva M A; Martinelli, Adriana P

    2016-01-01

    The genus Brachiaria (Trin.) Griseb. belongs to the family Poaceae, order Poales, class Monocotyledonae. In Brachiaria brizantha (Hochst. ex A. Rich.) Stapf., embryogenic callus can be induced from seeds from apomictic plants, which results in high frequency somatic embryo development and plant regeneration. We report here a detailed protocol for callus induction from apomictic seed; followed by in vitro morphogenesis (somatic embryo and bud differentiation), plant regeneration, and acclimatization in the greenhouse. Important details regarding the positioning of seeds for callus induction and precautions to avoid endophytic contamination and the occurrence of albino plants are presented. PMID:26619875

  4. Abnormal meiosis in tetraploid genotypes of Brachiaria brizantha (Poaceae) induced by colchicine: its implications for breeding.

    PubMed

    Mendes-Bonato, A B; Ferrari Felismino, M; Souza Kaneshima, A M; Pessim, C; Calisto, V; Suely Pagliarini, M; Borges do Valle, C

    2009-01-01

    Meiotic behavior was analyzed in 6 progenies from 3 artificially induced tetraploid (2n = 4x = 36) sexual genotypes (C31, C41, and C48) of the normally apomictic Brachiaria brizantha (Hochst. ex A. Rich.) Stapf., syn. Urochloa brizantha (Hochst. ex A. Rich.) R. Webster. These are key plants to allow intraspecific hybridization of this important forage species, widely used for pastures in the tropics. The percentage of abnormal cells among the plants ranged from 39.8% to 63.2%. In the single plant derived from C48, only the common meiotic abnormalities typical of polyploids were observed, while in plants derived from C31 and C41, a distinct behavior was found. In the majority of cells of those plants, the chromosomes remained scattered in the cytoplasm in the first division, without forming a metaphase plate. This abnormality blocked chromosome movements at anaphase I. Several micronuclei of various sizes were formed and, after the occurrence of an irregular first cytokinesis, the meiocytes progressed normally to the second division, generating polyads with unbalanced microspores. Pollen viability was not correlated with meiotic abnormalities. The importance of these findings to the Brachiaria breeding program is discussed. The sexual progeny of C48 seems most suitable as female parents to be used in intra- and interspecific hybridization. PMID:19433904

  5. Ultrahigh-Performance Liquid Chromatography-High-Resolution Quadrupole Time-of-Flight Mass Spectrometry Based Metabolomics Reveals Key Differences between Brachiaria decumbens and B. brizantha, Two Similar Pastures with Different Toxicities.

    PubMed

    Pérez, Andy J; Hussain, Syeda M; Pecio, Łukasz; Kowalczyk, Mariusz; Herling, Valdo R; Stochmal, Anna

    2016-06-01

    Several species of Brachiaria (Poaceae) currently cover extensive grazing areas in Brazil, providing valuable source of feed for a large cattle population. However, numerous cases of toxicity outbreaks in livestock have raised concerns on safety of using these plants, especially B. decumbens. In this study, chemometric analysis of ultrahigh-performance liquid chromatography-high-resolution quadrupole time-of-flight mass spectrometry (UHPLC-HR-QTOF-MS) data has for the first time uncovered qualitative and quantitative differences between metabolomes of toxic B. decumbens and nontoxic B. brizantha. The steroidal saponin protoneodioscin was established as the main biomarker for B. decumbens when compared to B. brizantha, and therefore the key explanation for their phytochemical differentiation. Quantification of protodioscin in both plants showed no significant differences; consequently, the idea that this compound is solely responsible for toxicity outbreaks must be discarded. Instead, we propose that the added occurrence of its stereoisomer, protoneodioscin, in B. decumbens, can be considered as the probable cause of these events. Interestingly, the greatest concentrations of saponins for both species were reached during winter (B. decumbens = 53.6 ± 5.1 mg·g(-1) dry weight (D.W.); B. brizantha = 25.0 ± 1.9 mg·g(-1) D.W.) and spring (B. decumbens = 49.4 ± 5.0 mg·g(-1) D.W.; B. brizantha = 27.9 ± 1.4 mg·g(-1) D.W.), although in the case of B. decumbens these values do not vary significantly among seasons. PMID:27192362

  6. Foamy macrophages in the liver of cattle fed Brachiaria brizantha hay.

    PubMed

    Torres, Márcia Bersane Araújo de Medeiros; Coelho, Kunie Iabuki Rabello

    2003-06-01

    Liver and lymph nodes injuries characterized by clusters of foamy macrophages, some of them containing birefringent crystals, were observed in cattle fed on Brachiaria brizantha hay. The cattle were from an experimental group poisoned with Senecio brasiliensis known to cause hepatic fibrosis and hepatocyte megalocytosis. One of the animals developed photosensitivity but the exact cause wasn't determined since both plants were fed. The foamy macrophages were present from the 30th d of feeding. Early appearance of these lesions may be particular to the animal specie used or due to the presence of both toxic plants. PMID:12776798

  7. Correspondence analysis evaluation of linear nutrient distribution in root tips of the tropical forage Brachiaria brizantha

    NASA Astrophysics Data System (ADS)

    Pineda-Vargas, C. A.; Prozesky, V. M.; Przybylowicz, W. J.; Mayer, J. E.

    2001-07-01

    The technique of correspondence analysis was applied to a set of data obtained from X-ray elemental analysis by nuclear microscopy. Hydroponic experiments simulating tropical acid soil conditions were carried out to determine possible mechanisms of Al-toxicity stress on specific varieties of the genus Brachiaria. In particular the species Brachiaria brizantha was tested for gradient variation along the central cylinder of selected root tips. Single-point irradiations by nuclear microscopy gave some indication of a possible trace element profile gradient along the root axis. To be able to extrapolate the possible correlation and trace elemental concentrations gradients to a more confident level, this nuclear microscopy data obtained was analysed by correspondence analysis. A clear gradient on the plot of the first two axes of the correspondence analysis was found. The correlation of Ca and Cu as well as that of K and Cl were established.

  8. Performance of Nellore heifers, forage mass, and structural and nutritional characteristics of Brachiaria brizantha grass in integrated production systems.

    PubMed

    de Oliveira, Caroline Carvalho; Villela, Severino Delmar Junqueira; de Almeida, Roberto Giolo; Alves, Fabiana Villa; Behling-Neto, Arthur; Martins, Paulo Gustavo Macedo de Almeida

    2014-01-01

    Our objective was to evaluate production, nutritive value and carrying capacity of piatã grass (Brachiaria brizantha cv. BRS Piatã), and performance of Nellore heifers in agrosilvopastoral systems (ASPS) with three eucalyptus (Eucalyptus urograndis) tree densities, during winter, spring, summer, and fall. Three integrated systems were evaluated: ASPS-1 (357 trees ha(-1)), ASPS-2 (227 trees ha(-1)), and CON (5 trees ha(-1)). In each system, two sward heights were evaluated: short and tall. A total of 80 11-month-old Nellore heifers were randomly allocated in a randomized split-plot block, 3 × 2 factorial. Greater dry matter availability was observed on CON pastures during the fall season. Greater percentage of leaf lamina was detected on ASPS-1 with short sward height and greater during summer, compared with other seasons. A greater forage production was observed between tree rows and for tall sward height. Spring was the season with less forage nutritive value. Average daily gain was greater during summer and fall. Gain per hectare and stocking rate were greater on CON system and on ASPS-2. Pastures with short sward height had greater gain per hectare and stocking rate. Agrosilvopastoral systems with intermediate tree density seem to be a good choice for producers willing to diversify their revenue sources without decreasing animal production. PMID:24043417

  9. Evidence for biological nitrification inhibition in Brachiaria pastures

    PubMed Central

    Subbarao, G. V.; Nakahara, K.; Hurtado, M. P.; Ono, H.; Moreta, D. E.; Salcedo, A. F.; Yoshihashi, A. T.; Ishikawa, T.; Ishitani, M.; Ohnishi-Kameyama, M.; Yoshida, M.; Rondon, M.; Rao, I. M.; Lascano, C. E.; Berry, W. L.; Ito, O.

    2009-01-01

    Nitrification, a key process in the global nitrogen cycle that generates nitrate through microbial activity, may enhance losses of fertilizer nitrogen by leaching and denitrification. Certain plants can suppress soil-nitrification by releasing inhibitors from roots, a phenomenon termed biological nitrification inhibition (BNI). Here, we report the discovery of an effective nitrification inhibitor in the root-exudates of the tropical forage grass Brachiaria humidicola (Rendle) Schweick. Named “brachialactone,” this inhibitor is a recently discovered cyclic diterpene with a unique 5-8-5-membered ring system and a γ-lactone ring. It contributed 60–90% of the inhibitory activity released from the roots of this tropical grass. Unlike nitrapyrin (a synthetic nitrification inhibitor), which affects only the ammonia monooxygenase (AMO) pathway, brachialactone appears to block both AMO and hydroxylamine oxidoreductase enzymatic pathways in Nitrosomonas. Release of this inhibitor is a regulated plant function, triggered and sustained by the availability of ammonium (NH4+) in the root environment. Brachialactone release is restricted to those roots that are directly exposed to NH4+. Within 3 years of establishment, Brachiaria pastures have suppressed soil nitrifier populations (determined as amoA genes; ammonia-oxidizing bacteria and ammonia-oxidizing archaea), along with nitrification and nitrous oxide emissions. These findings provide direct evidence for the existence and active regulation of a nitrification inhibitor (or inhibitors) release from tropical pasture root systems. Exploiting the BNI function could become a powerful strategy toward the development of low-nitrifying agronomic systems, benefiting both agriculture and the environment. PMID:19805171

  10. Selection of reference genes for quantitative real-time PCR expression studies in the apomictic and sexual grass Brachiaria brizantha

    PubMed Central

    Silveira, Érica Duarte; Alves-Ferreira, Márcio; Guimarães, Larissa Arrais; da Silva, Felipe Rodrigues; Carneiro, Vera Tavares de Campos

    2009-01-01

    Background Brachiaria brizantha is an important forage grass. The occurrence of both apomictic and sexual reproduction within Brachiaria makes it an interesting system for understanding the molecular pathways involved in both modes of reproduction. Quantitative real time PCR (qRT-PCR) has emerged as an important technique to compare expression profile of target genes and, in order to obtain reliable results, it is important to have suitable reference genes. In this work, we evaluated eight potential reference genes for B. brizantha qRT-PCR experiments, isolated from cDNA ovary libraries. Vegetative and reproductive tissues of apomictic and sexual B. brizantha were tested to validate the reference genes, including the female gametophyte, where differences in the expression profile between sexual and apomictic plants must occur. Results Eight genes were selected from a cDNA library of ovaries of B. brizantha considering the similarity to reference genes: EF1 (elongation factor 1 alpha), E1F4A (eukaryotic initiation factor 4A), GAPDH (glucose-6-phosphate dehydrogenase), GDP (glyceroldehyde-3-phosphate dehydrogenase), SUCOA (succinyl-CoA ligase), TUB (tubulin), UBCE (ubiquitin conjugating enzyme), UBI (ubiquitin). For the analysis, total RNA was extracted from 22 samples and raw Ct data after qRT-PCR reaction was analyzed for primer efficiency and for an overall analysis of Ct range among the different samples. Elongation factor 1 alpha showed the highest expression levels, whereas succinyl-CoA ligase showed the lowest within the chosen set of samples. GeNorm application was used for evaluation of the best reference genes, and according to that, the least stable genes, with the highest M values were tubulin and succinyl-CoA ligase and the most stable ones, with the lowest M values were elongation factor 1 alpha and ubiquitin conjugating enzyme, when both reproductive and vegetative samples were tested. For ovaries and spikelets of both sexual and apomictic B. brizantha

  11. Indirect measurements of Brachiaria brizantha cv. Marandu fermentable cell wall sugars for second generation biofuels production.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Results of a study conducted to evaluate the possibility of using IVDMD values of B. brizantha cv. Marandu to predict cell wall sugars that would be available in a biorefinery for ethanol production are reported. The study was conducted based on the similarity between rumen enzymes and those used i...

  12. Expressed sequence-tag analysis of ovaries of Brachiaria brizantha reveals genes associated with the early steps of embryo sac differentiation of apomictic plants.

    PubMed

    Silveira, Erica Duarte; Guimarães, Larissa Arrais; de Alencar Dusi, Diva Maria; da Silva, Felipe Rodrigues; Martins, Natália Florencio; do Carmo Costa, Marcos Mota; Alves-Ferreira, Márcio; de Campos Carneiro, Vera Tavares

    2012-02-01

    In apomixis, asexual mode of plant reproduction through seeds, an unreduced megagametophyte is formed due to circumvented or altered meiosis. The embryo develops autonomously from the unreduced egg cell, independently of fertilization. Brachiaria is a genus of tropical forage grasses that reproduces sexually or by apomixis. A limited number of studies have reported the sequencing of apomixis-related genes and a few Brachiaria sequences have been deposited at genebank databases. This work shows sequencing and expression analyses of expressed sequence-tags (ESTs) of Brachiaria genus and points to transcripts from ovaries with preferential expression at megasporogenesis in apomictic plants. From the 11 differentially expressed sequences from immature ovaries of sexual and apomictic Brachiaria brizantha obtained from macroarray analysis, 9 were preferentially detected in ovaries of apomicts, as confirmed by RT-qPCR. A putative involvement in early steps of Panicum-type embryo sac differentiation of four sequences from B. brizantha ovaries: BbrizHelic, BbrizRan, BbrizSec13 and BbrizSti1 is suggested. Two of these, BbrizSti1 and BbrizHelic, with similarity to a gene coding to stress induced protein and a helicase, respectively, are preferentially expressed in the early stages of apomictic ovaries development, especially in the nucellus, in a stage previous to the differentiation of aposporous initials, as verified by in situ hybridization. PMID:22068439

  13. Expression analyses of Brachiaria brizantha genes encoding ribosomal proteins BbrizRPS8, BbrizRPS15a, and BbrizRPL41 during development of ovaries and anthers.

    PubMed

    Lacerda, Ana Luiza Machado; Dusi, Diva Maria de Alencar; Alves, Elizangela Ribeiro; Rodrigues, Júlio Carlyle Macedo; Gomes, Ana Cristina Menezes Mendes; Carneiro, Vera Tavares de Campos

    2013-04-01

    Brachiaria brizantha is a forage grass of the Poaceae family. Introduced from Africa, it is largely used for beef cattle production in Brazil. Brachiaria reproduces sexually or asexually by apomixis, and development of biotechnological tools for gene transfer is being researched to support the breeding programs. The molecular bases of reproduction have not yet been fully elucidated; it is known that gametophyte formation and main reproductive events occur inside the anthers and ovaries. There is therefore much interest in identifying genes expressed in these organs and their corresponding upstream regulatory sequences. In this work we characterized three cDNA from ovaries of B. brizantha plants (CL 09, CL10, and CL21) which show similarity in databases with genes encoding ribosomal proteins S8, S15a, and L41 and were named BbrizRPS8, BbrizRPS15a, and BbrizRPL41, respectively. These clones show higher expression in ovaries, anthers and roots, mitotically active tissues, when compared to leaves of B. brizantha. Localization of transcripts of BbrizRPS8, BbrizRPS15a, and BbrizRPL41 was investigated in the reproductive organs, ovaries, and anthers, from the beginning of development up to maturity. Their activity was higher in early stages of anther development, while expression was detected in all developmental stages in the ovaries, except for BbrizS15a, which was detected only in synergids of apomictic plants. PMID:22833119

  14. Death of pastures syndrome: tissue changes in Urochloa hybrida cv. Mulato II and Urochloa brizantha cv. Marandu.

    PubMed

    Ribeiro-Júnior, N G; Ariano, A P R; Silva, I V

    2016-07-11

    The quality of forage production is a prerequisite to raising livestock. Therefore, income losses in this activity, primarily cattle raising, can result in the impossibility of economic activity. Through the qualitative and quantitative anatomical study of Urochloa hybrida cv. Mulato II and U. brizantha cv. Marandu, we searched for descriptions and compared changes in the individual vegetative body from populations with death syndrome pastures (DPS). Specimens were collected at different physiological stages from farms in northern Mato Grosso. After collection, the individuals were fixed in FAA50 and stored in 70% alcohol. Histological slides were prepared from the middle third of the sections of roots, rhizomes, and leaves, and the proportions and characteristics of tissues were evaluated in healthy, intermediate, and advanced stages of DPS. Changes were compared between cultivars. With the advancement of the syndrome, the following changes were observed: a more marked decrease in the length of roots in U. hybrida; disorganization of the cortical region of the roots and rhizome cultivars; fungal hyphae in roots and aerenchyma formation in U. hybrida; a decrease in sclerenchyma fiber proportions in roots and leaves; sclerification of the epidermis of U. brizantha rhizomes; and an increase in pericyclic fibers in U. hybrida. Furthermore, there was a decrease in the volume of epidermal cells of the abaxial face of the leaves of both cultivars, with a greater reduction in U. hybrida; a gradual decrease in thickness in the midrib of leaves similar to leaf mesophyll; conduction system obstructions; partial or total cell lysis in roots and rhizomes affected by the syndrome. Obstructions in sieve tube element and companion cells, and sometimes obstruction in xylem vessel elements. The evolution of DPS in cultivars was similar, but there were variations, arising probably from the physiological response to stress, such as aerenchyma formation in the root and increased

  15. The Damage Capacity of Mahanarva spectabilis (Distant, 1909) (Hemiptera: Cercopidae) Adults on Brachiaria ruziziensis Pasture

    PubMed Central

    Resende, Tiago Teixeira; Auad, Alexander Machado; Fonseca, Marcy das Graças; Souza Sobrinho, Fausto; Ribeiro dos Santos, Dayane; da Silva, Sandra Elisa Barbosa

    2013-01-01

    The aim of this study was to determine the damage caused by adult Mahanarva spectabilis (Distant, 1909) (Hemiptera: Cercopidae) on Brachiaria ruziziensis (Germain & Evard) under field conditions. A total of 0, 4, 8, 12, or 16 M. spectabilis adults per plot were maintained for 6 days. Thereafter, the insects were removed from the plant, and the following parameters were evaluated: chlorophyll content, damage score, dry as well as fresh weights, percentage of shoots' dry matter, and the forage's ability to regrow. The chlorophyll content was significantly reduced; the damage score and percentage of dry matter in plants increased depending on the increased insect infestation density after 6 days of exposure. In contrast, no change was observed on the B. ruziziensis fresh and dry weights as well as the regrowth capacity depending on the M. spectabilis infestation densities. Attacks by 8 adult M. spectabilis per clump of B. ruziziensis with an average of 80 tillers for 6 days were sufficient to reduce the chlorophyll content and the functional plant loss index. This density can be a reference for spittlebug integrated management in Brachiaria. PMID:24453825

  16. The damage capacity of Mahanarva spectabilis (Distant, 1909) (Hemiptera: Cercopidae) adults on Brachiaria ruziziensis pasture.

    PubMed

    Resende, Tiago Teixeira; Auad, Alexander Machado; Fonseca, Marcy das Graças; Souza Sobrinho, Fausto; dos Santos, Dayane Ribeiro; da Silva, Sandra Elisa Barbosa

    2013-01-01

    The aim of this study was to determine the damage caused by adult Mahanarva spectabilis (Distant, 1909) (Hemiptera: Cercopidae) on Brachiaria ruziziensis (Germain & Evard) under field conditions. A total of 0, 4, 8, 12, or 16 M. spectabilis adults per plot were maintained for 6 days. Thereafter, the insects were removed from the plant, and the following parameters were evaluated: chlorophyll content, damage score, dry as well as fresh weights, percentage of shoots' dry matter, and the forage's ability to regrow. The chlorophyll content was significantly reduced; the damage score and percentage of dry matter in plants increased depending on the increased insect infestation density after 6 days of exposure. In contrast, no change was observed on the B. ruziziensis fresh and dry weights as well as the regrowth capacity depending on the M. spectabilis infestation densities. Attacks by 8 adult M. spectabilis per clump of B. ruziziensis with an average of 80 tillers for 6 days were sufficient to reduce the chlorophyll content and the functional plant loss index. This density can be a reference for spittlebug integrated management in Brachiaria. PMID:24453825

  17. Changes in nutrient dynamics throughout water transfers in a Tropical Forest and Pasture of Rondonia, Brazil

    NASA Astrophysics Data System (ADS)

    Piccolo, M. D.; Neill, C.; Krusche, A.; Laclau, J. P.; Cerri, C. C.

    2006-12-01

    The clearing of tropical forest in the Brazilian Amazon for cattle pasture since the 70s is a globally important land use change that has consequences for soil biogeochemical cycles. Generally, five to ten years after deforestation, pastures become degraded due to inadequate management practices. Development of strategies for restoration of low productivity pastures constitutes the main goal for Rondônia state. We analyzed the concentrations of the main nutrient of the biogeochemical cycles in three representative land uses at Fazenda Nova Vida, in central Rondônia (10o30'S, 62o30'W). The treatments were: (1) native forest; (2) pasture dominated by the forage grass Brachiaria brizantha but containing some weeds, under non- intensive management and; (3) a section of the same pasture that was subjected to tilling, replanting and fertilization (NPK + micronutrients) to eliminate weeds and improve grass productivity. Water samples from rain, throughfall, overland flow, tension lysimeter and zero-tension lysimeter (1.0 m soil depth), were collected during the rainy seasons from January to May of 2002 and 2003. The concentrations of C (DOC and DIC), inorganic-N (NH4+, NO3- and NO2-), Na+, K+, Mg2+, Ca2+, SO42- and Cl- were measured in all treatments. Rain water was dominated by the nutrients (NH4+, Na+, K+, Ca2+ and Cl-) and DOC. Forest throughfall was enriched in most of the elements. Concentrations of elements in the overland flow showed higher variations in the pasture and in the plowed pasture, however samples were not collected in forest. Soil solution waters (tension lysimeter) and lysimeter waters (zero-tension lysimeter) too had higher variations for elements concentrations in all treatments. Forest clearing for pasture and pasture submitted to tillage practices profoundly influence soil properties and, consequently, the nutrient availability in soil profiles. The soil solution composition may be indicative of altered patterns of nutrient availability in this

  18. Spatial Simulation of the Dynamics of Establishment of Secondary Forest in Abandoned Pasture in the Central Amazon

    NASA Astrophysics Data System (ADS)

    Rebel, K. T.; Riha, S. J.; Rondon, M. A.; Feldpausch, T. R.; Fernandes, E. C.

    2001-05-01

    In the Amazon, approximately 35 million hectares of primary forest that was converted to pasture is now being abandoned. This represents about 70% of all pastureland that was previously established. The dynamics of reconversion of this land to secondary forest is of interest because the length of time required for pasture to convert to secondary forest will impact net primary productivity and the amount of carbon being stored on abandoned pastures. In addition, the length of time required for pasture to convert to secondary forest may depend on the size of the pasture, whether it is surrounded by primary or secondary forest, and on pasture productivity at the time of abandonment. Pasture productivity at the time of abandonment will depend primarily on the age structure of the pasture grasses and on weediness, which are influenced by grazing and fire history. Also, an understanding of the dynamics of conversion of pastureland to forest can serve as the basis for management strategies to inhibit pasture conversion. A spatial, dynamic model of the conversion of pasture to secondary forest was developed using the PCRaster Dynamic Modeling Package. This software provides a computer language specially developed for modeling temporal and spatial processes in a GIS, and is well suited for the development of ecological, dynamic models. The model of pasture conversion is implemented for the central Amazon. We assume that succession involves only three plant types: pasture grass, weeds and woody plants. The pasture grass is parameterized for Brachiaria (brizantha, humidicola), the weeds for Borreria and Rolandra, and the woody plants for Vismia spp. The model uses a 1m x 1m grid and 2-month time step. Each initial plant and each surviving propagule is referred to as a plant and only occupies one grid cell. A number of values are calculated for each grid cell for each time-step. These include whether vegetation is present and, if so, which species, the age of the species, the

  19. Evaluation of solar exposure on the experimental intoxication by Brachiaria decumbens in sheep

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twenty-six five-month-old lambs originated from flocks with no previous contact with Brachiaria spp. pastures were divided into three groups. Two groups (GS and GSB) were fed daily with fresh harvested Brachiaria decumbens ad libitum. GS was kept in an area with solar exposure and GSB was kept in st...

  20. Production and economic potentials of cattle in pasture-based systems of the western Amazon region of Brazil.

    PubMed

    Rueda, B L; Blake, R W; Nicholson, C F; Fox, D G; Tedeschi, L O; Pell, A N; Fernandes, E C M; Valentim, J F; Carneiro, J C

    2003-12-01

    Our objectives were to evaluate strategies to improve productivity and economic returns from beef and dual-purpose cattle systems based on data collected on one dual-purpose (Bos taurus x Bos indicus) and two beef (Nellore) cattle farms in the western Amazon region of Brazil. Forage chemical composition and digestion rates of carbohydrate fractions of grazed Brachiaria decumbens and Brachiaria brizantha cv. Marandu grasses and Pueraria phaseoloides (tropical kudzu) legume were measured monthly during a 9-mo period from the end of one dry season to the end of the subsequent rainy season. Measurements of milk and growth responses to grazing these forages were used to predict animal productivity responses to dietary nutrient availability throughout an annual cycle. The ME available for gain in our simulations was always more limiting than metabolizable protein. The predicted ME available for gain was 0.50 kg/d for steers grazing B. brizantha and 0.40 kg/d for finishing steers grazing B. decumbens. Grasses contained more NDF and neutral detergent insoluble protein and less ME (P < 0.05) in the rainiest months than in the less rainy season, which resulted in 20% less predicted weight gain by growing steers (P < 0.05). Supplementation with sorghum grain was required to increase milk production and growth by 25 or 50% per animal, respectively, but this strategy was less profitable than current forage-only diets. Greater productivity of land and labor from higher stocking indicated greater net margins for beef production, but not for milk. This study suggested that more intensive beef production by judicious fertilization of grass-legume pastures and greater stocking density is the preferable strategy for owners of these cattle systems to improve economic returns under current conditions. It also might help decrease the motivation for additional forest clearing. PMID:14677847

  1. Phytotoxic substance with allelopathic activity in Brachiaria decumbens.

    PubMed

    Kobayashi, Ai; Kato-Noguchi, Hisashi

    2015-05-01

    The grass Brachiaria decumbens becomes naturalized and quickly dominant in non-native areas. It was hypothesized that phytotoxic substances of plants may contribute to the domination and invasion of the plants. However, no potent phytotoxic substance has been reported in B. decumbens. Therefore, we searched for phytotoxic substances with allelopathic activity in this species. An aqueous methanol extract of B. decumbens inhibited the growth of roots and shoots of cress (Lepidium sativum), lettuce (Lactuca sativa), timothy (Phleum pratense) and ryegrass (Lolium multiflorum) seedlings. The extract was then purified using chromatographic methods and a phytotoxic substance with allelopathic activity was isolated and identified by spectral analysis as (6R,9S)-3-oxo-α-ionol. These results suggest that this compound may contribute to the allelopathic effect caused by the B. decumbens extract and may be in part responsible for the invasion and domination of B. decumbens. Two other Brachiaria species, B. brizantha and a Brachiaria hybrid were also confirmed to contain (6R,9S)-3-oxo-α-ionol. Therefore, this compound may play an important role in the phytotoxicity of the Brachiaria species. PMID:26058152

  2. Study of the nutrient distribution in root tips of the tropical forage Brachiaria

    NASA Astrophysics Data System (ADS)

    Pineda, C. A.; Wenzl, P.; Mayer, J.; Mesjasz-Przybylowicz, J.; Przybylowicz, W. J.; Prozesky, V. M.

    1997-07-01

    A Brachiaria breeding project is being conducted at CIAT, Colombia to combine acid soil adaptation of B. decumbens with other favourable traits of Brachiaria species that are less adapted to acid soils. Micro-PIXE was applied to investigate nutrient uptake and distribution in root tips of different species grown in hydroponic culture under control and simulated acid soil stress conditions. Different sample measurement approaches were evaluated, including: (1) linear scans with single point measurements along the root axis; (2) mapping of whole root tips; and (3) mapping of root cross sections. Different tissue types could be distinguished on the base of differences in nutrient concentrations and/or Al stress. Al, if supplied under nutrient stress conditions, increased P accumulation in the central vascular tissue of the meristematic and elongation zone of B. decumbens and B. brizantha. Furthermore, a negative correlation was found between Al and Cl accumulation in the root cap of B. decumbens.

  3. Chromosomal distribution and evolution of abundant retrotransposons in plants: gypsy elements in diploid and polyploid Brachiaria forage grasses.

    PubMed

    Santos, Fabíola Carvalho; Guyot, Romain; do Valle, Cacilda Borges; Chiari, Lucimara; Techio, Vânia Helena; Heslop-Harrison, Pat; Vanzela, André Luís Laforga

    2015-09-01

    Like other eukaryotes, the nuclear genome of plants consists of DNA with a small proportion of low-copy DNA (genes and regulatory sequences) and very abundant DNA sequence motifs that are repeated thousands up to millions of times in the genomes including transposable elements (TEs) and satellite DNA. Retrotransposons, one class of TEs, are sequences that amplify via an RNA intermediate and reinsert into the genome, are often the major fraction of a genome. Here, we put research on retrotransposons into the larger context of plant repetitive DNA and genome behaviour, showing features of genome evolution in a grass genus, Brachiaria, in relation to other plant species. We show the contrasting amplification of different retroelement fractions across the genome with characteristics for various families and domains. The genus Brachiaria includes both diploid and polyploid species, with similar chromosome types and chromosome basic numbers x = 6, 7, 8 and 9. The polyploids reproduce asexually and are apomictic, but there are also sexual species. Cytogenetic studies and flow cytometry indicate a large variation in DNA content (C-value), chromosome sizes and genome organization. In order to evaluate the role of transposable elements in the genome and karyotype organization of species of Brachiaria, we searched for sequences similar to conserved regions of TEs in RNAseq reads library produced in Brachiaria decumbens. Of the 9649 TE-like contigs, 4454 corresponded to LTR-retrotransposons, and of these, 79.5 % were similar to members of the gypsy superfamily. Sequences of conserved protein domains of gypsy were used to design primers for producing the probes. The probes were used in FISH against chromosomes of accesses of B. decumbens, Brachiaria brizantha, Brachiaria ruziziensis and Brachiaria humidicola. Probes showed hybridization signals predominantly in proximal regions, especially those for retrotransposons of the clades CRM and Athila, while elements of Del and Tat

  4. Effects of Different Treatments of Pasture Restoration on Soil Trace Gas Emissions in the Cerrados of Central Brazil

    EPA Science Inventory

    Planted pastures ( mainly Brachiaria spp) are the most extensive land use in the cerrado (savannas of central Brazil) with an area of approximately 50 x 10(6) ha. The objective of the study was to assess the effects of pasture restoration on the N dynamics ( net N mineralization/...

  5. [Photosensitization in cattle grazing on pastures of Brahciaria decumbens Stapf infested with Pithomyces chartarum (Berk. & Curt.) M.B. Ellis].

    PubMed

    Andrade, S O; da Silva Lopes, H O; de Almeida Barros, M; Leite, G G; Dias, S M; Saueressig, M; Nobre, D; Temperini, J A

    1978-01-01

    Aspects of photosensitization in bovines grazing on pastures of Brachiaria decumbens Stapf infested with Pithomyces chartarum (Berk. & Curt.) M.B. Ellis infested all pastures 45(2):117-136, 1978. This paper reports experimental studies on photosensitization in bovines grazing on different pastures of Brachiaria decumbens Stapf in the "Cerrados" region (Planaltina, DF). Climatic conditions, zinc content and occurence of fungi on pastures were investigated. Pithomyces chartarum (Berk. & Curt.) M.B. Ellis infested all pastures examined. Photosensitization was observed in one animal maintained on a pasture of B. decumbens formed with seeds from Australia. Clinical and necropsy data were similar to those related in literature for sporidesmin-intoxicated animals. An isolate of P. chartarum and samples of bovine bile were assayed for sporidesmin presence. PMID:573108

  6. Queensland Pastures

    Atmospheric Science Data Center

    2013-04-16

    ... Local graziers hope for good long-term responses in pasture growth from the heavy rains. These images and maps from the Multi-angle Imaging ... for atmospheric scattering and absorption effects, and uses plant canopy structural models to determine the partitioning of solar ...

  7. SOIL FLUXES OF CO2, CO, NO AND N2O FROM AN OLD-PASTURE AND FROM NATIVE SAVANNA IN BRAZIL

    EPA Science Inventory

    We compared fluxes of CO2, CO, NO and N2O, soil microbial biomass, and N-mineralization rates in a 20-year old Brachiaria pasture and a native cerrado area (savanna in Central Brazil). In order to assess the spatial variability of CO2 fluxes, we tested the relation between elect...

  8. Characterizing Herbivore Resistance Mechanisms: Spittlebugs on Brachiaria spp. as an Example

    PubMed Central

    Parsa, Soroush; Sotelo, Guillermo; Cardona, Cesar

    2011-01-01

    Plants can resist herbivore damage through three broad mechanisms: antixenosis, antibiosis and tolerance1. Antixenosis is the degree to which the plant is avoided when the herbivore is able to select other plants2. Antibiosis is the degree to which the plant affects the fitness of the herbivore feeding on it1.Tolerance is the degree to which the plant can withstand or repair damage caused by the herbivore, without compromising the herbivore's growth and reproduction1. The durability of herbivore resistance in an agricultural setting depends to a great extent on the resistance mechanism favored during crop breeding efforts3. We demonstrate a no-choice experiment designed to estimate the relative contributions of antibiosis and tolerance to spittlebug resistance in Brachiaria spp. Several species of African grasses of the genus Brachiaria are valuable forage and pasture plants in the Neotropics, but they can be severely challenged by several native species of spittlebugs (Hemiptera: Cercopidae)4.To assess their resistance to spittlebugs, plants are vegetatively-propagated by stem cuttings and allowed to grow for approximately one month, allowing the growth of superficial roots on which spittlebugs can feed. At that point, each test plant is individually challenged with six spittlebug eggs near hatching. Infestations are allowed to progress for one month before evaluating plant damage and insect survival. Scoring plant damage provides an estimate of tolerance while scoring insect survival provides an estimate of antibiosis. This protocol has facilitated our plant breeding objective to enhance spittlebug resistance in commercial brachiariagrases5. PMID:21712800

  9. Characterizing herbivore resistance mechanisms: spittlebugs on Brachiaria spp. as an example.

    PubMed

    Parsa, Soroush; Sotelo, Guillermo; Cardona, Cesar

    2011-01-01

    Plants can resist herbivore damage through three broad mechanisms: antixenosis, antibiosis and tolerance(1). Antixenosis is the degree to which the plant is avoided when the herbivore is able to select other plants(2). Antibiosis is the degree to which the plant affects the fitness of the herbivore feeding on it(1).Tolerance is the degree to which the plant can withstand or repair damage caused by the herbivore, without compromising the herbivore's growth and reproduction(1). The durability of herbivore resistance in an agricultural setting depends to a great extent on the resistance mechanism favored during crop breeding efforts(3). We demonstrate a no-choice experiment designed to estimate the relative contributions of antibiosis and tolerance to spittlebug resistance in Brachiaria spp. Several species of African grasses of the genus Brachiaria are valuable forage and pasture plants in the Neotropics, but they can be severely challenged by several native species of spittlebugs (Hemiptera: Cercopidae)(4).To assess their resistance to spittlebugs, plants are vegetatively-propagated by stem cuttings and allowed to grow for approximately one month, allowing the growth of superficial roots on which spittlebugs can feed. At that point, each test plant is individually challenged with six spittlebug eggs near hatching. Infestations are allowed to progress for one month before evaluating plant damage and insect survival. Scoring plant damage provides an estimate of tolerance while scoring insect survival provides an estimate of antibiosis. This protocol has facilitated our plant breeding objective to enhance spittlebug resistance in commercial brachiariagrases(5). PMID:21712800

  10. Pasture Fallowing Fact Sheet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pasture fallowing is the practice of leaving pastures ungrazed for a period to encourage grass reseeding and increase pasture diversity. Fallowing may have negative effects as well, by reducing legume cover and allowing thistles and other invasive weeds to increase. We looked at the effects of fallo...

  11. Pastures and biodiversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Farmers often plant monocultures or simple grass-legume mixtures in their pastures. Increased biodiversity in pastures may be one tool to improve sustainability and productivity. This fact sheet addresses some common questions regarding biodiversity in pastures. Very broadly, biodiversity refers to ...

  12. Pasture diversity and management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite the economic importance of pastures in the northeastern United States, not much is known about their ecology, including taxonomic and functional diversity. This factsheet presents results from a 1998-2005 survey of pastures on 44 farms from Maine to Maryland. Pastures are quite diverse; the ...

  13. Pasture diversity and management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scientists at the USDA-ARS Pasture Systems and Watershed Management Research Unit have been collecting pasture plant biodiversity data for over ten years and across the northeastern United States. We have identified more than three hundred species of vascular plants. The average pasture in this regi...

  14. Hepatic photosensitization in buffaloes intoxicated by Brachiaria decumbens in Minas Gerais state, Brazil.

    PubMed

    De Oliveira, C H S; Barbosa, J D; Oliveira, C M C; Bastianetto, E; Melo, M M; Haraguchi, M; Freitas, L G L; Silva, M X; Leite, R C

    2013-10-01

    The aim of this paper is to report the study of hepatogenous photosensitization in buffaloes during two outbreaks provoked by ingestion of Brachiaria decumbens in Minas Gerais state, Brazil. Ten young buffaloes in outbreak 1 and seven buffaloes in outbreak 2 were intoxicated by B. decumbens. Nine clinically healthy buffaloes raised under the same conditions as the sick animals served as the control group. All animals were subjected to clinical examination, and serum was collected to measure gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), direct bilirubin (DB), indirect bilirubin (IB) and total bilirubin (TB) as indicators of liver function and urea and creatinine as indicators of renal function. Histopathology of liver fragments from five different animals was carried out. During the outbreaks and every two months for one year, samples of grass from paddocks where the animals got sick were collected for quantitative evaluation of the saponin protodioscin, combined with observations of pasture characteristics and daily rainfall. Clinical signs included apathy, weight loss, restlessness, scar retraction of the ears and intense itching at the skin lesions, mainly on the rump, the tail head, neck and hindlimbs, similar to the signs observed in other ruminants. Only the GGT enzyme presented significantly different (P < 0.01) serum levels between intoxicated animals (n = 17) and healthy animals (n = 9), indicating liver damage in buffaloes bred in B. decumbens pastures. Microscopy of the liver showed foamy macrophages and lesions of liver disease associated with the presence of crystals in the bile ducts, which have also been found in sheep and cattle poisoned by grasses of the genus Brachiaria. During the outbreaks, protodioscin levels were higher than 3%, and shortly after, these levels were reduced to less than 0.80%, suggesting a hepatic injury etiology. The outbreaks took place at the beginning of the rainy season, and there was a positive

  15. Managing Intensively Grazed Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage production during periods of summer drought can be increased by including additional species in the pasture mixture, especially if those species have desirable attributes such as improved water use efficiency or deep root systems. Conversion of plowed fields to pasture also has the potential ...

  16. Priming and temperature limits for germination of dispersal units of Urochloa brizantha (Stapf) Webster cv. basilisk.

    PubMed

    Nakao, E A; Cardoso, V J M

    2015-01-01

    The objective of this study was to evaluate the effect of priming treatments on the upper and lower thermal limits for germination of Urochloa brizantha cv. basilisk, and testing the hypothesis that pré-imbibition affect thermal parameters of the germination. Pre-imbibed seeds both in distilled water (0 MPa) and PEG 6000 solution (-0.5 MPa) were put to germinate in different temperatures. It is suggested that U. brizantha seeds have low response to priming when they were placed to germinate in medium where water is not limiting. The response of U. brizantha seeds to priming is dependent on the temperature and water potential conditions at which the seeds are pre-imbibed, as well as on the germination temperature. The optimum temperature for germination of U. brizantha shift toward warmer temperatures in primed seeds. Priming effect was more pronounced at temperatures closer to the upper and lower limit for germination, but probably that response cannot be accounted for changes in the thermal time constant (θT(g)) and ceiling temperature (Tc(g)). Otherwise, a decrease in the base temperature (Tb) was observed in primed seeds, suggesting that the Tb distribution in U. brizantha seeds is influenced by priming. PMID:25945643

  17. Plant physiology for profitable pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A basic question of pasture-based livestock production is whether producers should manage pastures on the basis of what is best for the animal or what is best for the plant. Given that pastures are the principal and most economical source of feed, producers should carefully consider how they manage...

  18. Pasture seed banks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In our surveys of northeastern pastures, we found the equivalent of more than 8 million seeds per acre in the surface soil (the top four inches) from the seed bank study. These seeds came from 58 species of plants. The annual forbs (all broadleaf plants with the exception of legumes and trees) domin...

  19. Pasture Research Summaries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our goal is to develop diverse, stable, and persistent forage and pasture lands that provide a permanent cover and protect the natural resource base for future generations. Research on forage-livestock systems seeks to improve the productivity, sustainability, and profitability of northeastern forag...

  20. Phosphorus, carbon- and nitrogen interactions in productive and degraded tropical pastures

    NASA Astrophysics Data System (ADS)

    Oberson, A.; Hegglin, D. D.; Nesper, M.; Rao, I.; Fonte, S.; Ramirez, B.; Velasquez, J.; Tamburini, F.; Bünemann, E. K.; Frossard, E.

    2011-12-01

    Pastures are the main land use in deforested areas of tropical South America. The highly weathered soils of these regions usually have low total and available phosphorus (P) contents. Low P availability can strongly limit plant and animal productivity and other soil ecosystem functions. Most introduced pastures of Brachiaria spp. are grass-alone (GA) while some are grass-legume (GL) pastures. The majority of the introduced pastures, particularly the grass-alone are at some state of degradation (GD). Pasture degradation induces severe loss of plant biomass production, with drastic ecological and economic implications. Although the importance of P deficiency in pasture degradation has been recognized, the knowledge generated on stoichiometry of carbon (C), nitrogen (N) and P along pathways of the nutrient cycles of pastures, with different botanical composition and productivity, has been very limited. We will present results of a case study realized during 2010 to 2011 in the forest margins agro-ecosystem of the department of Caquetá, Colombia. Our objectives were to determine: i) whether P availability is lower in degraded compared to productive pastures, and ii) whether the introduction of legumes in the pasture increases P availability through enhanced biological P cycling through plant growth, plant litter decomposition and the soil microbial biomass; and iii) whether pasture types (GA vs GL) and the state of pasture degradation affect the C:N:P ratios in nutrient pools of the soil-plant system. An on-farm study was conducted on nine farms in the department of Caquetá, Colombia. On every farm three different pasture types were studied: degraded grass alone pastures (GD), productive grass-alone pastures (GA) and productive grass-legume pastures (GL). Basic soil characteristics and indicators on soil P status, microbial P cycling, plant biomass production, plant litter deposition and nutrient concentrations in plant tissue were determined. Analysis of P, C and N

  1. Waterlogging-induced changes in root architecture of germplasm accessions of the tropical forage grass Brachiaria humidicola

    PubMed Central

    Cardoso, Juan Andrés; Jiménez, Juan de la Cruz; Rao, Idupulapati M.

    2014-01-01

    Waterlogging is one of the major factors limiting the productivity of pastures in the humid tropics. Brachiaria humidicola is a forage grass commonly used in zones prone to temporary waterlogging. Brachiaria humidicola accessions adapt to waterlogging by increasing aerenchyma in nodal roots above constitutive levels to improve oxygenation of root tissues. In some accessions, waterlogging reduces the number of lateral roots developed from main root axes. Waterlogging-induced reduction of lateral roots could be of adaptive value as lateral roots consume oxygen supplied from above ground via their parent root. However, a reduction in lateral root development could also be detrimental by decreasing the surface area for nutrient and water absorption. To examine the impact of waterlogging on lateral root development, an outdoor study was conducted to test differences in vertical root distribution (in terms of dry mass and length) and the proportion of lateral roots to the total root system (sum of nodal and lateral roots) down the soil profile under drained or waterlogged soil conditions. Plant material consisted of 12 B. humidicola accessions from the gene bank of the International Center for Tropical Agriculture, Colombia. Rooting depth was restricted by 21 days of waterlogging and confined to the first 30 cm below the soil surface. Although waterlogging reduced the overall proportion of lateral roots, its proportion significantly increased in the top 10 cm of the soil. This suggests that soil flooding increases lateral root proliferation of B. humidicola in the upper soil layers. This may compensate for the reduction of root surface area brought about by the restriction of root growth at depths below 30 cm. Further work is needed to test the relative efficiency of nodal and lateral roots for nutrient and water uptake under waterlogged soil conditions. PMID:24876299

  2. The effect of ensiling and haymaking on the concentrations of steroidal saponin in two Brachiaria grass species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brachiaria (signalgrass) is now the most widely used tropical grass genus in Central and South America. However, Brachiaria spp. can cause hepatogenous photosensitization in livestock. Steroidal saponins, specifically protodioscin, present in Brachiaria spp. may be responsible for liver injury and s...

  3. Independence of resistance in Brachiaria spp. to nymphs or to adult spittlebugs (Hemiptera: Cercopidae): implications for breeding for resistance.

    PubMed

    Cardona, Cesar; Miles, John W; Zuñiga, Edier; Sotelo, Guillermo

    2010-10-01

    Both nymphal and adult spittlebugs (Hemiptera: Cercopidae) cause serious economic damage to susceptible brachiariagrass [genus Brachiaria (Trin.) Griseb], pastures in tropical America. Both life stages are xylem feeders: nymphs feed primarily on roots and stems, whereas the adults feed mainly on foliage. Numerous interspecific brachiariagrass hybrids with high levels of antibiosis resistance to nymphs of several important spittlebug species have been obtained. Recent studies revealed major inconsistencies between reaction to nymphs and reaction to adults on the same host genotype. Because both insect life stages can cause severe economic damage on susceptible brachiariagrass pastures, a cultivar development strategy must take into account resistance to both life stages. To assess the degree of association between resistance to spittlebug nymphs and to adult feeding, we tested 164 hybrids and six check genotypes for resistance to both life stages of three spittlebug species: Aeneolamia varia (F.), Aeneolamia reducta (Lallemand), and Zulia carbonaria (Lallemand). Most hybrids tested were classified as resistant to nymphs. On the contrary, for all three species, the overall mean damage score of the 164 hybrids did not differ from the mean score of the susceptible checks. None of the hybrids was classified as resistant to adult feeding damage. Correlations between percentage nymph survival and adult damage scores were consistently low (r = 0.0104-0.0191). Correlations between nymphal and adult damage scores were also low (0.109-0.271), suggesting that resistances to the different life stages are largely independent. Chi-square analyses comparing frequency distributions of responses of the 164 breeding hybrids to nymphs or adults confirmed essential genetic independence of these two traits. We conclude that attention to improving genetic resistance specifically to adult feeding damage is warranted. PMID:21061990

  4. Phenotypic characteristics for discrimination between advanced genotypes of Brachiaria ruziziensis.

    PubMed

    Rezende, B A; Ribeiro, C B; Teixeira, D H L; Gonçalves, F M A; Souza Sobrinho, F

    2016-01-01

    The aim of this study was to use multivariate methods and Pearson and partial correlations to disregard phenotypic characteristics that contribute little to differentiation between Brachiaria ruziziensis genotypes. Eighty-one genotypes of B. ruziziensis were assessed in completely randomized blocks with three replications. Ten phenotypic characteristics were assessed: plant height, leaf length, leaf width, sheath length, length of the flower stem, length of the inflorescence axis, number of racemes per inflorescence, length of the basal raceme, number of spikelets per basal raceme, and width of the rachis. The best traits for differentiation between genotypes were determined by assessing relative contribution to diversity, canonical variables, as well as Pearson and partial correlations. Four canonical variables were found to account for 57% of the overall variation, while plant height, sheath length, and number of racemes per inflorescence were considered traits that could potentially be disregarded in future assessments. PMID:27051034

  5. CHEMICAL AND BACTERIOLOGICAL QUALITY OF PASTURE RUNOFF

    EPA Science Inventory

    Natural background characteristics and grazing cattle both influence the chemical and bacteriological quality of pasture runoff in south central Nebraska. The chemical quality of runoff from unstocked grassland was poorer than that from grazed pasture. The chemical quality of pas...

  6. Guide to Managing Pasture Water: Streamside Buffers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Properly managed pasture water not only provides high-quality water which promotes healthy and productive livestock, but also contributes to maintaining water quality downstream. Riparian (streamside) areas serve as a transition between upland pastures and waterways. In other words, they link pastur...

  7. Pasture quality variation throughout the grazing season

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is important for dairy producers and their nutritionists to have an idea of the nutritional quality of the pasture they are providing to their cows. This article uses data gathered from several on-going pasture research projects to demonstrate how pasture quality varies during the grazing season,...

  8. Stocking Rates for Horse Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Decision on which stocking rate to graze a horse pasture is critical, particularly if the forage is expected to meet the nutrient needs of the horses. Challenges and management for targeting the optimum stocking rate, defined as the stocking rate that allows forage consumption to approximately equ...

  9. Weather and plant age affect the levels of steroidal saponin and Pithomyces chartarum spores in Brachiaria grass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brachiaria species are cultivated worldwide in tropical and subtropical climates as the main forage source for ruminants. Numerous tropical and warm-season grasses cause hepatogenous photosensitization, among them several species of Brachiaria. Steroidal saponins present in these plants may be respo...

  10. Pasture improvement in Spanish Dehesas

    NASA Astrophysics Data System (ADS)

    Murillo Vilanova, M.; González López, F.

    2009-04-01

    In the south-west of the Iberian Peninsula, the dehesa is a widespread agro-silvo-pastoral land use system, characterized by a grassland with a disperse cover of oak trees and shrubs, where the main production is extensive livestock combined with agriculture and forestry. Many years of inappropriate management of dehesas (deforestation, overgrazing, excessive agricultural activities, etc.) has led to the degradation of vegetation and soils in extensive areas, causing reductions in biomass and biodiversity, affecting the permanence of plants and causing important losses of palatable species. As there is growing interest in these wooded rangeland ecosystems due to their economic importance and high environmental value, the recovery of the original pasture biodiversity and the increase of productivity, together with the conservation of the environment, are the main goals in these areas of low productive potential, degraded and subject to soil erosion. Soil and climate conditions have a great influence on grassland production, with rainfall producing strong seasonal and interannual variations. These natural pastures, mainly composed of summer withering annual species, reach maximum productions in spring and register low values in autumn, slowing down in winter. During the summer dry season, the wilting pastures can offer a good forage for animals. Autochthonous annual legumes play an important role because they are well adapted to local edaphic and climatic conditions and produce hard seeds which germinate in autumn. This helps them to survive the frequent droughts and offer a high quality forage, which is a valuable complement to other pasture plants with lower protein content. Therefore, for several decades, legume seeding combined with the application of phosphate fertilizer has been the most common strategy used to improve pastures in SW Spain, where dehesas cover an area of about four million hectares. This paper examines the whole process of pasture improvement

  11. Sward characteristics and performance of dairy cows in organic grass-legume pastures shaded by tropical trees.

    PubMed

    Paciullo, D S C; Pires, M F A; Aroeira, L J M; Morenz, M J F; Maurício, R M; Gomide, C A M; Silveira, S R

    2014-08-01

    The silvopastoral system (SPS) has been suggested to ensure sustainability in animal production systems in tropical ecosystems. The objective of this study was to evaluate pasture characteristics, herbage intake, grazing activity and milk yield of Holstein×Zebu cows managed in two grazing systems (treatments): SPS dominated by a graminaceous forage (Brachiaria decumbens) intercropped with different leguminous herbaceous forages (Stylosanthes spp., Pueraria phaseoloides and Calopogonium mucunoides) and legume trees (Acacia mangium, Gliricidia sepium and Leucaena leucocephala), and open pasture (OP) of B. decumbens intercropped only with Stylosanthes spp. Pastures were managed according to the rules for organic cattle production. The study was carried out by following a switch back format with 12 cows, 6 for each treatment, over 3 experimental years. Herbage mass was similar (P>0.05) for both treatments, supporting an average stocking rate of 1.23 AU/ha. Daily dry matter intake did not vary (P>0.05) between treatments (average of 11.3±1.02 kg/cow per day, corresponding to 2.23±0.2% BW). Milk yield was higher (P0.05) in subsequent years. The highest (P0.05) milk yields. Low persistence of Stylosanthes guianensis was observed over the experimental period, indicating that the persistence of forage legumes under grazing could be improved using adapted cultivars that have higher annual seed production. The SPS and a diversified botanical composition of the pasture using legume species mixed with grasses are recommended for organic milk production. PMID:24703358

  12. PASTURE PLANT COMMUNITIES IN THE NORTHEAST

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pastures are important to the economy of the northeastern United States, but we still don't know much about their ecology. One of the areas where we need more information is in understanding how environment affects the success of forage and weedy species in pastures. We surveyed 44 farms from Maryla...

  13. Soil carbon cycling in pasture systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbon accumulation in soil under pastures occurs to various degrees depending upon management and length of time. This presentation describes research results on soil carbon sequestration under pastures from the southeastern USA to help inform the scientific basis for development of a protocol to ...

  14. Cycling and loss of nutrients in pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pastures are fundamentally different than croplands. When cropland is harvested, large amounts of plant nutrients are removed so relatively large rates of nutrients are often needed. In pasture, most of the nutrients harvested by livestock are returned. The proportion of nutrients returned by livest...

  15. Pasture Plants of the Northeastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This factsheet contains summary information about the most common plant species encountered in northeastern pastures. Some information, such as plant size and flowering time, comes from standard reference works. Information on frequency and abundance in northeastern pastures is derived from an eight...

  16. Advantages of pasture-based milk products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent research has focused on determining the biologically active compounds naturally occurring in milk from pasture-fed cows and evaluating the impact of processing on these compounds. This research addresses one of the critical goals of the Northeast Pasture Consortium to “summarize conjugated li...

  17. Multiple spindles and cellularization during microsporogenesis in an artificially induced tetraploid accession of Brachiaria ruziziensis (Gramineae).

    PubMed

    Risso-Pascotto, Claudicéia; Pagliarini, Maria Suely; do Valle, Cacilda Borges

    2005-01-01

    The genus Brachiaria is characterized by a majority of polyploid accessions--mainly tetraploid--and apomictic reproduction. Sexuality is found among diploids. To overcome incompatibility barriers, accessions with the same ploidy level are necessarily used in hybridization. Thus, sexual diploid accessions were tetraploidized to be used as female genitors. This paper reports microsporogenesis in an artificially induced tetraploid accession of Brachiaria ruziziensis. Chromosome pairing at diakinesis ranged from univalents to tetravalents, with predominance of bivalents. Irregular chromosome segregation was frequent in both meiotic divisions. During the first division, multiple spindles showing different arrangements were recorded. The spindle position determined the plane of first cytokinesis and the number of chromosomes determined the size of the cell. Meiotic products were characterized by polyads with spores of different sizes. Pollen sterility was estimated at 61.38%. The limitations of using this accession in the breeding program are discussed. PMID:15365762

  18. Plant Species Diversity and Pasture Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Farmers face many challenges in pasture management, such as evolving agri-environmental schemes to protect natural resources, and need new management techniques to remain sustainable. Ecological research indicates that increased plant biodiversity benefits ecosystem functions such as primary product...

  19. New Developments in Grasses for Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New forage varieties with improved traits are an essential component of best management practices for livestock agriculture. This paper discusses new varieties of several cool-season forage grasses used for pasture production....

  20. Characterization of fungi from ruminal fluid of beef cattle with different ages and raised in tropical lignified pastures.

    PubMed

    Abrão, Flávia Oliveira; Duarte, Eduardo Robson; Freitas, Cláudio Eduardo Silva; Vieira, Edvaldo Alves; Geraseev, Luciana Castro; da Silva-Hughes, Alice Ferreira; Rosa, Carlos Augusto; Rodrigues, Norberto Mario

    2014-11-01

    The objective of this study was to evaluate the aerobic rumen mycobiota from three age groups of Nelore beef cattle reared extensively on lignified pasture. The experiment was randomized and sampled 50 steers, 50 cows, and 50 calves grazed on Brachiaria spp. pasture during the dry season. Rumen fluid in all animals was aromatic, slightly viscous, and greenish-brown in color. Microscopic examination revealed monocentric and polycentric anaerobic fungi in similar proportions (P > 0.05) in the rumen fluid of cows and steers. However, these microorganisms were not identified in any of the samples from calves. In culture exams, aerobic filamentous population was significantly higher for rumen fluid of cows compared to the other two groups. Microculture and rDNA sequence analyses showed Aspergillus spp. as the most frequent aerobic fungus among the isolates from the three bovine groups evaluated. Biochemical profiles were determined by the growth level of yeast isolates with 44 nutrient sources. Ten different yeast profiles were obtained, and yeast isolates from cow ruminal fluid showed ability to catabolize greater diversity of carbon and nitrogen sources. The differences in the fungal populations observed in this study could be explained by microbial and physiological interactions existing in the ruminal ecosystem of each age bovine group. The present study showed the fungal population of the rumen related with differences among age of cattle raised in lignified pastures. Metabolic capabilities of mycelial fungi or yeast identified in this study may be employed in new probiotics or microbial additives for different bovine categories. PMID:24962597

  1. Studies of pasture production in Extremadura (Spain)

    NASA Astrophysics Data System (ADS)

    Murillo Vilanova, M.; González López, F.; Paredes Galán, J.; Prieto Macías, P. M.; Blanco, V. Maya

    2009-04-01

    The region of Extremadura covers more than four million hectares in the South West of Spain, with dehesas occupying almost 1.5 million hectares of its surface. This agro-silvo-pastoral land use system constitutes the most recommendable model for extensive exploitation in Mediterranean areas in which the semiarid climate and the poor, shallow soils are constraints on any other type of agricultural use. It is characterized by a grassland with a disperse cover of oak trees and shrubs, where the main production is extensive livestock combined with agriculture and forestry. The pastures are the basis for animal breeding in the dehesas being these ecosystems of great economic, social as well as environmental value in the southwestern Iberian Peninsula. These facts justify the investigation on pasture improvement and the study on spatial and temporal variations of pasture production in the whole region. Pasture production is quite variable, highly determined by soil and climate conditions. Rainfall variability produces large seasonal and annual variations, with the highest production in spring, low production in autumn and very scarce in winter. During summer, while pastures are wilting, hard seeds stay latent in the soil and gradually germinate in consecutive months. But variability of pasture production in such a heterogeneous ecosystem does not only depend on edaphic and climate conditions, but also on other factors, such as grazing management, improvement measures, fertilization, exploitation infrastructures, stocking rates, etc. The present study, carried out in the framework of the "Montado/Dehesa" INTERREG project, aimed to sample pasture production in Extremadura, in order to provide a large amount of real data for determining the influence of the different factors involved, which will constitute the basis for the developement of a production model. The latter will be integrated into a tool helping to decide on the best practice of dehesa management. Pastures were

  2. Carbon budgets for an irrigated intensively grazed dairy pasture and an unirrigated winter-grazed pasture

    NASA Astrophysics Data System (ADS)

    Hunt, John E.; Laubach, Johannes; Barthel, Matti; Fraser, Anitra; Phillips, Rebecca L.

    2016-05-01

    Intensification of pastoral agriculture is occurring rapidly across New Zealand, including increasing use of irrigation and fertiliser application in some regions. While this enables greater gross primary production (GPP) and livestock grazing intensity, the consequences for the net ecosystem carbon budget (NECB) of the pastures are poorly known. Here, we determined the NECB over one year for an irrigated, fertilised and rotationally grazed dairy pasture and a neighbouring unirrigated, unfertilised, winter-grazed pasture. Primary terms in the NECB calculation were: net ecosystem production (NEP), biomass carbon removed by grazing cows and carbon (C) input from their excreta. Annual NEP was measured using the eddy-covariance method. Carbon removal was estimated with plate-meter measurements calibrated against biomass collections, pre- and post-grazing. Excreta deposition was calculated from animal feed intake. The intensively managed pasture gained C (NECB = 103 ± 42 g C m-2 yr-1) but would have been subject to a non-significant C loss if cattle excreta had not been returned to the pasture. The unirrigated pasture was C-neutral (NECB = -13 ± 23 g C m-2 yr-1). While annual GPP of the former was almost twice that of the latter (2679 vs. 1372 g C m-2 yr-1), ecosystem respiration differed by only 68 % between the two pastures (2271 vs. 1352 g C m-2 yr-1). The ratio of GPP to the total annual water input of the irrigated pasture was 37 % greater than that of the unirrigated pasture, i.e. the former used the water input more efficiently than the latter to produce biomass. The NECB results agree qualitatively with those from many other eddy-covariance studies of grazed grasslands, but they seem to be at odds with long-term carbon-stock studies of other New Zealand pastures.

  3. DO GRAZING CATTLE SEEK NUTRITIONALLY SUPERIOR PORTIONS OF PASTURES?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the hypothesis that grazing cattle will most often frequent nutritionally superior portions of large pastures. Forage quantity/quality characteristics were mapped among three pastures and cattle grazing patterns subsequently tracked with GPS collars. Cattle preferred locations...

  4. 1. South approach to the horse pasture store, looking north; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. South approach to the horse pasture store, looking north; U.S. Highway 58 (toward Martinsville) is in the foreground - Horsepasture Store, U.S. Route 58 & State Route 687, Horse Pasture, Henry County, VA

  5. PLANT SPECIES DIVERSITY, ECOSYSTEM FUNCTION, AND PASTURE MANAGEMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grassland farmers face new challenges in pasture management including improving sustainability, reducing inputs of fertilizers and pesticides, and protecting soil resources. Managing plant diversity within and among pastures may be one tool to aid producers in meeting these new challenges. Pasture e...

  6. Fact Sheet: Ten Questions about Pastures and Biodiversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traditionally, pasture management has emphasized balancing the quantity and quality of forage for livestock production. Thus, producers have often planted single species or simple grass-legume mixtures in their pastures. Today, producers face new challenges in pasture management, including sustainab...

  7. Fact Sheet: Accurately measuring forage yield in pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Farmers have a few options for measuring pasture yield. These include pasture rulers, plate meters, and electronic gauges. Pasture rulers simply measure canopy height and assume that forage yield is directly related to height. Plate meters improve accuracy by measuring compressed height. Electronic ...

  8. Nitrous Oxide and Methane Emissions from Grazed Pasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contribution of nitrous oxide and methane to the atmosphere from grazed pastures in the eastern U.S. is not well known. Small, vented chambers have been deployed periodically since May 2005 in a rotationally-grazed pasture in central Pennsylvania. Since locations in pastures where livestock uri...

  9. Exploiting the Potential Differences in Pasture Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperate grasses grown for pasture in Wisconsin exhibit a range of chemical and physical characteristics that influence their utilization by grazing cattle. Potential intake of all grasses declines with maturity due to decreasing cell wall digestiblity, but the leaves and stems of orchardgrass and...

  10. Measuring Carbon Sequestration in Pasture Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conversion of croplands to pasture can greatly increase sequestration of carbon in soil organic matter, removing carbon dioxide from the atmosphere and helping to reduce the impacts of climate change. The measurement of soil carbon, and its limitations, could impact future carbon credit programs. ...

  11. Fact Sheet: Soil Carbon Sequestration in Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sequestration of carbon as soil organic matter is one way to remove carbon dioxide from the atmosphere and lower the potential for global climate change. Cultivation typically caused the loss of 20 to 50% the native soil organic matter. Establishing pasture on former croplands is expected to a...

  12. Measuring and budgeting available forage in pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We modeled two farms that differed in size, grazing management, and feeding strategy. We first modeled the optimal management and performance conditions for each farm with the assumption that forage on pasture was measured accurately and budgeted optimally. We also established an economically optimu...

  13. Nutrient management on pasture and haylands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nutrient management on pastures is a critical part of maintaining and improving their ability to provide key ecosystem services including forage and fuel production, clean air and water, and climate mitigation. Our objective was to determine the scientific underpinning for purported benefits of nutr...

  14. Characterization of resistance to adult spittlebugs (Hemiptera: Cercopidae) in Brachiaria spp.

    PubMed

    Aguirre, Lina M; Cardona, César; Miles, John W; Sotelo, Guillermo

    2013-08-01

    Nymphs and adults of several spittlebug (Hemiptera: Cercopidae) species are key pests of forage brachiariagrasses (Brachiaria spp.) in tropical America. To support current breeding programs, a series of experiments aimed at characterizing the mechanisms of resistance to adult feeding damage were carried out. Five genotypes were used: two susceptible checks (CIAT 0606 and CIAT 0654) and three nymph-resistant genotypes (CIAT 36087, CIAT 6294, and SX01NO/0102). Test insects were Aeneolamia varia (F.), A. reducta (Lallemand), and Zulia carbonaria (Lallemand). The nymph-resistant genotypes showed tolerance to all spittlebug species tested. Tolerance in these genotypes can be classified as only moderate given the extent of losses (60-80%) caused by both female and male adults. None of the nymph-resistant genotypes had antibiotic effects on adults feeding on foliage. The results also indicated that antixenosis for feeding is not a plausible explanation for lower damage scores and less biomass losses in resistant genotypes. The fact that adult longevity (usually 8 d) was not affected when the adults were forced to feed on roots of a genotype with strong antibiotic resistance to nymphs is regarded as additional evidence that resistances to nymphs and to adults in Brachiaria are largely independent. PMID:24020305

  15. Soil carbon under perennial pastures; benchmarking the influence of pasture age and management

    NASA Astrophysics Data System (ADS)

    Orgill, Susan E.; Spoljaric, Nancy; Kelly, Georgina

    2015-07-01

    This paper reports baseline soil carbon stocks from a field survey of 19 sites; 8 pairs/triplet in the Monaro region of New South Wales. Site comparisons were selected by the Monaro Farming Systems group to demonstrate the influence of land management on soil carbon, and included: nutrient management, liming, pasture age and cropping history. Soil carbon stocks varied with parent material and with land management. The fertilised (phosphorus) native perennial pasture had a greater stock of soil carbon compared with the unfertilised site; 46.8 vs 40.4 Mg.C.ha to 0.50 m. However, the introduced perennial pasture which had been limed had a lower stock of soil carbon compared with the unlimed site; 62.8 vs 66.7 Mg.C.ha to 0.50 m. There was a greater stock of soil carbon under two of the three younger (<10 yr old) perennial pastures compared with older (>35 yr old) pastures. Cropped sites did not have lower soil carbon stocks at all sites; however, this survey was conducted after three years of above average annual rainfall and most sites had been cropped for less than three years. At all sites more than 20% of the total carbon stock to 0.50 m was in the 0.30 to 0.50 m soil layer highlighting the importance of considering this soil layer when investigating the implications of land management on soil carbon. Our baseline data indicates that nutrient management may increase soil carbon under perennial pastures and highlights the importance of perennial pastures for soil carbon sequestration regardless of age.

  16. Testing the Amazon savannization hypothesis: fire effects on invasion of a neotropical forest by native cerrado and exotic pasture grasses

    PubMed Central

    Silvério, Divino V.; Brando, Paulo M.; Balch, Jennifer K.; Putz, Francis E.; Nepstad, Daniel C.; Oliveira-Santos, Claudinei; Bustamante, Mercedes M. C.

    2013-01-01

    Changes in climate and land use that interact synergistically to increase fire frequencies and intensities in tropical regions are predicted to drive forests to new grass-dominated stable states. To reveal the mechanisms for such a transition, we established 50 ha plots in a transitional forest in the southwestern Brazilian Amazon to different fire treatments (unburned, burned annually (B1yr) or at 3-year intervals (B3yr)). Over an 8-year period since the commencement of these treatments, we documented: (i) the annual rate of pasture and native grass invasion in response to increasing fire frequency; (ii) the establishment of Brachiaria decumbens (an African C4 grass) as a function of decreasing canopy cover and (iii) the effects of grass fine fuel on fire intensity. Grasses invaded approximately 200 m from the edge into the interiors of burned plots (B1yr: 4.31 ha; B3yr: 4.96 ha) but invaded less than 10 m into the unburned plot (0.33 ha). The probability of B. decumbens establishment increased with seed availability and decreased with leaf area index. Fine fuel loads along the forest edge were more than three times higher in grass-dominated areas, which resulted in especially intense fires. Our results indicate that synergies between fires and invasive C4 grasses jeopardize the future of tropical forests. PMID:23610179

  17. Influence of topography on density of grassland passerines in pastures

    USGS Publications Warehouse

    Renfrew, R.B.; Ribic, C.A.

    2002-01-01

    Pastures provide substantial habitat for grassland birds of management concern in the Driftless Area of southwestern Wisconsin. The rolling topography in this region is characterized by lowland valleys surrounded by relatively steep and often wooded slopes which are set apart from more expansive treeless uplands. We hypothesized that there would be lower densities of area sensitive grassland passerines in lowland grasslands compared to upland grasslands because of their preference for larger more open grasslands. To test this hypothesis and assess how well pasture area and vegetation structure predicted grassland passerine density compared to upland/lowland status, we conducted point counts of birds in 60 pastures in May-June 1997 and 1998. Upland pastures generally supported greater densities of grassland passerines than lowland pastures. Densities of Savannah sparrow (Passerculus sandwichensis) and bobolink (Dolichonyx oryzivorus) were significantly higher in upland pastures than in lowland pastures. Grasshopper sparrow (Ammodramus savannarum) density was significantly higher on uplands in one of the study years. The density of eastern meadowlark (Sturnella magna), western meadowlark (S. neglecta) and sedge wren (Cistothorus platensis) did not differ significandy between uplands and lowlands. Grassland passerine density was also predicted by pasture size and vegetation structure. Densities of bobolink and grasshopper sparrow were higher in larger pastures. Bobolink and Savannah sparrow occurred on pastures with greater vegetation height-density and less bare ground; bobolink also preferred shallower litter depths. Lowland pastures supported grassland bird species of management concern and should not be neglected. However, we recommend that pasture management for grassland passerines in areas of variable topography favor relatively large upland pastures that will contain higher densities of species of management concern.

  18. Uele River, Cleared Pasture Lands, Zaire, Africa

    NASA Technical Reports Server (NTRS)

    1992-01-01

    In this view of the Uele River and cleared pasturelands in Zaire (3.5N, 27.0E), the distinctive dendritic drainage pattern of the region becomes obvious. Cleared pasture lands shown as light green, contrasts with the dark green of the remaining closed conopy forests. The remnant woodlands along the streams indicates the intricate drainage network of this hilly region. Scattered vegetation free spots show the deep red tropical soils.

  19. New pasture plants intensify invasive species risk.

    PubMed

    Driscoll, Don A; Catford, Jane A; Barney, Jacob N; Hulme, Philip E; Inderjit; Martin, Tara G; Pauchard, Aníbal; Pyšek, Petr; Richardson, David M; Riley, Sophie; Visser, Vernon

    2014-11-18

    Agricultural intensification is critical to meet global food demand, but intensification threatens native species and degrades ecosystems. Sustainable intensification (SI) is heralded as a new approach for enabling growth in agriculture while minimizing environmental impacts. However, the SI literature has overlooked a major environmental risk. Using data from eight countries on six continents, we show that few governments regulate conventionally bred pasture taxa to limit threats to natural areas, even though most agribusinesses promote taxa with substantial weed risk. New pasture taxa (including species, subspecies, varieties, cultivars, and plant-endophyte combinations) are bred with characteristics typical of invasive species and environmental weeds. By introducing novel genetic and endophyte variation, pasture taxa are imbued with additional capacity for invasion and environmental impact. New strategies to prevent future problems are urgently needed. We highlight opportunities for researchers, agribusiness, and consumers to reduce environmental risks associated with new pasture taxa. We also emphasize four main approaches that governments could consider as they build new policies to limit weed risks, including (i) national lists of taxa that are prohibited based on environmental risk; (ii) a weed risk assessment for all new taxa; (iii) a program to rapidly detect and control new taxa that invade natural areas; and (iv) the polluter-pays principle, so that if a taxon becomes an environmental weed, industry pays for its management. There is mounting pressure to increase livestock production. With foresight and planning, growth in agriculture can be achieved sustainably provided that the scope of SI expands to encompass environmental weed risks. PMID:25368175

  20. New pasture plants intensify invasive species risk

    PubMed Central

    Driscoll, Don A.; Catford, Jane A.; Barney, Jacob N.; Hulme, Philip E.; Inderjit; Martin, Tara G.; Pauchard, Aníbal; Pyšek, Petr; Richardson, David M.; Riley, Sophie; Visser, Vernon

    2014-01-01

    Agricultural intensification is critical to meet global food demand, but intensification threatens native species and degrades ecosystems. Sustainable intensification (SI) is heralded as a new approach for enabling growth in agriculture while minimizing environmental impacts. However, the SI literature has overlooked a major environmental risk. Using data from eight countries on six continents, we show that few governments regulate conventionally bred pasture taxa to limit threats to natural areas, even though most agribusinesses promote taxa with substantial weed risk. New pasture taxa (including species, subspecies, varieties, cultivars, and plant-endophyte combinations) are bred with characteristics typical of invasive species and environmental weeds. By introducing novel genetic and endophyte variation, pasture taxa are imbued with additional capacity for invasion and environmental impact. New strategies to prevent future problems are urgently needed. We highlight opportunities for researchers, agribusiness, and consumers to reduce environmental risks associated with new pasture taxa. We also emphasize four main approaches that governments could consider as they build new policies to limit weed risks, including (i) national lists of taxa that are prohibited based on environmental risk; (ii) a weed risk assessment for all new taxa; (iii) a program to rapidly detect and control new taxa that invade natural areas; and (iv) the polluter-pays principle, so that if a taxon becomes an environmental weed, industry pays for its management. There is mounting pressure to increase livestock production. With foresight and planning, growth in agriculture can be achieved sustainably provided that the scope of SI expands to encompass environmental weed risks. PMID:25368175

  1. Chromosome numbers and meiotic analysis in the pre-breeding of Brachiaria decumbens (Poaceae).

    PubMed

    Ricci, Gléia Cristina Laverde; De Souza-Kaneshima, Alice Maria; Felismino, Mariana Ferrari; Mendes-Bonato, Andrea Beatriz; Pagliarini, Maria Suely; Do Valle, Cacilda Borges

    2011-08-01

    A total of 44 accessions of Brachiaria decumbens were analysed for chromosome count and meiotic behaviour in order to identify potential progenitors for crosses. Among them, 15 accessions presented 2n = 18; 27 accessions, 2n = 36; and 2 accessions, 2n = 45 chromosomes. Among the diploid accessions, the rate of meiotic abnormalities was low, ranging from 0.82% to 7.93%. In the 27 tetraploid accessions, the rate of meiotic abnormalities ranged from 18.41% to 65.83%. The most common meiotic abnormalities were related to irregular chromosome segregation, but chromosome stickiness and abnormal cytokinesis were observed in low frequency. All abnormalities can compromise pollen viability by generating unbalanced gametes. Based on the chromosome number and meiotic stability, the present study indicates the apomictic tetraploid accessions that can act as male genitor to produce interspecific hybrids with B. ruziziensis or intraspecific hybrids with recently artificially tetraploidized accessions. PMID:21869477

  2. A Parthenogenesis Gene Candidate and Evidence for Segmental Allopolyploidy in Apomictic Brachiaria decumbens

    PubMed Central

    Worthington, Margaret; Heffelfinger, Christopher; Bernal, Diana; Quintero, Constanza; Zapata, Yeny Patricia; Perez, Juan Guillermo; De Vega, Jose; Miles, John; Dellaporta, Stephen; Tohme, Joe

    2016-01-01

    Apomixis, asexual reproduction through seed, enables breeders to identify and faithfully propagate superior heterozygous genotypes by seed without the disadvantages of vegetative propagation or the expense and complexity of hybrid seed production. The availability of new tools such as genotyping by sequencing and bioinformatics pipelines for species lacking reference genomes now makes the construction of dense maps possible in apomictic species, despite complications including polyploidy, multisomic inheritance, self-incompatibility, and high levels of heterozygosity. In this study, we developed saturated linkage maps for the maternal and paternal genomes of an interspecific Brachiaria ruziziensis (R. Germ. and C. M. Evrard) × B. decumbens Stapf. F1 mapping population in order to identify markers linked to apomixis. High-resolution molecular karyotyping and comparative genomics with Setaria italica (L.) P. Beauv provided conclusive evidence for segmental allopolyploidy in B. decumbens, with strong preferential pairing of homologs across the genome and multisomic segregation relatively more common in chromosome 8. The apospory-specific genomic region (ASGR) was mapped to a region of reduced recombination on B. decumbens chromosome 5. The Pennisetum squamulatum (L.) R.Br. PsASGR-BABY BOOM-like (psASGR–BBML)-specific primer pair p779/p780 was in perfect linkage with the ASGR in the F1 mapping population and diagnostic for reproductive mode in a diversity panel of known sexual and apomict Brachiaria (Trin.) Griseb. and P. maximum Jacq. germplasm accessions and cultivars. These findings indicate that ASGR–BBML gene sequences are highly conserved across the Paniceae and add further support for the postulation of the ASGR–BBML as candidate genes for the apomictic function of parthenogenesis. PMID:27206716

  3. A Parthenogenesis Gene Candidate and Evidence for Segmental Allopolyploidy in Apomictic Brachiaria decumbens.

    PubMed

    Worthington, Margaret; Heffelfinger, Christopher; Bernal, Diana; Quintero, Constanza; Zapata, Yeny Patricia; Perez, Juan Guillermo; De Vega, Jose; Miles, John; Dellaporta, Stephen; Tohme, Joe

    2016-07-01

    Apomixis, asexual reproduction through seed, enables breeders to identify and faithfully propagate superior heterozygous genotypes by seed without the disadvantages of vegetative propagation or the expense and complexity of hybrid seed production. The availability of new tools such as genotyping by sequencing and bioinformatics pipelines for species lacking reference genomes now makes the construction of dense maps possible in apomictic species, despite complications including polyploidy, multisomic inheritance, self-incompatibility, and high levels of heterozygosity. In this study, we developed saturated linkage maps for the maternal and paternal genomes of an interspecific Brachiaria ruziziensis (R. Germ. and C. M. Evrard) × B. decumbens Stapf. F1 mapping population in order to identify markers linked to apomixis. High-resolution molecular karyotyping and comparative genomics with Setaria italica (L.) P. Beauv provided conclusive evidence for segmental allopolyploidy in B. decumbens, with strong preferential pairing of homologs across the genome and multisomic segregation relatively more common in chromosome 8. The apospory-specific genomic region (ASGR) was mapped to a region of reduced recombination on B. decumbens chromosome 5. The Pennisetum squamulatum (L.) R.Br. PsASGR-BABY BOOM-like (psASGR-BBML)-specific primer pair p779/p780 was in perfect linkage with the ASGR in the F1 mapping population and diagnostic for reproductive mode in a diversity panel of known sexual and apomict Brachiaria (Trin.) Griseb. and P. maximum Jacq. germplasm accessions and cultivars. These findings indicate that ASGR-BBML gene sequences are highly conserved across the Paniceae and add further support for the postulation of the ASGR-BBML as candidate genes for the apomictic function of parthenogenesis. PMID:27206716

  4. Low phosphorus tolerance mechanisms: phosphorus recycling and photosynthate partitioning in the tropical forage grass, Brachiaria hybrid cultivar Mulato compared with rice.

    PubMed

    Nanamori, Masahito; Shinano, Takuro; Wasaki, Jun; Yamamura, Takuya; Rao, Idupulapati M; Osaki, Mitsuru

    2004-04-01

    The Brachiaria hybrid cv. Mulato is well adapted to low-fertility acid soils deficient in phosphorus (P). To study the grassy forage's mechanisms for tolerating low P supply, we compared it with rice (Oryza sativa L. cv. Kitaake). We tested by using nutrient solution cultures, and quantified the effects of P deficiency on the enzymatic activities of phosphohydrolases and on carbon metabolism in P-deficient leaves. While P deficiency markedly induced activity of phosphohydrolases in both crops, the ratio of inorganic phosphorus to total P in leaves was greater in Brachiaria hybrid. Phosphorus deficiency in leaves also markedly influenced the partitioning of carbon in both crops. In the Brachiaria hybrid, compared with rice, the smaller proportion of (14)C partitioned into sugars and the larger proportion into amino acids and organic acids in leaves coincided with decreased levels of sucrose and starch. Hence, in P-deficient leaves of the Brachiaria hybrid, triose-P was metabolized into amino acids or organic acids. Results thus indicate that the Brachiaria hybrid, compared with rice, tolerates low P supply to leaves by enhancing sugar catabolism and by inducing the activity of several phosphohydrolases. This apparently causes rapid P turnover and enables the Brachiaria hybrid to use P more efficiently. PMID:15111721

  5. Development and validation of microsatellite markers for Brachiaria ruziziensis obtained by partial genome assembly of Illumina single-end reads

    PubMed Central

    2013-01-01

    Background Brachiaria ruziziensis is one of the most important forage species planted in the tropics. The application of genomic tools to aid the selection of superior genotypes can provide support to B. ruziziensis breeding programs. However, there is a complete lack of information about the B. ruziziensis genome. Also, the availability of genomic tools, such as molecular markers, to support B. ruziziensis breeding programs is rather limited. Recently, next-generation sequencing technologies have been applied to generate sequence data for the identification of microsatellite regions and primer design. In this study, we present a first validated set of SSR markers for Brachiaria ruziziensis, selected from a de novo partial genome assembly of single-end Illumina reads. Results A total of 85,567 perfect microsatellite loci were detected in contigs with a minimum 10X coverage. We selected a set of 500 microsatellite loci identified in contigs with minimum 100X coverage for primer design and synthesis, and tested a subset of 269 primer pairs, 198 of which were polymorphic on 11 representative B. ruziziensis accessions. Descriptive statistics for these primer pairs are presented, as well as estimates of marker transferability to other relevant brachiaria species. Finally, a set of 11 multiplex panels containing the 30 most informative markers was validated and proposed for B. ruziziensis genetic analysis. Conclusions We show that the detection and development of microsatellite markers from genome assembled Illumina single-end DNA sequences is highly efficient. The developed markers are readily suitable for genetic analysis and marker assisted selection of Brachiaria ruziziensis. The use of this approach for microsatellite marker development is promising for species with limited genomic information, whose breeding programs would benefit from the use of genomic tools. To our knowledge, this is the first set of microsatellite markers developed for this important species

  6. Hepatogenous photosensitization of ruminants by Brachiaria decumbens and panicum dichotomiflorum in the absence of sporidesmin: lithogenic saponins may be responsible.

    PubMed

    Meagher, L P; Wilkins, A L; Miles, C O; Collin, R G; Fagliari, J J

    1996-08-01

    As part of a study of plants involved in crystal-associated hepatogenous photosensitization diseases, samples of Brachiaria decumbens and Panicum dichotomiflorum on which cattle and goats had recently been photosensitized were analyzed. The level of saponins associated with these photosensitization outbreaks were determined by GC-MS. Only low levels of Pithomyces chartarum spores were present on the B decumbens, and all isolates obtained failed to produce sporidesmin. PMID:8829344

  7. Pasture monitoring at a farm scale with the USDA-NRCS pasture condition score system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Pasture Condition Score (PCS) system, developed by the USDA-Natural Resources Conservation Service (NRCS), is an assessment tool for pastureland enrolled in conservation programs. Ten indicators of vegetation and soils status are rated on a 1 to 5 scale and summed to give an aggregate score, whi...

  8. Lake-dredged material for beef cattle pasture establishment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbonatic lake-dredged materials can be used as soil amendments (lime and fertilizer) for early establishment of bahiagrass in beef cattle pastures in Florida. Some of the indirect benefits of the liming effects of this material for pastures include enhancing nutrient availability, nitrification, n...

  9. EFFECTS OF LIVESTOCK PASTURING ON NONPOINT SURFACE RUNOFF

    EPA Science Inventory

    This project was initiated to evaluate the effects of livestock pasturing in the humid regions of the United States on the quality of nonpoint surface runoff. Three pasturing regimes which are more commonly practiced in the corn belt states were evaluated to determine their poten...

  10. Perennial Forage Kochia for Increased Production of Winter Grazed Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazing forage kochia (Kochia prostrata) during fall/winter has improved livestock health and reduced winter feeding costs. The objectives of this study were to compare forage production/quality and livestock performance of traditional winter pastures versus pastures with forage kochia. Two kochia...

  11. Pasture growth and decomposition under continuous and rotational grazing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Past research has shown that grazing management can affect both pasture growth and litter decomposition. The objective of this study was to compare forage appearance (growth) and forage disappearance (decomposition) on both continuous and rotational grazed beef cattle pasture in Ohio. Data was colle...

  12. Productivity, botanical composition, and nutritive value of commercial pasture mixtures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pastures in the northeastern USA often are planted to mixtures of grasses and legumes. There is limited public sector information on the performance of commercial forage mixtures. We evaluated a range of commercial pasture mixtures to determine if the number of species in a mixture affected yield an...

  13. Influence of transient flooding on methane fluxes from subtropical pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seasonally flooded subtropical pastures are major methane (CH4) sources, where transient flooding drives episodic and high-magnitude emissions from the underlying landscape. Understanding the mechanisms that drive these patterns is needed to better understand pasture CH4 emissions and their response...

  14. 2. Overall view of the horse pasture store from the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Overall view of the horse pasture store from the east; U.S. Highway 58 runs from left to right across the view, while Route 687 rices into the distance at the left - Horsepasture Store, U.S. Route 58 & State Route 687, Horse Pasture, Henry County, VA

  15. 5. East and north (rear) elevations of the horse pasture ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. East and north (rear) elevations of the horse pasture store, looking southwest; the store's two outbuildings can ben seen at the right of the view - Horsepasture Store, U.S. Route 58 & State Route 687, Horse Pasture, Henry County, VA

  16. 4. West and south elevations of the horse pasture store, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. West and south elevations of the horse pasture store, looking northeast; a "Greenhouse" structure can be seen extending to the west of the store at the left of the view - Horsepasture Store, U.S. Route 58 & State Route 687, Horse Pasture, Henry County, VA

  17. Pasture condition scoring at the whole-farm scale

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers need monitoring and assessment tools to aid in pasture management. The Pasture Condition Score (PCS) system was developed by the USDA-NRCS as a monitoring and management tool. Information is lacking, however, on how PCS results vary within and among grazing seasons and within and among far...

  18. Ruminal motility of stocker cattle grazed on winter wheat pasture.

    PubMed

    Horn, G W; Frost, D F

    1982-10-01

    A 2-yr study was conducted to determine whether bloat of stocker cattle grazing winter wheat pasture is a primary bloat or a secondary bloat as a result of reduced ruminal motility. Amplitude (mm Hg) and frequency of ruminal contractions (contractions/min) of steers were measured before and after the steers were placed on wheat pasture, and at about weekly intervals during the pasture grazing periods. Implantable pressure transducers and water-filled balloon cannulas were used to measure ruminal motility. During the first year, amplitude of contractions increased (P less than .005) during grazing of wheat pasture (i.e., 20.5 vs 6.7 and 21.6 vs 12.9, respectively, for steers with implanted pressure transducers and water-filled balloon cannulas). Frequency of ruminal contractions of steers on wheat pasture was not decreased (P greater than .05). In the second year, amplitudes of ruminal contractions of steers on wheat pasture ranged from 11.0 to 33.5, and were either similar or greater (P less than .05) than the mean for the pre- and post-wheat pasture period (16.5). Frequencies of ruminal contractions that ranged from 1.66 to 1.80 were observed on four dates during the pasture grazing period, and were decreased (P less than .05) as compared with the mean for the pre- and post-wheat pasture period (2.43). However, the reduced frequencies were not accompanied by reduced (P greater than .05) amplitude x frequency of contractions. The data indicate that ruminal motility is not decreased in stocker cattle grazing winter wheat pasture. PMID:7142058

  19. Biodiversity on Swedish pastures: estimating biodiversity production costs.

    PubMed

    Nilsson, Fredrik Olof Laurentius

    2009-01-01

    This paper estimates the costs of producing biological diversity on Swedish permanent grasslands. A simple model is introduced where biodiversity on pastures is produced using grazing animals. On the pastures, the grazing animals create a sufficient grazing pressure to lead to an environment that suits many rare and red-listed species. Two types of pastures are investigated: semi-natural and cultivated. Biological diversity produced on a pasture is estimated by combining a biodiversity indicator, which measures the quality of the land, with the size of the pasture. Biodiversity is, in this context, a quantitative measure where a given quantity can be produced either by small area with high quality or a larger area with lower quality. Two areas in different parts of Sweden are investigated. Box-Cox transformations, which provide flexible functional forms, are used in the empirical analysis and the results indicate that the biodiversity production costs differ between the regions. The major contribution of this paper is that it develops and tests a method of estimating biodiversity production costs on permanent pastures when biodiversity quality differs between pastures. If the method were to be used with cost data, that were more thoroughly collected and covered additional production areas, biodiversity cost functions could be estimated and used in applied policy work. PMID:18079049

  20. Perspectives on pasture versus indoor feeding of dairy cows.

    PubMed

    Knaus, Wilhelm

    2016-01-15

    The dairy industry in many regions of the world has moved towards a high-input/high-output system maximising annual milk production per cow, primarily through increasing concentrate-based total mixed rations fed indoors year round, as opposed to allowing cows to feed on pasture. Pasture-based dairy systems in regions like New Zealand and Ireland are oriented towards maximum milk yield per unit of pasture, which has led to Holstein strains that are 50 to 100 kg lighter, exhibit a higher body condition score, and produce roughly half the annual amount of milk as compared to their Holstein counterparts kept in confinement in North America and Europe. Freedom from hunger might not be guaranteed when high-yielding dairy cows are kept on pasture without any supplemental feed, but at the same time no access to pasture can be considered an animal welfare concern, because pasturing is generally beneficial to the animals' health. On pasture, lighter-weight dairy cows with a medium milk production potential have proven to be superior with regard to feed efficiency and fertility. The year-round indoor feeding of high-yielding dairy cows with total mixed rations containing substantial amounts of human-edible crops from arable land puts global food security at risk and fails to utilise the evolutionary advantages of ruminants. PMID:26010136

  1. Crop and pasture response to climate change.

    PubMed

    Tubiello, Francesco N; Soussana, Jean-François; Howden, S Mark

    2007-12-11

    We review recent research of importance to understanding crop and pasture plant species response to climate change. Topics include plant response to elevated CO(2) concentration, interactions with climate change variables and air pollutants, impacts of increased climate variability and frequency of extreme events, the role of weeds and pests, disease and animal health, issues in biodiversity, and vulnerability of soil carbon pools. We critically analyze the links between fundamental knowledge at the plant and plot level and the additional socio-economic variables that determine actual production and trade of food at regional to global scales. We conclude by making recommendations for current and future research needs, with a focus on continued and improved integration of experimental and modeling efforts. PMID:18077401

  2. Production potential of warm-season annual pastures in rotation with corn silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Warm-season grasses can provide a pasture resource and give relief to cool-season pastures during the hot summer months when cool-season pasture production declines. Increased pasture availability is especially important for organic producers because of the newly defined grazing requirement for org...

  3. Spectrometry of pasture condition and biogeochemistry in the central Amazon

    NASA Astrophysics Data System (ADS)

    Asner, Gregory P.; Townsend, Alan R.; Bustamante, Mercedes M. C.

    Regional analyses of Amazon cattle pasture biogeochemistry are difficult due to the complexity of human, edaphic, biotic and climatic factors and persistent cloud cover in satellite observations. We developed a method to estimate key biophysical properties of Amazon pastures using hyperspectral reflectance data and photon transport inverse modeling. Remote estimates of live and senescent biomass were strongly correlated with plant-available forms of soil phosphorus and calcium. These results provide a basis for monitoring pasture condition and biogeochemistry in the Amazon Basin using spaceborne hyperspectral sensors.

  4. Spectrometry of Pasture Condition and Biogeochemistry in the Central Amazon

    NASA Technical Reports Server (NTRS)

    Asner, Gregory P.; Townsend, Alan R.; Bustamante, Mercedes M. C.

    1999-01-01

    Regional analyses of Amazon cattle pasture biogeochemistry are difficult due to the complexity of human, edaphic, biotic and climatic factors and persistent cloud cover in satellite observations. We developed a method to estimate key biophysical properties of Amazon pastures using hyperspectral reflectance data and photon transport inverse modeling. Remote estimates of live and senescent biomass were strongly correlated with plant-available forms of soil phosphorus and calcium. These results provide a basis for monitoring pasture condition and biogeochemistry in the Amazon Basin using spaceborne hyperspectral sensors.

  5. [Hyperspectral Remote Sensing Estimation Models for Pasture Quality].

    PubMed

    Ma, Wei-wei; Gong, Cai-lan; Hu, Yong; Wei, Yong-lin; Li, Long; Liu, Feng-yi; Meng, Peng

    2015-10-01

    Crude protein (CP), crude fat (CFA) and crude fiber (CFI) are key indicators for evaluation of the quality and feeding value of pasture. Hence, identification of these biological contents is an essential practice for animal husbandry. As current approaches to pasture quality estimation are time-consuming and costly, and even generate hazardous waste, a real-time and non-destructive method is therefore developed in this study using pasture canopy hyperspectral data. A field campaign was carried out in August 2013 around Qinghai Lake in order to obtain field spectral properties of 19 types of natural pasture using the ASD Field Spec 3, a field spectrometer that works in the optical region (350-2 500 nm) of the electromagnetic spectrum. In additional to the spectral data, pasture samples were also collected from the field and examined in laboratory to measure the relative concentration of CP (%), CFA (%) and CFI (%). After spectral denoising and smoothing, the relationship of pasture quality parameters with the reflectance spectrum, the first derivatives of reflectance (FDR), band ratio and the wavelet coefficients (WCs) was analyzed respectively. The concentration of CP, CFA and CFI of pasture was found closely correlated with FDR with wavebands centered at 424, 1 668, and 918 nm as well as with the low-scale (scale = 2, 4) Morlet, Coiflets and Gassian WCs. Accordingly, the linear, exponential, and polynomial equations between each pasture variable and FDR or WCs were developed. Validation of the developed equations indicated that the polynomial model with an independent variable of Coiflets WCs (scale = 4, wavelength =1 209 nm), the polynomial model with an independent variable of FDR, and the exponential model with an independent variable of FDR were the optimal model for prediction of concentration of CP, CFA and CFI of pasture, respectively. The R2 of the pasture quality estimation models was between 0.646 and 0.762 at the 0.01 significance level. Results suggest

  6. Greenhouse gas emission from cattle urine deposition in pasture under tropical conditions.

    NASA Astrophysics Data System (ADS)

    Mancebo Mazzetto, Andre; Simões Barneze, Arlete; Josefine Feigl, Brigitte; Clemente Cerri, Carlos; Willem van Groenigen, Jan

    2014-05-01

    Animal production systems are important sources of greenhouse gases (GHG), especially methane (CH4) and nitrous oxide (N2O). Brazilian beef production is almost exclusively (more than 90%) pasture-based, and most GHG emissions from this system originate from urine patches. GHG emissions from urine patches have been extensively studied in temperate climates, but not for tropical conditions. Here we examined the driving factors of N2O emission from urine patches (U treatment) in the tropics, as well as the role of the nitrification inhibitor DCD (dicyandiamide - U+DCD treatment) in mitigating emissions. We measured the emission of CH4 and N2O from beef cattle urine (360 kg N ha-1) in Rondônia state (Brazil, tropical climate), during two different seasons (winter and summer), with and without the application of DCD (10 kg ha-1). We hypothesized that the high temperature and periodical rainfall can decrease GHG emissions from urine patches through accelerating mineralization of urine-N. The cumulative emissions during winter were 10.8 and 39.2 mg N-N2O m-2 (U and U+DCD treatment, respectively), and 126.2 and 129.5 mg N-N2O m-2 during summer (U and U+DCD treatment, respectively). No effects of DCD were detected in summer, but DCD retarded the main peak of N2O emission. Otherwise, during winter U+DCD treatment had the higher cumulative N2O emission (p≤0.05). The emission factors determined were 0.08 and 0.13% (winter U and U+DCD, respectively) and 0.38 and 0.37% (summer U and U+DCD, respectively), significantly lower than the IPCC default value of 1%. We hypothesize that biological nitrification inhibition (BNI) is the main reason for such low emission factors, since Brachiaria grasses naturally inhibits the nitrification process. In this situation the use of DCD is not recommended. The fast decomposition of DCD in warmer climates leads to a short-term effect in nitrification inhibition. The excess of N due to DCD decomposition can trigger a priming-effect, increasing

  7. Screening for resistance to adult spittlebugs (Hemiptera: Cercopidae) in Brachiaria spp.: methods and categories of resistance.

    PubMed

    López, Francisco; Cardona, Cesar; Miles, John W; Sotelo, Guillermo; Montoya, James

    2009-06-01

    Both nymphal and adult stages of several species of spittlebugs (Hemiptera: Cercopidae) are key economic pests of brachiariagrasses (Brachiaria spp.) in tropical America. Progress has been made in the characterization and development of antibiosis resistance to nymphs in brachiariagrasses. Essentially no attention has been given to screening germplasm for resistance to adults. To support current breeding programs, a series of experiments was conducted to develop a methodology to screen for adult damage and to study categories of resistance to adult feeding damage. Six host brachiariagrass genotypes were used: two susceptible checks (CIAT 0606 and CIAT 0654) and four nymph-resistant genotypes (CIAT 6294, CIAT 36062, CIAT 36087, and SX01NO/0102). Test insects were Aeneolamia varia (F.) and Zulia carbonaria (Lallemand). None of the nymph-resistant genotypes was antibiotic to adults. All four nymph-resistant genotypes showed tolerance to A. varia and Z. carbonaria feeding damage. The levels of tolerance to adults of Z. carbonaria, a larger, more aggressive species, were lower. Of the four nymph-resistant genotypes, only CIAT 6294 and CIAT 36087 showed some tolerance to Z. carbonaria expressed as lower leaf damage scores, less chlorophyll loss, and lower functional plant loss indices. The fact that a genotype like SX01NO/0102, which is highly antibiotic to nymphs, is susceptible to adult damage suggests that mechanisms of resistance to the two spittlebug life stages may be independent. Results of these studies suggest a need to incorporate routine screening for tolerance to adult feeding damage as an additional selection criterion in the breeding scheme. PMID:19610452

  8. Fertile transgenic Brachiaria ruziziensis (ruzigrass) plants by particle bombardment of tetraploidized callus.

    PubMed

    Ishigaki, Genki; Gondo, Takahiro; Suenaga, Kazuhiro; Akashi, Ryo

    2012-03-15

    We have produced transgenic plants of the tropical forage crop Brachiaria ruziziensis (ruzigrass) by particle bombardment-mediated transformation of multiple-shoot clumps and embryogenic calli. Cultures of multiple-shoot clumps and embryogenic calli were induced on solidified MS medium supplemented with 0.5mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 2mg/L 6-benzylaminopurine (BAP) or 4mg/L 2,4-D and 0.2mg/L BAP, respectively. Both cultures were bombarded with a vector containing an herbicide resistance gene (bar) as a selectable marker and the β-glucuronidase (GUS) reporter gene. Sixteen hours after bombardment, embryogenic calli showed a significantly higher number of transient GUS expression spots per plate and callus than multiple-shoot clumps, suggesting that embryogenic callus is the more suitable target tissue. Following bombardment and selection with 10mg/L bialaphos, herbicide-resistant embryogenic calli regenerated shoots and roots in vitro, and mature transgenic plants have been raised in the greenhouse. Polymerase chain reaction (PCR) and DNA gel blot analysis verified that the GUS gene was integrated into the genome of the two regenerated lines. In SacI digests, the two transgenic lines showed two or five copies of GUS gene fragments, respectively, and integration at different sites. Histochemical analysis revealed stable expression in roots, shoots and inflorescences. Transgenic plants derived from diploid target callus turned out to be sterile, while transgenics from colchicine-tetraploidized callus were fertile. PMID:22236981

  9. West wing, west elevation, seen entirety from the pasture at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    West wing, west elevation, seen entirety from the pasture at the west edge of state park property. (recreation of HABS No. CA-38-P152-1). - Vallejo Adobe, Adobe Road at Casa Grande, Petaluma, Sonoma County, CA

  10. 75 FR 7153 - National Organic Program; Access to Pasture (Livestock)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-17

    ..., NOP published an Advanced Notice of Proposed Rulemaking (ANPR) (71 FR 19131) seeking input on: (1... the ``National Organic Program (NOP)--Access to Pasture (Livestock)'' proposed rule (73 FR 63584)....

  11. Pasture-scale measurement of methane emissions of grazing cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantifying methane emission of cattle grazing on southern Great Plains pastures using micrometeorology presents several challenges. Cattle are elevated, mobile point sources of methane, so that knowing their location in relation to atmospheric methane concentration measurements becomes critical. St...

  12. GENERAL OVERVIEW, LOOKING EAST, FROM RECLAIMED PASTURE TO 8750 PIT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GENERAL OVERVIEW, LOOKING EAST, FROM RECLAIMED PASTURE TO 8750 PIT WITH STRIPPING AND RECLAMATION ACTIVITY ONGOING SIDE BY SIDE. - Drummond Coal Company Cedrum Mine, 8750 Pit, County Road 124, Townley, Walker County, AL

  13. VIEW OF RIDING STABLE AND PASTURE FROM ENTRANCE ROAD, PART ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF RIDING STABLE AND PASTURE FROM ENTRANCE ROAD, PART TWO OF PANORAMA, FACING NORTHEAST - Overhills, Fort Bragg Military Reservation, Approximately 15 miles NW of Fayetteville, Overhills, Harnett County, NC

  14. View east of the irrigation ditch in the upslope pasture ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View east of the irrigation ditch in the upslope pasture above the ranch core. The ditch flows toward the eastern barbed wire fenceline in the background. - Tassi Ranch, Tassi Springs, Littlefield, Mohave County, AZ

  15. 1. Distant view, showing bridge in context with agricultural (pastures ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Distant view, showing bridge in context with agricultural (pastures and cornfields) setting; looking southeast. - Eureka Bridge, Spanning Yellow River (Moved to City Park, Castalia), Frankville, Winneshiek County, IA

  16. 8. OBLIQUE VIEW OF WALKER BRIDGE FROM PASTURE SOUTH OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. OBLIQUE VIEW OF WALKER BRIDGE FROM PASTURE SOUTH OF THE KLAMATH RIVER; FACING NORTHEAST. - Walker Bridge, Spanning Klamath River and connecting Highway 96 and Walker Road, Klamath River, Siskiyou County, CA

  17. 4. CONTEXTUAL VIEW OF WALKER BRIDGE FROM IRRIGATED PASTURE BETWEEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. CONTEXTUAL VIEW OF WALKER BRIDGE FROM IRRIGATED PASTURE BETWEEN THE KLAMATH RIVER AND WALKER ROAD; FACING WEST. - Walker Bridge, Spanning Klamath River and connecting Highway 96 and Walker Road, Klamath River, Siskiyou County, CA

  18. Energy content of tropical grasses and legumes grown for bioenergy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biomass samples of the tropical grasses Brachiaria brizantha (Hochst. ex A. Rich.) Staph, Brachiaria humidicola (Rendle) Schweick, Brachiaria decumbens Staph, Panicum maximum Jacq., Pennistetum alopecuroides (L.) Spreng and three species of the tropical legume Stylosanthes grown in Mato Grosso do Su...

  19. Determination of pasture quality using airborne hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Pullanagari, R. R.; Kereszturi, G.; Yule, Ian J.; Irwin, M. E.

    2015-10-01

    Pasture quality is a critical determinant which influences animal performance (live weight gain, milk and meat production) and animal health. Assessment of pasture quality is therefore required to assist farmers with grazing planning and management, benchmarking between seasons and years. Traditionally, pasture quality is determined by field sampling which is laborious, expensive and time consuming, and the information is not available in real-time. Hyperspectral remote sensing has potential to accurately quantify biochemical composition of pasture over wide areas in great spatial detail. In this study an airborne imaging spectrometer (AisaFENIX, Specim) was used with a spectral range of 380-2500 nm with 448 spectral bands. A case study of a 600 ha hill country farm in New Zealand is used to illustrate the use of the system. Radiometric and atmospheric corrections, along with automatized georectification of the imagery using Digital Elevation Model (DEM), were applied to the raw images to convert into geocoded reflectance images. Then a multivariate statistical method, partial least squares (PLS), was applied to estimate pasture quality such as crude protein (CP) and metabolisable energy (ME) from canopy reflectance. The results from this study revealed that estimates of CP and ME had a R2 of 0.77 and 0.79, and RMSECV of 2.97 and 0.81 respectively. By utilizing these regression models, spatial maps were created over the imaged area. These pasture quality maps can be used for adopting precision agriculture practices which improves farm profitability and environmental sustainability.

  20. Open pasture, silvopasture, and sward herbage maturity effects on nutritive value and fermentation characteristics of cool-season pasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Appalachian USA, growing forages within woodlots offers promise of increased farm productivity. A synchronized, temporal understanding of open (OP) and silvopasture (SP) nutritive characteristics is essential for grazing system development. We examined pasture type nutritive value relationships w...

  1. Spatiotemporal moisture dynamics in a prairie pasture

    NASA Astrophysics Data System (ADS)

    Peterson, Amber; Ireson, Andrew; Helgason, Warren

    2016-04-01

    For most practical applications, soil moisture estimates are needed at field scale, integrated over the root zone. We present here results from a field study in a pasture site in Saskatchewan, Canada. We combine observations of point scale soil moisture content from an array of neutron probes with continuous, field scale, shallow soil moisture content observations from the COSMOS instrument. The neutron probe data provide insights into the spatial variability of soil moisture processes, which is highly significant at this site. In particular, we find that the field comprises non-participating profiles, where infiltration, change in storage and drainage are minimal, and dynamic profiles, where these processes are highly dynamic. This strongly affects the relationship between the spatial mean vs standard deviation of moisture content, with important implications for upscaling of point scale observations to field scale. The COSMOS performs well, but only captures changes in water content to a depth of around 20 cm, meaning that upscaling with depth is required to produce a field scale, root zone integrated estimation of soil moisture content. We compare three upscaling approaches.

  2. Sublethal effects of antibiosis resistance on the reproductive biology of two spittlebug (Hemiptera: Cercopidae) species affecting Brachiaria spp.

    PubMed

    Sotelo, Paola A; Miller, María F; Cardona, Cesar; Miles, John W; Sotelo, Guillermo; Montoya, James

    2008-04-01

    Several greenhouse experiments were used to measure how high levels of antibiosis resistance to nymphs in two interspecific Brachiaria (brachiariagrass) hybrids affect life history parameters of the spittlebugs Aeneolamia varia (F.) and Zulia carbonaria (Lallemand), two of the most important spittlebug (Hemiptera: Cercopidae) species affecting Brachiaria production in Colombia. The A. varia-resistant hybrid CIAT 36062, the Z. carbonaria-resistant hybrid SX01NO/0102, and the susceptible accession CIAT 0654 were used to compare the effect of all possible combinations of food sources for nymphs and adults. Calculation of growth indexes showed a significant impact of antibiosis resistance on the biology of immature stages of both species. Median survival times of adults feeding on resistant genotypes did not differ from those recorded on the susceptible genotype, suggesting that factors responsible for high mortality of nymphs in the resistant hybrids did not affect adult survival. Rearing nymphs of A. varia on CIAT 36062 and of Z. carbonaria on SX01NO/0102 had deleterious sublethal effects on the reproductive biology of resulting adult females. It is concluded that high nymphal mortality and subsequent sublethal effects of nymphal antibiosis on adults should have a major impact on the demography of the two spittlebug species studied. PMID:18459425

  3. CO2 balance of an intensively grazed temperate pasture during pasture renewal via cultivation or direct drilling

    NASA Astrophysics Data System (ADS)

    Rutledge, Susanna; Mudge, Paul; Wall, Aaron; Campbell, Dave; Schipper, Louis

    2015-04-01

    The management practice of pasture renewal (PR, also referred to as 'restoration') of permanent pastures offers the opportunity to replace low producing pasture, remove weeds and pests, improve drainage, and introduce improved pasture varieties, thereby increasing pasture production. PR can consist of a range of practices including spraying existing pasture with herbicide, followed by direct drilling or full cultivation (ploughing). Although PR is common in some farming systems, little is known about the impact of PR of permanent pastures on soil C and CO2 dynamics. Here we report on the CO2 balance following four PR events of intensively grazed permanent pastures in temperate New Zealand. Three events of PR followed the same method which included two herbicide sprays and a full cultivation (CULT). PR events took place in either spring or autumn, which meant soil moisture conditions varied greatly between PR events. For the fourth PR event, pasture was sprayed only once, and was not cultivated but instead seeds were directly drilled (DD) into the sprayed-off pasture. Chambers and the eddy covariance technique were used to measure the CO2 exchange before, during and after PR. In addition to the direct loss of CO2 measured during the PR events, we also quantified the 'net impact of PR' which we defined as the difference between net CO2 exchange of the pasture that underwent PR and that of an undisturbed pasture which served as a control. This way, we also accounted for the temporary lack of photosynthetic carbon inputs when plants were absent during the PR events. Both the rate of direct CO2 respiratory losses and the 'net impact of PR' appeared highly dependent on soil moisture status, with the lowest rate of loss measured under severe drought conditions and the highest rate of loss measured in spring when ample moisture was present. Because the rate of CO2 loss did not decrease over time during PR, the longer the soil was bare, the more CO2 was lost. The duration

  4. The motivation of dairy cows for access to pasture.

    PubMed

    Charlton, Gemma L; Rutter, S Mark; East, Martyn; Sinclair, Liam A

    2013-07-01

    Several factors influence whether dairy cattle prefer to be indoors or at pasture, including weather conditions and milk yield, but it is unclear how motivated cows are for access to pasture. One way to measure motivation is to require the animal to work (e.g., walk different distances) for access to a resource. This study investigated whether pasture access located 60, 140, or 260m from the indoor housing would affect the proportion of time dairy cows spent at pasture. Thirty-two Holstein-Friesian dairy cows were used during the study, which took place in the United Kingdom from May to July 2010. The experiment consisted of four 18-d experimental periods, with 8 cows in each period, which were further divided into 2 groups of 4 cows. Following a training period, the cows were randomly allocated to distances of 60, 140, or 260m to pasture over three 4-d measurement periods. A video camera was used to record time spent indoors and outdoors 24h/d, and manual behavior observations (0700 to 2200h) took place 6 times during each period to record how the cows spent their time in each location. The video data showed that cows spent, on average, 57.8% (±3.44) of their time outside (either at pasture or on the track). One-sample t-tests revealed that this value was different from 0% (t=16.80), 50% (t=2.26), and 100% (t=-12.28). Analysis of the percentage time spent outside revealed that distance did not influence nighttime pasture use (2100 to 0430h; F2,8=0.16; 81.0% vs. 81.0% vs. 76.7%, for 60m vs. 140m vs. 260m, respectively). In contrast, during the day (0700 to 2100h; from behavior observations), time spent at pasture declined as distance increased; that is, cows spent more time at pasture when they had to walk 60m (F2,80=10.09) than when they had to walk 140 or 260m (45.3% vs. 27.4% vs. 21.2%, respectively). Time spent at pasture decreased on rainy days (y=-1.0672x + 59.646, R(2)=0.09, n=48d), but the indoor temperature-humidity index (THI), the outdoor THI, and body

  5. Improvement of natural pastures using liquid organic fertilizers

    NASA Astrophysics Data System (ADS)

    Ghambashidze, Giorgi; Gabedava, Giorgi; Abuladze, Paata

    2016-04-01

    Nowadays natural pastures remains the main source to supply livestock with fresh feed material in Georgia. Due to that common pasturelands are under continues grazing pressure and normally no measures are taken in order to improve pasture productivity and to protect soil from erosion. Unregulated stocking rate leads to overutilization of natural pastures causing reduction in productivity and soil fertility. It is especially evident in arid regions, where bare soil after removal of vegetation dries out and is subject to wind erosion. In many areas even with regulated stocking rate plant available soil nutrient pool is already diminished and vegetation cannot be recovered easily after grazing. Therefore it is essential to improve soil fertility, which provide adequate amount of nutrients to plants to regenerate. Ongoing study aims to compare effect of different types of organic fertilizers on natural pastures in combination with pasture rotation scheme in order to maintain soil fertility and prepare the basis for its gradual improvement. Initial results shows positive impact of liquid organic fertilizers which increased aboveground biomass production by 200-300 kg per hectare.

  6. Factors affecting pasture intake and total dry matter intake in grazing dairy cows.

    PubMed

    Vazquez, O P; Smith, T R

    2000-10-01

    We investigated the most relevant variables for estimating pasture intake and total dry matter (DM) intake in grazing dairy cows using 27 previously published studies. Variables compared were pasture allowance, days in milk, amount of forage, amount of concentrate and total supplementation, pasture allowance and supplementation interaction, fat-corrected milk, body weight (BW), metabolic BW, daily change in BW, percentage of legumes in pasture, neutral detergent fiber (NDF) contents of pasture, and NDF in pasture selected. The variables were selected using stepwise regression analysis for total DM intake and pasture DM intake. Variables selected in the total DM intake regression equation (R2 = 0.95) were pasture allowance, total supplementation, interaction of pasture allowance and supplementation, fat-corrected milk, BW, daily change in BW, percentage of legumes and pasture NDF content. Pasture DM intake regression equation (R2 = 0.90) was similar to total DM intake equation, but supplementation coefficient was negative, showing substitution effect in supplementing grazing cows. The intake of NDF as a percentage of BW was higher than 1.3% when considering NDF content of the pasture allowance. Low pasture allowance groups had values higher than 1.3%. PMID:11049073

  7. Dryland pasture and crop conditions as seen by HCMM. [Oklahoma

    NASA Technical Reports Server (NTRS)

    Rosenthal, W. D. (Principal Investigator); Harlan, J. C.; Blanchard, B. J.

    1978-01-01

    The author has identified the following significant results. The soil moisture difference between the flight lines was partly due to water-holding capacity differences of the two soil types. Fields along the east flight line were in clay; while along the west flight line, the soil was sandy loam which holds less moisture. Due to differences in the amount of green material, the pastures were wetter than the wheat fields. Most of the pastures average from 40-80% green material, while wheat averages from 90-100% green material. A large amount of green material transpired more water and depleted the soil water content faster than dead vegetation. Visicorder data found temperature differences between the rangeland and winter wheat fields. Pasture had a larger percentage of dead material with different thermal properties than live vegetation, and surface temperature was primarily dependent on insolation. Dead material transpired less, but warms up faster than wheat fields.

  8. Greener Pastures in Northern Queensland, Australia

    NASA Technical Reports Server (NTRS)

    2004-01-01

    After a 19 month rainfall deficiency, heavy rainfall during January 2004 brought drought relief to much of northern Queensland. Local graziers hope for good long-term responses in pasture growth from the heavy rains. These images and maps from the Multi-angle Imaging SpectroRadiometer (MISR) portray part of Australia's Mitchell Grasslands bioregion before summer rainfall, on October 18, 2003 (left) and afterwards, on February 7, 2004 (right).

    The top pair of images are natural color views from MISR's nadir camera. The green areas in the post-rainfall image highlight the growth of vegetation. The middle panels show the reflectivity of the surface over the photosynthetically active region (PAR) of visible light (400 - 700 nm), expressed as a directional-hemispherical reflectance (DHR-PAR), or albedo. That portion of the radiation that is not reflected back to the atmosphere or space is absorbed by either the vegetation or the soil. The fraction of PAR radiation absorbed by green vegetation, known as FPAR, is shown in the bottom panels. FPAR is one of the quantities that establishes the photosynthetic and carbon uptake efficiency of live vegetation. MISR's FPAR product makes use of aerosol retrievals to correct for atmospheric scattering and absorption effects, and uses plant canopy structural models to determine the partitioning of solar radiation. Both of these aspects are facilitated by the multiangular nature of the MISR measurements.

    The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 20397 and 22028. The panels cover an area of about 290 kilometers x 228 kilometers, and utilize data from blocks 106 to 108 within World Reference System-2 path 96.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA

  9. Brachiaria ruziziensis responses to different fertilization doses and to the attack of Mahanarva spectabilis (Hemiptera: Cercopidae) nymphs and adults.

    PubMed

    Aguiar, Daniela de Melo; Auad, Alexander Machado; Fonseca, Marcy das Graças; Leite, Melissa Vieira

    2014-01-01

    Cropping practices are necessary in order to help reduce the population of pest insect, such as the induction of resistance through fertilization. Therefore, this study aimed to assess alterations on the production and quality of Brachiaria ruziziensis when receiving the fertilization composed by the macronutrients NPK and/or exposed to the attack of Mahanarva spectabilis nymphs and adults. B. ruziziensis plants were fertilized according to the recommendation (R), half of the recommended fertilization (H), or non-fertilization (C). They were also exposed to different M. spectabilis nymph and adult densities. The damage, regrowth, and bromatological components were evaluated. The fertilization treatment promoted a higher M. spectabilis nymph survival on B. ruziziensis; however, it reduced the damage caused by the forage exposed to nymphs and adults of pest insect, and it did not alter the quality of the signal grass. Moreover, the fertilization treatment enabled forage recovery, even when exposed to 5 nymphs or 10 spittlebug adults. PMID:24578645

  10. Brachiaria ruziziensis Responses to Different Fertilization Doses and to the Attack of Mahanarva spectabilis (Hemiptera: Cercopidae) Nymphs and Adults

    PubMed Central

    Aguiar, Daniela de Melo; Auad, Alexander Machado; Fonseca, Marcy das Graças; Leite, Melissa Vieira

    2014-01-01

    Cropping practices are necessary in order to help reduce the population of pest insect, such as the induction of resistance through fertilization. Therefore, this study aimed to assess alterations on the production and quality of Brachiaria ruziziensis when receiving the fertilization composed by the macronutrients NPK and/or exposed to the attack of Mahanarva spectabilis nymphs and adults. B. ruziziensis plants were fertilized according to the recommendation (R), half of the recommended fertilization (H), or non-fertilization (C). They were also exposed to different M. spectabilis nymph and adult densities. The damage, regrowth, and bromatological components were evaluated. The fertilization treatment promoted a higher M. spectabilis nymph survival on B. ruziziensis; however, it reduced the damage caused by the forage exposed to nymphs and adults of pest insect, and it did not alter the quality of the signal grass. Moreover, the fertilization treatment enabled forage recovery, even when exposed to 5 nymphs or 10 spittlebug adults. PMID:24578645

  11. Antibiosis and tolerance to five species of spittlebug (Homoptera: Cercopidae) in Brachiaria spp.: implications for breeding for resistance.

    PubMed

    Cardona, Cesar; Fory, Paola; Sotelo, Guillermo; Pabon, Alejandro; Diaz, Giovanna; Miles, John W

    2004-04-01

    Several genera and species of spittlebugs (Homoptera: Cercopidae) are economic pests of Brachiaria spp. grasses in tropical America. To support current breeding programs aimed at obtaining multiple spittlebug resistance, we undertook a series of studies on antibiosis and tolerance as possible mechanisms of resistance to five major spittlebug species affecting Brachiaria spp. in Colombia: Aeneolamia varia (F.), Aeneolamia reducta (Lallemand), Zulia carbonaria (Lallemand), Zulia pubescens (F.), and Mahanarva trifissa (Jacobi). Four host genotypes, well known for their reaction to A. varia attack, were used to compare their resistance to other spittlebug species: CIAT 0654 and CIAT 0606 (susceptible) and CIAT 6294 and CIAT 36062 (resistant). CIAT 0654 and CIAT 36062 were used in antibiosis studies. Tolerance studies were conducted with CIAT 0654, CIAT 6294, and CIAT 36062. Sixty-five hybrid-derived clones were used to identify levels of multiple resistance to three spittlebug species. The levels of antibiosis resistance in CIAT 36062 clearly differed by spittlebug species and were classified as follows: very high for M. trifissa, high for A. varia and A. reducta, moderate for Z. pubescens, and absent for Z. carbonaria. Our results suggest the presence of true tolerance to Z. carbonaria in CIAT 6294 and CIAT 36062, true tolerance to Z. pubescens in CIAT 6294 and a combination of tolerance and antibiosis as mechanisms of resistance to Z. pubescens in CIAT 36062. Of the 65 hybrid clones tested with A. varia, A. reducta, and Z. carbonaria, 15 combined resistance to two species and three showed antibiosis resistance to all three spittlebug species. PMID:15154493

  12. Effects of pasture renovation on hydrology, nutrient runoff, and forage yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proper pasture management is important in promoting optimal forage growth and reducing runoff and nutrient loss. Pasture renovation was performed prior to manure application (poultry litter or swine slurry) on different pasture soils and rainfall simulations were conducted to identify the effects o...

  13. Effect of mineral supplementation on the performance by stocker cattle grazing winter wheat pasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To evaluate the efficacy of mineral supplementing stocker cattle grazing wheat pasture, 2 experiments were conducted. In Exp 1, 72 steer and heifer calves (avg BW = 228 kg) were randomly assigned to 12, 4.9-ha pastures on November 12 at 1.2 calves/ha (4 pastures), and February 5 at 2.5 calves/ha (8...

  14. Regionalized levels of soil phosphorus and phosphorus saturation in beef cattle pastures with and without grazing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Available soil phosphorus (P) in various agro-ecosystems is regulated by climate, soil type, vegetation, and management practices. Available soil P in bahiagrass beef cattle pastures were compared with rhizoma peanut pastures and bermudagrass pastures. For each location, the pain plot was represente...

  15. SOIL PHOSPHOROUS SPATIAL DISTRIBUTION IN PASTURES RECEIVING POULTRY LITTER APPLICATIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Environmentally-based P management strategies could be improved by delineating management zones incorporating the effects of landscape position on soil morphology, hydrology, and soil P distribution. Three farm pasture sites in SW Missouri receiving long-term poultry litter applications were sampled...

  16. Cattle use patterns of riparian pastures in northeastern Oregon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock use of riparian areas has been fraught with controversy, with some arguing that livestock should be excluded while others emphasize the benefits of controlled grazing. Our study was designed to 1) characterize the nature of cattle grazing in riparian pastures, 2) determine intensity and s...

  17. Grazing management effects on pasture productivity – extent of grazing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    How does grazing using the “take half – leave half” rule actually affect annual pasture productivity? Is residue height a concern when mature grasses are mob grazed, a management alternative to grazing at a vegetative stage? A range of grazing management systems was implemented at the U.S. Dairy For...

  18. New Genomic Resources for Pasture and Range Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the initial requirements of utilizing genomic approaches in plant improvements is the availability of DNA sequence information. Toward the goal of generating sequence information for forage and pasture grasses, we are developing EST libraries from orchardgrass (Dactylis glomerata) and sever...

  19. Evaluating Pasture Grasses: Fescues and Other Freaks of Nature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Meadow fescue (Festuca pratensis Huds.) has excellent potential for grazing-based dairy and beef systems in Wisconsin, but producer awareness of this temperate grass is lacking. Previous research established that its intake potential is comparable or superior to other pasture grasses, and winter-ha...

  20. Canopy-Coverage Method Compares Pasture and Prairie

    ERIC Educational Resources Information Center

    Jantzen, Paul G.

    1973-01-01

    Describes the procedures used by a high school biology class in an ecological study related to the degeneration of grasslands. The canopy-coverage method of vegetational analysis was used to compare a low-grade, over-grazed pasture with a nearby high-quality prairie. An interpretation of the results is also presented. (JR)

  1. Comparison of Two Pasture Growth Models of Differing Complexity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two pasture growth models that share many common features but differ in model complexity have been developed for incorporation into the Integrated Farm System Model (IFSM). Major differences between models include the explicit representation of roots in the more complex model, and their effects on c...

  2. Ecosystem carbon-water interactions of tropical pasture and afforestation

    NASA Astrophysics Data System (ADS)

    Wolf, S.; Eugster, W.; Buchmann, N.

    2010-12-01

    Despite the importance of tropical ecosystems for global carbon and water cycling, eddy covariance flux measurements in the tropics are still scarce and globally underrepresented within FLUXNET. In addition, previous studies have been predominantly conducted in tropical forests with only very few observations, often unpublished, from other tropical land-use types like pastures, croplands and savannas. As recently emphasized by global synthesis activities, C4 dominated ecosystems account for more than 20 % of terrestrial gross primary production (GPP) but represent less than 20 site-years of data within FLUXNET. Consequently, an expansion of observations for tropical C4 ecosystems is needed to understand their role in the global carbon and water cycling. We have performed comparative eddy covariance measurements of carbon dioxide and water vapour fluxes in a tropical pasture and an adjacent, young afforestation in Panama from 2007 to 2009. Our results show a larger intra-annual variability of CO2 and H2O fluxes at the pasture compared to the afforestation. In addition, the tropical pasture was more sensitive to water limitations and seasonal drought. Moreover, observed differences in water use efficiency (WUE) between both ecosystems tend to become smaller after the establishment phase of the afforestation. Our results highlight the role of land management on ecosystem carbon and water fluxes in the tropics. Implications of our results for further research and synthesis activities will be discussed.

  3. Utilization of Pasture and Forages by Ruminants: A Historical Perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pastures, forages and grasslands dominate the landscape across the United States and support a large ruminant population that supplies the nation with value-added animal products. An historical perspective is presented of the innovations as they occurred in the Journal of Animal Science over the pas...

  4. Using lake dredged material to enhance pasture establishment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cow-calf (Bos taurus) industry in subtropical United States and other parts of the world depends almost totally on grazed pastures. Establishment of complete, uniform stand of bahiagrass in a short time period is vital economically. Domestic wastewater sludge or sewage sludge, composted urban pl...

  5. Reestablishing Chicory into Multi-Species Perennial Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chicory (Cichorium intybus L.) has the potential to provide abundant, high quality forage during periods of drought stress, but poor persistence limits its usefulness in permanent pasture. This experiment compared the ability of three seeding methods to reestablish chicory into a grazed multi-specie...

  6. Heifer growth performance from fall-oat pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fall-grown oat has shown promise as an emergency fall forage option, or to extend the grazing season in Wisconsin. Our objectives for this project were: i) to assess the pasture productivity and forage characteristics of 2 fall-grown oat cultivars (Ogle and ForagePlus; OG and FP, respectively) using...

  7. Leveraging the beneficial compounds of organic and pasture milk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much discussion has arisen over the possible benefits of organic food, including milk. Organic milk comes from cows that are on pasture during the growing season, and would be expected to contain some compounds that are not found in animals receiving conventional feed, or at higher concentrations. ...

  8. Sediment carbon concentration and transport from small pastured watersheds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the current emphasis on the role of carbon in the environment, agricultural systems and their impacts on the carbon cycle are important parts of the overall issue. Pasture systems and carbon that is transported attached to sediment has been addressed at the North Appalachian Experimental Waters...

  9. Utilization of Pasture Seed Mixtures in the Northeast USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Terms such as “plant species diversity” and “species mixture complexity” are used to describe and quantify characteristics of plant communities found in pastures, and have drawn increased attention from the scientific community. Livestock producers use many methods to alter these characteristics in...

  10. Distribution of cattle grazing in a northeastern Oregon riparian pasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock grazing of a northeastern Oregon riparian pasture was monitored using high-frequency GPS tracking of cattle and high-resolution aerial photography. Tracking collars recorded positions, velocity, date, and time at 1-sec intervals. Areas where animals rested and moved were identified and re...

  11. Nutritive value in relation to plant species diversity of pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Planting forage mixtures may benefit pasture herbage production; however, changes in botanical composition could cause unstable nutritive value. Data from two grazing studies and a farm survey were used to examine how plant species diversity influenced herbage nutritive value. In one grazing study,...

  12. Fact Sheet: Tapping into the pasture seed bank

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A seed bank is a reserve of dormant seeds in the soil that enables some types of plants to re-establish themselves after a drastic disturbance of the established vegetation. In some ways it forms a “memory” for the pasture, a record of its vegetation history. To explore that history, we visited seve...

  13. Soil nitrogen and carbon impacts of raising chickens on pasture

    NASA Astrophysics Data System (ADS)

    Ryals, R.; Leach, A.; Tang, J.; Hastings, M. G.; Galloway, J. N.

    2014-12-01

    Chicken is the most consumed meat in the US, and production continues to intensify rapidly around the world. Chicken manure from confined feeding operations is typically applied in its raw form to nearby croplands, resulting in hotspots of soil nitrous oxide (N2O) emissions. Pasture-raised chicken is an alternative to industrial production and is growing in popularity with rising consumer demand for more humanely raised protein sources. In this agricultural model, manure is deposited directly onto grassland soils where it is thought to increase pools of soil carbon and nitrogen. The fate of manure nitrogen from pasture-raised chicken production remains poorly understood. We conducted a controlled, replicated experiment on a permaculture farm in Charlottesville, Virginia (Timbercreek Organics) in which small chicken coops (10 ft x 12 ft) were moved daily in a pasture. We measured manure deposition rates, soil inorganic nitrogen pools, soil moisture, and soil N2O and CO2 emissions. Measurements were made for the 28-day pasture life of three separate flocks of chickens in the spring, summer, and fall. Each flock consisted of approximately 200-300 chickens occupying three to five coops (~65 chickens/coop). Measurements were also made in paired ungrazed control plots. Manure deposition rates were similar across flocks and averaged 1.5 kgdrywt ha-1 during the spring grazing event and 4.0 kgdrywt ha-1 during the summer and fall grazing events. Manure deposition was relatively constant over the four weeks pasture-lifetime of the chickens. Compared to control plots, grazed areas exhibited higher soil N2O and CO2 fluxes. The magnitude of these fluxes diminished significantly over the four-week span. Soil gas fluxes significantly increased following rainfall events. For a given rainfall event, higher fluxes were observed from transects that were grazed more recently. Soil gaseous reactive nitrogen losses were less in this pasture system compared to cultivated field amended

  14. Eastern Gamagrass Management for Pastures in the Mid-Atlantic Region: I. Animal Performance and Pasture Productivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eastern gamagrass [Tripsacum dactyloides (L.) L.] is a native, warm-season perennial grass with potential as pasture for the eastern USA, but its value has not been well studied. The objective of this 4-yr experiment was to estimate forage mass (FM) for eastern gamagrass (EG) that maximizes steer pe...

  15. Forages and pastures symposium: fungal endophytes of tall fescue and perennial ryegrass: pasture friend or foe?

    PubMed

    Young, C A; Hume, D E; McCulley, R L

    2013-05-01

    Tall fescue [Lolium arundinaceum (Schreb.) Darbysh. syn. Festuca arundinacea Schreb.] and perennial ryegrass (Lolium perenne L.) are important perennial forage grasses utilized throughout the moderate- to high-rainfall temperate zones of the world. These grasses have coevolved with symbiotic fungal endophytes (Epichloë/Neotyphodium spp.) that can impart bioactive properties and environmental stress tolerance to the grass compared with endophyte-free individuals. These endophytes have proven to be very important in pastoral agriculture in the United States, New Zealand, and Australia, where forage grasses are the principal feed for grazing ruminants. In this review, we describe the biology of these grass-endophyte associations and implications for the livestock industries that are dependent on these forages. Endophyte alkaloid production is put in context with endophyte diversity, and we illustrate how this has facilitated utilization of grasses infected with different endophyte strains that reduce livestock toxicity issues. Utilization of tall fescue and use of perennial ryegrass in the United States, New Zealand, and Australia are compared, and management strategies focused predominantly on the success of endophyte-infected perennial ryegrass in New Zealand and Australia are discussed. In addition, we consider the impact of grass-endophyte associations on the sustainability of pasture ecosystems and their likely response to future changes in climate. PMID:23307839

  16. [Morphological and molecular identification of Prosapia simulans (Walker) (Hemiptera: Cercopidae), and screening and mechanisms of resistance to this spittlebug in Brachiaria hybrids].

    PubMed

    Castro, Ulises; Cardona, Cesar; Vera-Graziano, Jorge; Miles, John; Garza-Garcia, Ramón

    2007-01-01

    Prosapia simulans (Walker) is an important spittlebug species that attacks forage grasses of the genus Brachiaria (Trin.) Griseb. from Mexico to Colombia. This, and several other species of spittlebugs, cause important economic losses to the livestock production industry. Development of resistant cultivars is regarded as the best method of control. In the present study we used taxonomic keys, dissection of male genitalia and RAPD-PCR patterns to reconfirm the identity of P. simulans specimens collected in Colombia and Mexico. We were able to reconfirm that P. simulans occurs as a pest of Brachiaria from Mexico to Colombia. We also studied the levels and mechanisms of resistance present in 34 Brachiaria hybrids developed by CIAT. Infestations were made with six eggs per plant. We used 10 replications (plants) per genotype in a completely randomized design. Seven hybrids were found to be susceptible, 16 showed intermediate resistance and 11 were resistant. Antibiosis was the mechanism of resistance expressed in resistant hybrids as well as in the resistant checks CIAT 6294 and CIAT 36062. Tolerance was absent. The genotypes BRX 4402 and CIAT 0606 were classified as highly susceptible. PMID:17934620

  17. Controlling runoff from subtropical pastures has differential effects on nitrogen and phosphorus loads.

    PubMed

    Bohlen, Patrick J; Villapando, Odi R

    2011-01-01

    A 4-yr (2005-2008) study was conducted to evaluate the potential of pasture water management for controlling nutrient losses in surface runoff in the Northern Everglades. Two pasture water management treatments were investigated on Bahia grass ( Flüggé) pastures: reduced flow and unobstructed flow. The reduced flow treatment was applied to four of eight 20.23-ha pastures by installing water control structures in pasture drainage ditches with flashboards set at a predetermined height. Four other pastures received the unobstructed-flow treatment, in which surface runoff exited pastures unimpeded. Automated instruments measured runoff volume and collected surface water samples for nutrient analysis. In analyzing data for before-after treatment analysis, the 2005 results were removed because of structural failure in water control structures and the 2007 results were removed because of drought conditions. Pasture water retention significantly reduced annual total nitrogen (TN) loads, which were 11.28 kg ha and 6.28 kg ha, respectively, in pastures with unobstructed and reduced flow. Total phosphorus (TP) loads were 27% lower in pastures with reduced flow than in pastures with unobstructed flow, but this difference was not statistically significant. Concentrations of available soil P were significantly greater in pastures with reduced flow. Pasture water retention appears to be an effective approach for reducing runoff volume and TN loads from cattle pastures in the Northern Everglades, but the potential to reduce TP loads may be diminished if higher water table conditions cause increased P release from soils, which could result in higher P concentration in surface runoff. PMID:21546685

  18. Pasture Drought Insurance Based on NDVI and SAVI

    NASA Astrophysics Data System (ADS)

    Escribano Rodríguez, J. A.; Tarquis, A. M.; Hernandez Díaz-Ambrona, C. G.

    2012-04-01

    Drought is a complex phenomenon, which is difficult to define. The term is used to refer to deficiency in rainfall, soil moisture, vegetation greenness, ecological conditions or socio economic conditions, and different drought types can be inferred. In this study, drought is considered as a period when the pasture growth is low in regard to long-term average conditions. The extensive livestock production is based on the natural resources available. The good management practices concurs the maximum livestock nutrition needs with the maximum pasture availability. Therefore, early drought detection and impact assessment on the amount of pasture biomass are important in several areas in Spain, whose economy strongly depends on livestock production. The use of remote sensing data presents a number of advantages when determining drought impact on vegetation. The information covers the whole of a territory and the repetition of images provides multi-temporal measurements. In addition, vegetation indexes, being NDVI (normalized difference vegetation index) and SAVI (soil-adjusted vegetation index) the most common ones, obtainedfrom satellite data allow areas affected by droughts to be identified. These indices are being used for estimation of vegetation photosynthesis activity and monitoring drought. The present study shows the application of these vegetation indices for pasture drought monitoring in three places in Spain and their correlation with several field measurements. During 2010 and 2011 three locations, El Cubo de Don Sancho (Salamanca), Trujillo (Cáceres) and Pozoblanco (Córdoba), were selected and a periodic pasture monitoring and botanic composition were achieved. Daily precipitation, temperature and monthly soil water content were measurement as well as fresh and dry pasture weight. At the same time, remote sensing images were capture by DEIMOS-1 of the chosen places.This satellite is based on the concept Microsat-100 from Surrey. It is conceived for

  19. Pasture trees in tropical México: the effect of soil nutrients on seedling growth.

    PubMed

    Martínez-Sáanchez, José Luis

    2006-06-01

    Environment and seedling community under isolated trees in pastures are different from those in the open pasture. The effect of the pasture trees on the soil nutrients and on the seedling growth were investigated. Seven isolated trees and eight plots were selected in two pastures of 12-yr and 32-yr old derived from a lowland rain forest with nutrient-rich soil at Los Tuxtlas, Mexico. The soil concentrations of total N, P Bray, K+, Na+, Ca2+ and Mg2+, plus others physical and chemical characteristics, were compared between the pasture trees and the open-pasture. An experiment was done to test the hypothesis that soil from under the pasture trees was better for seedling growth than soil from the open pasture. Seedlings of two native tree species and two domesticated species were grown in soil from the two different sites in a shade-house. The dry weight of the shoot and root/shoot ratio were compared. Only total N, P and Na+ differed slightly in concentrations between the sites, but did not promote more seedling biomass. It seems that the soil at this location is sufficiently nutrient-rich even in the open pastures and over-ride any effect of the pasture trees on nutrient availability. PMID:18494306

  20. Rumen conditions that predispose cattle to pasture bloat.

    PubMed

    Majak, W; Howarth, R E; Cheng, K J; Hall, J W

    1983-08-01

    Rumen contents from the dorsal sac were examined before alfalfa ingestion to determine factors that predispose cattle to pasture bloat. Chlorophyll concentration, buoyancy of particulate matter, and rates of gas production were significantly higher in cattle that subsequently bloated than in those that did not. Higher chlorophyll in bloat cases indicated accumulation of suspended chloroplast particles in the dorsal sac, perhaps due to increased buoyancy of the particulate matter. The higher fermentation rates (in the presence of glucose) suggested that the latent capacity for gas production was due to microbial colonization of suspended feed particles. Chlorophyll 4 h after feeding was also higher in bloated as compared to unbloated animals. In short, the microbial colonization and retention of particulate matter provided active inocula for promoting rapid legume digestion. Consequently, gas production was enhanced when feeding commenced, but the fermentation gases were trapped by the buoyant, frothy ingesta, resulting in the condition of pasture bloat. PMID:6619348

  1. Influence of transient flooding on methane fluxes from subtropical pastures

    NASA Astrophysics Data System (ADS)

    Chamberlain, Samuel D.; Gomez-Casanovas, Nuria; Walter, M. Todd; Boughton, Elizabeth H.; Bernacchi, Carl J.; DeLucia, Evan H.; Groffman, Peter M.; Keel, Earl W.; Sparks, Jed P.

    2016-03-01

    Seasonally flooded subtropical pastures are major methane (CH4) sources, where transient flooding drives episodic and high-magnitude emissions from the underlying landscape. Understanding the mechanisms that drive these patterns is needed to better understand pasture CH4 emissions and their response to global change. We investigated belowground CH4 dynamics in relation to surface fluxes using laboratory water table manipulations and compared these results to field-based eddy covariance measurements to link within-soil CH4 dynamics to ecosystem fluxes. Ecosystem CH4 fluxes lag flooding events, and this dynamic was replicated in laboratory experiments. In both cases, peak emissions were observed during water table recession. Flooding of surface organic soils and precipitation driven oxygen pulses best explained the observed time lags. Precipitation oxygen pulses likely delay CH4 emissions until groundwater dissolved oxygen is consumed, and emissions were temporally linked to CH4 production in surface soil horizons. Methane accumulating in deep soils did not contribute to surface fluxes and is likely oxidized within the soil profile. Methane production rates in surface organic soils were also orders of magnitude higher than in deep mineral soils, suggesting that over longer flooding regimes CH4 produced in deep horizons is not a significant component of surface emissions. Our results demonstrate that distinct CH4 dynamics may be stratified by depth and flooding of surface organic soils drives CH4 fluxes from subtropical pastures. These results suggest that small changes in pasture water table dynamics can drive large changes in CH4 emissions if surface soils remain saturated over longer time scales.

  2. Soil fertility management on natural pastures in Eastern Georgia

    NASA Astrophysics Data System (ADS)

    Ghambashidze, Giorgi; Jolokhava, Tamar; Kenchiashvili, Naira; Tarkhnishvili, Maia

    2015-04-01

    The development of livestock production in Georgia is mainly based on productivity of natural common pasturelands as it is the cheapest way to keep animals. Therefore it is crucial to manage those pastures in order to supply domestic animals with adequate amount of green grass during whole grazing season. The problems associated with poor grassland management is especially evident under limited rainfall conditions. Usually farmers do not consider suitability of existing stocking rates with pasture productivity leading to overutilization of pastureland causing reduction of palatable plant species and total grass cover stimulating soil erosion processes, which deflates soil nutrients and soil organic matter. Intensification of negative processes may result in loss of soil fertility and poor grass regrowth capacities. Current study aims to evaluate existing grazing system on a selected plots from common pasturelands in Eastern Georgia and to develop a proper soil fertility management plan accepted in organic agriculture taking into account local soil-climatic conditions, pasture vegetation stand and its richness with palatable plant species.

  3. How many adults of Mahanarva spectabilis (Hemiptera: Cercopidae) should be used for screening Brachiaria ruziziensis (Poales: Poaceae) resistance?

    PubMed

    Resende, T T; Auad, A M; Fonseca, M G

    2014-02-01

    This study determined the number of spittlebug adults, Mahanarva spectabilis Distant (Hemiptera: Cercopidae), that should be used in selection tests of the forage grass, Brachiaria ruziziensis (Germain and Evrard). In this study, 0, 1, 2, 4, or 8 M. spectabilis adults were kept in plants for 4 or 8 d per experimental plot. After these periods, the insects were removed from the plants and chlorophyll content, damage score, dry weight, fresh weight, and percent dry matter of shoots were evaluated. Chlorophyll content decreased significantly with higher density of M. spectabilis in plants exposed to the pest for 4 or 8 d. Plants that were exposed to eight spittlebugs for 8 d showed a approximately 60% loss of chlorophyll content. When the forage was infested with eight adults for 4 d, the average damage score was 3 (50% of the leaf area was affected). The damage score and fresh and dry weights of the forage did not change depending on the exposure time of the plants to the spittlebugs. The percentage of dry matter of the plants infested was higher with the increase insect density and exposure time for all densities. Thus, the minimum recommended number is eight M. spectabilis adults for 4 d in resistance tests of B. ruziziensis to this pest species. PMID:24665725

  4. Effect of stocking rate on milk and pasture productivity and supplementary feed use for spring calving pasture fed dairy systems.

    PubMed

    Patton, D; Pierce, K M; Horan, B

    2016-07-01

    The productivity of grazing systems is primarily limited by the scale and efficiency of systems applied to the grazable land platform adjacent to the milking parlor. The objective of this study was to compare forage production, utilization and quality, milk production, and requirement for supplementary feeds for 2 different grazing platform stocking rate (GPSR) treatments over 4 yr. Animals were randomly allocated to 1 of 2 GPSR treatments: high-closed (HC; 3.1 cows/ha) and high-open (HO; 4.5 cows/ha), which were designed to represent alternative GPSR in a post-European Union milk quota, spring calving, pasture-based milk production system. Animal production data were analyzed using Proc MIXED of SAS with GPSR, year, and parity included as fixed effects in the final model. Within a seasonal spring calving grazing system, at high GPSR and offering moderate amounts of additional supplements based on pasture supply deficits, both systems produced more milk and fat plus protein per hectare in comparison with Irish commercial dairy farms. Although requiring additional supplementation, increased GPSR resulted in increased milk production per hectare but also in an increased requirement for concentrate and forage supplementation during lactation. No significant influence of GPSR was found on body weight and body condition score or reproductive performance during the 4-yr study period. In addition, GPSR also had no effect on pasture production, utilization, or quality during the study period. The strategic use of additional supplements with restricted pasture availability at higher GPSR maintained milk production per cow and significantly increased milk production per hectare. PMID:27108176

  5. Pasture Management Strategies for Sequestering Soil Carbon - Final Report

    SciTech Connect

    Franzluebbers, Alan J.

    2006-03-15

    Pasturelands account for 51 of the 212 Mha of privately held grazing land in the USA. Tall fescue is the most important cool-season perennial forage for many beef cattle producers in the humid region of the USA. A fungal endophyte, Neotyphodium coenophialum, infects the majority of tall fescue stands with a mutualistic association. Ergot alkaloids produced by the endophyte have negative impacts on cattle performance. However, there are indications that endophyte infection of tall fescue is a necessary component of productive and persistent pasture ecology. The objectives of this research were to characterize and quantify changes in soil organic carbon and associated soil properties under tall fescue pastures with and without endophyte infection of grass. Pastures with high endophyte infection had greater concentration of soil organic carbon, but lower concentration of biologically active soil carbon than pastures with low endophyte infection. A controlled experiment suggested that endophyte-infected leaf tissue may directly inhibit the activity of soil microorganisms. Carbon forms of soil organic matter were negatively affected and nitrogen forms were positively affected by endophyte addition to soil. The chemical compounds in endophyte-infected tall fescue (ergot alkaloids) that are responsible for animal health disorders were found in soil, suggesting that these chemicals might be persistent in the environment. Future research is needed to determine whether ergot alkaloids or some other chemicals are responsible for increases in soil organic matter. Scientists will be able to use this information to better understand the ecological impacts of animals grazing tall fescue, and possibly to identify and cultivate other similar associations for improving soil organic matter storage. Another experiment suggested that both dry matter production and soil microbial activity could be affected by the endophyte. Sampling of the cumulative effects of 20 years of tall fescue

  6. Carbon fluxes of Kobresia pygmaea pastures on the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Babel, Wolfgang; Biermann, Tobias; Falge, Eva; Ingrisch, Johannes; Leonbacher, Jürgen; Schleuss, Per; Kuzyakov, Yakov; Ma, Yaoming; Miehe, Georg; Foken, Thomas

    2014-05-01

    With an approximate cover of 450,000 km² on the Tibetan Plateau (TP), the Cyperaceae Kobresia pygmaea forms he world's largest alpine ecosystem. This species, especially adapted to grazing pressure, grows to a height of only 2-6 cm and can be found in an altitudinal range of 4000 to 5960 m a.s.l. A special characteristic of this ecosystem is the stable turf layer, which is built up from roots and plays a significant role in protecting soil from erosion. This is of great importance since soils on the TP store 2.5 % of the global soil organic carbon stocks. The aim of the investigation was the study of the carbon storage and the impact of human-induced land use change on these Kobresia pygmaea pastures. We therefore applied eddy-covariance measurements and modelling as a long-term control of the fluxes between the atmosphere and the pastures and 13C labelling for the investigation of flux partitioning, and chamber measurements to investigate the degradation of the pastures. Combining CO2 budgets observed in 2010 with eddy-covariance measurements and relative partitioning of carbon fluxes estimated with 13C labelling enabled us to characterise the C turnover for the vegetation period with absolute fluxes within the plant-soil-atmosphere continuum. These results revealed that this ecosystem indeed stores a great amount of C in below-ground pools, especially in the root turf layer. To further investigate the importance of the root layer, the experiments in 2012 focused on flux measurements over the different surface types which make up the heterogeneity of the Kobresia pygmaea pastures and might result from degradation due to extensive grazing. The three surface types investigated with a LiCOR long-term monitoring chamber system include Kobresia pygmaea with intact turf layer (IRM), a surface type where the turf layer is still present but the vegetation is sparse and mainly consists of Cryptogam crusts (DRM) and finally areas without the turf layer (BS). According to

  7. Digestible energy content of pasture species in growing European wild boar (Sus scrofa L.).

    PubMed

    Quijada, R P; Bitsch, N I; Hodgkinson, S M

    2012-06-01

    The objectives were to determine the apparent energy digestibility of six pasture species frequently grazed by European wild boar (Sus scrofa L.) and to estimate the digestible energy (DE) consumption from pasture by grazing wild boar. Seven diets were prepared; a base diet (BD) which did not contain any pasture species, diets D1 to D5 which included 75% of the BD and 25% of the dried pasture species Lolium perenne (D1), Festuca arundinacea (D2), Agrostis capillaris (D3), Bromus staminius (D4) or Trifolium repens (D5) and D6 which contained 85% BD and 15% dried Plantago lanceolata. Seven purebred European wild boar (initial liveweight 24.4 ± 0.8 kg, average ± SEM) were given access to the diets following a Latin Square design. The animals received each diet for eight days, with faecal sampling on days 6, 7 and 8. The total apparent DE consumption from pasture by grazing wild boar was estimated using previously collected pasture consumption data from wild boar. The digestibility coefficients and DE contents of the pasture species ranged from 0.29 to 0.65, and 5.8 to 12.6 MJ/kg DM respectively, with L. perenne and P. lanceolata having the greatest digestibility coefficients and DE contents. The wild boar were estimated to satisfy between 52% and 142% of their maintenance energy requirements through pasture consumption. Grazing wild boar are able to utilise an important proportion of the energy present in pasture species. PMID:21575078

  8. Breeding objectives for sheep should be customised depending on variation in pasture growth across years.

    PubMed

    Rose, G; Mulder, H A; Thompson, A N; van der Werf, J H J; van Arendonk, J A M

    2015-08-01

    Breeding programmes for livestock require economic weights for traits that reflect the most profitable animal in a given production system, which affect the response in each trait after selection. The profitability of sheep production systems is affected by changes in pasture growth as well as grain, meat and wool prices between seasons and across years. Annual pasture growth varies between regions within Australia's Mediterranean climate zone from low growth with long periods of drought to high growth with shorter periods of drought. Therefore, the objective of this study was to assess whether breeding objectives need to be adapted for regions, depending on how reliable the pasture growth is across years. We modelled farms with Merino sheep bred for wool and meat in 10 regions in Western Australia. Across these 10 regions, mean annual pasture growth decreased, and the CV of annual pasture growth increased as pasture growth for regions became less reliable. We calculated economic values for nine traits, optimising management across 11 years, including variation for pasture growth and wool, meat and grain prices between and within years from 2002 to 2012. These economic values were used to calculate responses to selection for each trait for the 10 regions. We identified two potential breeding objectives, one for regions with low or high reliability and the other for regions with medium reliability of pasture growth. Breeding objectives for high or low pasture growth reliability had more emphasis on live weight traits and number of lambs weaned. Breeding objectives for medium reliability of pasture growth had more emphasis on decreasing fibre diameter. Relative economic weights for fleece weight did not change across the regions. Regions with low or high pasture reliability had similar breeding objectives and response to selection, because the relationship between the economic values and CV of pasture growth were not linear for live weight traits and the number of

  9. Biomass estimation to support pasture management in Niger

    NASA Astrophysics Data System (ADS)

    Schucknecht, A.; Meroni, M.; Kayitakire, F.; Rembold, F.; Boureima, A.

    2015-04-01

    Livestock plays a central economic role in Niger, but it is highly vulnerable due to the high inter-annual variability of rain and hence pasture production. This study aims to develop an approach for mapping pasture biomass production to support activities of the Niger Ministry of Livestock for effective pasture management. Our approach utilises the observed spatiotemporal variability of biomass production to build a predictive model based on ground and remote sensing data for the period 1998-2012. Measured biomass (63 sites) at the end of the growing season was used for the model parameterisation. The seasonal cumulative Fraction of Absorbed Photosynthetically Active Radiation (CFAPAR), calculated from 10-day image composites of SPOT-VEGETATION FAPAR, was computed as a phenology-tuned proxy of biomass production. A linear regression model was tested aggregating field data at different levels (global, department, agro-ecological zone, and intersection of agro-ecological and department units) and subjected to a cross validation (cv) by leaving one full year out. An increased complexity (i.e. spatial detail) of the model increased the estimation performances indicating the potential relevance of additional and spatially heterogeneous agro-ecological characteristics for the relationship between herbaceous biomass at the end of the season and CFAPAR. The model using the department aggregation yielded the best trade-off between model complexity and predictive power (R2 = 0.55, R2cv = 0.48). The proposed approach can be used to timely produce maps of estimated biomass at the end of the growing season before ground point measurements are made available.

  10. Response of resistant and susceptible Brachiaria spp. genotypes to simultaneous infestation with multiple species of spittlebugs (Hemiptera: Cercopidae).

    PubMed

    Pabón, Alejandro; Cardona, Cesar; Miles, John W; Sotelo, Guillermo

    2007-12-01

    The response of one susceptible and three resistant Brachiaria spp. (Hemiptera: Cercopidae) genotypes to individual or combined attacks by nymphs of Aeneolamia varia (F.), Aeneolamia reducta (Lallemand), Zulia carbonaria (Lallemand), and Zulia pubescens (F.) was studied. We assessed the effect of infesting plants of the susceptible check BRX 44-02 and of the A. varia-resistant genotypes CIAT 6294 and CIAT 36062 with A. varia, Z. carbonaria, or Z. pubescens either alone or in two-species combinations. In a second trial, we studied the performance of BRX 44-02, CIAT 6294, and the multiple resistant clone SX01NO/0102 exposed to individual or combined attack by A. reducta and Z. carbonaria. In a third trial, we compared the response of BRX 44-02, CIAT 6294, and CIAT 36062 to individual A. varia, Z. carbonaria, or Z. pubescens attack as opposed to a combined three-species attack. Plant damage scores and percentage of nymphal survival were recorded in all three trials. Data on percentage of survival indicated that competition between and among spittlebug species occurs. However, we found no evidence of interaction between species competition and different levels of resistance to spittlebug. Rather, host genotype reactions conformed to previously known categories of resistance regardless of the presence of more than one spittlebug species. Resistance rather than competition seems to have been the overriding factor determining nymph survival and resistance expression (damage scores) in these experiments. Our results corroborate the need to develop brachiariagrass genotypes with multiple resistance to spittlebugs. PMID:18232408

  11. Effects of biostimulation and nutritional supplementation on pubertal age and pregnancy rates of Nelore heifers (Bos indicus) in a tropical environment.

    PubMed

    Oliveira, C M G; Oliveira Filho, B D; Gambarini, M L; Viu, M A O; Lopes, D T; Sousa, A P F

    2009-07-01

    To determine effects of biostimulation (BIO) and dietary supplementation (BIO+S) on pubertal age and pregnancy rates, Nelore heifers (n=392) were randomly assigned to one of four treatment groups (n=98/group). All animals were in tropical environmental conditions, in the middle-west region of Brazil, grazing in pastures of Brachiaria brizantha, cv. Marandu; Panicum Maximum, cv. Tanzânia and Brachiaria humidícula. The heifers of the BIO group were kept in the presence of bulls while being maintained on pasture; the animals in the BIO+S group were kept in the presence of bulls while being managed on pasture and were fed a diet with greater energy and protein content to produce 0.49 kg of BW gain/day; the animals in control group (the NBIO) were kept away from bulls and under pasture conditions; and the animals in the NBIO+S group were kept away from bulls, were maintained on pasture, and were fed the same diet as the BIO+S group. Heifers were bred at 22-23 months of age, and pregnancy diagnosis was made 45 days after the end of the breeding season. There were differences (P<0.05) between groups regarding pubertal heifers up to 19 months (NPH), final body weight (FBW) and pregnancy rates (P<0.01), with an advantage for the animals in the BIO and BIO+S groups. Although the effect of a diet with greater protein and energy content was not clear in this experiment, the exposure of heifers to a male during the prepubertal period decreased age at the first breeding season, resulting in a significant reduction in age of first pregnancy in Nelore heifers kept under extensive management systems in a tropical environment. PMID:18805660

  12. ESTIMATION OF FORAGE NITROGEN CONCENTRATION AND IN VITRO DRY MATTER DIGESTIBILITY OF GRASS PASTURES USING PLANT CANOPY HYPERSPECTRAL REFLECTANCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Timely assessment of forage nitrogen (N) concentration and in vitro dry matter digestibility (IVDMD) during the growing season can help livestock managers make decisions for adjusting stocking rate and managing pastures. Nondestructive measurements of pasture canopy hyperspectral reflectance may pro...

  13. Influence of land-use change on near-surface hydrological processes: Undisturbed forest to pasture

    NASA Astrophysics Data System (ADS)

    Germer, Sonja; Neill, Christopher; Krusche, Alex V.; Elsenbeer, Helmut

    2010-01-01

    SummarySoil compaction that follows the clearing of tropical forest for cattle pasture is associated with lower soil hydraulic conductivity and increased frequency and volume of overland flow. We investigated the frequency of perched water tables, overland flow and stormflow in an Amazon forest and in an adjacent 25-year-old pasture cleared from the same forest. We compared the results with the frequencies of these phenomena estimated from comparisons of rainfall intensity and soil hydraulic conductivity. The frequency of perched water tables based on rainfall intensity and soil hydraulic conductivity was expected to double in pasture compared with forest. This corresponded closely with an approximate doubling of the frequency of stormflow and overland flow in pasture. In contrast, the stormflow volume in pasture increased 17-fold. This disproportional increase of stormflow resulted from overland flow generation over large areas of pasture, while overland flow generation in the forest was spatially limited and was observed only very near the stream channel. In both catchments, stormflow was generated by saturation excess because of perched water tables and near-surface groundwater levels. Stormflow was occasionally generated in the forest by rapid return flow from macropores, while slow return flow from a continuous perched water table was more common in the pasture. These results suggest that deforestation for pasture alters fundamental mechanisms of stormflow generation and may increase runoff volumes over wide regions of Amazonia.

  14. Monitoring Pasture Production in Mamawatu, New Zealand, Using Proba-V Data

    NASA Astrophysics Data System (ADS)

    Tuohy, Mike; Mansion, Valentin

    2015-12-01

    The Enhanced Vegetation Index (EVI) was calculated from Proba-V data over 18 months (S10) and 12 months (S5). These values were compared with pasture biomass as measured by weekly farm rides on a 4WD towing the Rapid Pasture Meter. Trends in the data were well matched, especially during the summer and after rain in autumn.

  15. Seed bank characterization of pastures and hayfields of the University of New Hampshire Organic Dairy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Buried seed in pasture soils are often reservoirs of weedy plants. The seed bank was characterized in pastures and hayfields with different management histories at the University of New Hampshire Organic Research Dairy. Three hayfields [two of alfalfa (Medicago sativa L.) and one grass] and five pas...

  16. THE SALEM ROAD STUDY: RESTORATION OF DEGRADED LAND WITH PASTURE - SOIL QUALITY AND CARBON SEQUESTRATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pasture management is of importance to the understanding of agronomic and animal productivity, soil quality, greenhouse gas emissions, and environmental quality. Pastures have the potential to serve as a significant sink for C sequestered in soil organic matter. Efficient utilization of N is of co...

  17. Land use intensity trajectories on Amazonian pastures derived from Landsat time series

    NASA Astrophysics Data System (ADS)

    Rufin, Philippe; Müller, Hannes; Pflugmacher, Dirk; Hostert, Patrick

    2015-09-01

    Monitoring changes in land use intensity of grazing systems in the Amazon is an important prerequisite to study the complex political and socio-economic forces driving Amazonian deforestation. Remote sensing offers the potential to map pasture vegetation over large areas, but mapping pasture conditions consistently through time is not a trivial task because of seasonal changes associated with phenology and data gaps from clouds and cloud shadows. In this study, we tested spectral-temporal metrics derived from intra-annual Landsat time series to distinguish between grass-dominated and woody pastures. The abundance of woody vegetation on pastures is an indicator for management intensity, since the duration and intensity of land use steer secondary succession rates, apart from climate and soil conditions. We used the developed Landsat-based metrics to analyze pasture intensity trajectories between 1985 and 2012 in Novo Progresso, Brazil, finding that woody vegetation cover generally decreased after four to ten years of grazing activity. Pastures established in the 80s and early 90s showed a higher fraction of woody vegetation during their initial land use history than pastures established in the early 2000s. Historic intensity trajectories suggested a trend towards more intensive land use in the last decade, which aligns well with regional environmental policies and market dynamics. This study demonstrates the potential of dense Landsat time series to monitor land-use intensification on Amazonian pastures.

  18. Management effects on the distribution of soil characteristics of two pasture types in Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pastures of native prairie and winter wheat are among the primary resources used to graze cattle in central Oklahoma. These pastures are subject to numerous stressors that affect land condition including grazing, climate, soil fertility, and farming operations. Understanding responses of soil charac...

  19. SOIL SEED BANK COMPOSITION IN PASTURES OF DIVERSE MIXTURES OF TEMPERATE FORAGES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed banks may contribute useful or weedy species that fill gaps in pastures. In a previous study, pastures planted to complex mixtures of forages had fewer weedy species in the aboveground vegetation. In this study, we relate changes in the species composition of the seed bank to changes in the abo...

  20. Dispersal and post-dispersal predation of Italian ryegrass seed in unimproved pasture.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dispersal and post-dispersal predation of Italian ryegrass seed in unimproved pasture. Italian ryegrass (Lolium multiflorum L.) can be a productive and high-quality cool-season forage, but is considered a weed in some pastures. Italian ryegrass does not form a persistent seed bank and needs to prod...

  1. Quantifying phosphorus levels in landscapes associated with Bahiagrass-based pastures and beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Relatively little information exists regarding possible magnitudes of P losses from grazed pastures. Whether or not P losses from grazed pastures are significantly greater than background losses and how these losses are affected by soil, forage management, or stocking density are not well understood...

  2. Perennial Forage Kochia for Improved Productivity of Grass Dominated Winter Grazing Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazing forage kochia (Kochia prostrata) during fall/winter has been shown to improve livestock health and reduce winter feeding costs. The objectives of this study were to compare the differences of traditional winter pastures versus pastures with forage kochia. Fifty mature, pregnant, Black Angu...

  3. Soil seed bank community structure of pastures and hayfields on an organic farm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the composition of seed banks in pasture soils would help farmers anticipate and manage for weed problems. We characterized the soil seed bank in eight pastures and hayfields [two alfalfa (Medicago sativa L.) and two predominantly grass hayfields; two recently established and two perma...

  4. Incorporating A Total Mixed Ration into Pasture-Based Dairy Systems: The Best of Both Worlds?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pastures containing multiple plant species have been shown to have greater plant productivity than pasture planted with a single plant species. However, it has not been determined whether this increase in plant productivity translates into increased animal productivity. Therefore, a study was design...

  5. Yield, Root Growth and Soil Water Content of Drought-Stressed Pasture Mixtures Containing Chicory

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chicory (Cichorium intybus L.) is a deep-rooted forb that has increasingly been investigated for inclusion in pasture mixtures because of its reported drought tolerance and high productivity during summer months. This study examined how adding chicory to pasture mixtures impacted forage yield, root ...

  6. Assessment of Prior Grazing Experiences on Adaption to Pasture and Performance of Dairy Heifers.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate how previous grazing experience affects animal behavior on pasture. Animal behavior was monitored in 32 Holstein (n = 21) and Holstein-Jersey (n = 11) yearlings. Two heifer groups (n = 8 per group) had been exposed to pasture from August through October 20...

  7. Relationship between residual feed intake, performance, and carcass parameters of pasture finished cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2009 and 2010, Angus-crossbred steers (n = 39) were used to evaluate the relationship between residual feed intake (RFI), pasture-finishing performance and carcass parameters. During RFI determinations prior to pasture finishing initiation in mid-April, animals were fed an alfalfa hay cube diet....

  8. High biomass removal limits carbon sequestration potential of mature temperate pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Decades of plowing have depleted organic carbon stocks in many agricultural soils. Conversion of plowed fields to pasture has the potential to reverse this process, recapturing organic matter that was lost under more intensive cropping systems. Temperate pastures in the northeast USA are highly prod...

  9. Assessing the land resource capacity for pasture-based dairy farming in the Northeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research has demonstrated that pasture-based dairy farming can offer many potential benefits for farmer incomes, animal welfare, and environmental quality. However, a common criticism of pasture-based dairies is that relative to confinement production, they produce less milk per acre of farmland, so...

  10. Development of a quantitative pasture phosphorus management tool using the SWAT model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Pasture Phosphorus Management (PPM) Calculator allows conservation planners to predict phosphorus loss from pastures in eastern Oklahoma. The computer based tool is a vastly simplified interface for the popular, yet complicated Soil and Water Assessment Tool (SWAT). PPM Calculator allows users...

  11. THE EFFECTS OF PASTURE FALLOWING ON THE SEED BANK AND FORAGE SPECIES COMPOSITION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fallowing, the practice of leaving a pasture ungrazed during the growing season, is sometimes used as a tool for improving pasture quality by allowing grasses to reseed naturally. Fallowing has been shown to provide benefits in New Zealand, but has been adopted on rotationally-stocked farms in the n...

  12. Timing and rate of Chaparral treatment affects tall fescue seedhead development and pasture plant densities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The herbicide Chaparral™ has been shown to suppress seedhead development in tall fescue (Neotyphodium coenophialum) pastures and reduce the symptoms of tall fescue toxicosis in cattle. However, little is known about the logistics of herbicide treatment on tall fescue pastures. The objective of thi...

  13. Management of tall fescue pastures and nutrients in a Southern Piedmont environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pastures have replaced row-crop agriculture in many parts of the Southern Piedmont in response to soil and water conservation needs where tall fescue (Festuca arundinacea Schreb) is a common pasture grass. However, nutrient losses from livestock manure and/or poultry fertilization can contribute to ...

  14. Allocating fresh pasture during the afternoon enhances daily weight gains… what about milk yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research conducted in Argentina, US, Australia and Europe has shown significant variations in chemical composition of pasture throughout the day, which results in an increase in pasture digestibility and energy concentration as the day progresses. Cattle have adapted their grazing patterns during th...

  15. Comparing pasture c sequestration estimates from eddy covariance and soil cores

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperate pastures in the northeast USA are highly productive and could act as significant sinks for soil organic carbon (SOC). However, soils under mature pastures are often considered to have reached equilibrium such that no further sequestration of SOC is expected. This study quantified changes i...

  16. Monitoring runoff from cattle-grazed pastures for a phosphorus loss quantification tool

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen (N) and phosphorus (P) loss from agriculture persists as a water quality impairment issue. For dairy farms, nutrients can be lost from cropland, pastures, barnyards, and outdoor cattle lots. We monitored N and P loss in runoff from dairy and beef grazed pastures for two years in southwest W...

  17. Tall fescue management: Pasture and cattle responses to endophyte and fertilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yearling heifers grazing tall fescue pastures had greatest performance in winter and spring on endophyte-free and novel endophyte associations, because of high forage quality and lack of ergot alkaloids produced by a common “wild” tall fescue-endophyte association. Pasture and cattle responses were...

  18. Countermeasures for pasture-associated laminitis in ponies and horses.

    PubMed

    Harris, Patricia; Bailey, Simon R; Elliott, Jonathan; Longland, Annette

    2006-07-01

    Laminitis occurs throughout the world in horses and ponies and has major welfare implications. It is obviously important to be able to recognize and treat the condition in its early stages so that pain and suffering are kept to a minimum. However, ideally it would be preferred to be able to recommend certain interventions/countermeasures that avoid or prevent the condition from occurring in the first place. Because pasture-associated laminitis occurs with grass consumption, one obvious way to avoid the condition is to prevent access to pasture and to feed forage alternatives that are known to be low in rapidly fermentable material. For the majority of horses, total restriction is not always a viable or desired option for financial, welfare, and health reasons. It also may not be necessary for those animals that are not predisposed to laminitis. This review discusses the possible countermeasures that could be considered now and in the future in the following 7 key areas: 1) Identifying animals predisposed to the condition; 2) Limiting development of insulin resistance; 3) Avoiding high intakes of rapidly fermentable material; 4) Preventing/reducing the formation and absorption of the various "triggering factors"; 5) Reducing/preventing oxidative damage; 6) Preventing/reducing matrix metalloproteinase activity; and 7) Preventing changes in blood flow. It is unfortunate that little or no hard data exist at present on effective countermeasures, only mechanistic evidence for avoiding risk factors. However, there is much to gain, and research in this area is urgently required. PMID:16772514

  19. Spatial and temporal variation in mined land pastures

    SciTech Connect

    Teutsch, C.D.; Collins, M.; Ditsch, D.C.; Johns, J.; Larson, B.; Turner, W.; Hamilton, T.; May, C.; Clay, L.

    1998-12-31

    Kentucky has large areas of reclaimed surface mined land that could provide grazing for livestock. Research is needed to define optimum stocking densities and to determine the sustainability of such grazing systems for this region. A long-term field study was initiated in 1997 on 151 ha of reclaimed land near Chavies, KY to assess spatial and temporal variation under grazing with stocking densities of 0, 0.28, 0.42, or 0.83 beef cow/calf pairs/ha. Global Positioning System and GIS technologies were employed to interpolate surface maps of the site using 11,000 points. Herbage and soil samples were collected around permanent markers systematically placed over the entire area at a density of 1 per 0.4 ha. Elevation ranged from 295 to 371 m and pasture slope ranged from 0 to 57{degree} with a mean of 13{degree}. Biomass density in late April ranged from 0 to 2500 kg/ha and was lowest at the highest stocking density, where grazing activity was highest. Spring-born calves averaged 240 kg at weaning. Cow weight and body condition score at the end of the grazing season was reduced at the highest stocking density and suggests that the highest stocking density may be excessive for mined land pastures in this region.

  20. Heavy metal levels of pasture grasses in metropolitan area

    NASA Astrophysics Data System (ADS)

    Luilo, G. B.; Othman, O. C.

    2003-05-01

    Urban agriculture is becoming an important lucrative activity in Dar es Salaam City even though the city is subject to traffic and industrial pollution pressures. Poor planning has left only limited spaces, particularly road reserves, for cultivation and foraging animals. While there is increasing road traffic no study bas been conducted determine levels of trace metals in pasture grasses. This study, therefore, reports on the levels of cadmium, manganese, lead and zinc of cynodon grasses in road vicinity in the city. Results show that the trace metal levels (ppm ± SDE) in Cynodon grass species were: Cd (0.24 ± 0.06-2.58 ± 0.15), Mn (41.5 ± 13.6-345.0 ± 124.3), Pb (1.15 ± 0.64-25.53 ± 1.29) and Zn (25.97 ± 3.69-95.36 ± 19.61). The mean levels of lead and zinc varied exponentially with distance off the road up to 15 m distance. Lead and zinc levels correlated with average daily traffic in the roads while cadmium and manganese did not. This suggests that lead and zinc in grasses owe their sources from the passing motor vehicles in agreement with other reported studies. It is recommended that pasture grasses in road vicinities must not be used for foraging dairy cattle and goats for public health reasons.

  1. Carbon fluxes of Kobresia pygmaea pastures on the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Foken, T.; Biermann, T.; Babel, W.; Ma, Y.

    2013-12-01

    With an approximate cover of 450,000 km2 on the Tibetan Plateau (TP), the Cyperaceae Kobresia pygmaea forms he world's largest alpine ecosystem. This species, especially adapted to grazing pressure, grows to a height of only 2-6 cm and can be found in an altitudinal range of 4000 to 5960 m a.s.l. A special characteristic of this ecosystem is the stable turf layer, which is built up from roots and plays a significant role in protecting soil from erosion. This is of great importance since soils on the TP store 2.5 % of the global soil organic carbon stocks. The aim of the investigation was the study of the carbon storage and the impact of human-induced land use change on these Kobresia pygmaea pastures. We therefore applied eddy-covariance measurements and modelling as a long-term control of the fluxes between the atmosphere and the pastures and 13C labelling for the investigation of flux partitioning, and chamber measurements to investigate the degradation of the pastures. Combining CO2 budgets observed in 2010 with eddy-covariance measurements and relative partitioning of Carbon fluxes estimated with 13C labelling enabled us to characterise the C turnover for the vegetation period with absolute fluxes within the plant-soil-atmosphere continuum. These results revealed that this ecosystem indeed stores a great amount of C in below-ground pools, especially in the root turf layer. To further investigate the importance of the root layer, the experiments in 2012 focused on flux measurements over the different surface types which make up the heterogeneity of the Kobresia pygmaea pastures and might result from degradation due to extensive grazing. The three surface types investigated with a LiCOR long-term monitoring chamber system include Kobresia pygmaea with intact turf layer (IRM), a surface type where the turf layer is still present but the vegetation is sparse and mainly consists of Cryptogam crusts (DRM) and finally areas without the turf layer (BS). According to

  2. Grazing management effects on sediment, phosphorus, and pathogen loading of streams in cool-season grass pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Erosion and precipitation runoff from pastures may lead to degradation of surface water. A two-year grazing study was conducted to quantify effects of grazing management on sediment, phosphorus (P), and pathogen loading of streams in cool-season grass pastures. Six adjoining 12.1-ha pastures bisecte...

  3. Prevalence and concentration of Salmonella and Campylobacter in the processing environment of small-scale pastured broiler farms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A growing niche in the locally grown food movement is the small scale production of broiler chickens using the pasture-raised poultry production model. Little research exists that focuses on Salmonella and Campylobacter contamination in the environment associated with on-farm processing of pasture-r...

  4. The effectiveness of faecal removal methods of pasture management to control the cyathostomin burden of donkeys

    PubMed Central

    2014-01-01

    Background The level of anthelmintic resistance within some cyathostomin parasite populations has increased to the level where sole reliance on anthelmintic-based control protocols is not possible. Management-based nematode control methods, including removal of faeces from pasture, are widely recommended for use in association with a reduction in anthelmintic use to reduce selection pressure for drug resistance; however, very little work has been performed to quantitatively assess the effectiveness of such methods. Methods We analysed data obtained from 345 donkeys at The Donkey Sanctuary (Devon, UK), managed under three different pasture management techniques, to investigate the effectiveness of faeces removal in strongyle control in equids. The management groups were as follows: no removal of faeces from pasture, manual, twice-weekly removal of faeces from pasture and automatic, twice-weekly removal of faeces from pasture (using a mechanical pasture sweeper). From turn-out onto pasture in May, monthly faecal egg counts were obtained for each donkey and the dataset subjected to an auto regressive moving average model. Results There was little to no difference in faecal egg counts between the two methods of faecal removal; both resulted in significantly improved cyathostomin control compared to the results obtained from the donkeys that grazed pasture from which there was no faecal removal. Conclusions This study represents a valuable and unique assessment of the effectiveness of the removal of equine faeces from pasture, and provides an evidence base from which to advocate twice-weekly removal of faeces from pasture as an adjunct for equid nematode control. Widespread adoption of this practice could substantially reduce anthelmintic usage, and hence reduce selection pressure for nematode resistance to the currently effective anthelmintic products. PMID:24460700

  5. Grazing Soybean to Increase Voluntary Cow Traffic in a Pasture-based Automatic Milking System

    PubMed Central

    Clark, C. E. F.; Horadagoda, A.; Kerrisk, K. L.; Scott, V.; Islam, M. R.; Kaur, R.; Garcia, S. C.

    2014-01-01

    Pasture-based automatic milking systems (AMS) require cow traffic to enable cows to be milked. The interval between milkings can be manipulated by strategically allocating pasture. The current experiment investigated the effect of replacing an allocation of grazed pasture with grazed soybean (Glycine max) with the hypothesis that incorporating soybean would increase voluntary cow traffic and milk production. One hundred and eighty mixed age, primiparous and multiparous Holstein-Friesian/Illawarra cows were randomly assigned to two treatment groups (n = 90/group) with a 2×2 Latin square design. Each group was either offered treatments of kikuyu grass (Pennisetum clandestinum Hoach ex Chiov.) pasture (pasture) or soybean from 0900 h to 1500 h during the experimental period which consisted of 2 periods of 3 days following 5 days of training and adaptation in each period with groups crossing over treatments after the first period. The number of cows trafficking to each treatment was similar together with milk yield (mean ≈18 L/cow/d) in this experiment. For the cows that arrived at soybean or pasture there were significant differences in their behaviour and consequently the number of cows exiting each treatment paddock. There was greater cow traffic (more cows and sooner) exiting pasture allocations. Cows that arrived at soybean stayed on the allocation for 25% more time and ate more forage (8.5 kg/cow/d/allocation) relative to pasture (4.7 kg/cow/d/allocation). Pasture cows predominantly replaced eating time with rumination. These findings suggest that replacing pasture with alternative grazeable forages provides no additional incentive to increase voluntary cow traffic to an allocation of feed in AMS. This work highlights the opportunity to increase forage intakes in AMS through the incorporation of alternative forages. PMID:25049970

  6. Objective indicators of pasture degradation from spectral mixture analysis of Landsat imagery

    NASA Astrophysics Data System (ADS)

    Davidson, Eric A.; Asner, Gregory P.; Stone, Thomas A.; Neill, Christopher; Figueiredo, Ricardo O.

    2008-03-01

    Degradation of cattle pastures is a management concern that influences future land use in Amazonia. However, "degradation" is poorly defined and has different meanings for ranchers, ecologists, and policy makers. Here we analyze pasture degradation using objective scalars of photosynthetic vegetation (PV), nonphotosynthetic vegetation (NPV), and exposed soil (S) derived from Landsat imagery. A general, probabilistic spectral mixture model decomposed satellite spectral reflectance measurements into subpixel estimates of PV, NPV, and S covers at ranches in western and eastern Amazonia. Most pasture management units at all ranches fell along a single line of decreasing PV with increasing NPV and S, which could be considered a degradation continuum. The ranch with the highest stocking densities and most intensive management had greater NPV and S than a less intensively managed ranch. The number of liming, herbiciding, and disking treatments applied to each pasture management unit was positively correlated with NPV and negatively correlated with PV. Although these objective scalars revealed signs of degradation, intensive management kept exposed soil to <40% cover and maintained economically viable cattle production over several decades. In ranches with few management inputs, the high PV cover in young pastures declined with increasing pasture age, while NPV and S increased, even where grazing intensity was low. Both highly productive pastures and vigorous regrowth of native vegetation cause high PV values. Analysis of spectral properties holds promise for identifying areas where grazing intensity has exceeded management inputs, thus increasing coverage of senescent foliage and exposed soil.

  7. Unexpected changes in soil phosphorus dynamics along pasture chronosequences in the humid tropics

    NASA Astrophysics Data System (ADS)

    Townsend, Alan R.; Asner, Gregory P.; Cleveland, Cory C.; Lefer, Margaret E.; Bustamante, Mercedes M. C.

    2002-10-01

    Phosphorus (P) is widely believed to limit plant growth and organic matter storage in a large fraction of the world's lowland tropical rain forests. We investigated how the most common land use change in such forests, conversion to cattle pasture, affects soil P fractions along pasture chronosequences in the central Brazilian Amazon and in southwestern Costa Rica. Our sites represent a broad range in rainfall, soil type, management strategies, and total soil P (45.2-1228.0 μg P/g soil), yet we found some unexpected and at times quite similar changes in soil P in all sites. In the Brazilian sites, where rainfall is relatively low and pasture management is more intense than in the Costa Rican sites, significant losses in total soil P and soil organic carbon (SOC) were seen with pasture age on already P-deficient Oxisol and Entisol soils. However, P losses were from inorganic soil P fractions, while organic forms of soil P remained constant or increased with pasture age, despite the declines in SOC. In Costa Rica, SOC remained constant across the Oxisol sites and increased from forest to pasture on the Mollisols, while soil organic P increased with pasture age in both sequences.

  8. Assessing effects of climate change and adaptation strategies on irrigated pastures using DAISY

    NASA Astrophysics Data System (ADS)

    Hagimoto, Y.; Cuenca, R. H.

    2013-12-01

    The DAISY ecological model was applied for the flood-irrigated cool-season pastures in the Upper Klamath Basin, Oregon to study 1) the current condition of the pastures in the semi-arid environment, 2) effects of projected climate change, and 3) effects of introducing white clover and a sprinkler system as a potential adaptation strategy. The calibrated model indicated that productivity of the cool-season pastures was limited primarily by nitrogen (N) availability and temperature. The results of our scenario analysis indicated that the projected climate change would increase seasonal forage production (YF) and crop water use (AET) due to longer and warmer growing season. This study also found that introduction of white clover would significantly increase YF without changing AET by improving N availability due to increased nutrients deposition by cattle and increased symbiotic N fixation by white clover. In consequence, the mixed pasture could significantly improve water use efficiency (YF/AET) and, therefore the adaptability of the pasture in an area with high value water. Installing sprinkler system to the mixed pasture would increase YF by increasing net N input by increasing N mineralization and reducing denitrification. Furthermore, upgraded irrigation systems could increase water availability of the area during growing season by releasing significant amount of subsurface water to nearby surface water pools. This study demonstrated that ecological models such as DAISY can be a useful tool to model pasture systems and assess effects of projected climate changes and adaptation strategies.

  9. Reviving wood-pastures for biodiversity and people: A case study from western Estonia.

    PubMed

    Roellig, Marlene; Sutcliffe, Laura M E; Sammul, Marek; von Wehrden, Henrik; Newig, Jens; Fischer, Joern

    2016-03-01

    Wood-pastures are associated with high cultural and biodiversity values in Europe. However, due to their relatively low productivity, large areas of wood-pastures have been lost over the last century. In some areas, incentive schemes have been developed to revive wood-pastures. We investigated the effects of one such scheme in western Estonia. We compared the structure of grazed wood-pastures (old and restored) to those of abandoned wood-pastures and ungrazed forest stands to explore the effects of management, and conducted interviews with 24 farmers to investigate their motivations to carry out the management. We found a positive influence of active management on the semi-open structure of wood-pastures. Financial support was vital for management, but personal values related to tradition also played an important role. The interviewees differed widely in their range of motivations, suggesting that other strategies in addition to financial incentives would further improve the management of wood-pastures in the region. PMID:26458391

  10. More Stable Productivity of Semi Natural Grasslands than Sown Pastures in a Seasonally Dry Climate

    PubMed Central

    Ospina, Sonia; Rusch, Graciela M.; Pezo, Danilo; Casanoves, Fernando; Sinclair, Fergus L.

    2012-01-01

    In the Neotropics the predominant pathway to intensify productivity is generally thought to be to convert grasslands to sown pastures, mostly in monoculture. This article examines how above-ground net primary productivity (ANPP) in semi-natural grasslands and sown pastures in Central America respond to rainfall by: (i) assessing the relationships between ANPP and accumulated rainfall and indices of rainfall distribution, (ii) evaluating the variability of ANPP between and within seasons, and (iii) estimating the temporal stability of ANPP. We conducted sequential biomass harvests during 12 periods of 22 days and related those to rainfall. There were significant relationships between ANPP and cumulative rainfall in 22-day periods for both vegetation types and a model including a linear and quadratic term explained 74% of the variation in the data. There was also a significant correlation between ANPP and the number of rainfall events for both vegetation types. Sown pastures had higher ANPP increments per unit rainfall and higher ANPP at the peak of the rainy season than semi-natural grasslands. In contrast, semi-natural grasslands showed higher ANPP early in the dry season. The temporal stability of ANPP was higher in semi-natural grasslands than in the sown pastures in the dry season and over a whole annual cycle. Our results reveal that, contrary to conventional thinking amongst pasture scientists, there appears to be no increase in ANPP arising from replacing semi-natural grasslands with sown pastures under prevailing pasture management practices in seasonally dry climates, while the temporal distribution of ANPP is more even in semi-natural grasslands. Neither sown pastures nor semi-natural grasslands are productive towards the end of the dry season, indicating the potential importance of the widespread practice of retaining tree cover in pastures. PMID:22590506

  11. Cadmium concentrations in new zealand pastures: relationships to soil and climate variables.

    PubMed

    Reiser, René; Simmler, Michael; Portmann, Denise; Clucas, Lynne; Schulin, Rainer; Robinson, Brett

    2014-05-01

    Cadmium (Cd) is a nonessential element that occurs at above-background concentrations in many New Zealand (NZ) soils. Most of this Cd is due to the historical application of single superphosphate that was made from Nauru phosphate rock containing between 400 and 600 mg Cd kg P. Pasture Cd uptake exacerbates the entry of Cd into animal products. We sought to determine the critical environmental factors affecting Cd uptake in NZ pastures and to calculate the likely Cd intake of sheep and cattle. We tested 69 pastures throughout NZ for a range of variables, including Cd. Soil Cd and pasture Cd were positively correlated with soil P and soil concentrations of other elements found in phosphate fertilizers. We found that no single environmental variable adequately predicted pasture Cd uptake. Nevertheless, pseudo-total soil Cd and Cd extracted using a 0.05 mol L Ca(NO) solution were positively correlated with pasture Cd. Although soil pH, soil Fe, and soil Cd provided an excellent predictor of the Ca(NO)-extractable soil Cd fraction, regression models explained just 38% of the variation of the Cd concentration in pasture grasses. Incorporating the effect of pasture species composition is a crucial next step in improving these models. A calculation of the likely exposure to Cd of sheep and cattle revealed that no pastures tested resulted in sheep and cattle ingesting Cd at a rate that would result in breaching muscle-tissue food standards. For offal products, which the NZ meat industry does not sell for human consumption, food safety standards exceedence was calculated in a few cases. PMID:25602820

  12. Conversion of Grazed Pastures to Energy Cane as a Biofuel Feedstock Alters Soil GHG Fluxes

    NASA Astrophysics Data System (ADS)

    Gomez-Casanovas, N.; DeLucia, N.; Bernacchi, C.; DeLucia, E. H.

    2013-12-01

    Changes in land use profoundly affect climate through variations in soil Greenhouse Gas (GHG) exchange. The need for alternative energies is accelerating land use change as marginal land or managed ecosystems are being converted to highly productive second-generation bioenergy crops such as energy cane (Saccharum spp. L). Although the deployment of energy cane is a promising strategy to meet global bioenergy industry demands, few studies have investigated soil GHG fluxes in these crops and sub-tropical low-intensity grazing pasture (bahiagrass, Paspalum notatum L., as forage for cattle, Bos taurus L.) with which they are competing for land. Here, we showed that soil N2O fluxes in bioenergy crops were higher (>250%) than those observed in pastures following fertilization when soil moisture and temperature were high. In the absence of recent fertilization, the N2O source strength in energy cane and pasture sites was similar. Under drier and cooler soil conditions, both pastures and bioenergy crops were weak sources of N2O even when energy cane plots were recently fertilized. Soils on grazed pastures were sources of CH4 during the wet season but became sinks under drier, colder conditions. Energy cane plantations were weak sources of CH4 over a complete wet-dry seasonal cycle. The heterotrophic component of soil respiration was larger (139-155%) in pastures than in energy cane crops, suggesting lower decomposition of SOC in bioenergy crops. In terms of global warming potential, grazed pastures were stronger (120-150%) soil GHG emitters than energy cane crops over a complete wet-dry seasonal cycle. Moreover, pastures became a substantial source of GHG emitters when including estimates of CH4 flux from cattle. Our results suggest that the conversion of pasture to energy cane will be beneficial in relation to GHGs emitted from soils and cattle. Improved understanding of land use impact on soil GHG dynamics will provide valuable information for decision makers debating

  13. [Control of gastrointestinal helminthiasis in pasture-reared lambs].

    PubMed

    Chroust, K

    1997-03-01

    Two sheep herds kept in different geographic conditions with spring lambing by the end of March and April (herd No. 1: 400 ewes, 600 metres above sea level; herd No. 2: 450 ewes, 300 metres above sea level) were examined. The dynamics of gastrointestinal nematode and Moniezia spp. cestode egg counts in samples taken regularly every 4 to 5 weeks was studied during the year 1995 with the intention to verify the system of effective control of these helminth infections under pasture conditions of lamb rearing. In ewes a significant rise in gastrointestinal nematode egg counts was proved during the lambing season, "spring rise phenomenon", and during the summer pasture until autumn months with maximum EPG values reaching 150 (Figs. 1 and 2). In lambs that started grazing at 1 to 4 weeks of age, the excretion steeply rose to maximum EPG values 350 and 290, respectively, after 4 to 5 weeks of grazing (Figs. 1 and 2). In order to control these rising infections, ewes were treated with antihelmintic albendazol by the end of February (herd No. 1) and in March (herd No. 2) and lambs during the first or third decade of July. This anthelmintic treatment significantly lowered egg excretion to EPG values lower than 30 in ewes and 50 or 60, respectively, in lambs. Later, during the summer and autumn months, a mild rise of egg counts was found in lambs. These maxima were liquidated anthelmintis treatment in both herds in late autumn months and it also lowered helminth infections to minimum during winter months (EPG values lower than 50). The excretion of Moniezia spp. eggs had the same dynamics as that gastrointestinal nematodes. Values of lamb infection prevalence reached 21% in herd No. 1 and 29% in herd No. 2. Anthelmintic treatment during July controlled cestode findings in lambs. Albendazol (Vermitan susp. 2.5%), dosed 5 mg/kg of body weight, proved highly effective in the control of gastrointestinal nematodes and Moniezia spp. cestodes. PMID:9182393

  14. Long-term effects of municipal sewage on soils and pastures.

    PubMed

    van de Graaff, Robert H M; Suter, Helen C; Lawes, Sophy J

    2002-01-01

    Land application of municipal wastewater is widely practised worldwide as a means of treating wastes and obtaining a benefit from the water and nutrients by growing pastures, trees, and sometimes edible crops such as vegetables, fruit and fibre, etc. Irrigation of pastures by treated and untreated sewage near Melbourne, Australia, for more than a century has increased heavy metals concentrations in the soil, but appears not to have increased their concentrations in the herbage and in animal tissues of animals grazed on these pastures. There seem to be sound reasons why this practice may be sustainable. PMID:12046671

  15. Reduced deep soil water uptake through forest conversion to pasture in Amazonia

    SciTech Connect

    Jipp, P.H.; Nepstad, D.C. Woods Hole Research Center, MA )

    1993-06-01

    Forests of eastern Amazonia are being replaced by pastures and secondary forests. We measured soil water storage and flux in adjacent forest and pasture ecosystems using Time Domain Reflectometry sensors installed in the walls of deep (9-m) shafts. The forest withdrew 597+/-25 mm of soil water stored below 1 m depth during the 1991 dry season (Jun-Dec), 1.7 times more than the pasture. Uptake from the bottom of the forest soil profile continued even after rainfall resumed in early 1992. The hydrologic impacts of tropical deforestation may be most severe for evergreen forests with deep rooting zones in areas of seasonal drought.

  16. C storage in Amazonia pastures, effects of age, climate and management

    NASA Astrophysics Data System (ADS)

    Klumpp, Katja; Stahl, Clement; Blanfort, Vincent; Fontaine, Sebstien; Burban, Benoit; Darsonville, Olivier

    2016-04-01

    The Amazonian region is one of the major C storing areas, with 36-60% of ecosystem C being stored in forest soils. During last decades, more than 15% of Amazonian tropical forest has been converted to pastures. A number of studies provide evidence that soil C stocks of topsoil (0-20 cm) can be higher in grasslands than in native forests after more than 20 years after conversion (e.g. Don et al 2011). As for younger pastures (< 20 years old), results are less evident, showing either an increase or decrease of in topsoil C stock. The absence of a clear pattern was mostly explained due to conjoined changes following deforestation, such as climate conditions and pasture management. Accordingly, the question remains whether tropical permanent pastures can restore soil C stocks after deforestation and what is the capacity of tropical pastures to initiate a recurrent C storage. Pastures are largely affected by agricultural practices, influencing their carbon balance, in interaction with climate effect. In the past 10 years two major droughts (in 2005 and 2010 [2]) were reported for the Amazonian area. A better insight on effects of climatic variability and agricultural management on carbon storage is, thus, valuable to improve/maintain C storage of pastures in tropical regions. Here we like to assess whether tropical permanent pastures i) can restore soil C stocks after deforestation; ii) and to what extend and iii) which role play management practices with respect to climate variability to maintain a recurrent C storage. To establish reliable estimates of soil C storage in Amazonian region, the net C balance of pastures and native forests was quantified by two independent and complementary studies in French Guiana: a chronosequence study including a soil inventory of soil C stocks (0-100 cm depth) in 24 pastures of various ages (i.e. 0 to 42 yrs after deforestation) and 4 native forests, and 5 years of eddy covariance flux measurements (EC) for a young intensively used

  17. A Case Study of Behaviour and Performance of Confined or Pastured Cows During the Dry Period

    PubMed Central

    Black, Randi A.; Krawczel, Peter D.

    2016-01-01

    Simple Summary Pasture and freestall systems offer benefits and consequences during lactation but have not been investigated during the dry period. The effect of pasture or confined systems during the dry period on behaviour and milk quality was investigated. Freestall housing resulted in more resting behaviour and less locomotor activity during the dry period compared to pastured cows. At calving, freestall housed cows performed fewer lying bouts and less locomotor activity compared to pastured cows. Pasture resulted in less aggression around feeding but high respiration rates during peak heat times. Pasture during the dry period altered lying behavior, reduced feed bunk aggression and increased heat stress behaviors. Abstract The objectives of this study were to determine the effect of the dry cow management system (pasture or confined) on: (1) lying behaviour and activity; (2) feeding and heat stress behaviours; (3) intramammary infections, postpartum. Non-lactating Holstein cows were assigned to either deep-bedded, sand freestalls (n = 14) or pasture (n = 14) using rolling enrollment. At dry-off, cows were equipped with an accelerometer to determine daily lying time (h/d), lying bouts (bouts/d), steps (steps/d) and divided into periods: far-off (60 to 15 d prepartum), close-up (14 to 1 d prepartum), calving (calving date) and postpartum (1 to 14 d postpartum). Respiration rates were recorded once weekly from dry off to calving from 1300 to 1500 h. Feeding displacements were defined as one cow successfully displacing another from the feed bunk and were recorded once per week during the 2 h period, immediately after feeding at 800 h. Pastured cows were fed a commercial dry cow pellet during far-off and total mixed ration during close-up, with free access to hay and grazing. Freestall housed cows were fed a total mixed ration at far-off and close-up. Cows housed in freestalls were moved to a maternity pen with a mattress at commencement of labour. Pastured cows

  18. FORAGES AND PASTURES SYMPOSIUM: Improving efficiency of production in pasture- and range-based beef and dairy systems.

    PubMed

    Mulliniks, J T; Rius, A G; Edwards, M A; Edwards, S R; Hobbs, J D; Nave, R L G

    2015-06-01

    Despite overall increased production in the last century, it is critical that grazing production systems focus on improving beef and dairy efficiency to meet current and future global food demands. For livestock producers, production efficiency is essential to maintain long-term profitability and sustainability. This continued viability of production systems using pasture- and range-based grazing systems requires more rapid adoption of innovative management practices and selection tools that increase profitability by optimizing grazing management and increasing reproductive performance. Understanding the genetic variation in cow herds will provide the ability to select cows that require less energy for maintenance, which can potentially reduce total energy utilization or energy required for production, consequently improving production efficiency and profitability. In the United States, pasture- and range-based grazing systems vary tremendously across various unique environments that differ in climate, topography, and forage production. This variation in environmental conditions contributes to the challenges of developing or targeting specific genetic components and grazing systems that lead to increased production efficiency. However, across these various environments and grazing management systems, grazable forage remains the least expensive nutrient source to maintain productivity of the cow herd. Beef and dairy cattle can capitalize on their ability to utilize these feed resources that are not usable for other production industries. Therefore, lower-cost alternatives to feeding harvested and stored feedstuffs have the opportunity to provide to livestock producers a sustainable and efficient forage production system. However, increasing production efficiency within a given production environment would vary according to genetic potential (i.e., growth and milk potential), how that genetic potential fits the respective production environment, and how the grazing

  19. Afforestation or intense pasturing improve the ecological and economic value of abandoned tropical farmlands

    PubMed Central

    Knoke, Thomas; Bendix, Jörg; Pohle, Perdita; Hamer, Ute; Hildebrandt, Patrick; Roos, Kristin; Gerique, Andrés; Sandoval, María L.; Breuer, Lutz; Tischer, Alexander; Silva, Brenner; Calvas, Baltazar; Aguirre, Nikolay; Castro, Luz M.; Windhorst, David; Weber, Michael; Stimm, Bernd; Günter, Sven; Palomeque, Ximena; Mora, Julio; Mosandl, Reinhard; Beck, Erwin

    2014-01-01

    Increasing demands for livelihood resources in tropical rural areas have led to progressive clearing of biodiverse natural forests. Restoration of abandoned farmlands could counter this process. However, as aims and modes of restoration differ in their ecological and socio-economic value, the assessment of achievable ecosystem functions and benefits requires holistic investigation. Here we combine the results from multidisciplinary research for a unique assessment based on a normalization of 23 ecological, economic and social indicators for four restoration options in the tropical Andes of Ecuador. A comparison of the outcomes among afforestation with native alder or exotic pine, pasture restoration with either low-input or intense management and the abandoned status quo shows that both variants of afforestation and intense pasture use improve the ecological value, but low-input pasture does not. Economic indicators favour either afforestation or intense pasturing. Both Mestizo and indigenous Saraguro settlers are more inclined to opt for afforestation. PMID:25425182

  20. Treatment of pastures with diflubenzuron suppresses Horn Fly, Haematobia irritans (L.) (Diptera: Muscidae) development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diflubenzuron is an insect growth regulator labeled for application to pastures and rangeland to suppress grasshopper (Orthoptera: Acrididae) populations. Livestock are permitted access to land immediately after treatment. We hypothesized that the development and survivorship of horn fly Haematobia ...

  1. The janthitrems: fluorescent tremorgenic toxins produced by Penicillium janthinellum isolates from ryegrass pastures.

    PubMed Central

    Gallagher, R T; Latch, G C; Keogh, R G

    1980-01-01

    New tremorgenic mycotoxins named janthitrem A, B, and C (molecular weights 601, 585, and 569, respectively) were produced by more than half of 21 Penicillium janthinellum isolates obtained from ryegrass pastures involved in ryegrass staggers outbreaks in sheep. PMID:7356319

  2. Afforestation or intense pasturing improve the ecological and economic value of abandoned tropical farmlands.

    PubMed

    Knoke, Thomas; Bendix, Jörg; Pohle, Perdita; Hamer, Ute; Hildebrandt, Patrick; Roos, Kristin; Gerique, Andrés; Sandoval, María L; Breuer, Lutz; Tischer, Alexander; Silva, Brenner; Calvas, Baltazar; Aguirre, Nikolay; Castro, Luz M; Windhorst, David; Weber, Michael; Stimm, Bernd; Günter, Sven; Palomeque, Ximena; Mora, Julio; Mosandl, Reinhard; Beck, Erwin

    2014-01-01

    Increasing demands for livelihood resources in tropical rural areas have led to progressive clearing of biodiverse natural forests. Restoration of abandoned farmlands could counter this process. However, as aims and modes of restoration differ in their ecological and socio-economic value, the assessment of achievable ecosystem functions and benefits requires holistic investigation. Here we combine the results from multidisciplinary research for a unique assessment based on a normalization of 23 ecological, economic and social indicators for four restoration options in the tropical Andes of Ecuador. A comparison of the outcomes among afforestation with native alder or exotic pine, pasture restoration with either low-input or intense management and the abandoned status quo shows that both variants of afforestation and intense pasture use improve the ecological value, but low-input pasture does not. Economic indicators favour either afforestation or intense pasturing. Both Mestizo and indigenous Saraguro settlers are more inclined to opt for afforestation. PMID:25425182

  3. Salinity tolerance of foxtail barley (Hordeum jubatum) and desirable pasture grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Greenhouse studies were conducted to determine the relative salinity tolerance of foxtail barley and seven desirable pasture grasses. Grass species were reed canarygrass, timothy, altai wildrye, tall fescue, tall wheatgrass, orchardgrass, creeping meadow foxtail, and foxtail barley. Grasses were e...

  4. Stocker performance and production in mixed tall fescue-bermudagrass pastures of the Southern Piedmont USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stocker performance and production from mixed cool- and warm-season perennial pastures are important determinants of agricultural sustainability that can be influenced by management. We evaluated the factorial combination of three sources of nutrient application (inorganic only, organic + inorganic...

  5. Effects on ground-water quality from irrigating pasture with sewage effluent near Lakeland, Florida

    USGS Publications Warehouse

    Reichenbaugh, R.C.

    1977-01-01

    Since 1969 an average of 25,000 gpd of domestic secondary-treated effluent has been used to supplement irrigation of 30 acres of grazed pasture north of Lakeland, Florida. Monitor wells were contructed near the effluent-irrigated pasture. The water table in the surficial aquifer under the pasture varied from 1.0 to 3.3 feet below land surface. Total nitrogen was less than 20 percent of the effluent content after percolating 8 feet; no increase in nitrogen was detected 20 feet below the surface, or in down-gradient ground water. There was no evidence of phosphorus or carbon contamination of ground water. Low numbers of bacteria (generally coliform) were noted in some samples from nine wells. Four wells sampled contained bacteria of probable fecal origin. Low-rate application of the effluent to the pasture apparently has had little effect on the soil and ground water. (Woodard-USGS)

  6. A Case Study of Behaviour and Performance of Confined or Pastured Cows During the Dry Period.

    PubMed

    Black, Randi A; Krawczel, Peter D

    2016-01-01

    The objectives of this study were to determine the effect of the dry cow management system (pasture or confined) on: (1) lying behaviour and activity; (2) feeding and heat stress behaviours; (3) intramammary infections, postpartum. Non-lactating Holstein cows were assigned to either deep-bedded, sand freestalls ( n = 14) or pasture ( n = 14) using rolling enrollment. At dry-off, cows were equipped with an accelerometer to determine daily lying time (h/d), lying bouts (bouts/d), steps (steps/d) and divided into periods: far-off (60 to 15 d prepartum), close-up (14 to 1 d prepartum), calving (calving date) and postpartum (1 to 14 d postpartum). Respiration rates were recorded once weekly from dry off to calving from 1300 to 1500 h. Feeding displacements were defined as one cow successfully displacing another from the feed bunk and were recorded once per week during the 2 h period, immediately after feeding at 800 h. Pastured cows were fed a commercial dry cow pellet during far-off and total mixed ration during close-up, with free access to hay and grazing. Freestall housed cows were fed a total mixed ration at far-off and close-up. Cows housed in freestalls were moved to a maternity pen with a mattress at commencement of labour. Pastured cows calved in pasture. After calving, all cows were commingled in a pen identical to the freestall housing treatment. Cows housed in freestalls laid down for longer during far-off and close-up periods, had fewer lying bouts during the calving period and took fewer steps throughout the study period when compared to pastured cows. Freestall housed cows experienced more displacements after feeding than did pastured cows. Respiration rates increased with an increasing temperature humidity index, more in pastured cows than in freestall housed cows. Pastured cows altered their lying behaviour and activity, suggesting a shift in time budget priorities between pastured and confined dry cows. Pastured cows also experienced less aggression

  7. Pasture intake and milk production of dairy cows rotationally grazing on multi-species swards.

    PubMed

    Roca-Fernández, A I; Peyraud, J L; Delaby, L; Delagarde, R

    2016-09-01

    Increasing plant species diversity has been proposed as a means for enhancing annual pasture productivity and decreasing seasonal variability of pasture production facing more frequent drought scenarios due to climate change. Few studies have examined how botanical complexity of sown swards affects cow performance. A 2-year experiment was conducted to determine how sward botanical complexity, from a monoculture of ryegrass to multi-species swards (MSS) (grasses-legumes-forb), affect pasture chemical composition and nutritive value, pasture dry matter (DM) intake, milk production and milk solids production of grazing dairy cows. Five sward species: perennial ryegrass (L as Lolium), white clover and red clover (both referred to as T as Trifolium because they were always sown together), chicory (C as Cichorium) and tall fescue (F as Festuca) were assigned to four grazing treatments by combining one (L), three (LT), four (LTC) or five (LTCF) species. Hereafter, the LT swards are called mixed swards as a single combination of ryegrass and clovers, whereas LTC and LTCF swards are called MSS as a combination of at least four species from three botanical families. The experimental area (8.7 ha) was divided into four block replicates with a mineral nitrogen fertilisation of 75 kg N/ha per year for each treatment. In total, 13 grazing rotations were carried out by applying the same grazing calendar and the same pasture allowance of 19 kg DM/cow per day above 4 cm for all treatments. Clover represented 20% of DM for mixed and MSS swards; chicory represented 30% of DM for MSS and tall fescue represented 10% of DM for LTCF swards. Higher milk production (+1.1 kg/day) and milk solids production (+0.08 kg/day) were observed for mixed swards than for ryegrass swards. Pasture nutritive value and pasture DM intake were unaffected by the inclusion of clover. Pasture DM, organic matter and NDF concentrations were lower for MSS than for mixed swards. Higher milk production (+0.8 kg

  8. Biogeochemical Changes Associated With Conversion of Grazed Pastures to Plantation Forests in New Zealand

    NASA Astrophysics Data System (ADS)

    Scott, N. A.; Tate, K. R.; Ross, D. J.; Parfitt, R.; Parshotam, A.; Halliday, J.; McMurtrie, R.

    2001-05-01

    Since the 1930s, large areas of marginally productive pasture and/or scrubland have been converted to plantation forests dominated by Pinus radiata. In the 1990s, up to 100,000 hectares of new plantings occurred each year, many into land used previously for pasture. Current plantation forest area is about 1.7 million hectares. This land-use change impacts many biogeochemical and hydrological processes, and plays an important role in several current environmental issues. Conversion of pasture to plantation forests increases evapotranspiration, and can reduce streamflow and regional water availability. However, afforestation also stabilizes pasture soils that would be highly erodible when covered with pasture vegetation. Soil temperatures are also lower in plantation forests than in pasture, influencing carbon and nitrogen cycling rates. Because of differences in plant litter quality and distribution of carbon inputs to the soil, afforestation often leads to a reduction in soil pH, lower soil carbon turnover rates, lower net N mineralization, lower total mineral soil N, and reduced numbers of soil invertebrates (particularly earthworms). At many sites, these changes can lead to a reduction in mineral soil C stocks, with the reduction sometimes greater than the C accumulated in the forest floor. High N availability associated with pastures can often lead to N leaching losses when tree seedlings are established and uptake of N by pasture grasses inhibited by e.g. herbicide application. We discuss the ability of ecosystem models to simulate these complex biogeochemical changes associated with afforestation, the potential importance of forest management on these changes, and the implications for key environmental issues such as the rate of carbon sequestration in Kyoto forests and decreased emissions of agricultural trace gases.

  9. Tree water use and rainfall partitioning in a mature poplar-pasture system.

    PubMed

    Guevara-Escobar, A.; Edwards, W. R. N.; Morton, R. H.; Kemp, P. D.; Mackay, A. D.

    2000-01-01

    Traditionally, poplars (Populus) have been planted to control erosion on New Zealand's hill-slopes, because of their capacity to dry out and bind together the soil, by reducing effective rainfall and increasing evapotranspiration and soil strength. However, the effect of widely spaced poplars on the partitioning of soil water and rainfall has not been reported. This study determined rainfall partitioning for 18 mid-spring days in a mature P. deltoides (Bart. ex Marsh, Clone I78)-pasture association (37 stems per hectare, unevenly spaced at 16.4 +/- 0.4 m) and compared it with a traditional open pasture system in grazed areas of a hill environment. Tree transpiration was measured by the heat pulse technique. A time-driven mathematical model was used to set a zero offset, adjust anomalous values and describe simultaneous sap velocity time courses of trees. The model showed that daylight sap flow velocities can be represented with a nonlinear Beta function (R(2) > 0.98), and differences in the parameters representing the initiation, duration and conformation of the sap velocity can be tested statistically to discern tree transpiration differences during the day. Evapotranspiration was greater for the poplar-pasture association than for the open pasture (2.7-3.0 versus 2.2 mm day(-1)). The tree canopy alone contributed 0.92 mm day(-1) as transpiration and 1.37 mm day(-1) as interception, whereas evapotranspiration of the pasture understory was only 0.4-0.6 mm day(-1). Despite the higher water use of the poplar-pasture association, soil water in the 0-300 mm soil stratum was higher than, or similar to, that of the open pasture. Tree shading decreased evapotranspiration and pasture accumulation under the trees. PMID:12651477

  10. Seasonal variability of CO2 and H2O fluxes in tropical pasture and afforestation

    NASA Astrophysics Data System (ADS)

    Wolf, S.; Eugster, W.; Buchmann, N.

    2011-12-01

    Tropical ecosystems play an important role for the global carbon and water cycle. However, eddy covariance flux measurements in the tropics are still scarce and previous studies have been predominantly conducted in tropical forests. With ongoing deforestation, the tropics are increasingly influenced by agroecosystems and pastures but only few observations have covered these land-use types so far. Comparative eddy covariance measurements of carbon dioxide and water vapour fluxes were performed in a tropical pasture and an adjacent afforestation site in Sardinilla, Panama from 2007 to 2009. We observed a larger seasonal variability of ecosystem CO2 and H2O fluxes at the pasture compared to the afforestation site, which was largely related to the rooting depth of grasses versus trees. Radiation and soil moisture were the main environmental controls of these fluxes in both ecosystems. The pasture ecosystem was more sensitive to water limitations by seasonal drought and in addition, periodical overgrazing significantly contributed to persisting carbon losses from the pasture. Substantial carbon sequestration was found at the afforestation site and was in agreement with independent assessments of biomass and soil inventories. In contrast to the largely differing carbon budgets, the afforestation of tropical pasture only marginally increased total annual evapotranspiration in Sardinilla. Our results clearly indicate the potential for carbon sequestration of tropical afforestation but also highlight the risk of carbon losses from pasture ecosystems in a seasonal tropical climate. Predicted increases in precipitation variability will very likely impact the seasonal variability of CO2 and H2O fluxes in Panama, in particular of pasture ecosystems. At the end of this talk, the overall significance of seasonality in tropical ecosystems will be discussed.

  11. Unexprected Changes in Soil Phosphorus Dynamics Following Tropical Deforestation to Cattle Pasture

    NASA Technical Reports Server (NTRS)

    Townsend, Alan R.; Asner, Gregory P.; Cleveland, Cory C.; Lefer, Margaret E.; Bustamante, Mercedes M. C.

    2001-01-01

    Phosphorus (P) is widely believed to limit plant growth and organic matter storage in a large fraction of the world's lowland tropical rainforests. We investigated how the most common land use change in such forests, conversion to cattle pasture, affects soil P fractions along forest to pasture chronosequences in the central Brazilian Amazon and in southwestern Costa Rica. Our sites represent a broad range in rainfall, soil type, management strategies, and total soil P (45.2 - 1228.0 microng P / g soil), yet we found some unexpected and at times strikingly similar changes in soil P in all sites. In the Brazilian sites, where rainfall is relatively low and pasture management is more intense than in the Costa Rican sites, significant losses in total soil P and soil organic carbon (SOC) were seen with pasture age on both fine-textured oxisol and highly sandy entisol soils. However, P losses were largely from occluded, inorganic soil P fractions, while organic forms of soil P remained constant or increased with pasture age, despite the declines in SOC. In Costa Rica, SOC remained constant across the oxisol sites and increased from forest to pasture on the mollisols, while total soil P increased with pasture age in both sequences. The increases in total soil P were largely due to changes in organic P; occluded soil P increased only slightly in the mollisols, and remained unchanged in the older oxisols. We suggest that changes in the composition and/or the primary limiting resources of the soil microbial community may drive the changes in organic P. We also present a new conceptual model for changes in soil P following deforestation to cattle pasture.

  12. How to determine the GHG budget of a pasture field with grazing animals

    NASA Astrophysics Data System (ADS)

    Ammann, Christof; Neftel, Albrecht; Felber, Raphael

    2016-04-01

    Up to now the scientific investigation and description of the agriculture related greenhouse gas (GHG) exchange has been largely separated into (i) direct animal related and (ii) ecosystem area related processes and measurement methods. An overlap of the two usually separated topics occurs for grazed pastures, where direct animal and pasture area emissions are relevant. In the present study eddy covariance (EC) flux measurements on the field scale were combined with a source location attribution (footprint) model and with GPS position measurements of the individual animals. The experiment was performed on a pasture field in Switzerland under a rotational full grazing regime with dairy cows. The exchange fluxes of CH4, CO2, and N2O were measured simultaneously over the entire year. The observed CH4 emission fluxes correlated well with the presence of cows in the flux footprint. When converted to average emission per cow, the results agreed with published values from respiration chamber experiments with similar cows. For CO2 a sophisticated partitioning algorithm was applied to separate the pasture and animal contributions, because both were in the same order of magnitude. The N2O exchange fully attributable to the pasture soil showed considerable and continuous emissions through the entire seasonal course mainly modulated by soil moisture and temperature. The resulting GHG budget shows that the largest GHG effect of the pasture system was due to enteric CH4 emissions followed by soil N2O emissions, but that the carbon storage change was affected by a much larger uncertainty. The results demonstrate that the EC technique in combination with animal position information allows to consistently quantify the exchange of all three GHG on the pasture and to adequately distinguish between direct animal and diffuse area sources (and sinks). Yet questions concerning a standardized attribution of animal related emissions to the pasture GHG budget still need to be resolved.

  13. Limitations of Vegetation Indices For Detecting Pasture Degradation: A Case Study of Montane Pastoral Systems in Central Asia

    NASA Astrophysics Data System (ADS)

    Eddy, I. M. S.; Gergel, S. E.

    2015-12-01

    Grazing is the most extensive land use on Earth. Widespread consequences of overgrazing pastures include long-term decreases in plant biomass and limited recovery of vegetation. Remotely-sensed vegetation indices linked to biomass (e.g. NDVI) are routinely used to monitor pasture health over broad areas to track pasture degradation and recovery over time. Unfortunately, overgrazing can impact vegetation in various other ways not easily evaluated using satellite imagery, such as by altering species composition. Furthermore, the response of vegetation to grazing may be influenced by underlying terrain and topographic gradients. We examined multi-decadal trends in pasture condition in Kyrgyzstan, a country where pasture degradation is of serious concern. Using a chronosequence of Moderate-Resolution Imaging Spectroradiometer (MODIS) imagery, we compared fifteen-year trends in NDVI with contemporary field-based measurements of pasture health in thirty 1-km 2 sites. Multivariate regression was used to discern the relationship between long-term NDVI trends and pasture health in pastures of differing terrain (areas of varying topographic wetness index and solar insolation). Preliminary results suggest that pasture degradation can be correlated with either positive or negative changes in NDVI depending upon the topographic position of the pasture. Furthermore, terrain characteristics explained a considerable portion of the observed variance in NDVI trends across the region. Improving our understanding of grazing impacts in montane systems is critical given their vulnerability to impending climate change.

  14. Grazing alters the net C sink strength and the net global warming potential of a subtropical pasture

    NASA Astrophysics Data System (ADS)

    Gomez-Casanovas, N.; DeLucia, N.; DeLucia, E. H.; Boughton, E. H.; Keel, E.; Bernacchi, C.

    2014-12-01

    Grazing profoundly affects climate by altering the exchange of greenhouse gases (GHG; CO2 and CH4) between terrestrial ecosystems and the atmosphere. Little is known about how this disturbance affects the GHG exchange from subtropical pastures although they account for a substantial portion of global grazing lands. Here, we investigated how cattle grazing affect net ecosystem CO2 exchange (NEE) and CH4 emissions in subtropical semi-native pasture using the eddy covariance technique. Soil moisture was greater under grazed than ungrazed pastures but soil temperature was similar between treatments. By removing aboveground biomass, grazing reduced gross primary productivity (GPP, 16%). While ungrazed pastures had higher GPP than grazed pastures, they also had higher ecosystem respiration (Re, 20%) along with higher heterotrophic respiration. As a result, annual sums of NEE were similar in grazed and ungrazed pastures and both systems were net sinks for CO2 (-86 ± 5 gC m-2 yr-1 in grazed pasture, and -76 ± 6 gC m-2 yr-1 in ungrazed pasture). Including C removal by grazers in the C budget, grazing reduced the C sink strength (250%) and grazed pasture became a net source of C to the atmosphere. Increased soil wetness and CH4 production from enteric ruminant fermentation enhanced net ecosystem CH4 emissions (16%) in grazed than in ungrazed pastures. The net global warming potential (GWP) was higher (34%) in grazed than in ungrazed pastures, but both systems were net sources of GHGs when accounting for the radiative forcing of CH4. Our results suggest that grazing reduces the net C sink strength and increases the net GWP of subtropical pastures. Improved understanding of how grazing affects ecosystem GHG fluxes is essential to predicting the role of pastures on the global C cycle.

  15. Young restored forests increase seedling recruitment in abandoned pastures in the Southern Atlantic rainforest.

    PubMed

    Leitão, Flora H M; Marques, Marcia C M; Ceccon, Eliane

    2010-12-01

    Planting seedlings is a common technique for abandoned pastures restoration in the tropics, supposedly by increasing the seedling recruitment and accelerating succession. In this study we evaluated the role of a young restored forest (one year old) in enhancing seedling establishment from two sources (seed rain and seed bank), in the Atlantic Rainforest region in Southern Brazil. We compared abandoned pasture, young restored forest and old-growth forest with respect to the seedlings recruited from different sources, by monitoring 40 permanent plots (0.5 m x 0.5 m) over 20 months. From the three studied areas a total of 392 seedlings of 53 species were recruited. Species were mainly herbaceous (85%), pioneers (88%), zoochorous (51%) and small-seeded species (60%). Seedling recruitment from the seed bank (density and species richness) was higher and dominated by herbaceous species in the abandoned pasture and in the young restored forest; on the other hand, the recruitment of woody species from seed rain was more pronounced in the old-growth forest. The young restored forest increased the species richness of woody seedlings recruitment from the seed bank (two-fold) and from seed rain (three-fold) compared to the abandoned pasture. Also, the seedling density in young restored forest was still higher than abandoned pastures (seed bank: four times; seed rain: ten times). Our results show that even young restored areas enhance the establishment of woody species and should be considered an important step for pasture restoration. PMID:21246991

  16. Effect of Afforestation and Reforestation of Pastures on the Activity and Population Dynamics of Methanotrophic Bacteria▿

    PubMed Central

    Singh, Brajesh K.; Tate, Kevin R.; Kolipaka, Gokul; Hedley, Carolyn B.; Macdonald, Catriona A.; Millard, Peter; Murrell, J. Colin

    2007-01-01

    We investigated the effect of afforestation and reforestation of pastures on methane oxidation and the methanotrophic communities in soils from three different New Zealand sites. Methane oxidation was measured in soils from two pine (Pinus radiata) forests and one shrubland (mainly Kunzea ericoides var. ericoides) and three adjacent permanent pastures. The methane oxidation rate was consistently higher in the pine forest or shrubland soils than in the adjacent pasture soils. A combination of phospholipid fatty acid (PLFA) and stable isotope probing (SIP) analyses of these soils revealed that different methanotrophic communities were active in soils under the different vegetations. The C18 PLFAs (signature of type II methanotrophs) predominated under pine and shrublands, and C16 PLFAs (type I methanotrophs) predominated under pastures. Analysis of the methanotrophs by molecular methods revealed further differences in methanotrophic community structure under the different vegetation types. Cloning and sequencing and terminal-restriction fragment length polymorphism analysis of the particulate methane oxygenase gene (pmoA) from different samples confirmed the PLFA-SIP results that methanotrophic bacteria related to type II methanotrophs were dominant in pine forest and shrubland, and type I methanotrophs (related to Methylococcus capsulatus) were dominant in all pasture soils. We report that afforestation and reforestation of pastures caused changes in methane oxidation by altering the community structure of methanotrophic bacteria in these soils. PMID:17574997

  17. Soil carbon dynamics in pastures and forests of the eastern Amazon

    SciTech Connect

    Davidson, E.A.; Nepstad, D.C.; Trumbore, S.E. Univ. of California, Irvine )

    1993-06-01

    There is a dearth of information on below-ground C budgets of tropical forests and the ecosystems that are replacing them. Mean flux of CO[sub 2] from the soil surface was 0.29 and 0.14 g C m[sup [minus]2] h[sup [minus]1] in primary forests and degraded pastures, respectively, near Paragominas, Brazil. Litterfall and fine root inputs were about two times greater in forests than pastures. The [sup 14]C and [sup 13]C contents of SOM and CO[sub 2] in a pasture cleared in 1975 show that much of the labile forest SOM has been lost and little new C has been added by pasture vegetation. A preliminary estimate of the cumulative net C loss from the pasture soil is 2.7 kg C m[sup [minus]2] (about 10% of the forest soil C inventory), and it is still losing about 0.09 kg C m[sup [minus]2] yr[sup [minus]1]. Most of the soil C turnover occurs near the surface, but most of the long-term C storage occurs below 1 m in these oxisols. About 10% of the soil C at depth has a mean residence time of years to decades and is input by the deep roots of trees in this seasonally droughty region. Grasses have fewer deep roots, and about 1/3 of the total C lost from pasture soil was from below 1 m depth.

  18. Effect of afforestation and reforestation of pastures on the activity and population dynamics of methanotrophic bacteria.

    PubMed

    Singh, Brajesh K; Tate, Kevin R; Kolipaka, Gokul; Hedley, Carolyn B; Macdonald, Catriona A; Millard, Peter; Murrell, J Colin

    2007-08-01

    We investigated the effect of afforestation and reforestation of pastures on methane oxidation and the methanotrophic communities in soils from three different New Zealand sites. Methane oxidation was measured in soils from two pine (Pinus radiata) forests and one shrubland (mainly Kunzea ericoides var. ericoides) and three adjacent permanent pastures. The methane oxidation rate was consistently higher in the pine forest or shrubland soils than in the adjacent pasture soils. A combination of phospholipid fatty acid (PLFA) and stable isotope probing (SIP) analyses of these soils revealed that different methanotrophic communities were active in soils under the different vegetations. The C18 PLFAs (signature of type II methanotrophs) predominated under pine and shrublands, and C16 PLFAs (type I methanotrophs) predominated under pastures. Analysis of the methanotrophs by molecular methods revealed further differences in methanotrophic community structure under the different vegetation types. Cloning and sequencing and terminal-restriction fragment length polymorphism analysis of the particulate methane oxygenase gene (pmoA) from different samples confirmed the PLFA-SIP results that methanotrophic bacteria related to type II methanotrophs were dominant in pine forest and shrubland, and type I methanotrophs (related to Methylococcus capsulatus) were dominant in all pasture soils. We report that afforestation and reforestation of pastures caused changes in methane oxidation by altering the community structure of methanotrophic bacteria in these soils. PMID:17574997

  19. Sedimentation in Goose Pasture Tarn, 1965-2005, Breckenridge, Colorado

    USGS Publications Warehouse

    Elliott, John G.; Char, Stephen J.; Linhart, Samuel M.; Stephens, V. Cory; O'Neill, Gregory B.

    2006-01-01

    Goose Pasture Tarn, a 771-acre-foot reservoir in Summit County, Colorado, is the principal domestic water-storage facility for the Town of Breckenridge and collects runoff from approximately 42 square miles of the upper Blue River watershed. In the 40 years since the reservoir was constructed, deltaic deposits have accumulated at the mouths of two perennial streams that provide most of the inflow and sediment to the reservoir. The Blue River is a low-gradient braided channel and transports gravel- to silt-size sediment. Indiana Creek is a steep-gradient channel that transports boulder- to silt-size sediment. Both deltas are composed predominantly of gravel, sand, and silt, but silt has been deposited throughout the reservoir. In 2004, the U.S. Geological Survey, in cooperation with the Town of Breckenridge, began a study to determine the volume of accumulated sediment in Goose Pasture Tarn, the long-term sedimentation rate for the reservoir, and the particle-size and chemical characteristics of the sediment. Exposed delta deposits occupied 0.91 acre and had an estimated volume of 0.6 acre-foot in 2005. Aerial photographic analysis indicated both the Blue River and Indiana Creek deltas grew rapidly during time intervals that included larger-than-average annual flood peaks on the Blue River. Sediment-transport relations could not be developed for the Blue River or Indiana Creek because of minimal streamflow and infrequently observed sediment transport during the study; however, suspended-sediment loads ranged from 0.02 to 1.60 tons per day in the Blue River and from 0.06 to 1.55 tons per day in Indiana Creek. Bedload as a percentage of total load ranged from 9 to 27 percent. New reservoir stage-area and stage-capacity relations were developed from bathymetric and topographic surveys of the reservoir bed. The original 1965 reservoir bed topography and the accumulated sediment thickness were estimated from a seismic survey and manual probing. The surface area of Goose

  20. Thermal radiation absorbed by dairy cows in pasture

    NASA Astrophysics Data System (ADS)

    da Silva, Roberto Gomes; Guilhermino, Magda Maria; de Morais, Débora Andréia E. Façanha

    2010-01-01

    The goal of the present paper was to assess a method for estimating the thermal radiation absorbed by dairy cows (0.875 Holstein-0.125 Guzerath) on pasture. A field test was conducted with 472 crossbred dairy cows in three locations of a tropical region. The following environmental data were collected: air temperature, partial vapour pressure, wind speed, black globe temperature, ground surface temperature and solar radiation. Average total radiation absorbed by animals was calculated as {R_{abs}} = 640.0 ± 3.1 W.{m^{ - 2}} . Absorbed short-wave radiation (solar direct, diffuse and reflected) averaged 297.9 ± 2.7 W m-2; long wave (from the sky and from terrestrial surfaces) averaged 342.1 ± 1.5 W m-2. It was suggested that a new environmental measurement, the effective radiant heat load (ERHL), could be used to assess the effective mean radiant temperature ( {T_{mr}^* } ) . Average T_{mr}^* was 101.4 ± 1.2°C, in contrast to the usual mean radiant temperature, {T_{mr}} = 65.1 ± 0.5° C . Estimates of T_{mr}^* were considered as more reliable than those of T mr in evaluating the thermal environment in the open field, because T mr is almost totally associated only with long wave radiation.

  1. Dental pathology in conventionally fed and pasture managed dairy cattle.

    PubMed

    Fadden, A N; Poulsen, K P; Vanegas, J; Mecham, J; Bildfell, R; Stieger-Vanegas, S M

    2016-01-01

    Healthy teeth are important in the first stages of digestion for dairy cattle, yet little is known about bovine dental disease. This study aimed to investigate dental pathology of dairy cattle in two parts. First dairy cattle cadaver heads (n=11) were examined at the time of culling. Second, the authors performed oral exams in cattle fed a total mixed ration (TMR) (n=200) and pasture-based (n=71) grazing cattle. Cadaver heads were imaged using radiography and computed tomography before gross dissection to study dental anatomy and pathology. The most prevalent dental abnormalities were excessive transverse ridging of the occlusal surface, the presence of diastemas and third molar dental overgrowths (M3DO) in cadaver heads. Average thickness of subocclusal dentine ranged from 3.5 mm to 5.8 mm in cheek teeth but was >10 mm in maxillary teeth with M3DO. Radiographic findings were compared with oral examinations in live cattle. Prevalence of M3DO upon oral examination was 19 per cent and 28 per cent in herds of cattle fed a TMR diet and 0 per cent in a herd of grazing cattle. Dental abnormalities are prevalent in dairy cattle but due to thin subocclusal dentine in the cheek teeth, established equine dental treatment methodology is not appropriate for bovine cheek teeth with the exception of those that have developed M3DO. PMID:26700105

  2. High intensity, short duration rotational grazing on reclaimed cool season tall fescue/legume pastures: II. Forage production, soil and plant tissue comparisons between grazed and ungrazed pastures

    SciTech Connect

    Carlson, K.E.; Erickson, W.R.; Bonine, R.C.

    1995-09-01

    The Midway Mine is located 50 miles south of Kansas City, Kansas straddling the border of Kansas and Missouri. The Pittsburg & Midway Coal Mining Co. mined the area until 1989, when the mine was closed and reclaimed. Approximately 3,750 acres were topsoiled and revegetated with a cool season tall fescue/legume pasture. High intensity, short duration rotational grazing has become the preferred management practice on these pastures. This study evaluated soil and vegetation data collected on 1,250 acres of pasture which was grazed by about 550 cow/calf units. Ongoing monitoring programs are evaluating the effects of rotational grazing. Soil testing includes macro-nutrients, micro-nutrients and microbial activity. Plant tissue analyses monitor levels of principal macro-nutrients and micro-nutrients. Vegetation monitoring consists of measuring forage production. Results were contrasted between pregrazing and postgrazing, and grazed and ungrazed pasture. Agronomic data from the grazed versus ungrazed treatments documented the following results: (1) higher levels of plant tissue nitrate, phosphorus, potassium, calcium, magnesium, sodium and sulfur; (2) higher microbial activity; (3) similar levels of soil nitrate, phosphorus, potassium, calcium, magnesium, sodium and sulfur; and (4) increased biomass production.

  3. Consequence of forest-to-pasture conversion on CH4 fluxes in the Brazilian Amazon Basin

    NASA Astrophysics Data System (ADS)

    Steudler, Paul A.; Melillo, Jerry M.; Feigl, Brigitte J.; Neill, Christopher; Piccolo, Marisa C.; Cerri, Carlos C.

    1996-08-01

    Methane (CH4) fluxes between soils and the atmosphere were measured in two tropical forest-to-pasture chronosequences in the state of Rondônia, Brazil. Forest soils always consumed atmospheric CH4 with maximum uptake rates in the dry season. Pasture soils consumed atmospheric CH4 during the dry season, but at lower rates than those in the forests. When soil moisture increased in the pasture soils, they became a source of CH4 to the atmosphere. Integrated over the year, forest soils were a net sink of approximately 470 mg CH4-C/m2, while pastures were a net source of about 270 mg CH4-C/m2. Thus forest-to-pasture conversion resulted in a net source of CH4 from the soil of about 1 g CH4/m2/yr. The total pasture-related CH4 release for the entire Brazilian Amazon increased from 0.8 Tg CH4 in 1970 to about 2.5 Tg CH4 in 1990, with a maximum of 3.1 Tg CH4/yr in 1988. Soils accounted for a small part (about 5%) of the total CH4 release from the basin, while biomass burning and cattle emissions accounted for 95%. The average rate of increase in CH4 emission from pastures was about 0.2 Tg CH4/yr between 1975 and 1988. This represents between 12% and 14% of the global average rate of change in tropospheric CH4 content for this time period.

  4. Importance of molehill disturbances for invasion by Bunias orientalis in meadows and pastures

    NASA Astrophysics Data System (ADS)

    Kiełtyk, Piotr; Mirek, Zbigniew

    2015-04-01

    Small-scale soil disturbances by fossorial animals can change physical and biotic conditions in disturbed patches and influence spatial and temporal dynamics, and the composition of plant communities. They create regeneration niches and colonization openings for native plants and, according to the intermediate disturbance hypothesis, they are expected to increase plant community diversity. However, it also has been reported that increased disturbance resource availability and decreased competition with native species may result in the invasion of communities by alien plant species, as predicted by the fluctuating resources theory of invasibility. In this study, we investigated the importance of European mole disturbances for the invasion of semi-natural fresh meadows and pastures by the alien plant, Bunias orientalis, which has mainly spread throughout Central Europe on anthropogenically disturbed sites. We hypothesized that the invader, being particularly well adapted to anthropogenic disturbances, enters into dense vegetation of meadows and pastures mainly on mole mounds. To assess the seedling recruitment of B. orientalis in relation to disturbance, we counted the number of seedlings that emerged on molehills and control plots in meadows and pastures. The establishment of juvenile (0-1 year) rosette plants on and off molehills was surveyed on 5 × 5 m plots. In accordance with our hypothesis, mole disturbances were found to serve as a gateway for B. orientalis by which the invader may colonize semi-natural grasslands. The seedlings of the species emerged almost solely on molehills and the young rosettes were established predominantly on mole mounds. Although the seedling density did not differ significantly between the meadows and pastures, the number of established plants in the pastures was considerably higher. We suggest that the invasion by B. orientalis in pastures may be facilitated by vegetative regeneration following root fragmentation by sheep pasturing.

  5. Mapping of macro and micro nutrients of mixed pastures using airborne AisaFENIX hyperspectral imagery

    NASA Astrophysics Data System (ADS)

    Pullanagari, R. R.; Kereszturi, Gábor; Yule, I. J.

    2016-07-01

    On-farm assessment of mixed pasture nutrient concentrations is important for animal production and pasture management. Hyperspectral imaging is recognized as a potential tool to quantify the nutrient content of vegetation. However, it is a great challenge to estimate macro and micro nutrients in heterogeneous mixed pastures. In this study, canopy reflectance data was measured by using a high resolution airborne visible-to-shortwave infrared (Vis-SWIR) imaging spectrometer measuring in the wavelength region 380-2500 nm to predict nutrient concentrations, nitrogen (N) phosphorus (P), potassium (K), sulfur (S), zinc (Zn), sodium (Na), manganese (Mn) copper (Cu) and magnesium (Mg) in heterogeneous mixed pastures across a sheep and beef farm in hill country, within New Zealand. Prediction models were developed using four different methods which are included partial least squares regression (PLSR), kernel PLSR, support vector regression (SVR), random forest regression (RFR) algorithms and their performance compared using the test data. The results from the study revealed that RFR produced highest accuracy (0.55 ⩽ R2CV ⩽ 0.78; 6.68% ⩽ nRMSECV ⩽ 26.47%) compared to all other algorithms for the majority of nutrients (N, P, K, Zn, Na, Cu and Mg) described, and the remaining nutrients (S and Mn) were predicted with high accuracy (0.68 ⩽ R2CV ⩽ 0.86; 13.00% ⩽ nRMSECV ⩽ 14.64%) using SVR. The best training models were used to extrapolate over the whole farm with the purpose of predicting those pasture nutrients and expressed through pixel based spatial maps. These spatially registered nutrient maps demonstrate the range and geographical location of often large differences in pasture nutrient values which are normally not measured and therefore not included in decision making when considering more effective ways to utilized pasture.

  6. Monitoring pasture variability: optical OptRx(®) crop sensor versus Grassmaster II capacitance probe.

    PubMed

    Serrano, João M; Shahidian, Shakib; Marques da Silva, José Rafael

    2016-02-01

    Estimation of pasture productivity is an important step for the farmer in terms of planning animal stocking, organizing animal lots, and determining supplementary feeding needs throughout the year. The main objective of this work was to evaluate technologies which have potential for monitoring aspects related to spatial and temporal variability of pasture green and dry matter yield (respectively, GM and DM, in kg/ha) and support to decision making for the farmer. Two types of sensors were evaluated: an active optical sensor ("OptRx(®)," which measures the NDVI, "Normalized Difference Vegetation Index") and a capacitance probe ("GrassMaster II" which estimates plant mass). The results showed the potential of NDVI for monitoring the evolution of spatial and temporal patterns of vegetative growth of biodiverse pasture. Higher NDVI values were registered as pasture approached its greatest vegetative vigor, with a significant fall in the measured NDVI at the end of Spring, when the pasture began to dry due to the combination of higher temperatures and lower soil moisture content. This index was also effective for identifying different plant species (grasses/legumes) and variability in pasture yield. Furthermore, it was possible to develop calibration equations between the capacitance and the NDVI (R(2) = 0.757; p < 0.01), between capacitance and GM (R(2) = 0.799; p < 0.01), between capacitance and DM (R(2) =0.630; p < 0.01), between NDVI and GM (R(2) = 0.745; p < 0.01), and between capacitance and DM (R(2) = 0.524; p < 0.01). Finally, a direct relationship was obtained between NDVI and pasture moisture content (PMC, in %) and between capacitance and PMC (respectively, R(2) = 0.615; p < 0.01 and R(2) = 0.561; p < 0.01) in Alentejo dryland farming systems. PMID:26812951

  7. Effects of herbage intake on goat performance in the mediterranean type natural pastures.

    PubMed

    Hakyemez, Basri H; Gokkus, Ahmet; Savas, Turker; Yurtman, Ismail Y

    2009-02-01

    This study aimed at identifying changes in natural pastures during the grazing season and investigating the effects of these changes on pasture feeding potential for high yielding dairy goats. During the study, 12 dairy goats were grazed on a 1.5 ha natural pasture for three months from April to June in 2003, 2004 and 2005. The goats were fed 0.5 kg/day of concentrate as a supplement during the grazing season. Botanical composition, herbage production and intake, crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of the pasture were determined. Live weight, milk yield, milk dry matter (DM) and fat content of the goats were monitored. The data were analyzed using a linear model, which evaluated the effects of grazing seasons in each year. Based on the three-year average, 87% of pasture was herbaceous plants and the remaining was shrubs in DM basis with Cistus creticus, Quercus ithaburensis, Pistacia atlantica and Asparagus acutifolius being the major shrub species. The herbage yield in June was significantly lower than in other months in all years (P = 0.001). In all experimental years, the CP content of the pasture decreased but the structural carbohydrates increased as the grazing season proceeded. While live weight was not affected by grazing periods except for 2004 (P = 0.001), milk yield significantly decreased with advancing grazing period (P = 0.001). The results of the present study indicate that natural pasture has a supportive effect in April and May on the milk yield of lactating goats which are in mid-lactation, and suggested that supplementary feeding is required in consecutive grazing periods. PMID:20163465

  8. Pasture BMP effectiveness using an HRU-based subarea approach in SWAT.

    PubMed

    Sheshukov, Aleksey Y; Douglas-Mankin, Kyle R; Sinnathamby, Sumathy; Daggupati, Prasad

    2016-01-15

    Many conservation programs have been established to motivate producers to adopt best management practices (BMP) to minimize pasture runoff and nutrient loads, but a process is needed to assess BMP effectiveness to help target implementation efforts. A study was conducted to develop and demonstrate a method to evaluate water-quality impacts and the effectiveness of two widely used BMPs on a livestock pasture: off-stream watering site and stream fencing. The Soil and Water Assessment Tool (SWAT) model was built for the Pottawatomie Creek Watershed in eastern Kansas, independently calibrated at the watershed outlet for streamflow and at a pasture site for nutrients and sediment runoff, and also employed to simulate pollutant loads in a synthetic pasture. The pasture was divided into several subareas including stream, riparian zone, and two grazing zones. Five scenarios applied to both a synthetic pasture and a whole watershed were simulated to assess various combinations of widely used pasture BMPs: (1) baseline conditions with an open stream access, (2) an off-stream watering site installed in individual subareas in the pasture, and (3) stream or riparian zone fencing with an off-stream watering site. Results indicated that pollutant loads increase with increasing stocking rates whereas off-stream watering site and/or stream fencing reduce time cattle spend in the stream and nutrient loads. These two BMPs lowered organic P and N loads by more than 59% and nitrate loads by 19%, but TSS and sediment-attached P loads remained practically unchanged. An effectiveness index (EI) quantified impacts from the various combinations of off-stream watering sites and fencing in all scenarios. Stream bank contribution to pollutant loads was not accounted in the methodology due to limitations of the SWAT model, but can be incorporated in the approach if an amount of bank soil loss is known for various stocking rates. The proposed methodology provides an adaptable framework for

  9. Combining multi-spectral proximal sensors and digital cameras for monitoring grazed tropical pastures

    NASA Astrophysics Data System (ADS)

    Handcock, R. N.; Gobbett, D. L.; González, L. A.; Bishop-Hurley, G. J.; McGavin, S. L.

    2015-11-01

    Timely and accurate monitoring of pasture biomass and ground-cover is necessary in livestock production systems to ensure productive and sustainable management of forage for livestock. Interest in the use of proximal sensors for monitoring pasture status in grazing systems has increased, since such sensors can return data in near real-time, and have the potential to be deployed on large properties where remote sensing may not be suitable due to issues such as spatial scale or cloud cover. However, there are unresolved challenges in developing calibrations to convert raw sensor data to quantitative biophysical values, such as pasture biomass or vegetation ground-cover, to allow meaningful interpretation of sensor data by livestock producers. We assessed the use of multiple proximal sensors for monitoring tropical pastures with a pilot deployment of sensors at two sites on Lansdown Research Station near Townsville, Australia. Each site was monitored by a Skye SKR-four-band multi-spectral sensor (every 1 min), a digital camera (every 30 min), and a soil moisture sensor (every 1 min), each operated over 18 months. Raw data from each sensor were processed to calculate a number of multispectral vegetation indices. Visual observations of pasture characteristics, including above-ground standing biomass and ground cover, were made every 2 weeks. A methodology was developed to manage the sensor deployment and the quality control of the data collected. The data capture from the digital cameras was more reliable than the multi-spectral sensors, which had up to 63 % of data discarded after data cleaning and quality control. We found a strong relationship between sensor and pasture measurements during the wet season period of maximum pasture growth (January to April), especially when data from the multi-spectral sensors were combined with weather data. RatioNS34 (a simple band ratio between the near infrared (NIR) and lower shortwave infrared (SWIR) bands) and rainfall since 1

  10. Ecosystem services from converted land: the importance of tree cover in Amazonian pastures

    USGS Publications Warehouse

    Barrett, Kirsten; Valentim, Judson; Turner, B. L., II

    2013-01-01

    Deforestation is responsible for a substantial fraction of global carbon emissions and changes in surface energy budgets that affect climate. Deforestation losses include wildlife and human habitat, and myriad forest products on which rural and urban societies depend for food, fiber, fuel, fresh water, medicine, and recreation. Ecosystem services gained in the transition from forests to pasture and croplands, however, are often ignored in assessments of the impact of land cover change. The role of converted lands in tropical areas in terms of carbon uptake and storage is largely unknown. Pastures represent the fastest-growing form of converted land use in the tropics, even in some areas of rapid urban expansion. Tree biomass stored in these areas spans a broad range, depending on tree cover. Trees in pasture increase carbon storage, provide shade for cattle, and increase productivity of forage material. As a result, increasing fractional tree cover can provide benefits land managers as well as important ecosystem services such as reducing conversion pressure on forests adjacent to pastures. This study presents an estimation of fractional tree cover in pasture in a dynamic region on the verge of large-scale land use change. An appropriate sampling interval is established for similar studies, one that balances the need for independent samples of sufficient number to characterize a pasture in terms of fractional tree cover. This information represents a useful policy tool for government organizations and NGOs interested in encouraging ecosystem services on converted lands. Using high spatial resolution remotely sensed imagery, fractional tree cover in pasture is quantified for the municipality of Rio Branco, Brazil. A semivariogram and devolving spatial resolution are employed to determine the coarsest sampling interval that may be used, minimizing effects of spatial autocorrelation. The coarsest sampling interval that minimizes spatial dependence was about 22 m. The

  11. Dairy farm impacts of fencing riparian land: pasture production and farm productivity.

    PubMed

    Aarons, Sharon R; Melland, Alice R; Dorling, Lianne

    2013-11-30

    Dairy farmers are encouraged to restrict stock access by fencing riparian zones to reduce stream pollution and improve biodiversity. Many farmers are reluctant to create fenced riparian zones because of the perceived loss of productive pasture. Anecdotal reports indicate that pasture production in fenced areas is especially valued during summer months when water stress is likely to limit pasture growth in other areas of the farm. We measured pasture production, botanical composition, soil moisture, and fertility in Riparian (within 20 m of the riverbank), Flat (greater than 20 but less than 50 m from the riverbank), and Hill (elevated) areas on three commercial dairy farms from October 2006 to November 2007 in south eastern Australia. Riparian and Flat areas produced significantly more pasture, with on average approximately 25% more dry matter per ha grown in these areas compared with Hill paddocks. Percentage ryegrass was 14% lower on Hill slopes compared with Riparian and Flat areas and was compensated for by only a 5% increase in other grass species. Significant seasonal effects were observed with the difference in pasture production between Hill, and Riparian and Flat areas most pronounced in summer, due to soil moisture limitations on Hill paddocks. To examine potential productivity impacts of this lost pasture, we used a questionnaire-based survey to interview the farmers regarding their farm and riparian management activities. The additional pasture that would have been available if the riverbanks were not fenced to their current widths ranged from 6.2 to 27.2 t DM for the 2006/2007 year and would have been grown on 0.4-3.4% of their milking area. If this pasture was harvested instead of grazed, the farmers could have saved between $2000 and $8000 of their purchased fodder costs in that year. By fencing their riparian areas to 20 m for biodiversity benefits, between 2.2% and 9.8% of their milking area would be out of production amounting to about $16

  12. Permanent, biodiverse pastures in Montado ecosystems - biogeochemical and physiological implications for cork oak trees

    NASA Astrophysics Data System (ADS)

    Moura, C.; Dawson, T. E.; Santos Pereira, J.

    2012-12-01

    Sown biodiverse permanent pastures rich in legumes (SBPPRL) have been implemented in Portugal as a management tool to increase soil fertility, grassland productivity and animal carrying capacity and were later selected as a voluntary land-use change activity towards increased carbon sequestration within the context of the Kyoto protocol. SBPPRL are commonly found in the understory of Mediterranean-type agro-silvo-pastoral systems - Montados - with cork oak as a dominant tree species. However, little is known about the effects of these introduced pastures on co-occurring cork oak physiology and productivity. Understanding the impact of grassland conversion on carbon, water, and nutrient cycling - namely at the tree level - could be of great importance for future management and policy decisions. Cork oak trees growing in an LTER, flux-tower site in Southern Portugal have been selected among two types of understory land-use: natural grassland and sown biodiverse permanent pasture. A suite of leaf-based physiological and morphological parameters were measured in cork oak trees across both land-use scenarios and different seasons. Here we focus on the results from foliar 15δN and 13δC between spring and summer. 13δC ranged from-30.21 to -27.36, with an average value of -28.74 (± 0.12) and no significant differences found between pasture types (natural vs. improved) or time (spring vs. summer). Foliar 15δN on the other hand showed statistically significant differences between cork oaks in different pasture types (-2.96±0.09 natural vs. -2.21±0.17 improved pastures, t-test, p ≤ 0.05), but no differences across time points. Cork oak trees in the permanent pasture have a 15δN signature closer to zero, consistent with a higher percentage of legumes (and N2 fixation) in that system. Using a mixed-model approach we estimated these trees to be using ca. 25% of their nitrogen from legume-fixation in the pasture. Despite the clear signature influence of legume-fixed N

  13. Purple Prairie Clover (Dalea purpurea Vent) Reduces Fecal Shedding of Escherichia coli in Pastured Cattle.

    PubMed

    Jin, L; Wang, Y; Iwaasa, A D; Li, Y; Xu, Z; Schellenberg, M P; Liu, X L; McAllister, T A; Stanford, K

    2015-08-01

    A 3-year (2009 to 2011) grazing study was conducted to assess the effects of purple prairie clover (PPC; Dalea purpurea Vent) on fecal shedding of total Escherichia coli in cattle. Three pasture types were used in the experiment: bromegrass (Check), mixed cool season grasses with PPC (Simple), and mixed cool and warm grasses with PPC (Complex). Pastures were rotationally grazed during a summer and fall grazing period. PPC was grazed in summer at the vegetative or early flower stage and at the flower or early seed stage during the fall. Fecal samples were collected for enumeration of E. coli and chemical analyses. Forage samples were collected throughout grazing for analysis. Condensed tannins (CT) were only detected in Simple and Complex pastures that contained PPC, with higher concentrations found in the fall than in the summer. Fecal counts of E. coli in cattle grazing Simple and Complex pastures linearly decreased (P < 0.05) over summer to fall in all 3 years, an outcome not observed in cattle grazing the Check pasture. Across the three grazing seasons, fecal E. coli was lower (P < 0.05) in cattle grazing Simple and Complex pastures than in those grazing the Check pasture during the fall. During the fall, feces collected from cattle grazing the Check pasture had higher (P < 0.05) values for pH, N, NH3-N, total volatile fatty acids, and branched-chain volatile fatty acids, but a lower (P < 0.05) acetate:propionate ratio than feces collected from cattle grazing Simple or Complex pastures. In a second experiment, two strains of E. coli were cultured in M9 medium containing 25 to 200 μg/ml of PPC CT. Growth of E. coli was linearly (P < 0.01) reduced by increasing levels of PPC CT. Scanning electron micrographs showed electron-dense filamentous material associated with the outer membrane of E. coli cells exposed to CT. Incorporation of PPC into forage reduced the fecal shedding of E. coli from grazing cattle, likely due to the anti-E. coli properties of PPC CT. PMID

  14. Trace gas responses of tropical forest and pasture soils to N and P fertilization

    NASA Astrophysics Data System (ADS)

    Steudler, Paul A.; Garcia-Montiel, Diana C.; Piccolo, Marisa C.; Neill, Christopher; Melillo, Jerry M.; Feigl, Brigitte J.; Cerri, Carlos C.

    2002-05-01

    We measured the responses of nitric oxide (NO), nitrous oxide (N2O) and carbon dioxide (CO2) to nitrogen (N) and/or phosphorus (P) fertilization in a mature moist tropical forest and an 11-year-old pasture in the Brazilian Amazon. Nitrogen was applied in two forms, ammonium (NH4+) and nitrate (NO3-). In the forest, NO emissions increased by 4 to 9 times the controls in the NH4+ amended plots. Nitrous oxide emissions showed a small response only in the NH4+ amended plots. In the pasture, NO emissions during the first 7 days after fertilization with either form of N were about twice those in the control plots. Nitrous oxide emissions increased more than 18 times the controls in the NO3- amended plots 1 day after fertilization. The estimated yields of total nitrogen oxide loss from the forest were between 0.2 and 1.6% of the applied nitrogen, predominately as NO. Pasture yields were greater, up to 2.8% of the applied nitrogen, predominately as N2O. In the context of Rondônia and other regions in the Amazon Basin, pasture management practices are changing to include increased use of fertilizer, particularly in older pastures that have lower NO and N2O emissions than the original intact forests. This may lead to large short-term releases of N2O and alter the future N2O emissions from the Basin.

  15. Trace gas responses of tropical forest and pasture soils to N and P fertilization

    NASA Astrophysics Data System (ADS)

    Steudler, Paul A.; Garcia-Montiel, Diana C.; Piccolo, Marisa C.; Neill, Christopher; Melillo, Jerry M.; Feigl, Brigitte J.; Cerri, Carlos C.

    2002-06-01

    We measured the responses of nitric oxide (NO), nitrous oxide (N2O) and carbon dioxide (CO2) to nitrogen (N) and/or phosphorus (P) fertilization in a mature moist tropical forest and an 11-year-old pasture in the Brazilian Amazon. Nitrogen was applied in two forms, ammonium (NH4+) and nitrate (NO3-). In the forest, NO emissions increased by 4 to 9 times the controls in the NH4+ amended plots. Nitrous oxide emissions showed a small response only in the NH4+ amended plots. In the pasture, NO emissions during the first 7 days after fertilization with either form of N were about twice those in the control plots. Nitrous oxide emissions increased more than 18 times the controls in the NO3- amended plots 1 day after fertilization. The estimated yields of total nitrogen oxide loss from the forest were between 0.2 and 1.6% of the applied nitrogen, predominately as NO. Pasture yields were greater, up to 2.8% of the applied nitrogen, predominately as N2O. In the context of Rondônia and other regions in the Amazon Basin, pasture management practices are changing to include increased use of fertilizer, particularly in older pastures that have lower NO and N2O emissions than the original intact forests. This may lead to large short-term releases of N2O and alter the future N2O emissions from the Basin.

  16. Management of microbial contamination in storm runoff from California coastal dairy pastures.

    PubMed

    Lewis, David J; Atwill, Edward R; Lennox, Michael S; Pereira, Maria D G; Miller, Woutrina A; Conrad, Patricia A; Tate, Kenneth W

    2010-01-01

    A survey of storm runoff fecal coliform bacteria (FCB) from working farm and ranch pastures is presented in conjunction with a survey of FCB in manure management systems (MMS). The cross-sectional survey of pasture runoff was conducted on 34 pastures on five different dairies over 2 yr under varying conditions of precipitation, slope, manure management, and use of conservation practices such as vegetative filter strips. The MMS cross-sectional survey consisted of samples collected during 1 yr on nine different dairies from six loafing barns, nine primary lagoons, 12 secondary lagoons, and six irrigation sample points. Pasture runoff samples were additionally analyzed for Cryptosporidium sp. and Giardia duodenalis, whereby detectable concentrations occurred sporadically at higher FCB concentrations resulting in poor correlations with FCB. Prevalence of both parasites was lower relative to high-use areas studied simultaneously on these same farms. Application of manure to pastures more than 2 wk in advance of storm-associated runoff was related to a > or =80% reduction in FCB concentration and load compared to applications within 2 wk before a runoff event. For every 10 m of buffer length, a 24% reduction in FCB concentration was documented. A one-half (75%), one (90%), and two (99%) log10 reduction in manure FCB concentration was observed for manure holding times in MMS of approximately 20, 66, and 133 d, respectively. These results suggest that there are several management and conservation practices for working farms that may result in reduced FCB fluxes from agricultural operations. PMID:21043283

  17. Access to pasture for dairy cows: responses from an online engagement.

    PubMed

    Schuppli, C A; von Keyserlingk, M A G; Weary, D M

    2014-11-01

    An online engagement exercise documented the views of Canadian and U.S. participants affiliated and unaffiliated with the dairy industry on the issue of pasture access for dairy cows. A total of 414 people participated in 10 independent web forums. Providing access to more natural living conditions, including pasture, was viewed as important for the large majority of participants, including those affiliated with the dairy industry. This finding is at odds with current practice on the majority of farms in North America that provide little or no access to pasture. Participant comments showed that the perceived value of pasture access for dairy cattle went beyond the benefits of eating grass; participants cited as benefits exposure to fresh air, ability to move freely, ability to live in social groups, improved health, and healthier milk products. To accommodate the challenges of allowing pasture access on farms, some participants argued in favor of hybrid systems that provide a mixture of indoor confinement housing and grazing. Understanding the beliefs and concerns of participants affiliated and unaffiliated with the dairy industry allows for the identification of contentious topics as well as areas of agreement; this is important in efforts to better harmonize industry practices with societal expectations. PMID:25261215

  18. Quantifying regional, time-varying effects of cropland and pasture on vegetation fire

    NASA Astrophysics Data System (ADS)

    Rabin, S. S.; Magi, B. I.; Shevliakova, E.; Pacala, S. W.

    2015-07-01

    The global extent of agriculture demands a thorough understanding of the ways it impacts the Earth system through both the modification of the physical and biological characteristics of the landscape as well as through emissions of greenhouse gases and aerosols. People use fire to manage cropland and pasture in many parts of the world, impacting both the timing and amount of fire. So far, much previous research into how these land uses affect fire regimes has either focused on individual small regions or global patterns at annual or decadal scales. Moreover, because pasture is not mapped globally at high resolution, the amount of fire associated with pasture has never been quantified as it has for cropland. The work presented here resolves the effects of agriculture - including pasture - on fire on a monthly basis for regions across the world, using globally gridded data on fire activity and land use at 0.25° resolution. The first global estimate of pasture-associated fire reveals that it accounts for over 40 % of annual burned area. Cropland, generally assumed to reduce fire occurrence, is shown to enhance or suppress fire at different times of year within individual regions. These results bridge important gaps in the understanding of how agriculture and associated management practices influence vegetation fire, enabling the next generation of vegetation and Earth system models more realistically incorporate these anthropogenic effects.

  19. Quantifying regional, time-varying effects of cropland and pasture on vegetation fire

    NASA Astrophysics Data System (ADS)

    Rabin, S. S.; Magi, B. I.; Shevliakova, E.; Pacala, S. W.

    2015-11-01

    The global extent of agriculture demands a thorough understanding of the ways it impacts the Earth system through the modification of both the physical and biological characteristics of the landscape as well as through emissions of greenhouse gases and aerosols. People use fire to manage cropland and pasture in many parts of the world, impacting both the timing and amount of fire. So far, much previous research into how these land uses affect fire regimes has focused on either individual small regions or global patterns at annual or decadal scales. Moreover, because pasture is not mapped globally at high resolution, the amount of fire associated with pasture has never been quantified as it has for cropland. The work presented here resolves the effects of agriculture - including pasture - on fire on a monthly basis for regions across the world, using globally gridded data on fire activity and land use at 0.25° resolution. The first global estimate of pasture-associated fire reveals that it accounts for over 40 % of annual burned area. Cropland, generally assumed to reduce fire occurrence, is shown to enhance or suppress fire at different times of year within individual regions. These results bridge important gaps in the understanding of how agriculture and associated management practices influence vegetation fire, enabling the next generation of vegetation and Earth system models more realistically incorporate these anthropogenic effects.

  20. Pasture degradation modifies the water and carbon cycles of the Tibetan highlands

    NASA Astrophysics Data System (ADS)

    Babel, W.; Biermann, T.; Coners, H.; Falge, E.; Seeber, E.; Ingrisch, J.; Schleuß, P.-M.; Gerken, T.; Leonbacher, J.; Leipold, T.; Willinghöfer, S.; Schützenmeister, K.; Shibistova, O.; Becker, L.; Hafner, S.; Spielvogel, S.; Li, X.; Xu, X.; Sun, Y.; Zhang, L.; Yang, Y.; Ma, Y.; Wesche, K.; Graf, H.-F.; Leuschner, C.; Guggenberger, G.; Kuzyakov, Y.; Miehe, G.; Foken, T.

    2014-12-01

    The Tibetan Plateau has a significant role with regard to atmospheric circulation and the monsoon in particular. Changes between a closed plant cover and open bare soil are one of the striking effects of land use degradation observed with unsustainable range management or climate change, but experiments investigating changes of surface properties and processes together with atmospheric feedbacks are rare and have not been undertaken in the world's two largest alpine ecosystems, the alpine steppe and the Kobresia pygmaea pastures of the Tibetan Plateau. We connected measurements of micro-lysimeter, chamber, 13C labelling, and eddy covariance and combined the observations with land surface and atmospheric models, adapted to the highland conditions. This allowed us to analyse how three degradation stages affect the water and carbon cycle of pastures on the landscape scale within the core region of the Kobresia pygmaea ecosystem. The study revealed that increasing degradation of the Kobresia turf affects carbon allocation and strongly reduces the carbon uptake, compromising the function of Kobresia pastures as a carbon sink. Pasture degradation leads to a shift from transpiration to evaporation while a change in the sum of evapotranspiration over a longer period cannot be confirmed. The results show an earlier onset of convection and cloud generation, likely triggered by a shift in evapotranspiration timing when dominated by evaporation. Consequently, precipitation starts earlier and clouds decrease the incoming solar radiation. In summary, the changes in surface properties by pasture degradation found on the highland have a significant influence on larger scales.

  1. Pasture degradation modifies the water and carbon cycles of the Tibetan highlands

    NASA Astrophysics Data System (ADS)

    Babel, W.; Biermann, T.; Coners, H.; Falge, E.; Seeber, E.; Ingrisch, J.; Schleuß, P.-M.; Gerken, T.; Leonbacher, J.; Leipold, T.; Willinghöfer, S.; Schützenmeister, K.; Shibistova, O.; Becker, L.; Hafner, S.; Spielvogel, S.; Li, X.; Xu, X.; Sun, Y.; Zhang, L.; Yang, Y.; Ma, Y.; Wesche, K.; Graf, H.-F.; Leuschner, C.; Guggenberger, G.; Kuzyakov, Y.; Miehe, G.; Foken, T.

    2014-06-01

    The Tibetan Plateau has a significant role with regard to atmospheric circulation and the monsoon in particular. Changes between a closed plant cover and open bare soil are one of the striking effects of land use degradation observed with unsustainable range management or climate change, but experiments coupling changes of surface properties and processes with atmospheric feedbacks are rare and have not been undertaken in the world's two largest alpine ecosystems, the alpine steppe and the Kobresia pygmaea pastures of the Tibetan plateau. We coupled measurements of micro-lysimeter, chamber, 13C labeling, and eddy-covariance and combined the observations with land surface and atmospheric models, adapted to the highland conditions. This allowed us to analyze how three degradation stages affect the water and carbon cycle of pastures on the landscape scale within the core region of the Kobresia pygmaea ecosystem. The study revealed that increasing degradation of the Kobresia turf affects carbon allocation and strongly reduces the carbon uptake, compromising the function of Kobresia pastures as a carbon sink. Pasture degradation leads to a shift from transpiration to evaporation while the total sum of evapotranspiration remains unaffected. The results show an earlier onset of convection and cloud generation, likely triggered by enhanced evaporation. Consequently, precipitation starts earlier and clouds decrease the incoming solar radiation. In summary, the changes in surface properties by pasture degradation found on the highland have a~significant influence on larger scales.

  2. Tropical rain forest conversion to pasture: Changes in vegetation and soil properties

    SciTech Connect

    Reiners, W.A. ); Bouwman, A.F. ); Parsons, W.F.J. Institute of Marine and Coastal Sciences, Rugers Univ., New Brunswick, NJ ); Keller, M. )

    1994-05-01

    The effect of converting lowland tropical rainforest to pasture, and of subsequent succession of pasture lands to secondary forest, were examined in the Atlantic Zone of Costa Rica. Three replicate sites of each of four land-use types representing this disturbance-recovery sequence were sampled for changes in vegetation, pedological properties, and potential nitrogen mineralization and nitrification. The four land-use types included primary forest, actively grazed pasture (10-36 yr old), abandoned pasture (abandoned 4-10 yr) and secondary forest (abandoned 10-20 yr). Conversion and succession had obvious and significant effects on canopy cover, canopy height, species composition, and species richness; it appeared that succession of secondary forests was proceeding toward a floristic composition like that of the primary forests. Significant changes in soil properties associated with conversion of forest to pasture included: (1) a decrease in acidity and increase in some base exchange properties, (2) and increase in bulk density and a concomitant decrease in porosity, (3) higher concentrations of NH[sub 4][sup +], (4) lower concentrations of NO[sub 3][sup [minus

  3. Steers performance in dwarf elephant grass pastures alone or mixed with Arachis pintoi.

    PubMed

    Crestani, Steben; Ribeiro Filho, Henrique Mendonça Nunes; Miguel, Marcolino Frederico; de Almeida, Edison Xavier; Santos, Flávio Augusto Portela

    2013-08-01

    The inclusion of legumes in pasture reduces the need for mineral nitrogen applications and the pollution of groundwater; however, the agronomic and animal husbandry advantages with tropical legumes are still little known. The objective of this study was to quantify the effect of the use of forage peanut (Arachis pintoi cv. Amarillo) in dwarf elephant grass pastures (Pennisetum purpureum cv. BRS Kurumi) on forage intake and animal performance. The experimental treatments were dwarf elephant grass fertilized with 200 kg N/ha, and dwarf elephant grass mixed with forage peanut without mineral fertilizers. The animals used for the experiment were 12 Charolais steers (body weight (BW) = 288 ± 5.2 kg) divided into four lots (two per treatment). Pastures were managed under intermittent stocking with an herbage allowance of 5.4 kg dry matter of green leaves/100 kg BW. Dry matter intake (mean = 2.44% BW), the average daily gain (mean = 0.76 kg), and the stocking rate (mean = 3.8 AU/ha) were similar between the studied pastures, but decreased drastically in last grazing cycle with the same herbage allowance. The presence of peanut in dwarf elephant grass pastures was enough to sustain the stocking rate, but did not allow increasing forage intake and animal performance. PMID:23413007

  4. Environmental determinants of the old oaks in wood-pastures from a changing traditional social-ecological system of Romania.

    PubMed

    Moga, Cosmin Ioan; Samoilă, Ciprian; Öllerer, Kinga; Băncilă, Raluca I; Réti, Kinga-Olga; Craioveanu, Cristina; Poszet, Szilárd; Rákosy, László; Hartel, Tibor

    2016-05-01

    Large, old trees are keystone ecological structures, their decline having disproportional ecological consequences. There is virtually no information available regarding the status and occurrence of old trees in traditional cultural landscapes from Eastern Europe. In this study, we explore the environmental determinants of the old oaks found in wood-pastures from a changing traditional rural landscape from Central Romania. Both the old oaks and the wood-pastures harboring them have exceptional cultural, historical, and ecological values, yet are vulnerable to land-use change. We surveyed 41 wood-pastures from Southern Transylvania and counted the old oaks in them. We then related the number of old oaks from these wood-pastures to a set of local and landscape level variables related to wood-pastures. We found 490 old oaks in 25 wood-pastures. The number of old oaks was positively related to the size of the wood-pasture and the amount of pasture and forest around it (500 m buffer), and negatively related to the proximity of the village. Furthermore, we found a significant interaction between the effects of sheepfolds in the wood-pasture and the size of the wood-pasture on the number of old trees, indicating a negative influence of sheepfolds on the number of old trees in smaller sized wood-pastures. There is an increasing risk for losing old trees in the traditional cultural landscapes due to the lack of formal recognition of these trees. Therefore, while presenting the positive example of local initiatives and citizen science, we argue for an urgent development and implementation of conservation policies along with education strategies targeting the old trees and rural communities from the changing traditional cultural landscapes of Eastern Europe. PMID:26729244

  5. Characterization of two Agrostis-Festuca alpine pastures and their influence on cheese composition.

    PubMed

    Povolo, Milena; Pelizzola, Valeria; Passolungo, Luigi; Biazzi, Elisa; Tava, Aldo; Contarini, Giovanna

    2013-01-16

    Recently, there has been a renewed interest in mountain farming, and several studies have been carried out on milk and cheese obtained in the unique environmental conditions of the Alps, a 1300 km mountain chain, located in the north of Italy. In this paper, the influence, on some cheese constituents, of two very similar mountain grasslands, both dominated by Festuca - Agrostis , was investigated. The two pastures were located in the same area in the southeastern Italian alpine region and differed in sunshine orientation and exposure. Milk obtained from cows grazing on these pastures was used to produce a semi-hard traditional cheese. The differences observed between the cheeses of the two areas for both some hydrocarbons (1-phytene and 2-phytene) and trans-fatty acids can be explained by a different rumen environment created by the botanical composition of the two pastures. The multidisciplinary approach can be considered a successful strategy, suitable for studying markers of authenticity. PMID:23259614

  6. An application example of the LANDSAT data to the study of the relationship between the topography and pasture quality in areas of Paragominas. [Brazil

    NASA Technical Reports Server (NTRS)

    Dejesusparada, N. (Principal Investigator); Dossantos, A. P.; Demoraesnovo, E. M. L.; Duarte, V.

    1980-01-01

    The relationship between pasture quality and geomorphology was verified by applying visual and automatic interpretation techniques to LANDSAT data. The results show that LANDSAT data is useful to point out better areas to settle pastures.

  7. Urea metabolism in beef steers grazing bermudagrass, caucasian bluestem, or gamagrass pastures varying in plant morphology, protein content, and protein composition.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our objective was to evaluate pastures of bermudagrass (Cynodon dactylon, BG), caucasian bluestem (Bothriochloa caucasica, CBS), and gamagrass (Tripsacum dactyloides, GG) from the perspectives of forage composition, selection during grazing, and N metabolism in beef steers. All pastures were ferti...

  8. [Allelopathic effects of extracts from tuberous roots of Aconitum carmichaeli on three pasture grasses].

    PubMed

    Jiao, Yu-jie; Wang, Ya-qi; Yuan, Ling

    2015-11-01

    The tuberous roots of Aconitum carmichaeli are largely used in traditional Chinese medicine and widely grown in Jiangyou, Sichuan, China. During the growth process, this medicinal plant releases a large amount of allelochemicals into soil, which retard the growth and development of near and late crops. Therefore, a pure culture experiment was thus carried out by seed soaking to study the allelopathic effects of extracts from tuberous roots of A. carmichaeli (ETR) on the seed germination and young seedling growth of Lolium perenne, Trifolium repens, and Medicago sativa, the late pasture grasses after cultivation of A. carmichaeli. The results showed that three pasture grasses varied significantly in seed germination and young seedling growth in response to ETR concentrations. Seed germination of M. sativa was stimulated by low ERT concentration (0.01 x g(-1)), while all of pasture grass seeds germinated poorly in solution with 1.00 g x L(-1). Seed soaking with 1.00 g x L(-1) also inhibited significantly the growth of pasture young seedlings, with M. sativa showing the highest seedling height reduction of 42.05% in seeding height, followed by T. repens (40.21%) and L. perenne with about 11%. Cultivation of L. perenne could thus be beneficial to increase whole land productivity in A. carmichaeli-pasture grass cropping systems. In addition, hydrolysis of protein, starch, and inositol phosphates was blocked and free amino acids, soluble sugars and phosphorus were decreased in seeds by seed soaking with ETR, which could be one of the reason for the inhibition of seed germination. There was a significant reduction in root vigor, nitrate reductase, and chlorophyll after the seed treatment with ETR, indicating the suppression of nutrient uptake, nitrate assimilation, and photosynthesis by allelopathic chemicals in ETR, which could lead to the slow growth rate of pasture grass seedlings. PMID:27071248

  9. Plant Diversity in Live Fences and Pastures, Two Examples from the Mexican Humid Tropics

    NASA Astrophysics Data System (ADS)

    Ruiz-Guerra, Betsabé; Rosas, Noé Velázquez; López-Acosta, Juan Carlos

    2014-09-01

    This study analyzes the potential uses of live fences and pastures as reservoirs of plant diversity for two regions with different management histories, Los Tuxtlas (LT) and Uxpanapa (UX), Veracruz, México. We studied two habitats, live fences and pastures, analyzed their species richness, diversity, structure and plant composition and classified species according to plant regeneration modes (light-demanding and shade tolerant), seed dispersal syndrome and their local uses. We recorded 62 species of trees at LT and 48 at UX. Live fences were more diverse than pastures in both regions. The LT site showed to analyze the relationship a higher diversity of plants in regeneration stages than the one at UX. However, UX had higher diversity of adult plants in the pastures than LT. Composition and structure of live fences were different between regions, as well as within live fences and pastures, 53 % of species were light-demanding and 40 % were shade tolerant; 70 % of the species were dispersed by birds. Differences between sites are associated with the modifications in live fences structure, which changed according to managerial practices and the use of local species; this may influence plant regeneration modes as well as the visits of avian dispersal agents. In LT, all species found in live fences were useful to humans, whereas in UX, less than half were used by the local population. Our results underline the importance of live fences and isolated trees in pasture habitats as potential sites to host native and useful species from tropical rain forests in livestock landscapes.

  10. Influence of Poultry Litter Application Methods on the Longevity of Nutrient and E. coli in Runoff from Tall Fescue Pasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Significant quantities of the broiler (chicken, Gallus gallus domesticus) litter produced in the U.S. are being applied to pasture lands. The traditional surface- broadcast application of animal manure onto permanent pasture, however, may lead to high concentration of nutrients and pathogenic micro...

  11. Water quantity and quality from a small Georgia Piedmont pasture during 1998-2009: Impact of drought

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The water quality impact of pasture grazing in the Piedmont, which generally occurs under low-input management, is not well studied. Cattle, hydrologic and water quality data were collected from 1999 to 2009 from a rotationally grazed 7.8-ha pasture near Watkinsville Georgia. Grazing occurred during...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. Feeding strategy and pasture quality relative to nutrient requirements of grazing dairy cows in the Northeastern U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pasture samples (n = 229) collected during the grazing season from 14 organic dairy farms in 2012 (PA, ME, NY, NH, VT) and from 11 of the same farms in 2013 (PA, ME, NY, NH) were analyzed for nutritional composition. Frequency analysis was used to determine the proportions of pasture samples that me...

  14. Feeding strategy and pasture quality relative to nutrient requirements of dairy cows in the northeastern U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pasture samples (n = 380) collected during the grazing season on 14 dairy farms from 2012 to 2014 were analyzed for nutritional composition to determine the frequency of pasture samples that met minimum net energy for lactation (NEl), crude protein (CP), and macro-mineral requirements according to t...

  15. Effect of forage species during finishing on growth rate, final weight and carcass parameters from pasture finished cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2005 and 2006, angus-crossbred steers (n = 72) were used to compare growth rate, final weight and carcass parameters from pasture-finished cattle grazing cool-season mixed (MP), alfalfa (AL), or pearl millet (PM) pastures during the final 44 d of finishing. Steers were harvested on the same dates...

  16. Spatial Distribution of Soil Carbon in Pastures with Cow-Calf Operation: Effects of Slope Aspect and Slope Position

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The forests of the world have been the focus of most of the research on terrestrial C sequestration while other parts of the agro-ecological systems like pastures or grasslands have received less research attention. Broad knowledge of cattle movement in pasture situations is critical to understandin...

  17. Eastern Gamagrass Management for Pastures in the Mid-Atlantic Region: II. Diet and Canopy Characteristics and Stand Persistence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eastern gamagrass [Tripsacum dactyloides (L.) L.], a native warm-season perennial grass, lacks evaluation for use in grazing systems. Our objective was to test eastern gamagrass (EG) in a 4-yr experiment to estimate forage mass (FM) that maximizes steer performance and pasture productivity. Pasture ...

  18. Nitrous oxide emissions and herbage accumulation in smooth bromegrass pastures with nitrogen fertilizer and ruminant urine application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural soils contribute significantly to nitrous oxide (N2O) emissions, but little data is available on N2O emissions from smooth bromegrass (Bromus inermis Leyss.) pastures. This study evaluated soil N2O emissions and herbage accumulation from smooth bromegrass pasture in eastern Nebraska, US...

  19. The effects of protein supplement on leptin concentrations in lambs and meat goat kids grazing Bermudagrass pastures in Central Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lambs and kids weaned and pastured on bermudagrass (BG; Cynodon dactylon) may not receive enough protein to reach maximal growth during mid to late summer when protein in BG pastures declines. As an indicator of physiological status, leptin is an adipocyte-derived hormone that increases as body cond...

  20. Runoff phosphorus in a small rotationally-grazed pasture in Georgia with no history of broiler litter application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pastures are sources of phosphorus (P) into water sources and can contribute to eutrophication and impairment. Close to 4 million ha of land in the Southern Coastal Plain and the Southern Piedmont in eastern USA is used for pasture and hay production. We present an 11-yr (1999 to 2009) of dissolved ...

  1. Characterization of soil microbial community dynamics related to C and P cycling along a forest to pasture gradient

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the Appalachian Mountains region landscape fragmentation due to farming practices results in areas with gradual blending of forests and pastures ecosystems. Soil nutrient cycling in the open land-forest boundary may be significantly different than in the forest soil or in the pasture soil and th...

  2. Cattle and pasture responses to poultry and tall fescue-endophyte association in the Southern Piedmont USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tall fescue pastures are an important part of the agricultural landscape in the southeastern USA. Tall fescue seed sources with low-ergot-alkaloid-producing strains of Neotyphodium endophyte have raised a number of questions regarding pasture ecology, animal performance, and nutrient cycling. We e...

  3. Evaporation rates of pasture-mesquite vegetation in central Mexico

    NASA Astrophysics Data System (ADS)

    Sosa, E. G.; Escobar, A. G.

    2004-12-01

    from 1.1 to 2.0 mm d-1, maximum E was 4.3 mm d-1 on sunny days and the average E was 3.1 mm d-1. Average daily E increased during the measuring period at a rate of 0.05 mm d-1 (r2=0.2, p<0.05). Data suggest that evaporation from a pasture-mesquite vegetation is an important component in the water balance considering the limited rainfall occurring.

  4. Factors associated with the financial performance of spring-calving, pasture-based dairy farms.

    PubMed

    Ramsbottom, G; Horan, B; Berry, D P; Roche, J R

    2015-05-01

    As land becomes a limiting resource for pasture-based dairy farming, the inclusion of purchased supplementary feeds to increase milk production per cow (through greater dry matter intake) and per hectare (through increased stocking rate) is often proposed as a strategy to increase profitability. Although a plausible proposition, virtually no analysis has been done on the effect of such intensification on the profitability of commercial pasture-based dairy farm businesses. The objective of this study was to characterize the average physical and financial performance of dairy systems differing in the proportion of the cow's diet coming from grazed pasture versus purchased supplementary feeds over 4 yr, while accounting for any interaction with geographic region. Physical, genetic, and financial performance data from 1,561 seasonal-calving, pasture-based dairy farms in Ireland were available between the years 2008 and 2011; data from some herds were available for more than 1 yr of the 4-yr study period, providing data from 2,759 dairy farm-years. The data set was divided into geographic regions, based on latitude, rainfall, and soil characteristics that relate to drainage; these factors influence the length of the pasture growth season and the timing of turnout to pasture in spring and rehousing in autumn. Farms were also categorized by the quantity of feed purchased; farms in which cows received <10, 11-20, 21-30, or >30% of their annual feed requirements from purchased feed were considered to be categories representative of increasing levels of system intensification. Geographic region was associated with differences in grazing days, pasture harvested per hectare, milk production per cow and per hectare, and farm profitability. Farms in regions with longer grazing seasons harvested a greater amount of pasture [an additional 19kg of dry matter (DM)/ha per grazing day per hectare], and greater pasture harvested was associated with increased milk component yield per

  5. The multi-year cumulative effects of alternative stocking rate and grazing management practices on pasture productivity and utilization efficiency.

    PubMed

    McCarthy, B; Delaby, L; Pierce, K M; McCarthy, J; Fleming, C; Brennan, A; Horan, B

    2016-05-01

    The production and utilization of increased quantities of high quality pasture is of paramount importance in pasture-based milk production systems. The objective of this study was to evaluate the cumulative effects of alternative integrated grazing strategies, incorporating alternative stocking rate (SR) and grazing severities, on pasture productivity and grazing efficiency over multiple years within farm systems using perennial ryegrass dominant pastures. Three whole-farm SR treatments were compared over 4 complete grazing seasons (2009 to 2012 inclusive): low (2.51 cows/ha; LSR), medium (2.92 cows/ha; MSR), and high (3.28 cows/ha; HSR). Each system had its own farmlet containing 18 paddocks and remained on the same treatment for the duration of the study. Stocking rate had a significant effect on all grazing variables with the exception of soil fertility status and sward density. Increased SR resulted in increased total annual net pasture accumulation, improved sward nutritive value, and increased grazed pasture utilization. Total annual net pasture accumulation was greatest in HSR [15,410kg of dry matter (DM)/ha], intermediate for MSR (14,992kg of DM/ha), and least for LSR (14,479kg of DM/ha) during the 4-yr study period. A linear effect of SR on net pasture accumulation was detected with an increase in net pasture accumulation of 1,164.4 (SE=432.7) kg of DM/ha for each 1 cow/ha increase in SR. Pregrazing pasture mass and height and postgrazing residual pasture mass and height were greatest for LSR, intermediate for the MSR, and lowest for the HSR. In comparison with the LSR, the imposition of a consistently increased grazing severity coupled with increased whole farm SR in MSR and HSR treatments arrested the decline in sward nutritive value, typically observed during mid-season. Incorporating the individual beneficial effects of SR on pasture accumulation, nutritive value, and utilization efficiency, total proportional energy (unité fourragère lait

  6. Case study of a commercial sheep flock under extensive mountain grazing: Pasture derived lipid compounds in milk and cheese.

    PubMed

    Valdivielso, I; Bustamante, M A; Aldezabal, A; Amores, G; Virto, M; Ruiz de Gordoa, J C; de Renobales, M; Barron, L J R

    2016-04-15

    Terpenoid, fat-soluble antioxidant and fatty acid (FA) composition of pasture as well as those of milk and cheese from a commercial sheep flock managed under extensive mountain grazing in the east region of the Cantabrian mountain (Northern Spain) was investigated. The grazing period lasted for 2 months and ewes were at late lactation stage. Plants, feces, bulk milk and cheese samples were collected on two sampling dates. The abundance of the dominating botanical families in the mountain pasture prevailed in the sheep diet of the commercial flock. Major terpenoids and tocols in the pasture appeared as major ones in milk and cheese, whereas C18 unsaturated FAs in milk and cheese were derived from the intake of C18 polyunsaturated FAs which were prevalent in the pasture. No carotene was detected in the dairy samples but retinol (free or esterified), derived from the intake of β-carotene present in pasture plants, was found in milk and cheese. PMID:26616996

  7. The role of pasture and soybean in deforestation of the Brazilian Amazon

    NASA Astrophysics Data System (ADS)

    Barona, Elizabeth; Ramankutty, Navin; Hyman, Glenn; Coomes, Oliver T.

    2010-04-01

    The dynamics of deforestation in the Brazilian Amazon are complex. A growing debate considers the extent to which deforestation is a result of the expansion of the Brazilian soy industry. Most recent analyses suggest that deforestation is driven by the expansion of cattle ranching, rather than soy. Soy seems to be replacing previously deforested land and/or land previously under pasture. In this study, we use municipality-level statistics on agricultural and deforested areas across the Legal Amazon from 2000 to 2006 to examine the spatial patterns and statistical relationships between deforestation and changes in pasture and soybean areas. Our results support previous studies that showed that deforestation is predominantly a result of pasture expansion. However, we also find support for the hypothesis that an increase of soy in Mato Grosso has displaced pasture further north, leading to deforestation elsewhere. Although not conclusive, our findings suggest that the debate surrounding the drivers of Amazon deforestation is not over, and that indirect causal links between soy and deforestation may exist that need further exploration. Future research should examine more closely how interlinkages between land area, prices, and policies influence the relationship between soy and deforestation, in order to make a conclusive case for 'displacement deforestation'.

  8. Biogenic NO emissions from forest and pasture soils: Relating laboratory studies to field measurements

    NASA Astrophysics Data System (ADS)

    van Dijk, S. M.; Gut, A.; Kirkman, G. A.; Gomes, B. M.; Meixner, F. X.; Andreae, M. O.

    2002-10-01

    During September and October 1999, dynamic chamber measurements were carried out to determine nitric oxide (NO) fluxes from a primary forest soil and an old pasture in the Brazilian Amazon basin as part of the project "European Studies of Trace Gases and Atmospheric Chemistry as a Contribution to the Large-Scale Biosphere-Atmosphere Experiment in Amazonia" (LBA-EUSTACH). In addition, soil samples were collected from these two sites, and laboratory experiments were conducted to determine the NO production and consumption rate constants as functions of soil temperature and soil moisture. These laboratory results were converted into NO fluxes using a simple algorithm, which required additional information on the gas diffusion in soil, the soil bulk density, and the field conditions (soil temperature and soil moisture). Over the entire measurement period, the calculated and measured NO fluxes agreed well both for the forest (6.9 ± 2.9 and 5.0 ± 4.6 ng m-2 s-1, respectively) and for the pasture (0.67 ± 0.09 and 0.65 ± 0.37 ng m-2 s-1, respectively). Forest to pasture conversion decreased NO production and gas diffusion and resulted in smaller NO fluxes from pasture than forest soil.

  9. Plant Species Diversity and Distribution in Pastures of the Northeastern USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazed pastures in the northeastern United contain far more than planted forage species. These species may contribute to forage production, but they may also detract from forage production or palatability. As the first step toward identifying the role of plant diversity in forage systems, we collect...

  10. APPLYING THE NRCS PASTURE CONDITION SCORE SYSTEM AT THE WHOLE-FARM SCALE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Pasture Condition Score (PCS) system was developed by the USDA-NRCS as a monitoring and management tool. Ten key indicators (percent desirable plants, plant cover, plant diversity, plant residue, plant vigor, percent legume, uniformity of use, livestock concentration areas, soil compaction, and ...

  11. Calibration and use of plate meter regressions for pasture mass estimation in an Appalachian silvopasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A standardized plate meter for measuring pasture mass was calibrated at the Agroforestry Research and Demonstration Site in Blacksburg, VA, using six ungrazed plots of established tall fescue (Festuca arundinaceae) overseeded with orchardgrass (Dactylis glomerata). Each plot was interplanted with b...

  12. RESPONSE OF YELLOW BLUESTEM PASTURES TO PRESCRIBED BURNING AND HERBICIDE APPLICATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prescribed burning and herbicide application are commonly used for management of introduced pastures in the Southern Plains but their quantitative impact is not well documented. We determined the impact of prescribed burning or herbicide application on forb populations, the production and nutritive...

  13. Performance by Fall-Calving Cows Grazing Tall Fescue Pastures with Different Proportions Stockpiled

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tall fescue [Lolium arundinaceum (Schreb.) Darbysh.] is often stockpiled to reduce winter feed costs for cattle. Over two consecutive years, a total of 158 Gelbvieh × Angus fall-calving cows (599 ± 6.0 kg) were allocated randomly to one of eight 10-ha tall fescue pastures (subdivided into six 1.6-h...

  14. Diet Selection Fact Sheet - Choices, Choices, Choices- Interpreting the Pasture "Salad Bar"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This fact sheet summarizes some of the current knowledge regarding grazing behavior. A grazing ruminant is presented with a smorgasbord of choices when turned out onto a pasture. However, little is understood on how selection decisions are made by the animal. Grazing behavior research is attempting...

  15. Fatty acid composition in adipose tissue of pasture and feedlot-finished beef steers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twenty-seven Angus crossbred steers were used to evaluate the effects of N fertilization on pasture- vs. feedlot-finishing beef steers on fatty acid (FA) composition in subcutaneous adipose tissue. A completely randomized design with repeated measures was used with steers arranged into 3 treatments...

  16. Occurrence of condensed tannins in wheat and feasibility for reducing pasture bloat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Frothy bloat can be a serious problem with winter wheat (Triticum aestivum L.) pastures, the primary source of cool-season forage in the southern Great Plains. Some forage contains tannins that reduce the incidence and severity of bloat and promote better use of forage protein. The objective of our ...

  17. Quality of runoff from a small Piedmont pasture with periods of drought

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Approximately 11% of the Piedmont (1.8 million ha) is used as pastures and hay fields, mostly under low-input management. Animal manure can lead to enrichments of surface soils with nutrients leading to elevated water quality concerns. We present 11 years (1999-2009) of hydrologic and water quality...

  18. Meat goat kids finished on alfalfa, red clover, or orchardgrass pastures: Carcass merit and meat quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This experiment was conducted in 2005-2007 to evaluate carcass and meat quality parameters when meat goat kids were finished on alfalfa (Medicago sativa L; ALF); red clover (Trifolium pretense L.; RCG); or orchardgrass (Dactylis glomerata L; OGR) pastures. Final shrunk body weights were similar whe...

  19. Steer responses to feeding soybean hulls and steroid hormone implantation on toxic tall fescue pasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yearling steers were grazed on endophyte-infected ‘Kentucky-31’ tall fescue (Lolium arundinaceum) pastures for 77 days in 2007 and for 86 days in 2008 to evaluate effects of feeding pelleted soybean hulls (PSBH) and steroid hormone implants (SHI) on steer performance and physiology. Steers were str...

  20. Long-term dynamics of labile and stable phosphorus following poultry litter application to pasture soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nonpoint-source agricultural P runoff can accelerate eutrophication of surface water ecosystems. Land-applied animal manure is sometimes identified as a source of runoff P from agricultural soils. We evaluated the quantities and forms of P from pasture soils in Alabama receiving poultry litter (PL...

  1. Genome Sequence of "Pedosphaera parvula" Ellin514, an Aerobic Verrucomicrobial Isolate from Pasture Soil

    SciTech Connect

    Kant, Ravi; Van Passel, Mark W.J.; Palva, Airi; Lucas, Susan; Copeland, A; Lapidus, Alla L.; Glavina Del Rio, Tijana; Dalin, Eileen; Tice, Hope; Bruce, David; Goodwin, Lynne A.; Pitluck, Sam; Chertkov, Olga; Larimer, Frank W; Land, Miriam L; Hauser, Loren John; Brettin, Thomas S; Detter, J. Chris; Han, Cliff; De Vos, Willem M.; Janssen, Peter H.; Smidt, Hauke

    2011-01-01

    Pedosphaera parvula Ellin514 is an aerobically grown verrucomicrobial isolate from pasture soil. In contrast to the high abundance of members of Verrucomicrobia subdivision 3 based on molecular surveys in terrestrial environments, Ellin514 is one of the few cultured representatives of this group.

  2. A New Method of Poultry Litter Application to Perennial Pasture: Subsurface Banding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, incorporation of poultry litter by subsurface band application into pasture has been shown to dramatically reduce surface runoff transport of environmentally sensitive nutrients and pathogens. However, no data are currently available to evaluate the impact of this potential litter managem...

  3. The Impact of Coffee and Pasture Agriculture on Predatory and Omnivorous Leaf-Litter Ants

    PubMed Central

    Dias, Nivia da Silva; Zanetti, Ronald; Santos, Mônica Silva; Peñaflor, Maria Fernanda Gomes Villalba; Broglio, Sônia Maria Forti; Delabie, Jacques Hubert Charles

    2013-01-01

    Ants are known to function as reliable biological indicators for habitat impact assessment. They play a wide range of ecological roles depending on their feeding and nesting habits. By clustering ants in guilds, it is possible both to assess how agriculture and forest fragmentation can disturb ant communities and to predict the ecological impacts due to losses of a specific guild. This study aimed at determining the impact of non-shaded coffee and pasture agriculture on predatory and omnivorous guilds of leaf-litter ants of Atlantic Forest fragments in Minas Gerais, Brazil. Both coffee and pasture agriculture influenced leaf-litter ant community, although coffee was more disruptive than pasture. Coffee agriculture not only disturbed the diversity of predatory ants, but also negatively affected the number of predatory and omnivorous ants when compared to forest fragments. In contrast, pasture agriculture only disrupted the abundance of predatory ants. Fragment edges skirting crops were negatively affected in terms of leaf-litter ant abundance, but not diversity. Cluster analysis showed that forest fragments were similar irrespective of the cultivation, but the borders were similar to the crop. The study assessed agriculture impact by surveying ant guilds, and revealed that the predatory guild is more susceptible than omnivorous ants. PMID:23902334

  4. Streambank Erosion from Grazed Pastures, Grass Filters and Forest Buffers Over a Six-Year Period

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In agricultural landscapes, streambank erosion, as a source of non-point water pollution, is one of the major contributors to stream habitat degradation. Streambank erosion rates from riparian forest buffers, grass filters and grazed pastures (stocking rates ranged from 0.23 to 1.15 cow-days ha-1 m-...

  5. Composition of horse diets on cool-season grass pastures using microhistological analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazing patterns and diet composition can be difficult to determine with horses, but are important when pastures contain species that have the potential to cause animal toxicity. The objective of this study was to determine the composition of domesticated horse diets when grazing mixed cool-season p...

  6. Economic and environmental issues associated with confinement and pasture-based dairy systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Milk is produced in a continuum of dairy systems from full confinement to full pasture grazing. Climate, available feeds, and milk price: feed cost ratio influence the preferred system. All dairy systems have an environmental impact and inputs to maximise profit may lead to pollution levels unacce...

  7. Grazing strategy to decrease crude protein wastage in stocker calves grazing winter wheat pasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Annual cool-season grasses, primarily winter wheat, provide high quality forage for stocker calves during the fall, winter and spring grazing season in the southern Great Plains. The crude protein content of winter wheat pasture exceeds the stocker calf’s daily crude protein requirement by 100 to 12...

  8. BIRDSFOOT TREFOIL, A VALUABLE TANNIN-CONTAINING LEGUME FOR MIXED PASTURES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Birdsfoot trefoil is well suited for use in grazed pastures, performing especially well on calcareous soils but it has also proven to be better adapted on soils too acidic or limited in fertility, texture, or rooting depth for successful alfalfa production. Although somewhat slow to establish, with ...

  9. Relationship between annual canopy photosynthesis and ecosystem respiration in humid-temperate pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing nitrogen fertilization of a mature cool-season pasture increased annual photosynthetic C uptake (GPP) and forage yield but also increased ecosystem respiration (Re), such that net ecosystem exchange (NEE) and soil C sequestration were not affected by the increased fertility. A nine-year s...

  10. SURVIVAL OF ESCHERICHIA COLI IN COW PATS IN PASTURE AND IN LABORATORY CONDITIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: To compare survival of E. coli in bovine feces deposited in a pasture or incubated in a controlled laboratory environment at comparable temperature regimes. Methods and Results: Fecal samples were collected from three cow herds on different diets. Samples were deposited as shaded and non-sha...

  11. Subsurface Manure Application for Conservation Tillage and Pasture Soils and Their Impact on the Nitrogen Balance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incorporating manures into soil with conventional tillage is an effective means to reduce ammonia volatilization and conserve manure nitrogen. However, it is not possible in pasture and is not readily compatible with high-residue soil conservation practices for rowcrops. A variety of manure injecto...

  12. Computer program documentation for the pasture/range condition assessment processor

    NASA Technical Reports Server (NTRS)

    Mcintyre, K. S.; Miller, T. G. (Principal Investigator)

    1982-01-01

    The processor which drives for the RANGE software allows the user to analyze LANDSAT data containing pasture and rangeland. Analysis includes mapping, generating statistics, calculating vegetative indexes, and plotting vegetative indexes. Routines for using the processor are given. A flow diagram is included.

  13. Belowground cycling of carbon in forests and pastures of eastern Amazonia

    SciTech Connect

    Trumbore, S.E.; Davidson, E.A.; Nepstad, D.C.

    1995-12-01

    Measurements of carbon stocks and fluxes in Amazon soils were used to model subsurface carbon cycling for the purpose of predicting carbon fluxes associated with deforestation and subsequent pasture management. Isotopic measurement of soil organic matter and soil carbon dioxide, measurements of aboveground and belowground carbon inputs, and estimates of carbon dioxide production as a function of soil depth were incorporated into a model describing turnover times of years, decades, and more than centuries. In degraded pastures, reduced carbon inputs to the soil were observed to cause a reduction in soil carbon inventory and delta carbon 14. Increases in carbon and carbon 14 were observed in managed pastures, which were fertilized and planted with productive grasses, over forest values. Predicted carbon losses from destruction of forest roots more than one meter deep in the soil partially offset carbon inventory increases in the upper meter of managed pasture soils. The major changes in soil carbon inventory after implementation of land management occur within the first 10 years. Due to this short turnover time, land management is an important factor in determining the effects of land use change on the global carbon budget. 54 refs., 7 figs., 5 tabs.

  14. Tenderness of pasture versus grain fed beef aged 14 and 28 days

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumer interest in pasture versus grain fed beef has been on the rise in recent years. This interest could be sparked by the public’s concerns of beef management techniques and processing impacts on the nutrition and safety of their food, as well as the environmental impact of each management type...

  15. PASTURE MANAGEMENT, THE RED IMPORTED FIRE ANT (SOLENOPSIS INVICTA), AND DUNG BEETLE MEDIATED ECOSYSTEM SERVICES

    EPA Science Inventory

    It is expected to find greater diversity of dung beetle species and functional groups in the semi-natural pastures on MAERC, as it is suspected that intensive management practices such as high fertilizer use and frequent mechanical disturbance will result in localized extin...

  16. INFLUENCE OF FORAGE SPECIES ON PASTURE PERFORMANCE, CARCASS QUALITY, AND CONSUMER ACCEPTABILITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    British-type steers of predominantly Angus breeding were used to determine the influence of forage species fed during the final 30 to 45 days of finishing on performance, carcass characteristics, and meat quality. Finishing treatments included: 1) Mixed cool season pasture [bluegrass, orchardgrass,...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  18. Nutritive Value and Herbage Accumulation Rates of Pasture Sown to Grass, Legume, and Chicory

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Planting pastures to mixtures of forages may benefit herbage production; however, wide fluctuations in botanical composition could cause unstable nutritive value. A grazing study was conducted to examine how forage mixture complexity influenced nutritive value and accumulation rate during spring, su...

  19. Grazing management effects on stream bank erosion and phosphorus delivery to a pasture stream

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pasture lands may deliver significant sediment and phosphorus (P) to surface waters. To determine the effects of beef (Bos taurus) grazing practices on stream bank erosion and P losses, three treatments [rotational stocking (RS), continuous stocking with restricted stream access (CSR), and continuou...

  20. SPATIAL VARIABILITY OF WINTER WHEAT PASTURE AT THE ONSET OF GRAZING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat (Triticum aestivum L.) pastures are the primary source of cool-season forages available for millions of stocker calves in the southern Great Plains. Quality of wheat is considered excellent, but little or no weight gain may occur in the first 3 weeks of grazing. To better understand forage fac...

  1. Management effects on soil characteristics of two pasture types in Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Putting gain on yearling stocker cattle with forage is a significant activity in the Southern Great Plains (SGP). The use of forages in the region is likely to increase with rising fuel and feed costs, and concerns over the environmental impacts of confinement feeding. Pastures of native prairie and...

  2. The impact of coffee and pasture agriculture on predatory and omnivorous leaf-litter ants.

    PubMed

    Dias, Nivia da Silva; Zanetti, Ronald; Santos, Mônica Silva; Peñaflor, Maria Fernanda Gomes Villalba; Broglio, Sônia Maria Forti; Delabie, Jacques Hubert Charles

    2013-01-01

    Ants are known to function as reliable biological indicators for habitat impact assessment. They play a wide range of ecological roles depending on their feeding and nesting habits. By clustering ants in guilds, it is possible both to assess how agriculture and forest fragmentation can disturb ant communities and to predict the ecological impacts due to losses of a specific guild. This study aimed at determining the impact of non-shaded coffee and pasture agriculture on predatory and omnivorous guilds of leaf-litter ants of Atlantic Forest fragments in Minas Gerais, Brazil. Both coffee and pasture agriculture influenced leaf-litter ant community, although coffee was more disruptive than pasture. Coffee agriculture not only disturbed the diversity of predatory ants, but also negatively affected the number of predatory and omnivorous ants when compared to forest fragments. In contrast, pasture agriculture only disrupted the abundance of predatory ants. Fragment edges skirting crops were negatively affected in terms of leaf-litter ant abundance, but not diversity. Cluster analysis showed that forest fragments were similar irrespective of the cultivation, but the borders were similar to the crop. The study assessed agriculture impact by surveying ant guilds, and revealed that the predatory guild is more susceptible than omnivorous ants. PMID:23902334

  3. Performance by Fall-Calving Cows Grazing Tall Fescue Pastures With Different Proportions Stockpiled

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tall fescue [Lolium arundinaceum (Schreb.) S.J. Darbyshire.] is often stockpiled to reduce winter feed costs for cattle. Over two consecutive years, a total of 158 Gelbvieh × Angus fall-calving cows (1318 plus/minus 13.2 lb) were allocated randomly to one of eight 24-acre tall fescue pastures on 18 ...

  4. Feeding strategy and pasture quality relative to nutrient requirements of organic dairy cows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pasture samples (n = 216) were collected during the grazing season from 14 certified northeastern organic dairy farms in 2012 and 2013 for nutritive composition (Dairy One). A Mixed model (SAS Inst., 1998) was used to test effect of year of sampling, month of sampling, and farm on crude protein (CP...

  5. Recirculating elutriator for extracting gastrointestinal nematode larvae from pasture herbage samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gastrointestinal nematode parasites present an important limitation to ruminant production worldwide. Methods for quantifying infective larvae of GIN on pastures are generally tedious, time-consuming, and require bulky equipment set-ups. This limitation to expedient data collection is a bottleneck...

  6. DIFFERENT METHODS OF ESTIMATING CRUDE PROTEIN CONCENTRATION OF BERMUDAGRASS PASTURES FOR STOCKER CALF PRODUCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Providing supplemental protein during the last half of the summer grazing season to stocker calves grazing warm-season grass pastures can increase animal performance. The most efficient supplementation strategy for stocker calf enterprises is to monitor forage crude protein (CP) content and to begin...

  7. Performance of Lactating Dairy Cows Fed Varying Levels of Total Mixed Ration and Pasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two, 8–week experiments, each with 30 lactating Holstein cows, were conducted to examine performance of animals offered combinations of total mixed ration (TMR) and high–quality pasture. Experiment 1 was initiated in mid October 2004 and Experiment 2 was initiated in late March 2005. Cows were assig...

  8. Yield and soil carbon sequestration in grazed pastures sown with two or five forage species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing plant species richness is often associated with an increase in productivity and associated ecosystem services such as soil C sequestration. In this paper we report on a nine-year experiment to evaluate the relative forage production and C sequestration potential of grazed pastures sown to...

  9. The effect of pasture fallowing on plant community cover and seed bank properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The practice of fallowing pastures in a rotational grazing dairy system is believed to increase plant diversity, increase organic matter and improve the soil. Fallowing is practiced in New Zealand, and delivers these benefits, but has been adopted in the northeastern United States with little quanti...

  10. Chemical properties and consumer perception of fluid milk from conventional and pasture-based production system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical abstract: The continued popularity of organic and natural foods has generated interest in organic milk, and use of pasture for dairy cattle is a requirement for organic production. This process may improve the health benefits of fluid milk via increases in the unsaturated fatty acid cont...

  11. Carbon sequestration potential of grazed pasture depends on prior management history

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Effect of Replacing Total Mixed Ration with Pasture on Ruminal Fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two, 8–week experiments, each with 30 lactating Holstein cows, were conducted to examine performance of animals offered combinations of total mixed ration (TMR) and high–quality pasture. Experiment 1 was initiated in mid October 2004 and Experiment 2 was initiated in late March 2005. Cows were assig...

  13. Nutritive Valve of Herbage of Five Semi-Irrigated Pasture Species Across an Irrigation Gradient

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As water resources become limiting, the need to produce stable amounts of highly nutritional forage increases. An understanding of how levels of irrigation affect crude protein (CP), in vitro true digestibility (IVTD), and neutral detergent fiber (NDF) is critical in pasture forage management. Smo...

  14. Stocker growth on rye and ryegrass pastures affects subsequent feedlot gains and carcass traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stocker calves were stocked on annual rye (Secale cereale L.) and ryegrass (Lolium multiflorum Lam.) pastures using stocking strategies (STK) to create graded levels of gain to assess subsequent growth rates, feedlot performance, and carcass traits. During two consecutive years, yearling Angus, Here...

  15. Are herbage yield and yield stability affected by plant species diversity in sown pasture mixtures?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A tenet of plant biodiversity theory in grasslands is that increased diversity contributes to the stability of ecosystems. In managed grasslands, such as pastures, greater stability of herbage production as a result of increased plant species diversity would be beneficial. In this study, I combined ...

  16. Nitrous Oxide Emissions from a Bermudagrass Pasture: Interseeded Winter Rye and Poultry Litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of poultry litter applications and interseeded winter rye on nitrous oxide (N2O) emissions from pasture is not well documented. This study was conducted to estimate soil surface N2O fluxes as affect by poultry litter applications and interseeded winter rye as well as weather and soil vari...

  17. Small Ruminant Performance and Carcass Parameters when Finished on Pasture With and Without Whole Cottonseed Supplementation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The meat goat industry is growing rapidly in the U.S., particularly on small farms. Weight gain and carcass parameters were determined for traditional lambs (Suffolk, SX), hair sheep lambs (Katahdin, KA), and Boer x Kiko meat goats (GX) finished on a mixed pasture of orchardgrass (Dactylis glomerat...

  18. Steer and tall fescue pasture responses to grazing intensity and chemical seedhead suppression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tall fescue (Lolium arundinaceum) is the principal cool-season species within pastures of the southeastern USA and is known to have a mutualistic relationship with a fungal endophyte (Neotyphodium coenophialum) that produces the ergot alkaloids responsible for tall fescue toxicosis. Management of t...

  19. Effects of grazing intensity and chemical seedhead suppression on steers grazing tall fescue pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tall fescue (Lolium arundinaceum) is the principal cool-season species within pastures of the southeastern USA and is known to have a mutualistic relationship with a fungal endophyte (Neotyphodium coenophialum) that produces the ergot alkaloids responsible for tall fescue toxicosis. Management of t...

  20. Pasture is a risk factor for Toxoplasma gondii infection in fattening pigs.

    PubMed

    Wallander, Camilla; Frössling, Jenny; Dórea, Fernanda C; Uggla, Arvid; Vågsholm, Ivar; Lundén, Anna

    2016-07-15

    As consumer awareness of animal welfare increases throughout Europe, housing of pigs in more animal-friendly systems is becoming more common. There is concern that these free-range and organic management systems increase the prevalence of zoonotic meat-borne pathogens, such as Toxoplasma gondii. In this study we compared the seroprevalence of T. gondii between commercial fattening pigs raised on conventional and on organic farms in Sweden. Furthermore, potential associations between presence of T. gondii antibodies and type of production, access to pasture, and geographical region were analysed. A significant difference in T. gondii seroprevalence was found between conventional (1%) and organic pigs (8%). The higher odds of seropositivity in organic production was attributed to pasture access specifically (OR=1.8 for a one-month increase in length of pasture exposure). This study shows that the prevalence of T. gondii in Swedish conventional pigs is low. However, as pigs with access to pasture are at higher risk of infection and because the demand for animal-friendly production systems is increasing, there is an obvious need to practically manage the higher T. gondii presence in products from pigs raised in organic systems with outdoor access. PMID:27270386

  1. Using a Total Mixed Ration on a Pasture-Based Dairy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A case study was conducted to collect information on the use of a total mixed ration (TMR) on thirteen pasture-based dairy farms in New York and Pennsylvania with the objectives of monitoring TMR ingredient and nutrient content and summarizing what and how decisions are being made in relation to TMR...

  2. Ammonia emissions from urea application to permanent pasture on a volcanic soil

    NASA Astrophysics Data System (ADS)

    Salazar, F.; Martínez-Lagos, J.; Alfaro, M.; Misselbrook, T.

    2012-12-01

    Agriculture is the largest source of ammonia (NH3) emission to the atmosphere, deriving mainly from livestock urine and manures, but fertilizer applications to pastures and crops also represent an important source. In Chile, where agriculture and cattle production are important activities (accounting for 4.5% of GDP along with the forestry sector), there are very few published data regarding NH3 emissions from pasture and crop fertilization. This study aimed to provide the first empirical field data for Chile on N losses due to NH3 volatilization following urea application to permanent pasture on a volcanic soil and to assess the influence of environmental conditions on emissions. Four field experiments were carried out on a volcanic acid soil using the micrometeorological integrated horizontal flux (IHF) mass balance method. Measurements were made in winter 2005 and 2007, and spring 2007 and 2008 following urea N fertilization to a permanent pasture at a rate equivalent to 100 kg N ha-1. Cumulative NH3 emissions over the measurement period were 1.4 and 7.7 kg N ha-1 for winter applications, and 12.2 and 26.7 kg N ha-1 for spring dressings. These N losses due to NH3 volatilization are within the range of emissions reported elsewhere. Consideration of urea application timing in Chile, with regards to weather and soil conditions, could have important consequences on minimising potential N losses via volatilization with associated financial benefits to farmers.

  3. Grazing Stategy To Decrease Dietary Crude Protien Wastage In Stocker Calves Grazing Winter Wheat Pasture.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Annual cool-season grasses, primarily winter wheat, provide high quality forage for stocker calves during the fall, winter and spring grazing seasons for stocker enterprises in the southern Great Plains. The crude protein (CP) content of winter wheat pasture exceeds the stocker calf’s daily CP requi...

  4. Soil Potassium Levels in Pastures of Northeast Dairy and Beef Farms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Excessive levels of soil potassium (K) can lead to increased concentration of K in forages, causing metabolic disorders in ruminants, especially in pre-parturition cows and heifers. Composite soil samples (15 to 20 cores) were taken from pastures on five farms in the northeast USA: two farms in Pen...

  5. COASTAL AND TIFTON 44' BERMUDAGRASS AVAILABILITY ON ANIMAL AND PASTURE PRODUCTIVITY.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hybrid cultivars of bermudagrass are a major feed source for ruminants across the Southeastern USA. This 4-yr experiment compared animal and pasture performance of ‘Coastal’ and ‘Tifton 44’ Bermudagrasses [Cynodon dactylon (L.) Pers.] over three canopy heights designated as short (5.8 cm), medium (...

  6. Advantages of endophyte infection for irrigated pastures of semiarid, cold-desert environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little research has evaluated possible endophyte benefits to adaptation and production of grasses in the irrigated pastures of the semiarid, cold-desert environments of the western USA. Severe irrigation shortages are common; however, production demands are increasing, necessitating maximizing tall ...

  7. Subsurface application of poultry litter in pasture and no-till soils.

    PubMed

    Pote, D H; Way, T R; Kleinman, P J A; Moore, P A; Meisinger, J J; Sistani, K R; Saporito, L S; Allen, A L; Feyereisen, G W

    2011-01-01

    Poultry litter provides a rich nutrient source for crops, but the usual practice of surface-applying litter can degrade water quality by allowing nutrients to be transported from fields in surface runoff while much of the ammonia (NH3)-N escapes into the atmosphere. Our goal was to improve on conventional titter application methods to decrease associated nutrient losses to air and water while increasing soil productivity. We developed and tested a knifing technique to directly apply dry poultry litter beneath the surface of pastures. Results showed that subsurface litter application decreased NH3-N volatilization and nutrient losses in runoff more than 90% (compared with surface-applied litter) to levels statistically as low as those from control (no litter) plots. Given this success, two advanced tractor-drawn prototypes were developed to subsurface apply poultry litter in field research. The two prototypes have been tested in pasture and no-till experiments and are both effective in improving nutrient-use efficiency compared with surface-applied litter, increasing crop yields (possibly by retaining more nitrogen in the soil), and decreasing nutrient losses, often to near background (control plot) levels. A paired-watershed study showed that cumulative phosphorus losses in runoff from continuously grazed perennial pastures were decreased by 55% over a 3-yr period if the annual poultry litter applications were subsurface applied rather than surface broadcast. Results highlight opportunities and challenges for commercial adoption of subsurface poultry litter application in pasture and no-till systems. PMID:21520747

  8. Cinnagar supplementation of cattle grazing wheat or native pasture in northwest Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two experiments were conducted to evaluate CinnaGar (Provimi; Trappes, France) and monensin (Ruminsen; Elanco Animal Health, Greenfield, IN) as supplements for grazing stocker cattle in northwest Oklahoma. In Experiment 1, twelve 2.2-ha pastures of winter wheat were grazed (1.2 steers/ha) with stoc...

  9. Sediment-bound and dissolved carbon concentration and transport from a small pastured watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the current emphasis on the role of carbon in the environment, agricultural systems and their impacts on the carbon cycle are important parts of the overall issue. Pasture systems and organic carbon that is transported attached to sediment has been addressed at the North Appalachian Experimenta...

  10. Management intensive grazing and continuous grazing of hill pasture by beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Management Intensive Grazing (MIG) is an increasingly used practice that can offer producers many benefits including higher profit. The main objective of this study was to compare MIG and Continuous Grazing (CG)practices on pastures in Appalachian Ohio. The study was conducted at the North Appalac...

  11. Using NDVI to estimate carbon fluxes from small rotationally grazed pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Satellite-based Normalized Difference Vegetation Index (NDVI) data have been extensively used for estimating gross primary productivity (GPP) and yield of grazing lands throughout the world. However, the usefulness of satellite-based images for monitoring rotationally-grazed pastures in the northea...

  12. Invited review: Genetic considerations for various pasture-based dairy systems.

    PubMed

    Washburn, S P; Mullen, K A E

    2014-10-01

    Pasture-based dairy systems use grazing to supply significant percentages of the dry matter intake of cows and heifers. Such systems vary from those for which pasture is used only as a supplemental feed for cows primarily fed a total mixed ration to those for which pasture is the primary source of dry matter for the herd. Cows that are optimal in a pasture system share many general characteristics with cows that are appropriate for a nonpasture system, including feed efficiency, maintenance of body condition, reproductive fitness, udder health, longevity, and the ability to adapt to various management systems. However, in such divergent feeding systems, the relative importance of various traits can differ. In pasture systems where cow nutrient demand intentionally coincides with seasonal forage availability, the focus of selection has emphasized fertility and other fitness traits, as well as yields of milk or milk components. Breeds or strains with higher yields of protein and fat typically have advantages in grazing systems that supply milk to solids-based or cheese markets. Holstein cows with high percentages of North American ancestry can work well in grazing systems that include supplemental concentrates or partial mixed rations, particularly if calving intervals are less restrictive. Crossbred cows can be selected for use in specific grazing systems as well as for specific milk markets, with the added advantage of heterosis. Breeds and crosses with high fertility are important for seasonal breeding and calving. The ability of cattle to both milk and maintain sufficient body condition for reproduction is important for any dairy production system but is critical in a seasonal system. Dairy farms that depend on pasture for most of dry matter for cows typically have lower production per cow than nongrazing dairies but have the potential to be economically competitive because of lower operating and overhead costs. Although the principles of selection are similar

  13. Simulating modern-day cropland and pasture burning in an Earth system model

    NASA Astrophysics Data System (ADS)

    Rabin, Sam; Malyshev, Sergey; Shevliakova, Elena; Magi, Brian; Pacala, Steve

    2015-04-01

    Throughout the Holocene, humans have extended our influence across a larger and larger fraction of ecosystems, even creating some new ones in the process. Herds of livestock grazing either native vegetation (rangeland) or specially planted species (pasture) have modified huge areas of land. We have even developed new plant species and cultivated them as crops. The extent of our ecosystem modification intensified dramatically with the advent of industrialized agriculture, to the point where cropland and pasture (which will henceforth encompass rangeland as well) now cover over a third of the Earth's land area. One way we have altered the terrestrial biosphere is by intentionally and unintentionally altering fire's frequency, intensity, and seasonal timing. This is especially true for agricultural ecosystems. Because their maintenance and use require a level of human control, cropland and pasture often experience fire regimes substantially different from those of the ecosystems they replaced or what would occur in the absence of active fire management. For example, farmers might burn to prepare land for planting or to dispose of crop residues, and pastoralists often use fire to prevent encroachment of unpalatable woody plants. Due to the vast global extent of agriculture, and considering the myriad ways fire affects the Earth system, it is critical that we understand (a) the ways people manage fire on cropland and pasture and (b) the effects of this management on the Earth system. Earth system models are an ideal tool for examining this kind of question. By simulating the processes within and interactions among the atmosphere, oceans, land, and terrestrial ecosystems, Earth system models allow phenomena such as fire to be examined in their global context. However, while the past fifteen years have seen great progress in the simulation of vegetation fire within Earth system models, the direct human influence via cropland and pasture management burning has been mostly

  14. Pasture management controls soil organic matter stocks, properties, and biochemical functioning in Tibetan grasslands

    NASA Astrophysics Data System (ADS)

    Spielvogel, Sandra; Breidenbach, Andreas; de la Haye, Tilman; Schleuß, Per; Kuzyakov, Yakov; Guggenberger, Georg

    2016-04-01

    The Tibetan Plateau hosts the highest and largest pasture ecosystem worldwide, and provides tremendous sinks for carbon. Due to the sheer size of the of the Tibetan Plateau, feedback effects of soil organic carbon (OC) losses from inadequate grassland management are of undisputed relevance for ecosystem stability and future global change scenarios. Given the vital importance of the Tibetan steppes as global OC sinks, we combined data on OC stocks from own studies with an extensive literature review on soils developed under montane and alpine Kobresia pygmaea and Stipa grandis pastures. We calculated soil OC stocks at the Tibetan Plateau within the first 30 cm of the soil profile depending on pasture management and climate. Vertical gradients of δ13C values, neutral sugar, cutin and suberin contents, lignin phenol contents as well as microbial community composition (t-RFLP analysis, 16S rDNA und IST sequencing) and activities of six extracellular enzymes involved in the C, N, and P cycle were assessed. The depth gradients of these parameters reflected degradation processes from intact Kobresia pastures (stage 0) to pronounced degradation (bare soil; stage 5). Moderate husbandry is beneficial for the storage of OC, nitrogen (N) and other nutrients (e.g. phosphorus) for the majority of the montane grasslands of the Tibetan Plateau (i.e., Kobresia pygmaea pastures). However, Kobresia root mats originated from grazing are affected by desiccations and frost, which cause polygonal cracking and initiates soil erosion. This process is accelerated under high grazing pressure (overgrazing) that enhances root mat degradation. Increasing degradation caused by large herbivore densities resulted in an increased OC decomposition demonstrated by decreasing δ13C values. The δ13C shift towards more negative values reflects the relative enrichment of 13C depleted lignin components during OC decomposition in the strongly disturbed soil. Translocation of topsoil material into the

  15. Soil Organic Matter Dynamics from Forest to Pasture Conversion in the Brazilian Amazon using Modelling Approach

    NASA Astrophysics Data System (ADS)

    Cerri, C. P.; Easter, M.; Paustian, K.; Coleman, K.; Bernoux, M.; Melillo, J.; Cerri, C. C.

    2006-12-01

    Land use and land cover changes in the Brazilian Amazon have major implications for regional and even global carbon cycling. Cattle pasture represents the largest single use (about 70%) of this once-forested land in most of the region. The main objective of this study was to use a modelling approach to examine the dynamics of soil carbon when forest is converted to pasture in the Brazilian Amazon. We used data from eleven site- specific `forest to pasture' chronosequences with the Century Ecosystem Model and the Rothamsted Carbon Model. The Century and RothC models predicted that forest clearance and conversion to well managed pasture would cause an initial decline in soil C stocks (0-20 cm depth), followed by a slow rise to levels exceeding those under native forest. The only exception to this pattern was found for a chronosequence in Suia-Missu, which is under degraded pasture. Statistical tests were applied to determine levels of agreement between simulated soil organic carbon stocks and observed stocks for all the sites within the 11 chronosequences in the Brazilian Amazon. The models also provided reasonable estimates (coefficient of correlation = 0.8) of the microbial biomass C in the 0-10 cm soil layer for two chronosequences when compared with available measured data. The Century model adequately predicted the magnitude and the overall trend in 13C for the six chronosequences where measured 13C data were available. Our results suggest that modelling techniques can be successfully used for monitoring soil C stocks and changes, allowing both the identification of current patterns in the soil and the prediction of future conditions.

  16. Pasture burning in Amazonia: Dynamics of residual biomass and the storage and release of aboveground carbon

    NASA Astrophysics Data System (ADS)

    Barbosa, Reinaldo Imbrózio; Fearnside, Philip M.

    1996-11-01

    Aboveground biomass in cattle pasture converted from tropical dense forest was studied both before and after reburning in Brazilian Amazonia. In a 7-year-old pasture studied in Apiaú, Roraima, the aboveground dry weight of biomass (live plus dead) exposed to burning consisted of 96.3 t ha-1 of original forest remains, 6.2 t ha-1 of secondary successional vegetation (woody invaders in the pasture), and 8.0 t ha-1 of pasture grass (carbon contents 48.2%, 45.4%, and 42.2%, respectively). In terms of carbon, burning efficiencies for these three categories were 13.2%, 66.7% and 94.6%, respectively. Net charcoal formation was 0.35 t C ha-1 or 0.63% of the carbon exposed to the reburn, while the total accumulated since conversion (including the initial burn) is estimated at 2.3 t ha-1 (1.82% of the predeforestation aboveground biomass carbon stock). The dynamics of the original forest remains were represented in simulations that included parameters such as charcoal formation, burning efficiency and carbon concentration in different biomass components. Releases from initial burning of the cleared forest (44.0 t C ha-1) plus releases over the course of the succeeding decade through combustion (12.5 t C ha-1) and decay (51.5 t C ha-1) total 92% of the original forest biomass carbon (126 t C ha-1). Of biomass carbon remaining after the initial burn (84.3 t C ha-1), 76.0% is released: 61.1% through decay and 14.9% through combustion in reburns, while 1.2% is net conversion to charcoal in the reburns. These results indicate an amount of charcoal accumulation that is smaller than some carbon calculations have assumed, therefore suggesting a greater impact on global warming from conversion of forest to pasture.

  17. Community-Based Management: Under What Conditions Do Sámi Pastoralists Manage Pastures Sustainably?

    PubMed Central

    Hausner, Vera H.; Fauchald, Per; Jernsletten, Johnny-Leo

    2012-01-01

    Community-based management (CBM) has been implemented in socio-ecological systems (SES) worldwide. CBM has also been the prevailing policy in Sámi pastoral SES in Norway, but the outcomes tend to vary extensively among resource groups (“siidas”). We asked why do some siidas self-organize to manage common pool resources sustainably and others do not? To answer this question we used a mixed methods approach. First, in the statistical analyses we analyzed the relationship between sustainability indicators and structural variables. We found that small winter pastures that are shared by few siidas were managed more sustainably than larger pastures. Seasonal siida stability, i.e., a low turnover of pastoralists working together throughout the year, and equality among herders, also contributed to more sustainable outcomes. Second, interviews were conducted in the five largest pastures to explain the relationships between the structural variables and sustainability. The pastoralists expressed a high level of agreement with respect to sustainable policies, but reported a low level of trust and cooperation among the siidas. The pastoralists requested siida tenures or clear rules and sanctioning mechanisms by an impartial authority rather than flexible organization or more autonomy for the siidas. The lack of nestedness in self-organization for managing pastures on larger scales, combined with the past economic policies, could explain why CBM is less sustainable on the largest winter pastures. We conclude that the scale mis-match between self-organization and the formal governance is a key condition for sustainability. PMID:23240003

  18. Evaluation of Filters for Envisat Asar Speckle Suppression in Pasture Area

    NASA Astrophysics Data System (ADS)

    Wang, X.; Ge, L.; Li, X.

    2012-07-01

    In order to quantify real time pasture biomass from SAR image, regression model between ground measurements of biomass and ENVISAT ASAR backscattering coefficient should be built up. An important prerequisite of valid and accurate regression model is accurate grass backscattering coefficient which, however, cannot be obtained when there is speckle. Speckle noise is the best known problem of SAR images because of the coherent nature of radar illumination imaging system. This study aims to choose better adaptive filter from NEST software to reduce speckle noise in homogeneous pasture area, with little regard to linear feature (e.g. edge between pasture and forest) or point feature (e.g. pond, tree) preservation. This paper presents the speckle suppression result of ENVISAT ASAR VV/VH images in pasture of Western Australia (WA) using four built-in adaptive filters of the NEST software: Frost, Gamma Map, Lee, and Refined Lee filter. Two indices are usually used for evaluation of speckle suppression ability: ENL (Equivalent Number of Looks) and SSI (Speckle Suppression Index). These two, however, are not reliable because sometimes they overestimate mean value. Therefore, apart from ENL and SSI, the authors also used a new index SMPI (Speckle Suppression and Mean Preservation Index). It was found that, Lee filter with window size 7×7 and Frost filter (damping factor = 2) with window size 5×5 gave the best performance for VV and VH polarization, respectively. The filtering, together with radiometric calibration and terrain correction, paves the way to extraction of accurate backscattering coefficient of grass in homogeneous pasture area in WA.

  19. The GEOGLAM Rangelands and Pasture Productivity Activity: Recent Progress and Future Directions

    NASA Astrophysics Data System (ADS)

    Guerschman, J. P.; Held, A. A.; Donohue, R. J.; Renzullo, L. J.; Sims, N.; Kerblat, F.; Grundy, M.

    2015-12-01

    Rangelands and pastures cover about a third of the world's land area and support livestock production which represents ~40% of global agricultural gross domestic product. The global consumption of animal protein shows a clear increasing trend, driven by both total population and per capita income increases, putting a growing pressure on the sustainability of grazing lands worldwide. Despite their relevance, rangelands have received less attention than croplands regarding global monitoring of the resource productivity and condition. The Rangelands and Pasture Productivity (RaPP) activity is a component within the Global Agricultural Monitoring initiative established under the Group on Earth Observations (GEOGLAM) in 2013. GEOGLAM RaPP is aimed at providing the global community with the means to monitor the world's rangelands and pastures on a routine basis, and the capacity to produce animal protein in real-time, at global, regional and national levels. Since its launch two years ago GEOGLAM RAPP has made progress in the four implementation elements. These include: 1- the establishment of community of practice; 2- the development of a global monitoring system for rangeland condition; 3- the establishment of pilot sites in main rangeland systems for satellite data products validation and model testing; and 4- integration with livestock production models. Three international workshops have been held building the community of practice. A prototype monitoring system that provides global visualisations and querying capability of vegetation cover data and anomalies has been established. Pilot sites, mostly in areas with long records of field measurements of rangeland condition and productivity have been proposed for nine countries. The link to global livestock models, including physical and economic components, have been established. Future challenges for GEOGLAM RaPP have also been identified and include: better representation of the areas occupied by rangelands

  20. Predicting Greenhouse Gas Emissions and Soil Carbon from Changing Pasture to an Energy Crop

    PubMed Central

    Duval, Benjamin D.; Anderson-Teixeira, Kristina J.; Davis, Sarah C.; Keogh, Cindy; Long, Stephen P.; Parton, William J.; DeLucia, Evan H.

    2013-01-01

    Bioenergy related land use change would likely alter biogeochemical cycles and global greenhouse gas budgets. Energy cane (Saccharum officinarum L.) is a sugarcane variety and an emerging biofuel feedstock for cellulosic bio-ethanol production. It has potential for high yields and can be grown on marginal land, which minimizes competition with grain and vegetable production. The DayCent biogeochemical model was parameterized to infer potential yields of energy cane and how changing land from grazed pasture to energy cane would affect greenhouse gas (CO2, CH4 and N2O) fluxes and soil C pools. The model was used to simulate energy cane production on two soil types in central Florida, nutrient poor Spodosols and organic Histosols. Energy cane was productive on both soil types (yielding 46–76 Mg dry mass⋅ha−1). Yields were maintained through three annual cropping cycles on Histosols but declined with each harvest on Spodosols. Overall, converting pasture to energy cane created a sink for GHGs on Spodosols and reduced the size of the GHG source on Histosols. This change was driven on both soil types by eliminating CH4 emissions from cattle and by the large increase in C uptake by greater biomass production in energy cane relative to pasture. However, the change from pasture to energy cane caused Histosols to lose 4493 g CO2 eq⋅m−2 over 15 years of energy cane production. Cultivation of energy cane on former pasture on Spodosol soils in the southeast US has the potential for high biomass yield and the mitigation of GHG emissions. PMID:23991028

  1. Climate and topographic controls on pasture production in a semiarid Mediterranean watershed with scattered tree cover

    NASA Astrophysics Data System (ADS)

    Lozano-Parra, J.; Maneta, M. P.; Schnabel, S.

    2013-12-01

    Natural grasses in semiarid rangelands constitute an effective protection against soil erosion and degradation, are a source of natural food for livestock and play a critical role in the hydrologic cycle by contributing to the uptake and transpiration of water. However, natural pastures are threatened by land abandonment and the consequent encroachment of shrubs and trees as well as by changing climatic conditions. In spite of their ecological and economic importance, the spatio-temporal variations of pasture production at the decadal to century scales over whole watersheds are poorly known. We used a physics-based, spatially-distributed ecohydrologic model applied to a 99.5 ha semiarid watershed in western Spain to investigate the sensitivity of pasture production to climate variability. The ecohydrologic model was run using a 300 yr long synthetic daily climate dataset generated using a stochastic weather generator. The data set reproduced the range of climatic variations observed under current climate. Results indicated that variation of pasture production largely depended on factors that also determined the availability of soil moisture such as the temporal distribution of precipitation, topography, and tree canopy cover. The latter is negatively related with production, reflecting the importance of rainfall and light interception, as well as water consumption by trees. Valley bottoms and flat areas in the lower parts of the catchment are characterized by higher pasture production. A quantitative assessment of the quality of the simulations showed that ecohydrologic models are a valuable tool to investigate long term (century scale) water and energy fluxes, as well as vegetation dynamics, in semiarid rangelands.

  2. Predicting greenhouse gas emissions and soil carbon from changing pasture to an energy crop.

    PubMed

    Duval, Benjamin D; Anderson-Teixeira, Kristina J; Davis, Sarah C; Keogh, Cindy; Long, Stephen P; Parton, William J; DeLucia, Evan H

    2013-01-01

    Bioenergy related land use change would likely alter biogeochemical cycles and global greenhouse gas budgets. Energy cane (Saccharum officinarum L.) is a sugarcane variety and an emerging biofuel feedstock for cellulosic bio-ethanol production. It has potential for high yields and can be grown on marginal land, which minimizes competition with grain and vegetable production. The DayCent biogeochemical model was parameterized to infer potential yields of energy cane and how changing land from grazed pasture to energy cane would affect greenhouse gas (CO2, CH4 and N2O) fluxes and soil C pools. The model was used to simulate energy cane production on two soil types in central Florida, nutrient poor Spodosols and organic Histosols. Energy cane was productive on both soil types (yielding 46-76 Mg dry mass · ha(-1)). Yields were maintained through three annual cropping cycles on Histosols but declined with each harvest on Spodosols. Overall, converting pasture to energy cane created a sink for GHGs on Spodosols and reduced the size of the GHG source on Histosols. This change was driven on both soil types by eliminating CH4 emissions from cattle and by the large increase in C uptake by greater biomass production in energy cane relative to pasture. However, the change from pasture to energy cane caused Histosols to lose 4493 g CO2 eq · m(-2) over 15 years of energy cane production. Cultivation of energy cane on former pasture on Spodosol soils in the southeast US has the potential for high biomass yield and the mitigation of GHG emissions. PMID:23991028

  3. Seeing the pasture through the trees: A household model explaining silvo-pastoral landscapes in the Ecuadorian Amazon

    NASA Astrophysics Data System (ADS)

    Lerner, A. M.; Rudel, T.; Schneider, L.; Burbano, D.; McGroddy, M.

    2012-12-01

    In the Amazon basin the destruction of old growth forests has meant, for the most part, the expansion of pastures for livestock and destruction of a global carbon sink. As these pastures have grown in extent and age, questions about what happens to the biodiversity and carbon sequestration in these pastoral landscapes has assumed more importance. In the research reported here, we offer a preliminary answer to these questions. Our study focuses on the southern Ecuadorian Amazon, where there have recently been trends of spontaneous silvo-pastoral landscapes. These landscapes are a result of land managers allowing trees to grow in cattle pastures, potentially leading to seed sources for native species regeneration and carbon sequestration. This paper discusses demographic, economic and cultural shifts, potentially in light of the expansion of urban areas and off-farm employment, which could impact pasture management in Morona Santiago, Ecuador. Tree cover in pastures is modeled against household demographic, economic and environmental variables that demonstrate which variables affect tree cover in managed landscapes. This analysis sheds light into current processes affecting pasture management in the Amazon, and in turn important landscape outcomes such as dual management systems that include pastures and tree regeneration.

  4. Altitude, pasture type, and sheep breed affect bone metabolism and serum 25-hydroxyvitamin D in grazing lambs.

    PubMed

    Willems, Helen; Leiber, Florian; Kohler, Martina; Kreuzer, Michael; Liesegang, Annette

    2013-05-15

    This study aimed to investigate the bone development of two mountain sheep breeds during natural summer grazing either in the lowlands or on different characteristic alpine pastures. Pasture types differed in topographic slope, plant species composition, general nutritional feeding value, Ca and P content, and Ca:P ratio of herbage. Twenty-seven Engadine sheep (ES) lambs and 27 Valaisian Black Nose sheep (VS) lambs were divided into four groups of 6 to 7 animals per breed and allocated to three contrasting alpine pasture types and one lowland pasture type. The lambs were slaughtered after 9 wk of experimental grazing. The steep alpine pastures in combination with a high (4.8) to very high (13.6) Ca:P ratio in the forage decreased total bone mineral content as measured in the middle of the left metatarsus of the lambs from both breeds, and cortical bone mineral content and cortical bone mineral density of ES lambs. Breed × pasture type interactions occurred in the development of total and cortical bone mineral content, and in cortical thickness, indicating that bone metabolism of different genotypes obviously profited differently from the varying conditions. An altitude effect occurred for 25-hydroxyvitamin D with notably higher serum concentrations on the three alpine sites, and a breed effect led to higher concentrations for ES than VS. Despite a high variance, there were pasture-type effects on serum markers of bone formation and resorption. PMID:23471950

  5. Comparative measurements and seasonal variations in energy and carbon exchange over forest and pasture in South West Amazonia

    NASA Astrophysics Data System (ADS)

    von Randow, C.; Manzi, A. O.; Kruijt, B.; de Oliveira, P. J.; Zanchi, F. B.; Silva, R. L.; Hodnett, M. G.; Gash, J. H. C.; Elbers, J. A.; Waterloo, M. J.; Cardoso, F. L.; Kabat, P.

    Comparative measurements of radiation flux components and turbulent fluxes of energy and CO2 are made at two sites in South West Amazonia: one in a tropical forest reserve and one in a pasture. The data were collected from February 1999 to September 2002, as part of the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). During the dry seasons, although precipitation and specific humidity are greatly reduced, the soil moisture storage profiles down to 3.4m indicate that the forest vegetation continues to withdraw water from deep layers in the soil. For this reason, seasonal changes observed in the energy partition and CO2 fluxes in the forest are small, compared to the large reductions in evaporation and photosynthesis observed in the pasture. For the radiation balance, the reflected short wave radiation increases by about 55% when changing from forest to pasture. Combined with an increase of 4.7% in long wave radiation loss, this causes an average reduction of 13.3% in net radiation in the pasture, compared to the forest. In the wet season, the evaporative fraction (λE/Rn) at the pasture is 17% lower than at the forest. This difference increases to 24% during the dry season. Daytime CO2 fluxes are 20-28% lower (in absolute values) in the pasture compared to the forest. The night-time respiration in the pasture is also reduced compared to the forest, with averages 44% and 57% lower in the wet and dry seasons, respectively. As the reduction in the nocturnal respiration is larger than the reduction in the daytime uptake, the combined effect is a 19-67% higher daily uptake of CO2 in the pasture, compared to the forest. This high uptake of CO2 in the pasture site is not surprising, since the growth of the vegetation is constantly renewed, as the cattle remove the biomass.

  6. Consumer acceptability of conjugated linoleic acid-enriched milk and cheddar cheese from cows grazing on pasture.

    PubMed

    Khanal, R C; Dhiman, T R; Ure, A L; Brennand, C P; Boman, R L; McMahon, D J

    2005-05-01

    Two experiments were conducted to study the consumer acceptability attributes of conjugated linoleic acid (CLA)-enriched milk and cheese from cows grazing on pasture. In experiment 1, 15 cows were fed either a diet containing 51% alfalfa hay plus corn silage and 49% concentrate [total mixed ration (TMR)], were grazed on pasture, or were grazed on pasture and received 3.2 kg/d of a grain mix. The grain mix contained 75% full-fat extruded soybeans (FFES), 10% corn, 10% beet pulp, and 5% molasses. During the final 3 wk of the 6-wk experiment, milk was evaluated for sensory attributes. In experiment 2, 18 cows were fed similar diets as in experiment 1, except replacing the group of cows grazed on pasture and receiving the grain mix was a group of cows grazed on pasture and receiving 2.5 kg/d per cow of the FFES; Cheddar cheese was manufactured from milk. Average CLA contents (g/100 g of fatty acid methyl esters) were 0.52, 1.63, and 1.69 in milk and 0.47, 1.47, and 1.46 in cheese from cows fed a TMR, grazed on pasture, and grazed on pasture and fed the grain mix, respectively. An open and trained panel evaluated CLA-enriched milk for mouth-feel, color, flavor, and quality and evaluated cheese for color, flavor, texture, and quality. Open and trained panel evaluations of milk and cheese showed no differences among treatments for any of the attributes, except that the trained panel detected a more barny flavor in milk from cows grazing pasture compared with milk from cows fed the TMR only. Results suggest that consumer acceptability attributes of CLA-enriched milk and cheese from cows grazing pasture is similar to those of milk and cheese with low levels of CLA. PMID:15829677

  7. Performance, nitrogen balance and microbial efficiency of beef cattle under concentrate supplementation strategies in intensive management of a tropical pasture.

    PubMed

    Rocha, Tiago Cunha; Fontes, Carlos Augusto de Alencar; da Silva, Renata Tavares Soares; Processi, Elizabeth Fonsêca; do Valle, Felipe Roberto Amaral Ferreira; Lombardi, Cláudio Teixeira; Oliveira, Ronaldo Lopes; Bezerra, Leilson Rocha

    2016-03-01

    The objective of this study was to evaluate the effect of concentrate supplementation strategies on the nutritional characteristics of beef cattle in intensive management of tropical pasture. Twenty-four Nellore steer at 250 kg body weight (BW) were used, divided into two plots, with 12 animals in each plot. The experimental area consisted of 32 paddocks with 0.25 ha of Panicum maximum cv. Mombaça. The experiment consisted of 96-day experimental periods, with three periods of 32 days. The strategies studied were P = exclusively on pasture and without concentrate supplementation (control), ES = pasture and supplemented with a concentrate low in protein, PS = pasture and supplemented with high protein content, and PES = pasture and supplementation with balanced protein-energy. There was reduced intake of DM in animals of the treatment P in relation to supplemented pasture, regardless of supplementation. Animals fed on ES showed an intake of more nutrients than the animals on PS. The CP and TDN were also lower in P than in pastures where animals received the additional types of concentrate, and the PS animals showed greater digestibility of CP and TDN than the ES animals. However, the animals exhibited similar weight gains. Animals on P ingested smaller amounts of N and had lower fecal excretion compared to the supplemented animals, but there was no difference between treatments in nitrogen balance. Urea nitrogen and urea from the blood were higher in the supplemented animals than in animals fed on pasture; these levels were also higher in PS animals compared to animals receiving ES. Both the purines absorbed and microbial protein production were similar between treatments. However, the animals fed with concentrate supplementation, independent of the strategy involved, showed higher microbial efficiency compared to animals fed exclusively on pasture. PMID:26768894

  8. Grazing alters net ecosystem C fluxes and the net global warming potential of a subtropical pasture

    NASA Astrophysics Data System (ADS)

    Gomez-Casanovas, N.; DeLucia, N.; DeLucia, E. H.; Boughton, E.; Garrett, J. C.; Keel, E.; Bernacchi, C.

    2015-12-01

    The impact of grazing on CO2 and CH4 fluxes from subtropical pastures and thus on the climate system is uncertain, although these systems account for a substantial portion of global carbon storage. We investigated how cattle grazing affects net ecosystem CO2 exchange (NEE) and CH4 emissions in subtropical pastures using the eddy covariance technique over two complete wet-dry seasonal cycles. Grazing increased soil wetness but did not affect soil temperature. By removing aboveground biomass, grazing consistently decreased gross primary productivity (16% and 8 % in 2013-2014 and 2014-2015) and reduced ecosystem respiration (Re, 20% and 38% in 2013-2014 and 2014-2015). Lower Re in grazed (GP) than in ungrazed pasture (UP) was also explained by decreased soil and heterotrophic respiration and root biomass. Grazing increased the net CO2 sink strength of the pasture (-86 ± 5 gC m-2 yr-1 in GP vs. -76 ± 6 gC m-2 yr-1 in UP in 2013-2014; -118 ± 9 gC m-2 yr-1 in GP vs. +142 ± 6 gC m-2 yr-1 UP in 2014-2015). Over both wet-dry seasonal cycles, both ecosystems were net sources of CH4, and variations in fluxes without cattle present were driven by changes in soil wetness and temperature. The presence of cattle and greater soil moisture cased by the removal of aboveground biomass, caused greater total net ecosystem CH4 emissions from GP than from UP (16% and 8 % in 2013-2014 and 2014-2015). Wetter soils under GP were responsible for 21-56% of the difference in net CH4 emissions between pastures, suggesting that enhanced CH4 production from wetter soils due to cattle presence can be a major contributor to annual CH4 fluxes. Combining CO2 and CH4 to calculate a C budget revealed that grazing increased the net C sink strength of the pasture (-72 gC m-2 yr-1 in GP vs. -66 gC m-2 yr-1 in UP in 2013-2014; -114 gC m-2 yr-1 in GP vs. +144 gC m-2 yr-1 in UP in 2014-2015). Accounting for NEE and the radiative forcing of CH4, grazing increased the net global warming potential (GWP) of

  9. Water quality effects and placement of pasture best management practices in the Spring Creek Watershed (Centre County, PA)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pasture-based best management practices (BMPs), including stream bank fencing, stream crossings, and bank stabilization, improved water quality ten years after installation by reducing sediment, but did not affect nitrogen concentration. Abundance and diversity of aquatic macroinvertebrates increas...

  10. Gastro-intestinal nematode infection in lambs — A model based on climatic indices for forecasting peak pasture larval contamination

    NASA Astrophysics Data System (ADS)

    Paton, G.

    1987-06-01

    The parasite Ostertagia circumcincta is the primary cause of parasitic gastro-enteritis in lambs during their first season at grass. The life-cycle of this nematode parasite involves the development and survival of the free-living stages on pasture. Accordingly the pasture is the site of deposition, development and transmission of infection and meteorological factors affecting the pasture will affect the parasites. In this paper two empirical models for forecasting the timing of the “summer wave” of infective larvae on pasture are presented. These models are similar in form to that described by Starr and Thomas (1980) but involve different approaches to assessing the temperature and moisture components of the daily index value. Further, using the prediction model described by Paton, Thomas and Waller (1984) as an investigative tool, certain tentative suggestions are made as to a general fundamental weakness of empirical index methods.

  11. A Global Assessment of Long-Term Greening and Browning Trends in Pasture Lands Using the GIMMS LAI3g Dataset

    NASA Technical Reports Server (NTRS)

    Cook, Benjamin I.; Pau, Stephanie

    2013-01-01

    Pasture ecosystems may be particularly vulnerable to land degradation due to the high risk of human disturbance (e.g., overgrazing, burning, etc.), especially when compared with natural ecosystems (non-pasture, non-cultivated) where direct human impacts are minimal. Using maximum annual leaf area index (LAImax) as a proxy for standing biomass and peak annual aboveground productivity, we analyze greening and browning trends in pasture areas from 1982-2008. Inter-annual variability in pasture productivity is strongly controlled by precipitation (positive correlation) and, to a lesser extent, temperature (negative correlation). Linear temporal trends are significant in 23% of pasture cells, with the vast majority of these areas showing positive LAImax trends. Spatially extensive productivity declines are only found in a few regions, most notably central Asia, southwest North America, and southeast Australia. Statistically removing the influence of precipitation reduces LAImax trends by only 13%, suggesting that precipitation trends are only a minor contributor to long-term greening and browning of pasture lands. No significant global relationship was found between LAImax and pasture intensity, although the magnitude of trends did vary between cells classified as natural versus pasture. In the tropics and Southern Hemisphere, the median rate of greening in pasture cells is significantly higher than for cells dominated by natural vegetation. In the Northern Hemisphere extra-tropics, conversely, greening of natural areas is 2-4 times the magnitude of greening in pasture areas. This analysis presents one of the first global assessments of greening and browning trends in global pasture lands, including a comparison with vegetation trends in regions dominated by natural ecosystems. Our results suggest that degradation of pasture lands is not a globally widespread phenomenon and, consistent with much of the terrestrial biosphere, there have been widespread increases in

  12. Transfer of /sup 131/I and /sup 95m/Tc from pasture to goat milk

    SciTech Connect

    Bondietti, E.A.; Garten, C.T. Jr.

    1984-01-01

    Field measurements were made in 1983 on the transfer of /sup 131/I and /sup 95m/Tc from spray-contaminated pasture to goat's milk. The transfer of /sup 131/I to milk was similar to that used for mathematical models in US Nuclear Regulatory Commission Regulatory Guide 1.109, which was derived from stall-feeding experiments using capsulized doses. Compared to /sup 131/I, the /sup 95m/Tc transferred to milk was about 5600 times less. The lower transfer resulted from both immobilization of technetium on pasture prior to ingestion as well as reduced gastrointestinal absorption. The results show that the food chain transfer of technetium to milk is much less than that previously expected based on inferences made from metabolism studies. 6 references, 4 figures, 1 table.

  13. Pasture practices, milk distribution, and consumption in the continental U. S. in the 1950s

    SciTech Connect

    Dreicer, M.; Bouville, A.; Wachholz, B.W. )

    1990-11-01

    Determining the consumption of milk contaminated with 131I, resulting from atmospheric nuclear weapons tests conducted at the Nevada Test Site, by the United States population during the 1950s constitutes one part of the methodology used by the National Cancer Institute to assess radiation exposures to Americans. In order to make these estimates for locations throughout the United States, it is necessary to determine the pasture intake by cows and the distribution of the milk produced for human consumption at times when the weapons were tested. Since the milk industry has undergone many changes during the past 35 y, historical records and information must be used. The methodology developed to estimate the intake of contaminated pasture by dairy cows, milk production, and milk distribution on a county basis for the continental U.S. during the 1950s is described in detail. The relevant data on milk consumption by humans are also discussed.

  14. CO2 and Carbon Balance of an Intensively Grazed Temperate Pasture: Response to Cultivation

    NASA Astrophysics Data System (ADS)

    Rutledge, S.; Mudge, P. L.; Wallace, D.; Campbell, D.; Wall, A.; Hosking, C. L.; Schipper, L. A.

    2012-12-01

    Recent soil resampling studies have shown that soils on flat land used for intensive dairy farming in New Zealand have lost large amounts of carbon (~1 t C ha-1y-1) over the past few decades, and the causes of these losses are poorly understood. One of the management practices potentially contributing to the C losses from these dairy soils is the periodic cultivation commonly associated with pasture renewal or the rotation through summer or winter crops. Here we report the results of three experiments aimed at quantifying the effect of cultivation as part of pasture renewal on the CO2 and C balances of permanent pastures. In the first experiment, the net ecosystem CO2 exchange (NEE) of an intensively grazed dairy pasture was measured before, during and after cultivation using eddy covariance (EC) from 2008 to 2011 at a dairy farm in the Waikato region on the North Island of New Zealand. The net ecosystem carbon balance (NECB) was determined by combining NEE data with measurements and estimates of other C imports (feed) and C exports (milk, methane, silage and leaching). The other two experiments took place on the same farm and monitored two different cultivation events in 2008. We made chamber measurements of soil CO2 losses between spraying and seedling emergence. One of the cultivations took place in summer 2008 during a drought, whereas the other took place in spring 2008 when soil water was not limiting. For the first two years of experiment 1 the site was under permanent pasture and it was a sink for both CO2 (1.6 and 2.3 t C ha-1y-1 for 2008 and 2009, respectively) and C (0.59 and 0.90 t C ha-1y-1 for 2008 and 2009, respectively), despite a severe drought in summer 2008 which had led to a loss of approximately 1.1 t C ha-1 as CO2 over the three summer months. Pasture renewal took place in March 2010 and CO2 losses during this event were approximately 1.7 t C ha-1. However, the site seemed to recover quickly and was a sink of CO2 at an annual time scale of

  15. Field scale fluxes and uncertainties of CO2 and energy from a managed pasture in Scotland

    NASA Astrophysics Data System (ADS)

    Clement, Robert; Hill, Tim; Chocholek, Mel; Blei, Emanuel; Williams, Mat

    2016-04-01

    A field campaign of eddy covariance measurements was conducted to determine the field scale trace gas and energy exchanges of a representative managed pasture in south west Scotland. To better fit the parent projects goal of multi-scale uncertainty, multiply flux systems were deployed in an attempt to quantify temporal and spatial variability of fluxes from a quasi-uniform site. We briefly discuss the hurdles encountered when synthesizing multiple measurement systems into a coherent dataset and reflect on what this analysis would imply when interpreting singular flux datasets. Data from the campaign provide information on flux estimates with run specific uncertainties over a complete harvest cycle of the pasture. Initial estimates suggest a net uptake of 2 micromol m-2 sec-1 over the 6 week period between harvests. Uncertainties of this estimate and the environmental dependence of uncertainties of half hour estimates will also be presented.

  16. Dryland pasture and crop conditions as seen by HCMM. [Washita River watershed

    NASA Technical Reports Server (NTRS)

    Harlan, J. C. (Principal Investigator); Rosenthal, W. D.; Blanchard, B. J.

    1981-01-01

    The antecedent precipitation index (API) was related to surface temperatures as measured from the NASA C-130 and HCMM thermal data. Significant results from the aircraft flight in May 1978, include: (1) canopy temperature were measured accurately remotely; (2) pasture surface temperatures were related to pasture and wheat soil moisture conditions; (3) no relationship was developed with that data set between wheat yield and thermal infrared data due to a lack of moisture stress during the measurement period; and (4) lake surface temperatures were useful in normalizing the thermal IR data. Results from HCMM also suggested a relationship between thermal IR data and antecedent precipitation index. While HCMM was adequate in detecting relative soil moisture differences, the overpass timing was infrequent and prevented detailed analysis of the API/thermal relationship.

  17. Dryland pasture and crop conditions as seen by HCMM. [Washita Watershed, Oklahoma

    NASA Technical Reports Server (NTRS)

    Harlan, J. C. (Principal Investigator); Rosenthal, W. D.; Blanchard, B. J.

    1981-01-01

    Techniques developed from aircraft flights over the Washita watershed in central Oklahoma were applied to HCMM data analysis. Results show that (1) canopy temperatures were accurately measured remotely; (2) pasture surface temperature differences detected relative soil moisture differences; (3) pasture surface temperature differences were related to stress in nearby wheat fields; and (4) no relationship was developed between final yield differences, thermal infrared data, and soil moisture stress at critical growth stages due to a lack of satellite thermal data at critical growth stages. The HCMM thermal data proved to be quite adequate in detecting relative moisture differences; however, with a 16 day day/night overpass frequency, more frequent overpasses are required to analyze more cases within a 7 day period after the storm. Better normalization techniques are also required.

  18. Soil hydraulic conductivities of latosols under pasture, forest and teak in Rondonia, Brazil

    NASA Astrophysics Data System (ADS)

    Elsenbeer, Helmut; Newton, Bradley E.; Dunne, Thomas; de Moraes, Jorge M.

    1999-06-01

    We investigated the changes of saturated hydraulic conductivity, Ksat , with depth of latosols developed on Precambrian basement rocks under primary rainforest, pasture and teak. In all cases, Ksat decreased with depth, with most of the decrease occurring between the surface and a depth of 30 cm. In conjunction with prevailing rainfall intensities and frequencies, this anisotropy supports a pronounced lateral component of hillslope flow paths, and also of overland flow under pasture. Our results are at variance with data from other latosols where Ksat tends to increase with depth, and hence suggest that considerable restraint is needed in generalization and extrapolation until results from a co-ordinated effort at hydrology-oriented data collection become available.

  19. Bacteria on leaves: a previously unrecognised source of N2O in grazed pastures.

    PubMed

    Bowatte, Saman; Newton, Paul C D; Brock, Shona; Theobald, Phil; Luo, Dongwen

    2015-01-01

    Nitrous oxide (N2O) emissions from grazed pastures are a product of microbial transformations of nitrogen and the prevailing view is that these only occur in the soil. Here we show this is not the case. We have found ammonia-oxidising bacteria (AOB) are present on plant leaves where they produce N2O just as in soil. AOB (Nitrosospira sp. predominantly) on the pasture grass Lolium perenne converted 0.02-0.42% (mean 0.12%) of the oxidised ammonia to N2O. As we have found AOB to be ubiquitous on grasses sampled from urine patches, we propose a 'plant' source of N2O may be a feature of grazed grassland. PMID:25012902

  20. Potential Pasture Nitrogen Concentrations and Uptake from Autumn or Spring Applied Cow Urine and DCD under Field Conditions.

    PubMed

    Moir, Jim; Cameron, Keith; Di, Hong

    2016-01-01

    Nitrogen (N) cycling and losses in grazed grassland are strongly driven by urine N deposition by grazing ruminants. The objective of this study was to quantify pasture N concentrations, yield and N uptake following autumn and spring deposition of cow urine and the effects of fine particle suspension (FPS) dicyandiamide (DCD). A field plot study was conducted on the Lincoln University dairy farm, Canterbury, New Zealand from May 2003 to May 2005. FPS DCD was applied to grazed pasture plots at 10 kg·ha(-1) in autumn and spring in addition to applied cow urine at a N loading rate of 1000 kg·N·ha(-1), with non-urine control plots. Pasture N ranged between 1.9 and 4.8% with higher concentrations from urine. Results indicated that urine consistently increased N concentrations for around 220 days post deposition (mid December/early summer) at which point concentrations dropped to background levels. In urine patches, pasture yield and annual N uptake were dramatically increased on average by 51% for autumn and 28% for spring applied urine, in both years, when DCD was applied. This field experiment provides strong evidence that annual pasture N uptake is more strongly influenced by high urine N deposition than pasture N concentrations. FPS DCD has the potential to result in very high N uptake in urine patches, even when they are autumn deposited. PMID:27304974

  1. Changes in carbon isotope ratios of soil organic matter following conversion of tropical deciduous forest to pasture

    SciTech Connect

    Garcia-Oliva, F.; Maass, J.M. ); Casar, I. )

    1993-06-01

    Near the Chamela Biological Station in Jalisco Mexico, tropical deciduous forest was cut, burned and planted with C, grasses for conversion to cattle pastures by local farmers. We estimated soil organic matter (SOM) turnover under intact forest and in a pasture chronosequence (1, 3, 7, and 11 years old). Total SOM in the surface soil under intact forest was 30,098 kg ha[sup [minus]1] (0-12 cm depth) with more than 50% in the uppermost 4 cm. Total SOM increased by 18% following cutting and burning, but exhibited a net decrease of 19% in the 11 year old pasture. Carbon ratios were determined by mass spectrometry; the dominant forest trees are C[sub 3], and the [delta][sup 13]C of forest huer was [minus]27.4, while the [delta][sup 13]C of pasture litter was [minus]15.9. The [delta][sup 13]C signatures of the 7 and 11 year old pastures were significantly different than the forest (p < 0.0001, R[sup 2]=0.77) and in the 11 year old pasture, only 54% of the original forest SOM remained. The estimated turnover rate for forest SOM following clearing was 1.024 kg ha[sup [minus]1] yr[sup [minus]1] and interestingly, the SOM associated with the sand fraction displays a turnover rate considerably higher than that associated with the silt or clay fractions.

  2. Blood plasma magnesium, potassium, glucose, and immunoreactive insulin changes in cows moved abruptly from barn feeding to early spring pasture

    SciTech Connect

    Miller, J.K.; Madsen, F.C.; Lentz, D.E.; Wong, W.O.; Ramsey, N.; Tysinger, C.E.; Hansard, S.L.

    1980-07-01

    Cations and immunoreactive insulin in plasma were measured in 35 lactating cows moved abruptly to early spring pasture. After change of cows from grass-clover hay to fescue-bluegrass pasture containing 22 to 31 g potassium/kg dry matter, immunoreactive insulin of 5 Holstein cows increased 30% in 5 days and averaged 45% above prepasture concentrations for 40 days. Magnesium averaged 44% below prepasture content of plasma during this period and was correlated negatively with potassium -.17 and immunoreactive insulin -.37. Thirty Hereford cows were changed from corn silage and grass-clover hay to wheat-rye pasture containing 3.06% potassium in the dry matter. Each day on pasture, 10 cows each were fed 2.3 kg cornmeal, 10 were given 30 g magnesium oxide by capsule, and 10 were given no supplement. After unsupplemented cows were moved to pasture, immunoreactive insulin rose 51% in 8 days and plasma magnesium fell 24%. Both supplements reduced immunoreactive insulin, but magnesium was maintained higher by magnesium oxide than by cornmeal. Injection of two Holstein cows with insulin (2 IU/kg body weight) reduced plasma concentrations of both potassium and mgnesium 20% below that of two cows injected with only physiological saline. Whether elevated plasma insulin may accelerate development of hypomagnesemia in cattle on spring pasture with relatively high potassium content has not been established.

  3. Potential Pasture Nitrogen Concentrations and Uptake from Autumn or Spring Applied Cow Urine and DCD under Field Conditions

    PubMed Central

    Moir, Jim; Cameron, Keith; Di, Hong

    2016-01-01

    Nitrogen (N) cycling and losses in grazed grassland are strongly driven by urine N deposition by grazing ruminants. The objective of this study was to quantify pasture N concentrations, yield and N uptake following autumn and spring deposition of cow urine and the effects of fine particle suspension (FPS) dicyandiamide (DCD). A field plot study was conducted on the Lincoln University dairy farm, Canterbury, New Zealand from May 2003 to May 2005. FPS DCD was applied to grazed pasture plots at 10 kg·ha−1 in autumn and spring in addition to applied cow urine at a N loading rate of 1000 kg·N·ha−1, with non-urine control plots. Pasture N ranged between 1.9 and 4.8% with higher concentrations from urine. Results indicated that urine consistently increased N concentrations for around 220 days post deposition (mid December/early summer) at which point concentrations dropped to background levels. In urine patches, pasture yield and annual N uptake were dramatically increased on average by 51% for autumn and 28% for spring applied urine, in both years, when DCD was applied. This field experiment provides strong evidence that annual pasture N uptake is more strongly influenced by high urine N deposition than pasture N concentrations. FPS DCD has the potential to result in very high N uptake in urine patches, even when they are autumn deposited. PMID:27304974

  4. Visible spectroscopy on carcass fat combined with chemometrics to distinguish pasture-fed, concentrate-fed and concentrate-finished pasture-fed lambs.

    PubMed

    Huang, Y; Andueza, D; de Oliveira, L; Zawadzki, F; Prache, S

    2015-03-01

    We used visible spectroscopy of fat to discriminate lambs that were pasture-fed (n=76), concentrate-fed (n=79) or concentrate-finished after pasture-feeding (n=69). The reflectance spectrum of perirenal and subcutaneous caudal fat was measured at slaughter and 24h post mortem. In Method 1 (W450-510), the optical data were used at wavelengths in the range of 450-510nm to calculate an index quantifying light absorption by carotenoids. In Method 2 (W400-700), the full set of data at wavelengths in the range of 400-700nm was used to differentiate carcasses using PLS-DA as a classification method. W400-700 proved more reliable than W450-510 (P<0.0001). The proportion of correctly classified lambs using W400-700 was 95.6% and 95.9% for measurements made on perirenal fat at slaughter and 24h post mortem. The intensity of light absorption by carotenoids decreased exponentially with live weight gain during the finishing period. PMID:25462376

  5. Survey of Ticks Collected from Tennessee Cattle and Their Pastures for Anaplasma and Ehrlichia Species.

    PubMed

    Pompo, K; Mays, S; Wesselman, C; Paulsen, D J; Fryxell, R T Trout

    2016-02-01

    Anaplasma marginale is the causative agent for bovine anaplasmosis (BA) and Ehrlichia ruminantium is the causative agent for heartwater, 2 devastating diseases of cattle. BA is common in the United States and frequently reported in western Tennessee cattle; however, cases of heartwater are not yet established in the continental United States. Because both pathogens are transmitted via the bites of infected ticks, the objective of this study was to survey cattle and pastures for ticks and for each pathogen. University of Tennessee AgResearch has 7 research and education centers (REC) located throughout the state at which they manage cattle. Ticks were collected from selected cattle (every fourth to sixth animal) and pastures (via dragging) associated with the herd from each REC during the summer of 2013. A total of 512 ticks were collected from cattle (n = 386) and pastures (n = 126) and were PCR-screened for Anaplasma and Ehrlichia using genus-specific primers. Collections consisted of 398 (77.7%) Amblyomma americanum, 84 (16.4%) Amblyomma maculatum, and 30 (5.9%) Dermacentor variabilis. Ticks were not recovered from pastures or cattle east of the Tennessee Plateau. The North American vectors for An. marginale and E. ruminantium were identified (D. variabilis and A. maculatum, respectively), but neither pathogen was recovered. A large proportion of ticks were collected from cattle and, of these, a majority were attached to their host (compared to questing on their host or engorged on the host). Four A. americanum were positive for Ehrlichia spp. (Ehrlichia ewingii, Ehrlichia chaffeensis, and Panola Mountain Ehrlichia), all in western Tennessee. With the identification of a few Ehrlichia infections in cattle-associated ticks and current A. marginale rates in Tennessee beef cattle nearing 11%, additional research is needed to establish baseline tick, Anaplasma, and Ehrlichia data for future management studies. PMID:26348980

  6. Using normalized difference vegetation index to estimate carbon fluxes from small rotationally grazed pastures

    USGS Publications Warehouse

    Skinner, R.H.; Wylie, B.K.; Gilmanov, T.G.

    2011-01-01

    Satellite-based normalized difference vegetation index (NDVI) data have been extensively used for estimating gross primary productivity (GPP) and yield of grazing lands throughout the world. However, the usefulness of satellite-based images for monitoring rotationally-grazed pastures in the northeastern United States might be limited because paddock size is often smaller than the resolution limits of the satellite image. This research compared NDVI data from satellites with data obtained using a ground-based system capable of fine-scale (submeter) NDVI measurements. Gross primary productivity was measured by eddy covariance on two pastures in central Pennsylvania from 2003 to 2008. Weekly 250-m resolution satellite NDVI estimates were also obtained for each pasture from the moderate resolution imaging spectroradiometer (MODIS) sensor. Ground-based NDVI data were periodically collected in 2006, 2007, and 2008 from one of the two pastures. Multiple-regression and regression-tree estimates of GPP, based primarily on MODIS 7-d NDVI and on-site measurements of photosynthetically active radiation (PAR), were generally able to predict growing-season GPP to within an average of 3% of measured values. The exception was drought years when estimated and measured GPP differed from each other by 11 to 13%. Ground-based measurements improved the ability of vegetation indices to capture short-term grazing management effects on GPP. However, the eMODIS product appeared to be adequate for regional GPP estimates where total growing-season GPP across a wide area would be of greater interest than short-term management-induced changes in GPP at individual sites.

  7. Phosphorus in Hawaiian kikuyugrass pastures and potential phosphorus release to water.

    PubMed

    Mathews, B W; Carpenter, J R; Sollenberger, L E; Tsang, S

    2005-01-01

    Pasture systems in Hawaii are based primarily on kikuyugrass (Pennisetum clandestinum Hochst. ex Chiov.). Relationships among kikuyugrass P concentration, animal P requirements, and various soil P determinations are needed to help identify source areas for implementing pasture management strategies to limit P loss via overland flow. A total of 51 rotationally stocked kikuyugrass pastures (>20 yr old) with contrasting soil chemical properties were sampled. A satisfactory predictive relationship between modified-Truog (MT)-extractable phosphorus (P(MT)) and dissolved (<0.45-mum pore diameter), molybdate-reactive phosphorus (DRP) desorbed from soil in a water extract (DRP(WE)) was found when 0- to 4-cm-depth data for the soil orders with medium to high DRP(WE) (two Mollisols and an Inceptisol) were pooled separately from those with low DRP(WE) (five Andisols, three Ultisols, and an Oxisol). The oxalate phosphorus saturation index (PSI(ox)) procedure was the best predictor of DRP(WE) across soil orders when oxalate-extractable molybdate-reactive phosphorus (RP(ox)) was used to calculate PSI(ox) (PSI(ox)RP) rather than when total oxalate-extractable phosphorus (TP(ox)) was used (PSI(ox)TP). There was little DRP(WE) until PSI(ox)RP exceeded 6% or PSI(ox)TP exceeded 8%. A more empirical dilute-acid phosphorus saturation index (PSI(MT)) was also calculated using P(MT) and MT-extractable iron (Fe(MT)) and aluminum (Al(MT)). The PSI(MT) procedure showed some utility in predicting DRP(WE), was positively related to the PSI(ox) procedures, and can be more readily performed in agronomic soil testing laboratories than PSI(ox). The present research suggests that while Hawaiian kikuyugrass pastures tend to be sufficient to high in forage P, potential soil P release to water only appeared to be a possible environmental concern for the Mollisol and Inceptisol sites. PMID:15942040

  8. Spatial variation in spoil and vegetative characteristics of pastures on reclaimed surface mined land

    SciTech Connect

    Teutsch, C.D.; Collins, M.; Ditsch, D.C.

    1999-07-01

    Kentucky has large areas of reclaimed surface mined land that could provide grazing for livestock. Research is needed to determine optimal stocking densities and to evaluate the sustainability of such grazing systems for this region. A long-term grazing study was initiated in 1997 on 151 ha of reclaimed land near Chavies, KY to determine spatial and temporal variation with stocking densities of 0, 0.28, 0.42, or 0.83 beef cow-calf units/ha. Global Positioning System and GIS technologies were used to establish pasture boundaries, locate permanent sampling markers at a density of 1 per 0.4 ha, and interpolate maps of physical, spoil, and vegetable pasture characteristics. Herbage and spoil samples were collected around the permanent markers in May of 1997. Stepwise regression was used to determine factors affecting the vegetative characteristics of the sites. Biomass density ranged from 0 to 2500 kg/ha with a mean of 570 kg/ha. Factors affecting biomass included legume and weed proportions in the sward, grazing activity, soil potassium, elevation, and potential acidity, cumulatively accounting for 32% of the variation. Ground cover ranged from 10 to 100% with an average of 74%. Soil pH, potassium, and grass in the sward accounted for 14% of the variation in ground cover. Legumes made up 0 to 61% of the sward with a mean of 13% over the pasture area. Variables affecting the amount of legume in the sward included biomass density, slope, elevation, pH, and stocking density, together accounting for 21% of the variation. Spatial variation in the physical, spoil, and vegetative characteristics of the pastures was large. Overall, regression accounted for a limited amount of the variation in the vegetative characteristics of the site indicating that other important variables exist.

  9. Discerning the cows from the pasture when determining annual NEE and carbon budget

    NASA Astrophysics Data System (ADS)

    Ammann, Christof; Felber, Raphael; Neftel, Albrecht

    2015-04-01

    The CO2 exchange of ecosystems and the resulting annual net ecosystem exchange (NEE) and total carbon budget (soil carbon sequestration) is commonly investigated using the eddy covariance (EC) technique. For the carbon budget of managed ecosystems also the import and export of organic carbon has to be taken into account. Grazed pasture systems represent a special challenge because their respiration can considerably contribute to the measured CO2 flux, but this contribution depends on the spatial distribution of the cows relative to the footprint and thus is variable in time. This has implications for the gap filling of CO2 flux time series necessary to determine annual NEE. In few existing studies two procedures have been suggested to determine the NEE of grazed pasture: (a) discarding all cases with cows in the footprint and gap-filling the remaining dataset; (b) treating the cow respiration as part of total ecosystem respiration and gap fill the entire flux dataset including cow contributions. Both approaches rely on idealized assumptions and have limitations. In our study we evaluated and compared the two approaches (for the first time to our knowledge) for a grazed pasture in Switzerland. For this purpose, the grazing cows were equipped with GPS sensors to monitor their position relative to the flux footprint. We found that the resulting annual NEE strongly depends on the flux data selection (e.g. u* filtering) and the applied gap filling procedure. Using an optimized procedure, the annual NEE with approach (b) was several times larger than the result of approach (a), but the difference agreed fairly well with independent estimates of cow respiration. Necessary assumptions and requirements of the two approaches for the determination of the pasture carbon budget will be discussed.

  10. Performance, ruminal and serum characteristics of steers fed lasalocid on pasture.

    PubMed

    Spears, J W; Harvey, R W

    1984-02-01

    Seventy-two growing steers were used in a 126-d study to determine the influence of varying levels of lasalocid on performance, ruminal and serum characteristics of animals grazing pasture. Treatments consisted of: 1) control; 2) 200 mg lasalocid/d and 3) 300 mg lasalocid/d. Each treatment was replicated three times and each replicate of eight steers was maintained on 3.0 ha of pasture. Pastures consisted of a mixture of tall fescue, orchard grass and ladino clover. In addition to pasture, each replicate of steers was group fed ground corn at a rate of .91 kg X head-1 X d-1 with the lasalocid incorporated into the grain. Average daily gains were .50, .60 and .57 kg, respectively, for steers on the control, and for the 200 and 300 mg lasalocid treatments, which differed (P less than .05) from controls. Ruminal acetate (mol/100 mol) was lower (P less than .05) in steers fed lasalocid at 28 d, but similar for all treatments at 56 and 112 d. Molar proportion of propionate was higher (P less than .05) and butyrate and valerate were lower (P less than .10) in rumen fluid of steers receiving 200 or 300 mg/d of lasalocid. Plasma glucose concentrations were similar for controls and steers receiving 200 mg lasalocid/d, but higher (P less than .05) in steers fed 300 mg lasalocid/d. Serum Mg concentrations were lower (P less than .01) in steers receiving lasalocid. Potassium concentrations in serum were slightly lower (P less than .01) in animals fed lasalocid at 112 d, but not at 28 or 56 d.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6706878

  11. Controlling herbaceous competition in pasture planted with loblolly pine seedlings. Forest Service research note

    SciTech Connect

    Haywood, J.D.

    1995-09-01

    Three treatments designed to control herbaceous vegetation competing with loblolly pine (Pinus taeda L.) seedlings planted in grazed and ungrazed pasture were tested. Effects of the treatments on seedling survival and growth during the first 3 years after planting were determined. The treatments were directed application of herbicides (glyphosate in the first 2 years and hexazinone in the third year), rotary mowing, and mulching with pine straw around individual pine seedlings.

  12. Pasture Characteristics in Three Different Ecotypes at Khovd Aimag, Western Mongolia

    PubMed Central

    Beher, Jutta

    2014-01-01

    The transition of nomadic pastoralism to more sessile forms of rangeland utilization and increased stocking rates can result in the degradation of pasture. After political changes in the 1990s in Mongolia, population growth and missing alternative livelihoods intensified the grazing pressure on pastures, and further decreased the condition of the fragile arid ecosystems. To learn more about the productivity and quality of pasture land in Khovd Aimag in the western region of Mongolia, standing biomass was measured in the alpine region, mountain steppe and semi-desert. Plant samples were analyzed for nitrogen and fiber contents by wet chemistry and Near Infrared Spectroscopy (NIRS). Results show clear differences in distribution of biomass with reduced biomass in the vicinity of temporary settlements. From July to early September plant nitrogen contents decreased in the alpine region, remained unchanged in the mountain steppe and increased in the semi-desert. Nitrogen concentrations were elevated in vegetation close to temporary settlements. For fiber contents (ADF) no clear patterns were found. Neither biomass/m2 nor vegetation cover were appropriate indicators for food quality. PMID:25058023

  13. Natural Wetlands Mediate Non-point Source Water Pollution From Irrigated Pastures

    NASA Astrophysics Data System (ADS)

    Knox, K.; Dahlgren, R. A.; Tate, K. W.

    2005-12-01

    Non-point source discharge from grazed pastures may be high in nutrients, sediment, and pathogens, three major contributors to water quality impairment in California. Intercepting pollution at its source and managing water quality within the landscape are essential to maintaining healthy downstream waters. We investigated the efficacy of flow-through wetlands interspersed throughout the agricultural landscape to reduce non-point source pollution of tailwater from cattle-grazed, irrigated pastures in the Sierra Nevada Foothills of California. Wetlands are known to positively impact water quality through ecological processes such as filtration, sedimentation, microbial transformations and plant uptake of nutrients. Influent and effluent water of small (0.25 ha), natural wetlands located downstream from flood irrigated pastures was analyzed for Escherichia coli, NO3-N, total N, total suspended solids (TSS), total P, and dissolved organic carbon (DOC) throughout two summer irrigation seasons (June to October). We compared reductions of sediment, nutrients and E. coli provided by a healthy, non-degraded wetland with reductions from flow through a channelized, degraded wetland. Large reductions in E. coli (>75%) and TSS (>50%) were observed in water exiting the healthy wetland while nutrient and DOC (~ 20%) concentrations were less affected by flow through the wetland. The channelized wetland provided smaller reductions in all constituents than did the non-degraded wetland. Results from this study demonstrate that small flow-through wetlands can improve water quality through the attenuation of E. coli and suspended sediments, and to a lesser degree DOC and nutrients.

  14. Forest-to-pasture conversion increases the diversity of the phylum Verrucomicrobia in Amazon rainforest soils.

    PubMed

    Ranjan, Kshitij; Paula, Fabiana S; Mueller, Rebecca C; Jesus, Ederson da C; Cenciani, Karina; Bohannan, Brendan J M; Nüsslein, Klaus; Rodrigues, Jorge L M

    2015-01-01

    The Amazon rainforest is well known for its rich plant and animal diversity, but its bacterial diversity is virtually unexplored. Due to ongoing and widespread deforestation followed by conversion to agriculture, there is an urgent need to quantify the soil biological diversity within this tropical ecosystem. Given the abundance of the phylum Verrucomicrobia in soils, we targeted this group to examine its response to forest-to-pasture conversion. Both taxonomic and phylogenetic diversities were higher for pasture in comparison to primary and secondary forests. The community composition of Verrucomicrobia in pasture soils was significantly different from those of forests, with a 11.6% increase in the number of sequences belonging to subphylum 3 and a proportional decrease in sequences belonging to the class Spartobacteria. Based on 99% operational taxonomic unit identity, 40% of the sequences have not been detected in previous studies, underscoring the limited knowledge regarding the diversity of microorganisms in tropical ecosystems. The abundance of Verrucomicrobia, measured with quantitative PCR, was strongly correlated with soil C content (r = 0.80, P = 0.0016), indicating their importance in metabolizing plant-derived carbon compounds in soils. PMID:26284056

  15. Chronic copper poisoning in sheep grazing pastures fertilized with swine manure

    SciTech Connect

    Kerr, L.A.; McGavin, H.D. )

    1991-01-01

    Several pregnant ewes developed an acute hemolytic crisis and died. Liver and kidney copper concentrations were high, confirming chronic copper poisoning as the cause of death. Feed and water samples that the affected ewes had been consuming did not contain excess copper. Because swine manure slurry had been applied to the pasture where the sheep had grazed, a copper analysis was conducted on soil and forage samples from this field. High copper concentrations were detected in the soil and forage samples from the slurry pasture. Most sheep producers are aware of the catastrophic consequences that result when feeds containing copper and insufficient amounts of molybdenum are fed to sheep. However, producers and veterinarians often are unaware of some of the subtle sources of copper. Most of the copper that is added to swine and poultry feeds as growth promotants passes through the gastrointestinal tract unabsorbed and remains in the waste material. Pastures that have copper-containing waste material, but no molybdenum applied, can produce the same fatal results as giving sheep feed supplemented with copper but containing no molybdenum.

  16. Eddy covariance methane flux measurements over a grazed pasture: effect of cows as moving point sources

    NASA Astrophysics Data System (ADS)

    Felber, R.; Münger, A.; Neftel, A.; Ammann, C.

    2015-06-01

    Methane (CH4) from ruminants contributes one-third of global agricultural greenhouse gas emissions. Eddy covariance (EC) technique has been extensively used at various flux sites to investigate carbon dioxide exchange of ecosystems. Since the development of fast CH4 analyzers, the instrumentation at many flux sites has been amended for these gases. However, the application of EC over pastures is challenging due to the spatially and temporally uneven distribution of CH4 point sources induced by the grazing animals. We applied EC measurements during one grazing season over a pasture with 20 dairy cows (mean milk yield: 22.7 kg d-1) managed in a rotational grazing system. Individual cow positions were recorded by GPS trackers to attribute fluxes to animal emissions using a footprint model. Methane fluxes with cows in the footprint were up to 2 orders of magnitude higher than ecosystem fluxes without cows. Mean cow emissions of 423 ± 24 g CH4 head-1 d-1 (best estimate from this study) correspond well to animal respiration chamber measurements reported in the literature. However, a systematic effect of the distance between source and EC tower on cow emissions was found, which is attributed to the analytical footprint model used. We show that the EC method allows one to determine CH4 emissions of cows on a pasture if the data evaluation is adjusted for this purpose and if some cow distribution information is available.

  17. Humic fractions of forest, pasture and maize crop soils resulting from microbial activity.

    PubMed

    Tavares, Rose Luiza Moraes; Nahas, Ely

    2014-01-01

    Humic substances result from the degradation of biopolymers of organic residues in the soil due to microbial activity. The objective of this study was to evaluate the influence of three different ecosystems: forest, pasture and maize crop on the formation of soil humic substances relating to their biological and chemical attributes. Microbial biomass carbon (MBC), microbial respiratory activity, nitrification potential, total organic carbon, soluble carbon, humic and fulvic acid fractions and the rate and degree of humification were determined. Organic carbon and soluble carbon contents decreased in the order: forest > pasture > maize; humic and fulvic acids decreased in the order forest > pasture = maize. The MBC and respiratory activity were not influenced by the ecosystems; however, the nitrification potential was higher in the forest than in other soils. The rate and degree of humification were higher in maize soil indicating greater humification of organic matter in this system. All attributes studied decreased significantly with increasing soil depth, with the exception of the rate and degree of humification. Significant and positive correlations were found between humic and fulvic acids contents with MBC, microbial respiration and nitrification potential, suggesting the microbial influence on the differential formation of humic substances of the different ecosystems. PMID:25477932

  18. Deterioration of soil quality and pasture production linked to overgrazing in rangelands of Extremadura (SW Spain)

    NASA Astrophysics Data System (ADS)

    Pulido-Fernández, Manuel; Schnabel, Susanne; Francisco Lavado Contador, Joaquín; Lozano-Parra, Javier; González López, Francisco

    2015-04-01

    Soil degradation phenomena include water erosion and physical and biological processes have been already reported in rangelands of southwestern Spain. The increasing of the number of domestic animals since 1986 has been highlighted as one of the key causes. The main goal of this work is to analyze the effects of the excessive number of animals on soil quality and pasture production in privately-owned farms dedicated to extensive ranching. Soil properties, soil surface cover, erosion features, pasture production and composition, rainfall and land management variables such as livestock density were analyzed during a period of 3 years (2008-2011). The study was carried out in 22 fenced units belonging to 10 farms distributed throughout the Spanish region of Extremadura. The occurrence of bare soil patches, and consequently water erosion processes, as well as an increasing in the mean values of bulk density from 5 to 10 cm in depth were observed in the fenced units with animal stocking rates exceeding 1 AU ha-1 (AU: animal cattle equivalent unit). Some indications which may serve to confirm the negative effect of increased bulk density on pasture production and quality were also found.

  19. Humic fractions of forest, pasture and maize crop soils resulting from microbial activity

    PubMed Central

    Tavares, Rose Luiza Moraes; Nahas, Ely

    2014-01-01

    Humic substances result from the degradation of biopolymers of organic residues in the soil due to microbial activity. The objective of this study was to evaluate the influence of three different ecosystems: forest, pasture and maize crop on the formation of soil humic substances relating to their biological and chemical attributes. Microbial biomass carbon (MBC), microbial respiratory activity, nitrification potential, total organic carbon, soluble carbon, humic and fulvic acid fractions and the rate and degree of humification were determined. Organic carbon and soluble carbon contents decreased in the order: forest > pasture > maize; humic and fulvic acids decreased in the order forest > pasture=maize. The MBC and respiratory activity were not influenced by the ecosystems; however, the nitrification potential was higher in the forest than in other soils. The rate and degree of humification were higher in maize soil indicating greater humification of organic matter in this system. All attributes studied decreased significantly with increasing soil depth, with the exception of the rate and degree of humification. Significant and positive correlations were found between humic and fulvic acids contents with MBC, microbial respiration and nitrification potential, suggesting the microbial influence on the differential formation of humic substances of the different ecosystems. PMID:25477932

  20. Nutritional management to optimize fertility of dairy cows in pasture-based systems.

    PubMed

    Butler, S T

    2014-05-01

    The efficiency of milk production in pasture-based systems is heavily influenced by calving pattern, necessitating excellent reproductive performance in a short-breeding season. Where grazed pasture is the major component of the diet, cows are underfed relative to their intake potential. The cow responds by reducing milk output, but fertility is generally better than high intake confinement systems that achieve greater milk production per cow. A number of studies have identified body condition score (BCS) measurements that are related to likelihood of both submission and conception. Blood metabolites and metabolic hormones linked to fertility outcomes are now well characterized. In general, fertility variables have favourable associations with circulating concentrations of glucose, insulin and IGF-1 and unfavourable associations with non-esterified fatty acids, β-hydroxybutyrate and endogenous growth hormone. Nutritional strategies to impact these metabolic indicators have been utilized, but effects on herd fertility are inconsistent. Simply supplementing cows with additional energy in the form of standard concentrates does not appear to have a pronounced effect on fertility. Energy from additional concentrates fed during lactation is preferentially partitioned towards extra milk production rather than BCS repletion. The higher the genetic merit for milk production, the greater the partitioning of additional nutrients to the mammary gland. This review outlines the unique nutritional challenges of pasture-based systems, the role of specific metabolic hormones and metabolites in regulating reproductive function, and nutritional strategies to improve herd fertility. PMID:24844127

  1. Sorption, Leaching, and Surface Runoff of Beef Cattle Veterinary Pharmaceuticals under Simulated Irrigated Pasture Conditions

    PubMed Central

    Popova, Inna E.; Bair, Daniel A.; Tate, Kenneth W.; Parikh, Sanjai J.

    2014-01-01

    The use of veterinary pharmaceuticals in beef cattle has led to concerns associated with the development of antibiotic resistance in bacteria and endocrine disruption in aquatic organisms. Despite the potential negative consequences, data on the transport and mitigation of pharmaceuticals in grazed watersheds with irrigated pasture are scarce. The objective of this study was to assess the transport of common beef cattle pharmaceuticals (i.e., oxytetracycline, chlortetracycline, ivermectin) via surface runoff and leachate from manure amended to grass-vegetated soil boxes under irrigated pasture conditions. The transport of pharmaceuticals from animal manure in surface runoff and soil leachate was relatively low and appears to be limited by desorption and transport of pharmaceuticals entrained in the manure. In surface runoff, less than 4.2% of applied pharmaceuticals in manure (initial concentration: 0.2 mg kg−1 of manure) were detected after three weeks of irrigation. Concentrations of pharmaceuticals in surface runoff and leachate never exceeded 0.5 µg L−1. The major portion of pharmaceuticals (up to 99%) was retained in the manure or in the soil directly beneath the manure application site. Based on the minimal transport of oxytetracycline, chlortetracycline, and ivermectin, the risk of significant transport for these targeted beef cattle pharmaceuticals to surface water and groundwater from manure on irrigated pasture appears to be relatively low. PMID:24216368

  2. Forest-to-pasture conversion increases the diversity of the phylum Verrucomicrobia in Amazon rainforest soils

    PubMed Central

    Ranjan, Kshitij; Paula, Fabiana S.; Mueller, Rebecca C.; Jesus, Ederson da C.; Cenciani, Karina; Bohannan, Brendan J. M.; Nüsslein, Klaus; Rodrigues, Jorge L. M.

    2015-01-01

    The Amazon rainforest is well known for its rich plant and animal diversity, but its bacterial diversity is virtually unexplored. Due to ongoing and widespread deforestation followed by conversion to agriculture, there is an urgent need to quantify the soil biological diversity within this tropical ecosystem. Given the abundance of the phylum Verrucomicrobia in soils, we targeted this group to examine its response to forest-to-pasture conversion. Both taxonomic and phylogenetic diversities were higher for pasture in comparison to primary and secondary forests. The community composition of Verrucomicrobia in pasture soils was significantly different from those of forests, with a 11.6% increase in the number of sequences belonging to subphylum 3 and a proportional decrease in sequences belonging to the class Spartobacteria. Based on 99% operational taxonomic unit identity, 40% of the sequences have not been detected in previous studies, underscoring the limited knowledge regarding the diversity of microorganisms in tropical ecosystems. The abundance of Verrucomicrobia, measured with quantitative PCR, was strongly correlated with soil C content (r = 0.80, P = 0.0016), indicating their importance in metabolizing plant-derived carbon compounds in soils. PMID:26284056

  3. The effects of providing portable shade at pasture on dairy cow behavior and physiology.

    PubMed

    Palacio, S; Bergeron, R; Lachance, S; Vasseur, E

    2015-09-01

    Access to pasture has advantages for cows such as reduced lameness and improved udder health, but also may expose cows to stressors such as extreme heat. The objective of this study was to understand how portable shade affected physiological and behavioral responses of pastured dairy cows in a Canadian summer. Over 8wk, a total of 24 lactating Holstein cows were separated into 2 treatments, one with access to shade and a control without access to shade. The cows were pastured in groups of 4, with 3 field sections per treatment. Instantaneous scan sampling of behaviors (drinking, lying, grazing, other) performed in the shade or not were recorded every 5min for 3h/d during the hottest part of the day (peak hours: 1130-1530h) 3d/wk. Ambient temperature, humidity, and vaginal temperature were recorded at 10-min intervals. Daily milk production was also recorded. Differences between treatments by week were analyzed using the generalized linear mixed model with group as random effect and treatment as fixed effect. Cows with shade access were observed at the water trough up to 6.42 times less and lying down up to 1.75 times more. Cows with shade access grazed up to 1.5 times more but only when the temperature-humidity index was above their comfort threshold (≥72) during the hottest part of the day (wk 2). Cows sought shade when it was made available, but spent less than half of their time observed (%) in the shade (40.8±4.67) with the exception of wk 2 when most of the time was spent under the shade (74.3±4.77). Daily lying time was highest during peak hours for cows with shade access. However, no overall difference in total lying time between the 2 treatments was observed. No differences were found in vaginal temperature or milk production between treatments with the exception of wk 1 for daily milk production, which was higher for cows in the control treatment. In conclusion, cows sought shade when it was provided at pasture, whereas cows without access to shade

  4. Modelling Pasture-based Automatic Milking System Herds: The Impact of Large Herd on Milk Yield and Economics

    PubMed Central

    Islam, M. R.; Clark, C. E. F.; Garcia, S. C.; Kerrisk, K. L.

    2015-01-01

    The aim of this modelling study was to investigate the effect of large herd size (and land areas) on walking distances and milking interval (MI), and their impact on milk yield and economic penalties when 50% of the total diets were provided from home grown feed either as pasture or grazeable complementary forage rotation (CFR) in an automatic milking system (AMS). Twelve scenarios consisting of 3 AMS herds (400, 600, 800 cows), 2 levels of pasture utilisation (current AMS utilisation of 15.0 t dry matter [DM]/ha, termed as ‘moderate’; optimum pasture utilisation of 19.7 t DM/ha, termed as ‘high’) and 2 rates of incorporation of grazeable complementary forage system (CFS: 0, 30%; CFS = 65% farm is CFR and 35% of farm is pasture) were investigated. Walking distances, energy loss due to walking, MI, reduction in milk yield and income loss were calculated for each treatment based on information available in the literature. With moderate pasture utilisation and 0% CFR, increasing the herd size from 400 to 800 cows resulted in an increase in total walking distances between the parlour and the paddock from 3.5 to 6.3 km. Consequently, MI increased from 15.2 to 16.4 h with increased herd size from 400 to 800 cows. High pasture utilisation (allowing for an increased stocking density) reduced the total walking distances up to 1 km, thus reduced the MI by up to 0.5 h compared to the moderate pasture, 800 cow herd combination. The high pasture utilisation combined with 30% of the farm in CFR in the farm reduced the total walking distances by up to 1.7 km and MI by up to 0.8 h compared to the moderate pasture and 800 cow herd combination. For moderate pasture utilisation, increasing the herd size from 400 to 800 cows resulted in more dramatic milk yield penalty as yield increasing from c.f. 2.6 and 5.1 kg/cow/d respectively, which incurred a loss of up to $AU 1.9/cow/d. Milk yield losses of 0.61 kg and 0.25 kg for every km increase in total walking distance (voluntary

  5. Methane Emission and Milk Production of Dairy Cows Grazing Pastures Rich in Legumes or Rich in Grasses in Uruguay.

    PubMed

    Dini, Yoana; Gere, José; Briano, Carolina; Manetti, Martin; Juliarena, Paula; Picasso, Valentin; Gratton, Roberto; Astigarraga, Laura

    2012-01-01

    Understanding the impact of changing pasture composition on reducing emissions of GHGs in dairy grazing systems is an important issue to mitigate climate change. The aim of this study was to estimate daily CH₄ emissions of dairy cows grazing two mixed pastures with contrasting composition of grasses and legumes: L pasture with 60% legumes on Dry Matter (DM) basis and G pasture with 75% grasses on DM basis. Milk production and CH₄ emissions were compared over two periods of two weeks during spring using eight lactating Holstein cows in a 2 × 2 Latin square design. Herbage organic matter intake (HOMI) was estimated by chromic oxide dilution and herbage organic matter digestibility (OMD) was estimated by faecal index. Methane emission was estimated by using the sulfur hexafluoride (SF6) tracer technique adapted to collect breath samples over 5-day periods. OMD (0.71) and HOMI (15.7 kg OM) were not affected by pasture composition. Milk production (20.3 kg/d), milk fat yield (742 g/d) and milk protein yield (667 g/d) were similar for both pastures. This may be explained by the high herbage allowance (30 kg DM above 5 cm/cow) which allowed the cows to graze selectively, in particular in grass sward. Similarly, methane emission expressed as absolute value (368 g/d or 516 L/d) or expressed as methane yield (6.6% of Gross Energy Intake (GEI)) was not affected by treatments. In conclusion, at high herbage allowance, the quality of the diet selected by grazing cows did not differ between pastures rich in legumes or rich in grasses, and therefore there was no effect on milk or methane production. PMID:26486922

  6. Differential Response of Acidobacteria Subgroups to Forest-to-Pasture Conversion and Their Biogeographic Patterns in the Western Brazilian Amazon

    PubMed Central

    Navarrete, Acacio A.; Venturini, Andressa M.; Meyer, Kyle M.; Klein, Ann M.; Tiedje, James M.; Bohannan, Brendan J. M.; Nüsslein, Klaus; Tsai, Siu M.; Rodrigues, Jorge L. M.

    2015-01-01

    Members of the phylum Acidobacteria are among the most abundant soil bacteria on Earth, but little is known about their response to environmental changes. We asked how the relative abundance and biogeographic patterning of this phylum and its subgroups responded to forest-to-pasture conversion in soils of the western Brazilian Amazon. Pyrosequencing of 16S rRNA genes was employed to assess the abundance and composition of the Acidobacteria community across 54 soil samples taken using a spatially nested sampling scheme at the landscape level. Numerically, Acidobacteria represented 20% of the total bacterial community in forest soils and 11% in pasture soils. Overall, 15 different Acidobacteria subgroups of the current 26 subgroups were detected, with Acidobacteria subgroups 1, 3, 5, and 6 accounting together for 87% of the total Acidobacteria community in forest soils and 75% in pasture soils. Concomitant with changes in soil chemistry after forest-to-pasture conversion—particularly an increase in properties linked to soil acidity and nutrient availability—we observed an increase in the relative abundances of Acidobacteria subgroups 4, 10, 17, and 18, and a decrease in the relative abundances of other Acidobacteria subgroups in pasture relative to forest soils. The composition of the total Acidobacteria community as well as the most abundant Acidobacteria subgroups (1, 3, 5, and 6) was significantly more similar in composition across space in pasture soils than in forest soils. These results suggest that preponderant responses of Acidobacteria subgroups, especially subgroups 1, 3, 4, 5, and 6, to forest-to-pasture conversion effects in soils could be used to define management-indicators of agricultural practices in the Amazon Basin. These acidobacterial responses are at least in part through alterations on acidity- and nutrient-related properties of the Amazon soils. PMID:26733981

  7. Landscape dynamics in northwestern Amazonia: an assessment of pastures, fire and illicit crops as drivers of tropical deforestation.

    PubMed

    Armenteras, Dolors; Rodríguez, Nelly; Retana, Javier

    2013-01-01

    Many studies have identified drivers of deforestation throughout the tropics and, in most cases, have recognised differences in the level of threat. However, only a few have also looked at the temporal and spatial dynamics by which those drivers act, which is critical for assessing the conservation of biodiversity as well as for landscape planning. In this study, we analyse land cover change between 2000 and 2009 in north-western Colombian Amazonia to identify the interactions between the use of fire, cultivation of illicit crops and establishment of pastures, and their impacts on the loss of forest in the region. Yearly analyses were undertaken at randomly selected sample areas to quantify the average areas of transition of land cover types under different landscape compositions: forest-dominated mosaics, pasture mosaics, fire mosaics, and illicit crop mosaics. Our results indicate that despite the fact that forest areas were well-preserved, deforestation occurred at a low annual rate (0.06%). Conversion to pasture was the main factor responsible for forest loss (the area of pastures tripled within forest mosaics over 8 years), and this process was independent of the landscape matrix in which the forests were located. In fire mosaics, burning is a common tool for forest clearing and conversion to pasture. Thus, forests in fire mosaics were highly disturbed and frequently transformed from primary to secondary forests. The use of fire for illicit cropping was not detected, partly due to the small size of common illicit crops. Forest regeneration from pastures and secondary vegetation was observed in areas with large amounts of natural forest. Overall, assuming the continuation of the observed pasture conversion trend and the use of forest fire, we suggest that our results should be incorporated into a spatially explicit and integrated decision support tool to target and focus land-planning activities and policies. PMID:23382890

  8. Differential Response of Acidobacteria Subgroups to Forest-to-Pasture Conversion and Their Biogeographic Patterns in the Western Brazilian Amazon.

    PubMed

    Navarrete, Acacio A; Venturini, Andressa M; Meyer, Kyle M; Klein, Ann M; Tiedje, James M; Bohannan, Brendan J M; Nüsslein, Klaus; Tsai, Siu M; Rodrigues, Jorge L M

    2015-01-01

    Members of the phylum Acidobacteria are among the most abundant soil bacteria on Earth, but little is known about their response to environmental changes. We asked how the relative abundance and biogeographic patterning of this phylum and its subgroups responded to forest-to-pasture conversion in soils of the western Brazilian Amazon. Pyrosequencing of 16S rRNA genes was employed to assess the abundance and composition of the Acidobacteria community across 54 soil samples taken using a spatially nested sampling scheme at the landscape level. Numerically, Acidobacteria represented 20% of the total bacterial community in forest soils and 11% in pasture soils. Overall, 15 different Acidobacteria subgroups of the current 26 subgroups were detected, with Acidobacteria subgroups 1, 3, 5, and 6 accounting together for 87% of the total Acidobacteria community in forest soils and 75% in pasture soils. Concomitant with changes in soil chemistry after forest-to-pasture conversion-particularly an increase in properties linked to soil acidity and nutrient availability-we observed an increase in the relative abundances of Acidobacteria subgroups 4, 10, 17, and 18, and a decrease in the relative abundances of other Acidobacteria subgroups in pasture relative to forest soils. The composition of the total Acidobacteria community as well as the most abundant Acidobacteria subgroups (1, 3, 5, and 6) was significantly more similar in composition across space in pasture soils than in forest soils. These results suggest that preponderant responses of Acidobacteria subgroups, especially subgroups 1, 3, 4, 5, and 6, to forest-to-pasture conversion effects in soils could be used to define management-indicators of agricultural practices in the Amazon Basin. These acidobacterial responses are at least in part through alterations on acidity- and nutrient-related properties of the Amazon soils. PMID:26733981

  9. Landscape Dynamics in Northwestern Amazonia: An Assessment of Pastures, Fire and Illicit Crops as Drivers of Tropical Deforestation

    PubMed Central

    Armenteras, Dolors; Rodríguez, Nelly; Retana, Javier

    2013-01-01

    Many studies have identified drivers of deforestation throughout the tropics and, in most cases, have recognised differences in the level of threat. However, only a few have also looked at the temporal and spatial dynamics by which those drivers act, which is critical for assessing the conservation of biodiversity as well as for landscape planning. In this study, we analyse land cover change between 2000 and 2009 in north-western Colombian Amazonia to identify the interactions between the use of fire, cultivation of illicit crops and establishment of pastures, and their impacts on the loss of forest in the region. Yearly analyses were undertaken at randomly selected sample areas to quantify the average areas of transition of land cover types under different landscape compositions: forest-dominated mosaics, pasture mosaics, fire mosaics, and illicit crop mosaics. Our results indicate that despite the fact that forest areas were well-preserved, deforestation occurred at a low annual rate (0.06%). Conversion to pasture was the main factor responsible for forest loss (the area of pastures tripled within forest mosaics over 8 years), and this process was independent of the landscape matrix in which the forests were located. In fire mosaics, burning is a common tool for forest clearing and conversion to pasture. Thus, forests in fire mosaics were highly disturbed and frequently transformed from primary to secondary forests. The use of fire for illicit cropping was not detected, partly due to the small size of common illicit crops. Forest regeneration from pastures and secondary vegetation was observed in areas with large amounts of natural forest. Overall, assuming the continuation of the observed pasture conversion trend and the use of forest fire, we suggest that our results should be incorporated into a spatially explicit and integrated decision support tool to target and focus land-planning activities and policies. PMID:23382890

  10. Capturing urine while maintaining pasture intake, milk production, and animal welfare of dairy cows in early and late lactation.

    PubMed

    Clark, C E F; McLeod, K L M; Glassey, C B; Gregorini, P; Costall, D A; Betteridge, K; Jago, J G

    2010-05-01

    Capturing urine and spreading it evenly across a paddock reduces the risk of nitrogen loss to the environment. This study investigated the effect of 16h/d removal from pasture on the capture of urination events, milk production, pasture intake, and animal welfare from cows grazing fresh pasture in early and late lactation. Forty-eight Holstein-Friesian cows in early [470+/-47kg of body weight (BW); 35+/-9 days in milk] and late (498+/-43kg of BW; 225+/-23 days in milk) lactation were allocated to 3 treatment groups. Cows had access to pasture for either 4h after each milking (2 x 4), for 8h between morning and afternoon milkings (1 x 8), or for 24h, excluding milking times (control). When not grazing, the 2 x 4 and 1 x 8 groups were confined to a plastic-lined loafing area with a woodchip surface. In early lactation, the proportion of urinations on pasture and laneways was reduced from 89% (control) to 51% (1 x 8) and 54% (2 x 4) of total urinations. The 1 x 8 cows ate less pasture [10.9kg of dry matter (DM)/cow per day] than the control (13.6kg of DM/cow per day) and 2 x 4 (13.0kg of DM/cow per day) cows, which did not differ from each other. The 1 x 8 and 2 x 4 cows produced less milk (21 and 22kg of milk/cow per day, respectively) compared with control cows (24kg of milk/cow per day). There were no differences in BW or body condition score (BCS) change across treatment groups, with all groups gaining BW and BCS during the experimental period. In late lactation, there was no difference in pasture intake (mean=8.8kg of DM/cow per day), milk production (mean=10kg of milk/cow per day), and BW or BCS change (mean=3.7kg and -0.2U/cow per week, respectively) between treatment groups. As in early lactation, urinations on pasture and laneways were reduced from 85% (control) to 56% (1 x 8) and 50% (2 x 4) of total urinations. These findings highlight an opportunity to maintain performance and welfare of grazing cows in early and late lactation while capturing additional

  11. Milk volatile organic compounds and fatty acid profile in cows fed timothy as hay, pasture, or silage.

    PubMed

    Villeneuve, M-P; Lebeuf, Y; Gervais, R; Tremblay, G F; Vuillemard, J C; Fortin, J; Chouinard, P Y

    2013-01-01

    Nutrient composition and organoleptic properties of milk can be influenced by cow diets. The objective of this study was to evaluate the forage type effects on volatile organic compounds, fatty acid (FA) profile, and organoleptic properties of milk. Timothy grass was fed as hay, pasture, or silage during a period of 27 d to a group of 21 cows in a complete block design based on days in milk. Each cow also received 7.2 kg/d of a concentrate mix to meet their nutrient requirements. Forage dry matter intake averaged 13.9 kg/d and was not different among treatments. Milk yield was higher for cows fed pasture, intermediate for cows fed silage, and lowest for cows fed hay. However, milk fat content was higher for cows fed hay and silage, compared with cows fed pasture. As a result, fat-corrected milk and fat yield were not different among treatments. Increasing the supply of dietary cis-9,cis-12 18:2 (linoleic acid) and cis-9,cis-12,cis-15 18:3 (α-linolenic acid) when feeding pasture enhanced the concentration of these 2 essential FA in milk fat compared with feeding hay or silage. Moreover, the ratio of 16:0 (palmitic acid) to cis-9 18:1 (oleic acid), which is closely related to the melting properties of milk fat, was lower in milk from cows on pasture than in milk from cows fed hay or silage. Cows fed hay produced milk with higher levels of several free FA and γ-lactones, but less pentanal and 1-pentanol. More dimethyl sulfone and toluene were found in milk of cows on pasture. Cows fed silage produced milk with higher levels of acetone, 2-butanone, and α-pinene. Results from a sensory evaluation showed that panelists could not detect a difference in flavor between milk from cows fed hay compared with silage. However, a significant number of assessors perceived a difference between milk from cows fed hay compared with milk from cows fed pasture. In a sensory ranking test, the percentage of assessors ranking for the intensity of total (raw milk, fresh milk, and farm

  12. Methane Emission and Milk Production of Dairy Cows Grazing Pastures Rich in Legumes or Rich in Grasses in Uruguay

    PubMed Central

    Dini, Yoana; Gere, José; Briano, Carolina; Manetti, Martin; Juliarena, Paula; Picasso, Valentin; Gratton, Roberto; Astigarraga, Laura

    2012-01-01

    Simple Summary GHGs emissions are relevant in evaluating environmental impact of farming systems. Methane (CH4) produced by enteric fermentation accounts for half of all anthropogenic emissions of GHGs in Uruguay, where ruminant production is based on year round grazing of forages. Here we compared milk production and CH4 emissions by dairy cows grazing two contrasting mixed pastures (rich in legumes or rich in grasses) using the SF6 tracer technique adapted to collect breath samples over 5-days periods. There were no differences in milk or CH4 production between the contrasting pastures, probably because of the high herbage allowance that enabled selective grazing by cows. Abstract Understanding the impact of changing pasture composition on reducing emissions of GHGs in dairy grazing systems is an important issue to mitigate climate change. The aim of this study was to estimate daily CH4 emissions of dairy cows grazing two mixed pastures with contrasting composition of grasses and legumes: L pasture with 60% legumes on Dry Matter (DM) basis and G pasture with 75% grasses on DM basis. Milk production and CH4 emissions were compared over two periods of two weeks during spring using eight lactating Holstein cows in a 2 × 2 Latin square design. Herbage organic matter intake (HOMI) was estimated by chromic oxide dilution and herbage organic matter digestibility (OMD) was estimated by faecal index. Methane emission was estimated by using the sulfur hexafluoride (SF6) tracer technique adapted to collect breath samples over 5-day periods. OMD (0.71) and HOMI (15.7 kg OM) were not affected by pasture composition. Milk production (20.3 kg/d), milk fat yield (742 g/d) and milk protein yield (667 g/d) were similar for both pastures. This may be explained by the high herbage allowance (30 kg DM above 5 cm/cow) which allowed the cows to graze selectively, in particular in grass sward. Similarly, methane emission expressed as absolute value (368 g/d or 516 L/d) or expressed as

  13. The effects of a ration change from a total mixed ration to pasture on health and production of dairy cows.

    PubMed

    Schären, M; Jostmeier, S; Ruesink, S; Hüther, L; Frahm, J; Bulang, M; Meyer, U; Rehage, J; Isselstein, J; Breves, G; Dänicke, S

    2016-02-01

    In pasture-based dairy production systems, dairy cows often receive a silage- and concentrate-based ration [total mixed ration (TMR)] during wintertime and are gradually introduced to fresh herbage in spring. The present study aimed to investigate how the transition to this new nutritional situation influenced different production and health indicators. A 10-wk trial was performed in spring 2014, including 60 dairy cows of the German Holstein breed (166±23 d in milk, 23.5±3.7 kg of milk/d; means ± SD). The cows were divided into a pasture and a confinement group (PG and CG, respectively). The CG stayed on a TMR-based diet (35% corn silage, 35% grass silage, 30% concentrate; DM basis), whereas the PG was gradually transitioned from a TMR- to a pasture-based ration (wk 1=TMR-only, wk 2=3 h/d on pasture, wk 3 and 4=12 h/d on pasture, wk 5-10=pasture-only). A continuous grazing system was implemented on a ryegrass dominated pasture and temperature humidity indices were assessed based on continuous recording of temperature and humidity indoors as well as outdoors. Dry matter intake (DMI) from TMR, milk production, body weight (BW), and body condition score decreased as soon as the PG had partial access to pasture. Milk production and BW decreased even further in the first week on a full grazing ration, but thereafter BW increased again and milk production stabilized. The DMI estimation using the n-alkane method in wk 7 and 9 revealed an increase in DMI from pasture between the 2 time points and indicates an adaptation of grazing behavior and metabolism over several weeks. Increased serum β-hydroxybutyrate and fatty acids concentrations at several time points, as well as a continuous body condition score decrease during the whole course of the trial, indicate an energy deficit in the PG. A significant correlation between serum glucose concentrations and the temperature humidity indices was observed. An increase in serum and milk urea concentrations as well as an

  14. Carcass quality and meat tenderness of Hawaii pasture-finished cattle and Hawaii-originated, mainland feedlot-finished cattle.

    PubMed

    Kim, Yong Soo; Fukumoto, Glen Kazumi; Kim, Sunae

    2012-10-01

    The objective of this study was to compare the carcass quality and meat tenderness of Hawaii cattle finished on subtropical pasture with those of mainland US feedlot-finished cattle that were shipped from Hawaii after weaning. Rib-eye steak samples were collected from 30 feedlot-finished cattle harvested at a slaughter house in Washington State, USA and from 13 subtropical pasture-finished cattle harvested at a local slaughter house in Hawaii, then shipped to meat science laboratory at the University of Hawaii, Manoa. Samples were aged for 2 weeks at 4°C and frozen for later proximate analysis and meat tenderness measurement. Feedlot-finished cattle had significantly heavier carcass weight (353 vs 290 kg) and thicker backfat (13.5 vs 6.6 mm), but no significant difference was observed in rib-eye area between the two groups. Marbling score (Small) and United States Department of Agriculture quality grade (Choice) of the pasture-finished beef were not significantly (P < 0.05) different from those of feedlot-finished beef. The shear force value of pasture-finished beef (5.18 kg) was not statistically different (P < 0.05) from that of feedlot-finished beef (4.40 kg). In conclusion, results of this study suggest that Hawaii cattle finished on subtropical pasture produced as tender beef as mainland feedlot-finished cattle with less intramuscular fat. PMID:22274716

  15. Pasture evapotranspiration as indicators of degradation in the Brazilian Savanna: a case study for Alto Tocantins watershed

    NASA Astrophysics Data System (ADS)

    Andrade, Ricardo G.; de C. Teixeira, Antônio H.; Sano, Edson E.; Leivas, Janice F.; Victoria, Daniel C.; Nogueira, Sandra F.

    2014-10-01

    The Alto Tocantins watershed, located in the Brazilian Savanna (Cerrado biome), is under an intense land use and occupation process, causing increased pressure on natural resources. Pasture areas in the region are highly relevant to the rational use of natural resources in order to achieve economic and environmental sustainability. In this context, remote sensing techniques have been essential for obtaining information relevant to the assessment of vegetation conditions on a large scale. This study aimed to apply this tool in conjunction with field measurements to evaluate evapotranspiration (ET) against pasture degradation indicators. The SAFER algorithm was applied to estimate ET using MODIS images and weather station data from year 2012. Results showed that ET was lower in degraded pastures. It is noteworthy that during low rainfall period, ET values were 22.2% lower in relation to non-degraded pastures. This difference in ET indicates changes in the partition of the energy balance and may impact the microclimate. These results may contribute to public policies that aim to reduce the loss of the productive potential of pastures.

  16. High intensity, short duration rotational grazing on reclaimed cool season fescue/legume pastures: I. System development

    SciTech Connect

    Erickson, W.R.; Carlson, K.E.

    1995-09-01

    The Pittsburg & Midway Coal Mining Co.`s ({open_quotes}P&M{close_quotes}) Midway Mine lies 50 miles south of Kansas City, Kansas, straddling the border of Kansas and Missouri. P&M actively mined the area until 1989, when the mine was closed and reclaimed. Approximately 3,750 acres of surface mined land were topsoiled and revegetated to cool season fescue/legume pasture. Various pasture management methods are being utilized to meet reclamation success standards and achieve final bond release. The effectiveness and costs of various cool season fescue/legume pasture management methods are evaluated and contrasted. These methods include sharecropping, bush hogging, burning and livestock grazing. It presents guidelines used to develop a site specific rotational livestock grazing programs with land owners or contractors, and local, state and federal agencies. Rotational grazing uses both cow/calf or feeder livestock operations. Key managerial elements used to control grazing activities, either by the landowner or a contractor, are reviewed. Methods used to determine stocking levels for successful rotational grazing on this type of pasture are presented. Rotational grazing of livestock has proven to be the most effective method for managing established cool season fescue/legume pastures at this site. Initial stocking rates of 1 A.U.M. per 5 acres have been modified to a current stocking rate of 1 A.U.M. per 2.5 acres. Supporting physical and chemical data are presented and discussed.

  17. Soil carbon storage in silvopastoral systems and a treeless pasture in northwestern Spain.

    PubMed

    Howlett, David S; Mosquera-Losada, M Rosa; Nair, P K Ramachandran; Nair, Vimala D; Rigueiro-Rodríguez, Antonio

    2011-01-01

    Soil particle size and land management practices are known to have considerable influence on carbon (C) storage in soils, but such information is lacking for silvopastoral systems in Spain. This study quantified the amounts of soil C stored at various depths to 100 cm under silvopastoral plots of radiata pine ( D. Don) and birch ( Roth) in comparison to treeless pasture in Galicia, Spain. Soils were fractionated into three size classes (<53, 53-250, and 250-2000 μm), and C stored in them and in the whole (nonfractionated) soil was determined. Overall, the C stock to 1 m ranged from 80.9 to 176.9 Mg ha in these soils. Up to 1 m depth, 78.82% of C was found in the 0- to 25-cm soil depth, with 12.9, 4.92, and 3.36% in the 25- to 50-, 50- to 75-, and 75- to 100-cm depths, respectively. Soils under birch at 0 to 25 cm stored more C in the 250- to 2000-μm size class as compared with those under radiata pine; at that depth, pasture had more C than pine silvopasture in the smaller soil fractions (<53 and 53-250 μm). In the 75- to 100-cm depth, there was significantly more storage of C in the 250- to 2000-μm fraction in both silvopastures as compared with the pasture. The higher storage of soil C in larger fraction size in lower soil depths of silvopasture suggests that planting of trees into traditional agricultural landscapes will promote longer-term storage of C in the soil. PMID:21546668

  18. FORAGES AND PASTURES SYMPOSIUM: Improving soil health and productivity on grasslands using managed grazing of livestock.

    PubMed

    Russell, J R; Bisinger, J J

    2015-06-01

    Beyond grazing, managed grasslands provide ecological services that may offer economic incentives for multifunctional use. Increasing biodiversity of plant communities may maximize net primary production by optimizing utilization of available light, water, and nutrient resources; enhance production stability in response to climatic stress; reduce invasion of exotic species; increase soil OM; reduce nutrient leaching or loading in surface runoff; and provide wildlife habitat. Strategically managed grazing may increase biodiversity of cool-season pastures by creating disturbance in plant communities through herbivory, treading, nutrient cycling, and plant seed dispersal. Soil OM will increase carbon and nutrient sequestration and water-holding capacity of soils and is greater in grazed pastures than nongrazed grasslands or land used for row crop or hay production. However, results of studies evaluating the effects of different grazing management systems on soil OM are limited and inconsistent. Although roots and organic residues of pasture forages create soil macropores that reduce soil compaction, grazing has increased soil bulk density or penetration resistance regardless of stocking rates or systems. But the effects of the duration of grazing and rest periods on soil compaction need further evaluation. Because vegetative cover dissipates the energy of falling raindrops and plant stems and tillers reduce the rate of surface water flow, managing grazing to maintain adequate vegetative cover will minimize the effects of treading on water infiltration in both upland and riparian locations. Through increased diversity of the plant community with alterations of habitat structure, grazing systems can be developed that enhance habitat for wildlife and insect pollinators. Although grazing management may enhance the ecological services provided by grasslands, environmental responses are controlled by variations in climate, soil, landscape position, and plant community

  19. Rainfall variability drives interannual variation in N₂O emissions from a humid, subtropical pasture.

    PubMed

    Rowlings, D W; Grace, P R; Scheer, C; Liu, S

    2015-04-15

    Variations in interannual rainfall totals can lead to large uncertainties in annual N2O emission budget estimates from short term field studies. The interannual variation in nitrous oxide (N2O) emissions from a subtropical pasture in Queensland, Australia, was examined using continuous measurements of automated chambers over 2 consecutive years. Nitrous oxide emissions were highest during the summer months and were highly episodic, related more to the size and distribution of rain events than soil water content. Over 48% of the total N2O emitted was lost in just 16% of measurement days. Interannual variation in annual N2O estimates was high, with cumulative emissions increasing with decreasing rainfall. Cumulative emissions averaged 1826.7±199.9 g N2O-N ha(-1) yr(-1) over the two year period, though emissions from 2008 (2148±273 g N2O-N ha(-1) yr(-1)) were 42% higher than 2007 (1504±126 g N2O-N ha(-1) yr(-1)). This increase in annual emissions coincided with almost half of the summer precipitation from 2007 to 2008. Emissions dynamics were chiefly driven by the distribution and size of rain events which varied on a seasonal and annual basis. Sampling frequency effects on cumulative N2O flux estimation were assessed using a jackknife technique to inform future manual sampling campaigns. Test subsets of the daily measured data were generated for the pasture and two adjacent land-uses (rainforest and lychee orchard) by selecting measured flux values at regular time intervals ranging from 1 to 30 days. Errors associated with weekly sampling were up to 34% of the sub-daily mean and were highly biased towards overestimation if strategically sampled following rain events. Sampling time of day also played a critical role. Morning sampling best represented the 24 hour mean in the pasture, whereas sampling at noon proved the most accurate in the shaded rainforest and lychee orchard. PMID:25613765

  20. Shifts in leaf litter breakdown along a forest-pasture-urban gradient in Andean streams.

    PubMed

    Iñiguez-Armijos, Carlos; Rausche, Sirkka; Cueva, Augusta; Sánchez-Rodríguez, Aminael; Espinosa, Carlos; Breuer, Lutz

    2016-07-01

    Tropical montane ecosystems of the Andes are critically threatened by a rapid land-use change which can potentially affect stream variables, aquatic communities, and ecosystem processes such as leaf litter breakdown. However, these effects have not been sufficiently investigated in the Andean region and at high altitude locations in general. Here, we studied the influence of land use (forest-pasture-urban) on stream physico-chemical variables (e.g., water temperature, nutrient concentration, and pH), aquatic communities (macroinvertebrates and aquatic fungi) and leaf litter breakdown rates in Andean streams (southern Ecuador), and how variation in those stream physico-chemical variables affect macroinvertebrates and fungi related to leaf litter breakdown. We found that pH, water temperature, and nutrient concentration increased along the land-use gradient. Macroinvertebrate communities were significantly different between land uses. Shredder richness and abundance were lower in pasture than forest sites and totally absent in urban sites, and fungal richness and biomass were higher in forest sites than in pasture and urban sites. Leaf litter breakdown rates became slower as riparian land use changed from natural to anthropogenically disturbed conditions and were largely determined by pH, water temperature, phosphate concentration, fungal activity, and single species of leaf-shredding invertebrates. Our findings provide evidence that leaf litter breakdown in Andean streams is sensitive to riparian land-use change, with urban streams being the most affected. In addition, this study highlights the role of fungal biomass and shredder species (Phylloicus; Trichoptera and Anchytarsus; Coleoptera) on leaf litter breakdown in Andean streams and the contribution of aquatic fungi in supporting this ecosystem process when shredders are absent or present low abundance in streams affected by urbanization. Finally, we summarize important implications in terms of managing of

  1. Pasture-feeding of Charolais steers influences skeletal muscle metabolism and gene expression.

    PubMed

    Cassar-Malek, I; Jurie, C; Bernard, C; Barnola, I; Micol, D; Hocquette, J-F

    2009-10-01

    Extensive beef production systems on pasture are promoted to improve animal welfare and beef quality. This study aimed to compare the influence on muscle characteristics of two management approaches representative of intensive and extensive production systems. One group of 6 Charolais steers was fed maize-silage indoors and another group of 6 Charolais steers grazed on pasture. Activities of enzymes representative of glycolytic and oxidative (Isocitrate dehydrogenase [ICDH], citrate synthase [CS], hydroxyacyl-CoA dehydrogenase [HAD]) muscle metabolism were assessed in Rectus abdominis (RA) and Semitendinosus (ST) muscles. Activities of oxidative enzymes ICDH, CS and HAD were higher in muscles from grazing animals demonstrating a plasticity of muscle metabolism according to the production and feeding system. Gene expression profiling in RA and ST muscles was performed on both production groups using a multi-tissue bovine cDNA repertoire. Variance analysis showed an effect of the muscle type and of the production system on gene expression (P<0.001). A list of the 212 most variable genes according to the production system was established, of which 149 genes corresponded to identified genes. They were classified according to their gene function annotation mainly in the "protein metabolism and modification", "signal transduction", "cell cycle", "developmental processes" and "muscle contraction" biological processes. Selenoprotein W was found to be underexpressed in pasture-fed animals and could be proposed as a putative gene marker of the grass-based system. In conclusion, enzyme-specific adaptations and gene expression modifications were observed in response to the production system and some of them could be candidates for grazing or grass-feeding traceability. PMID:19996487

  2. Selective coal mine overburden treatment with topsoil and compost to optimise pasture or native vegetation establishment.

    PubMed

    Spargo, A; Doley, D

    2016-11-01

    Overburden at a coal mine in the Hunter Valley, New South Wales, was stored in a flat-topped artificial mound with 14-degree side slopes. Topsoil was scarce, dispersive and readily eroded. A split-plot factorial experiment applied an enhanced municipal solid waste compost at 0, 60 or 100 t ha(-1) to untreated overburden or to overburden covered with 0.1 m of topsoil. Two seeding treatments, of trees and shrubs or of pasture species, were applied to two 0.5-ha replicates of each surface treatment. Substrate physical and chemical properties and vegetation attributes were assessed 2.5 years later. Compost application to both topsoil and overburden significantly increased total N, P, Cu and Zn, soluble K, Ca and Mg, and significantly reduced soluble Na and pH. Mean tree density, size and total canopy cover were significantly greater with compost applied at 60 t ha(-1) to overburden than with all other treatments, especially those on topsoil where tree growth was inhibited by undesired species. Compost application to overburden and topsoil at 100 t ha(-1) significantly increased biomass of desired pasture species and significantly reduced undesired species cover compared with unamended topsoil and the extent of bare ground compared with unamended overburden. Successful development of woody species on overburden and pastures on both overburden and topsoil treated with compost provides opportunities for new combinations of landscape design, surface preparation and plant species introductions to increase the stability of final landforms, the effectiveness of resource use, and the delivery of commercial and biodiversity benefits from mine site rehabilitation. PMID:27497311

  3. Heterogeneous responses to ozone and nitrogen alter the species composition of Mediterranean annual pastures.

    PubMed

    Calvete-Sogo, H; González-Fernández, I; Sanz, J; Elvira, S; Alonso, R; García-Gómez, H; Ibáñez-Ruiz, M A; Bermejo-Bermejo, V

    2016-08-01

    Air pollution represents a threat to biodiversity throughout the world and particularly in the Mediterranean area, where high tropospheric ozone (O3) concentrations and atmospheric nitrogen (N) deposition are frequently recorded. Mediterranean annual pastures are among the most important ecosystems in southern Europe due to their high biodiversity and extension. Aiming to study the responses of these communities to the main atmospheric pollutants in the Mediterranean region, an experimental study was performed in an open-top chamber (OTC) facility. A mixture of six species representative of annual pastures was grown under field conditions inside the OTC. Plants were exposed for 39 days to four O3 treatments and three doses of N. The species responded heterogeneously to both factors. Legumes did not react to N but were very sensitive to O3: Trifolium species responded negatively, while Ornithopus responded positively, taking advantage of the greater sensitivity of clovers to O3. The grasses and the herb were more tolerant of O3 and grasses were the most responsive to N. Significant interactions between factors indicated a loss of effectiveness of N in O3-polluted atmospheres and an ability of O3 to counterbalance the damage induced by N input, but both effects were dependent on O3 and N levels. The inclusion of plant competition in the experimental design was necessary to reveal results that would otherwise be missed, such as the positive growth responses under elevated O3 levels. Surprisingly, competition within the legume family played the most important role in the overall response of the annual community to O3. Both tropospheric O3 and N deposition should be considered important drivers of the structure and biodiversity of Mediterranean annual pastures. PMID:27106851

  4. Surface and subsurface phosphorus losses from fertilized pasture systems in Ohio.

    PubMed

    Owens, L B; Shipitalo, M J

    2006-01-01

    Phosphorus is an essential plant nutrient and critical to agricultural production, but it is also a problem when excessive amounts enter surface waters. Summer rotational grazing and winter feeding beef pasture systems at two fertility levels (56 and 28 kg available P ha(-1)) were studied to evaluate the P losses from these systems via surface runoff and subsurface flow using eight small (0.3-1.1 ha), instrumented watersheds and spring developments. Runoff events from a 14-yr period (1974-1988) were evaluated to determine the relationships between event size in mm, total dissolved reactive phosphorous (TDRP) concentration, and TDRP transport. Most of the TDRP transported was via surface runoff. There were strong correlations (r2 = 0.45-0.66) between TDRP transport and event size for all watersheds, but no significant (P = 0.05) correlations between TDRP concentration and event size. Flow-weighted average TDRP concentrations from the pasture watersheds for the 14-yr period ranged from 0.64 to 1.85 mg L(-1) with a few individual event concentrations as high as 85.7 mg L(-1). The highest concentrations were in events that occurred soon after P fertilizer application. Average seasonal flow-weighted TDRP concentrations for subsurface flow were < 0.05 mg L(-1). Applying P fertilizer to pastures in response to soil tests should keep TDRP concentrations in subsurface flow at environmentally acceptable levels. Management to reduce runoff and avoidance of P fertilizer application when runoff producing rainfall is anticipated in the next few days will help reduce the surface losses of P. PMID:16738395

  5. Soil Carbon and Nutrient Changes Associated with Deforestation for Pasture in Southern Costa Rica

    NASA Technical Reports Server (NTRS)

    Huth, Timothy J.; Porder, Stephen; Chaves, Joaquin; Whiteside, Jessica H.

    2012-01-01

    We assessed the effects of deforestation on soil carbon (C) and nutrient stocks in the premontane landscape near Las Cruces Biological Station in southern Costa Rica, where forests were cleared for pasture in the mid-1960s. We excavated six soil pits to a depth of 1 m in both pasture and primary forest, and found that C stocks were 20 kg C per square meters in both settings. Nevertheless, soil delta C-13 suggests 50 percent of the forest-derived soil C above 40 cm depth has turned over since deforestation. Soil nitrogen (N) and phosphorus (P) stocks derived from the soil pits were not significantly different between land uses (P = 0.43 and 0.61, respectively). At a larger spatial scale, however, the ubiquity of ruts produced by cattle-induced erosion indicates that there are substantial soil effects of grazing in this steep landscape. Ruts averaged 13 cm deep and covered 45 percent of the landscape, and thus are evidence of the removal of 0.7 Mg C/ ha/yr, and 70, 9 and 40 kg/ha/yr of N, P and potassium (K), respectively. Subsoils in this region are 10 times less C- and N-rich, and 2 times less P- and K-rich than the topsoil. Thus, rapid topsoil loss may lead to a decline in pasture productivity in the coming decades. These data also suggest that the soil C footprint of deforestation in this landscape may be determined by the fate of soil C as it is transported downstream, rather than C turnover in situ.

  6. Energy and protected protein supplements to lambs on endophyte-infected tall fescue pasture.

    PubMed

    Daura, M T; Reid, R L

    1991-01-01

    The effect of supplements on intake, digestibility, N retention, ADG and blood and body composition of growing lambs fed cut herbage or grazing KY 31 tall fescue (Festuca arundinacea Schreb.) pastures at two levels of N fertilization (92 and 318 kg/ha) was determined. Supplements were corn (C), corn with soybean meal (U-SBM) and corn with heat-treated SBM (H-SBM). Metabolism trials were run at three growth stages in the 1st yr with 24 lambs. Although all supplements increased total DMI and DM digestibility, they decreased NDF digestibility relative to grass (G), with no difference between supplements; C depressed apparent CP digestibility. Nitrogen retention increased from -2.5 g/d on G to -.4 g/d on C and 3.2 and 4.1 g/d on U-SBM and H-SBM, respectively, for combined periods and N rates. Blood urea N (BUN) concentrations differed (P less than .01) in the following order: G greater than U-SBM greater than H-SBM greater than C. In the 2nd yr, lambs (n = 64) grazed fescue pastures at the same N fertilizer rates and were given the same supplements. Gains were not different (P less than .05) on low-N (LN) and high-N (HN) pastures. Seasonal ADG were 80, 115, 122 and 130 g/d for G, C, U-SBM and H-SBM treatments, respectively, with no difference (P less than .05) between U-SBM and H-SBM. At slaughter, lambs from G had lower dressing percentages (P less than .05) and fat content (P less than .01) than lambs on C, U-SBM and H-SBM treatments, with no differences between supplements. Results indicated a better performance of growing lambs on fescue with both energy and protein supplements. Response to protected vs unprotected protein was small. PMID:2005030

  7. Assessing pasture quality and degradation status using hyperspectral imaging: a case study from western Tibet

    NASA Astrophysics Data System (ADS)

    Lehnert, Lukas W.; Meyer, Hanna; Meyer, Nele; Reudenbach, Christoph; Bendix, Jörg

    2013-10-01

    Alpine grasslands on the Tibetan Plateau (TP) are suffering from pasture degradation induced by over-grazing, climate change and improper livestock management. Meanwhile, the status of pastures is largely unknown especially in poor accessible western parts on the TP. The aim of this case study was to assess the suitability of hyperspectral imaging to predict quality and amount of forage on the western TP. Therefore, 18 ground- based hyperspectral images taken along two transects on a winter pasture were used to estimate leaf chlorophyll content, photosynthetic-active vegetation cover (PV) and proportion of grasses. For calibration and validation purposes, chlorophyll content of 20 grass plants was measured in situ. From the images reference spectra of grass and non-grass species were collected. PV was assessed from similarity of images to mean vegetation spectra using spectral angle mapper and threshold classifications. A set of 48 previously published hyperspectral vegetation indices (VI) was used as predictors to estimate chlorophyll content and to discriminate grass and non-grass pixels. Separation into grass and non-grass species was performed using partial least squares (PLS) discriminant analysis and chlorophyll content was estimated with PLS regression. The accuracy of the models was assessed with leave-one-out cross validation and normalised root mean square errors (nRMSE) for chlorophyll and contingency matrices for grass classification and total PV separation. Highest error rates were observed for discrimination between vegetated and non-vegetated parts (Overall accuracy = 0.85), whilst accuracies of grass and non grass separation (Overall accuracy = 0.98) and chlorophyll estimation were higher (nRMSE = 10.7).

  8. Transport of water, solutes and nutrients from a pasture hillslope, southwestern Brazilian Amazon

    NASA Astrophysics Data System (ADS)

    Biggs, Trent Wade; Dunne, Thomas; Muraoka, Takashi

    2006-08-01

    A conceptual model of water and solute transport pathways was developed and applied to a pasture hillslope in the southwestern Brazilian Amazon basin using select field measurements. Infiltration-excess or Horton overland flow (HOF), saturation overland flow (SOF), and groundwater in both the near-stream zone and upslope were sampled on a hillslope draining a 3.9 hectare pasture for a total of ten storms during the first half of the rainy season (October-November) in 2002. A Soil Conservation Service SCS curve number model of HOF and an annual water balance of both upslope and near-stream zones were used to calculate the contribution of each flowpath to solute export. HOF occurred in rainstorms greater than 5 mm and accounted for 8% of annual rainfall. Flow generated in the near-stream zone was 8% of annual rainfall. Sub-surface flow from upslope groundwater dominated annual runoff (19-30% of annual rainfall). Solutes fell into three categories according to flowpath. HOF from upslope positions dominated the export of total phosphorus (TP) and total dissolved phosphorus (TDP, 51-72% of total annual export). The near-stream zones controlled the export of K (58-65%), total dissolved nitrogen (TDN, 76-80%), and total nitrogen (TN, 75%) owing to relatively high solute concentrations and the large volume of water that flowed through the near-stream zone. Na and Si export was via groundwater from upslope (50-67% of annual export). The flux calculations were based on a small number of storms and are preliminary estimates designed to identify broad patterns in solute export via different hydrologic pathways. Additional processes, especially N removal at the groundwater-stream interface and in the stream channel, may affect actual export rates at the watershed scale. Whereas HOF production is negligible in Amazon forests, it represents a significant pathway for additional loss of elements, especially phosphorus, from mature pasture systems. The evidence presented here shows

  9. Evaluation of pasture soil productivity in the semi-arid zone of Brazil by microbial analyses

    PubMed Central

    de Luna, Rômulo Gil; Coutinho, Henrique Douglas Melo; Grisi, Breno Machado

    2008-01-01

    The productivity of a pasture soil (caatinga) located in the region of São João do Cariri, PB, Brazil was evaluated based an the following microbiological parameters: biomass (measured by fumigation-incubation method), activity (estimated from basal respiration and cellulose decomposition rate), qCO2, and Cmic : Corg ratio. This analysis demonstrated that livestock management in the ‘caatinga’ is probably causing environment damage by affecting the soil properties, reducing the microbial biomass and soil respiration and increasing the qCO2, affecting the recovery of this ecosystem. PMID:24031238

  10. Reproductive dominance of pasture trees in a fragmented tropical forest mosaic

    PubMed

    Aldrich; Hamrick

    1998-07-01

    Tropical forest fragmentation threatens biodiversity, yet basic information on population responses for major groups such as plants is lacking. Hypervariable genetic markers were used to reconstruct a population-level pedigree in fragmented tropical forest for the tree Symphonia globulifera. Though seedlings occurred only in remnant forest, the pedigree showed that most seedlings had been produced by sequentially fewer adults in pasture, creating a genetic bottleneck. The pedigree also implicated shifts in the foraging of animals that disperse pollen and seed in a secondary constriction of the bottleneck. These results suggest that tropical conservation strategies should anticipate complex, cryptic responses to fragmentation. PMID:9651242

  11. Supplementing lactating dairy cows fed high-quality pasture with black wattle (Acacia mearnsii) tannin.

    PubMed

    Griffiths, W M; Clark, C E F; Clark, D A; Waghorn, G C

    2013-11-01

    A reduction in urinary nitrogen (N) excretion from dairy cows fed pasture containing a high N concentration in the dry matter (DM) will have environmental benefits, because losses to soil water and air by leachate and nitrous oxides (N2O) will be reduced. Condensed tannins (CT) reduce digestion of N, and provision as a dietary additive could have nutritional benefits for production, but the amount required and the responses to different sources of CT on milk production have not been defined. Two experiments were conducted to evaluate effects of supplementation with CT extracted from black wattle (Acacia mearnsii De Wild.) on milk production and faecal N concentration by lactating dairy cows grazing a vegetative Perennial ryegrass (Lolium perenne L.)-based pasture. In one experiment, CT was administered as a drench, twice daily, to 38 multiparous Holstein-Friesian cows assigned to four treatments; control (CONT, 0 g/day), low CT (LCT, 111 g/day), medium CT (MCT, 222 g/day) and high CT (HCT, 444 g/day), grazing as a single group. The CT supplementation affected milk yield (P < 0.001) with a trend of declining milk yield as CT concentration increased from about 0.6 to about 2.9% of dietary DM. Milk urea nitrogen (MUN) decreased at MCT and HCT levels of supplementation (P < 0.01) but milk fat, CP and lactose percentage were not affected by CT supplementation. The CT supplementation increased N concentration in faeces for LCT and MCT treatments (P < 0.05), suggesting partitioning of dietary N away from urine. When CT was pelleted with grain, in a second experiment and fed twice daily as a supplement at milking, it reduced the acceptability relative to pellets without CT, and tended to lower milk production from 25.4 to 24.5 kg/day, although the decline was not significant (P > 0.05). The diet of cows fed pellets with CT contained about 1.2% CT in the DM but neither milk constituents nor MUN were affected by CT-supplemented grain (P > 0.05). These findings demonstrate

  12. The role of livestock-poached pasture as a sediment source

    NASA Astrophysics Data System (ADS)

    Greenwood, Philip; Walling, Desmond; Quine, Timothy

    2015-04-01

    Historically, the occurrence of sediment-laden runoff has almost exclusively been associated with cultivated hillslopes and particularly with arable land. This association was commonly accompanied by the presumption that, in comparison with cultivated slopes, erosion from intensively-managed lowland pasture was relatively low. Recent developments in sediment source tracing and fingerprinting techniques have, however, challenged these assumptions by demonstrating that soil loss from grasslands may be greater than previously assumed. In attempting to identify potential source areas within grassland environments, attention has frequently focused on areas of livestock poaching where herd animals tend to congregate. However, the role of poached grassland as a sediment-source remains uncertain. Reasons include the difficulties associated with accurately documenting the movement or redistribution of small quantities of fine sediment over relevant spatial and temporal scales. Motivated by an urgent need for such information, this communication presents preliminary results from a tracing study aimed at measuring sediment redistribution within areas of poached pasture over short (i.e. event-based) timescales using the artificial radionuclides, caesium-134 (134Cs) and cobalt-60 (60Co). The approach involved labelling six small areas (0.2 * 0.2 m) of poached soil, each with a contrasting gradient, with either 134Cs or 60Co, and then measuring changes in the radiometric inventory at predetermined points before and after periods of rainfall. Each labelled area of poached pasture was measured on three separate occasions over a 65 day period. At the end of the monitoring phase, the mean net soil redistribution depth (mm) was negative for all plots, with values ranging from -6.8 mm to -15.2 mm. This is interpreted as evidence of the removal, or erosion, of surface material. The findings indicate that areas of livestock-poached pasture can act as significant sediment sources. These

  13. Low quality roughages for steers grazing wheat pasture. I. Effect on weight gains and bloat.

    PubMed

    Mader, T L; Horn, G W; Phillips, W A; McNew, R W

    1983-05-01

    The effect of feeding low quality roughages (LQR) on live and carcass weight gains and the incidence and severity of bloat of stocker cattle grazed on wheat pasture was evaluated in a 3 yr study. One hundred eighty-five steer calves (172 kg mean initial weight) grazed clean-tilled wheat pasture and were either fed no LQR or had ad libitum access to wheat straw (WS) or sorghum-Sudan hay (SS). Grazing periods were (I) fall grazing, (II) winter grazing, (III) period of lush spring growth of wheat forage and (IV) period of advancing forage maturity and declining quality. Mean dry matter (DM), crude protein and acid detergent fiber (ADF) content (percentage of DM) of wheat forage averaged across years ranged, respectively, from 23.8 to 33.0, 19.8 to 26.4 and 21.5 to 27.7. Mean daily consumption (kg DM/head) of WS and SS by steers ranged from .076 to .100 and .199 to .248, respectively. Live and carcass weight gains of steers during Periods I through III (i.e., the usual wheat pasture grazing period) were not influenced (P greater than .05) by treatments. Carcass weight gains were about 74% of live weight gains. Bloat was observed only during the last 2 wk of Period III of the first year. The incidence (steer days of bloat) and severity (bloat score) of control, WS- and SS-fed steers were 9.5 and 1.2, .5 and .5 and 2.0 and 1.0, and were not different (P greater than .05) among treatments. Intake of WS and SS [g/body weight (BW).75kg] during Periods I to III was, respectively, only about 5 and 12% of roughage intakes (i.e., 37.5 g/BW.75kg) reported in the literature to "effectively control" or aid the prevention of bloat. It seems unlikely that LQR consumed to amounts similar to those of this study would control bloat of stocker cattle on wheat pasture. PMID:6305902

  14. Remaining Sites Verification Package for the 100-F-54 Animal Farm Pastures, Waste Site Reclassification Form 2008-015

    SciTech Connect

    J. M. Capron

    2008-04-17

    The 100-F-54 waste site, part of the 100-FR-2 Operable Unit, is the soil associated with the former pastures for holding domestic farm animals used in experimental toxicology studies. Evaluation of historical information resulted in identification of the experimental animal farm pastures as having potential residual soil contamination due to excrement from experimental animals. The 100-F-54 animal farm pastures confirmatory sampling results support a reclassification of this site to No Action. The current site conditions achieve the remedial action objectives and the corresponding remedial action goals established in the Remaining Sites ROD. The results of confirmatory sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  15. Whole grains in the finishing of culled ewes in pasture or feedlot: Performance, carcass characteristics and meat quality.

    PubMed

    Fruet, Ana Paula Burin; Stefanello, Flávia Santi; Rosado Júnior, Adriano Garcia; Souza, Alexandre Nunes Motta de; Tonetto, Cléber José; Nörnberg, José Laerte

    2016-03-01

    In order to evaluate the performance, carcass characteristics and meat quality of culled ewes finished in pasture or exclusivelywith grain, 41 culled Polwarth ewes, were assigned to six treatments: RY (ryegrass pasture), RYGO (ryegrass and whole grain oats), RYGM (ryegrass and whole grain maize), GM (whole grain maize), GO (whole grain oats), GS (whole grain sorghum). The finishing systemof the ewes influenced weight gain,wherein the GM and GS treatments increased daily weight gain. The GO treatment decreased the dressing percentage. Nonetheless, a*, h*, pH, cooking loss and tenderness were similar across dietary treatments. Using principal component analysis, the variables C18:2n6, h*, n6/n3, TBARS, total lipids, L* and b* were assigned as characteristics of meat from the feedlot animals, while the pasture finishing system produced meat with higher CLA and n-3 fatty acids but lower TBARS values indicating lipid stability. PMID:26638020

  16. Flooded native pastures of the northern region of the Pantanal of Mato Grosso: biomass and primary productivity variations.

    PubMed

    Pozer, C G; Nogueira, F

    2004-11-01

    The Pantanal comprises a number of landscape units, submitted to a flood pulse with variable intensity or regularity. One of these units, the flooded plains, is important in cattle raising. This study was carried out in the northern portion of the Pantanal and presents data related to the productive dynamics of the flooded native pastures both protected from and exposed to cattle. The greatest total biomass values were for the protected pasture due to accumulated dead biomass. Net primary production presented smaller values at the flood-season start and increasing gradually beginning in the subsequent rainy season. However, consumption by cattle was also more intense during the months of greater precipitation. The effect of cattle in pastures is of fundamental importance to management since it prevents the dead biomass excess that increases fire risks. PMID:15744427

  17. Effect of dietary dehydrated pasture and citrus pulp on the performance and meat quality of broiler chickens.

    PubMed

    Mourão, J L; Pinheiro, V M; Prates, J A M; Bessa, R J B; Ferreira, L M A; Fontes, C M G A; Ponte, P I P

    2008-04-01

    Some feedstuffs containing significant levels of fiber may be a good source of bioactive compounds that may contribute to improving broiler meat quality. However, high fiber level can have a negative impact on broiler performance. A study was undertaken to investigate the impact of incorporating citrus pulp (5 or 10%) or dehydrated pasture (5 or 10%) on the performance, carcass yield, and characteristics of broiler chickens. A diet containing neither citrus pulp nor dehydrated pasture was used as control. The results on growth performances showed that daily weight gain was reduced by 26% in birds of the 10% citrus pulp treatment (P<0.05). Compared with the control treatment, increases in feed intake occurred in birds consuming diets with 5 or 10% citrus pulp, which resulted in significantly higher feed conversion rates with the 10% level. Under the same incorporation rate, dehydrated pasture had effects less evident on the performances of broiler chicken. In addition, diets containing citrus pulp, displaying higher percentages of soluble nonstarch polysaccharides, increased small intestine relative length, and reduced carcass yield. Inclusion of 10% dehydrated pasture in diets resulted in improved breast skin yellowness (P<0.05). Finally, the results revealed that incorporation of the nonstarch polysaccharide-rich feedstuffs had a major impact on the fatty acid profile (affected 16 of 21 fatty acids) of broiler meat. Polyunsaturated fatty acids content in meat was higher in birds consuming the highest levels of both citrus pulp and dehydrated pasture, leading to increased ratios of polyunsaturated to saturated fatty acids. Together, the results suggest that incorporation of moderate levels of dehydrated pastures in poultry diets has a minor impact on broiler performance and can contribute significantly to improve breast skin yellowness and fatty acid composition of meat. PMID:18339996

  18. Pasture age effects on N[sub 2]O, NO and CH[sub 4] emissions in the Atlantic Lowlands of Costa Rica

    SciTech Connect

    Keller, M. ); Reiners, W.A. ); Veldkamp, E. )

    1993-06-01

    A study conducted in Brazil indicated that N[sub 2]O emissions increased following forest conversion to pasture. Our first study in Costa Rica indicated the reverse. To explore this contradiction, we measured N[sub 2]O, NO, and CH[sub 4] emissions in a chronosequence of 8 sites comprising forest and derive pastures of ayes 2 to 25 years, all on the same soil type in the Atlantic Lowlands of Costa Rica. We found large differences through the chronosequence in the fluxes of these three gases. Flux changes were related to changes in available nitrogen, organic matter, moisture content, and bulk density in the soil. N[sub 2]O emissions from the 2-year pasture were much greater than from the forest. Emissions declined with pasture age so that 25-year pasture had much smaller emissions than the forest. NO emissions from young pastures were similar to forest emissions, then declined sharply with pasture age. Forest soils consumed CH[sub 4]. Pasture soils mainly produced CH[sub 4]. Prediction of the effects of land use change on trace gas fluxes in the tropics will require an assessment of the history and soil condition of individual land units.

  19. Effect of frame size and time-on-pasture on steer performance, longissimus muscle fatty acid composition and tenderness in a forage-finishing system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Angus-cross steers (n = 96; BW = 309 + 34 kg; 13.5 mo of age) were used to determine the effects of frame size (medium, MED or small, SM) and time-on-pasture (TOP) on meat composition and palatability in a two-year study. Finishing steers grazed mixed pastures (bluegrass/white clover; April start) a...

  20. Performance and Physiology of Steers Following Grazing of Toxic Tall Fescue as Influenced by Feeding Soybean Hulls on Pasture and Post-Graze Steroid Implantation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A grazing experiment was conducted for 2 yr using a pasture phase to evaluate effect of feeding soybean hulls (SBH) on weight gain by steers grazing toxic tall fescue [Schedonorus arundinaceus (Schreb.)]. To evaluate carryover effects of feeding SBH on pasture and effect of post-graze steroid impla...

  1. Changes in soil carbon stocks in Brazil due to land use: paired site comparisons and a regional pasture soil survey

    NASA Astrophysics Data System (ADS)

    Assad, E. D.; Pinto, H. S.; Martins, S. C.; Groppo, J. D.; Salgado, P. R.; Evangelista, B.; Vasconcellos, E.; Sano, E. E.; Pavão, E.; Luna, R.; Camargo, P. B.; Martinelli, L. A.

    2013-03-01

    In this paper we calculated soil carbon stocks in Brazil using 17 paired sites where soil stocks were determined in native vegetation, pastures and crop-livestock systems (CPS), and in other regional samplings encompassing more than 100 pasture soils, from 6.58° S to 31.53° S, involving three major Brazilian biomes: Cerrado, Atlantic Forest, and the Pampa. The average native vegetation soil carbon stocks at 10 and 30 cm soil depth were equal to approximately 33 and 65 Mg ha-1, respectively. In the paired sites, carbon losses of 7.5 Mg ha-1 and 11.9 Mg ha-1 in CPS systems were observed at 10 cm and 30 cm soil depth averages, respectively. In pasture soils, carbon losses were similar and equal to 8.3 Mg ha-1 and 12.2 Mg ha-1 at 10 cm and 30 cm soil depths, respectively. The average soil δ13C under native vegetation at 10 and 30 cm depth were equal to -25.4‰ and -24.0‰, increasing to -19.6 ‰ and -17.7‰ in CPS, and to -18.9‰, and -18.3‰ in pasture soils, respectively; indicating an increasing contribution of C4 carbon in these agrosystems. In the regional survey of pasture soils, the soil carbon stock at 30 cm was equal to approximately 51 Mg ha-1, with an average δ13C value of -19.6‰. Key controllers of soil carbon stock at pasture sites were sand content and mean annual temperature. Collectively, both could explain approximately half of the variance of soil carbon stocks. When pasture soil carbon stocks were compared with the average soil carbon stocks of native vegetation estimated for Brazilian biomes and soil types by Bernoux et al. (2002) there was a carbon gain of 6.7 Mg ha-1, which is equivalent to a carbon gain of 15% compared to the carbon soil stock of the native vegetation. The findings of this study are consistent with differences found between regional comparisons like our pasture sites and local paired study sites in estimating soil carbon stocks changes due to land use changes.

  2. Changes in soil carbon stocks in Brazil due to land use: paired site comparisons and a regional pasture soil survey

    NASA Astrophysics Data System (ADS)

    Assad, E. D.; Pinto, H. S.; Martins, S. C.; Groppo, J. D.; Salgado, P. R.; Evangelista, B.; Vasconcellos, E.; Sano, E. E.; Pavão, E.; Luna, R.; Camargo, P. B.; Martinelli, L. A.

    2013-10-01

    In this paper we calculated soil carbon stocks in Brazil studying 17 paired sites where soil stocks were determined in native vegetation, pastures and crop-livestock systems (CPS), and in other regional samplings encompassing more than 100 pasture soils, from 6.58 to 31.53° S, involving three major Brazilian biomes: Cerrado, Atlantic Forest, and the Pampa. The average native vegetation soil carbon stocks at 10, 30 and 60 cm soil depth were equal to approximately 29, 64, and 92 Mg ha-1, respectively. In the paired sites, carbon losses of 7.5 Mg ha-1 and 11.6 Mg ha-1 in CPS systems were observed at 10 cm and 30 cm soil depths, respectively. In pasture soils, carbon losses were similar and equal to 7.5 Mg ha-1 and 11.0 Mg ha-1 at 10 cm and 30 cm soil depths, respectively. Differences at 60 cm soil depth were not significantly different between land uses. The average soil δ13C under native vegetation at 10 and 30 cm depth were equal to -25.4‰ and -24.0‰, increasing to -19.6‰ and -17.7‰ in CPS, and to -18.9‰, and -18.3‰ in pasture soils, respectively; indicating an increasing contribution of C4 carbon in these agrosystems. In the regional survey of pasture soils, the soil carbon stock at 30 cm was equal to approximately 51 Mg ha-1, with an average δ13C value of -19.67‰. Key controllers of soil carbon stock in pasture sites were sand content and mean annual temperature. Collectively, both could explain approximately half of the variance of soil carbon stocks. When pasture soil carbon stocks were compared with the average soil carbon stocks of native vegetation estimated for Brazilian biomes and soil types by Bernoux et al. (2002) there was a carbon gain of 6.7 Mg ha-1, which is equivalent to a carbon gain of 15% compared to the carbon soil stock of the native vegetation. The findings of this study are consistent with differences found between regional comparisons like our pasture sites and plot-level paired study sites in estimating soil carbon stocks

  3. Modelling Pasture-based Automatic Milking System Herds: System Fitness of Grazeable Home-grown Forages, Land Areas and Walking Distances.

    PubMed

    Islam, M R; Garcia, S C; Clark, C E F; Kerrisk, K L

    2015-06-01

    To maintain a predominantly pasture-based system, the large herd milked by automatic milking rotary would be required to walk significant distances. Walking distances of greater than 1-km are associated with an increased incidence of undesirably long milking intervals and reduced milk yield. Complementary forages can be incorporated into pasture-based systems to lift total home grown feed in a given area, thus potentially 'concentrating' feed closer to the dairy. The aim of this modelling study was to investigate the total land area required and associated walking distance for large automatic milking system (AMS) herds when incorporating complementary forage rotations (CFR) into the system. Thirty-six scenarios consisting of 3 AMS herds (400, 600, 800 cows), 2 levels of pasture utilisation (current AMS utilisation of 15.0 t dry matter [DM]/ha, termed as moderate; optimum pasture utilisation of 19.7 t DM/ha, termed as high) and 6 rates of replacement of each of these pastures by grazeable CFR (0%, 10%, 20%, 30%, 40%, 50%) were investigated. Results showed that AMS cows were required to walk greater than 1-km when the farm area was greater than 86 ha. Insufficient pasture could be produced within a 1 km distance (i.e. 86 ha land) with home-grown feed (HGF) providing 43%, 29%, and 22% of the metabolisable energy (ME) required by 400, 600, and 800 cows, respectively from pastures. Introduction of pasture (moderate): CFR in AMS at a ratio of 80:20 can feed a 400 cow AMS herd, and can supply 42% and 31% of the ME requirements for 600 and 800 cows, respectively with pasture (moderate): CFR at 50:50 levels. In contrast to moderate pasture, 400 cows can be managed on high pasture utilisation (provided 57% of the total ME requirements). However, similar to the scenarios conducted with moderate pasture, there was insufficient feed produced within 1-km distance of the dairy for 600 or 800 cows. An 800 cow herd required 140 and 130 ha on moderate and high pasture-based AMS

  4. Modelling Pasture-based Automatic Milking System Herds: System Fitness of Grazeable Home-grown Forages, Land Areas and Walking Distances

    PubMed Central

    Islam, M. R.; Garcia, S. C.; Clark, C. E. F.; Kerrisk, K. L.

    2015-01-01

    To maintain a predominantly pasture-based system, the large herd milked by automatic milking rotary would be required to walk significant distances. Walking distances of greater than 1-km are associated with an increased incidence of undesirably long milking intervals and reduced milk yield. Complementary forages can be incorporated into pasture-based systems to lift total home grown feed in a given area, thus potentially ‘concentrating’ feed closer to the dairy. The aim of this modelling study was to investigate the total land area required and associated walking distance for large automatic milking system (AMS) herds when incorporating complementary forage rotations (CFR) into the system. Thirty-six scenarios consisting of 3 AMS herds (400, 600, 800 cows), 2 levels of pasture utilisation (current AMS utilisation of 15.0 t dry matter [DM]/ha, termed as moderate; optimum pasture utilisation of 19.7 t DM/ha, termed as high) and 6 rates of replacement of each of these pastures by grazeable CFR (0%, 10%, 20%, 30%, 40%, 50%) were investigated. Results showed that AMS cows were required to walk greater than 1-km when the farm area was greater than 86 ha. Insufficient pasture could be produced within a 1 km distance (i.e. 86 ha land) with home-grown feed (HGF) providing 43%, 29%, and 22% of the metabolisable energy (ME) required by 400, 600, and 800 cows, respectively from pastures. Introduction of pasture (moderate): CFR in AMS at a ratio of 80:20 can feed a 400 cow AMS herd, and can supply 42% and 31% of the ME requirements for 600 and 800 cows, respectively with pasture (moderate): CFR at 50:50 levels. In contrast to moderate pasture, 400 cows can be managed on high pasture utilisation (provided 57% of the total ME requirements). However, similar to the scenarios conducted with moderate pasture, there was insufficient feed produced within 1-km distance of the dairy for 600 or 800 cows. An 800 cow herd required 140 and 130 ha on moderate and high pasture-based AMS

  5. The availability and mobility of arsenic and antimony in an acid sulfate soil pasture system.

    PubMed

    Tighe, Matthew; Lockwood, Peter V; Ashley, Paul M; Murison, Robert D; Wilson, Susan C

    2013-10-01

    The Macleay floodplain on the north coast of New South Wales, Australia, has surface soil concentrations of up to 40 mg kg(-1) arsenic (As) and antimony (Sb), due to historical mining practices in the upper catchment. The floodplain also contains areas of active and potential acid sulfate soils (ASS). Some of these areas are purposely re-flooded to halt oxidation processes, but the effect of this management on the metalloid mobility and phytoavailability of the metalloids present is unknown. This study investigated the changes to soil solution As and Sb, associations of metalloids with soil solid phases, and uptake into two common pasture species following 20 weeks of flooding in a controlled environment. The effect of an ASS subsoil was also investigated. The soil solution concentration and availability of the metalloids was in some instances higher in the floodplain soils than would generally be expected in soils with comparable contamination. There appeared to be few changes to soil solution concentrations or phase associations with flooding in this short term study, due to the high acid buffering and poise of the investigated soils. A strong relationship was found between the relative uptake of Sb into pastures and the oxalate extractable Fe in the soil, which was taken as a proxy for non-crystalline iron (Fe) hydroxides. This relationship was dependent on flooding and was absent for As. Further targeted investigations into metalloid speciation kinetics and the stability of soil solid phases with flooding management are recommended. PMID:23792257

  6. Influence of cattle wastes on nitrous oxide and methane fluxes in pasture land

    SciTech Connect

    Flessa, H.; Doersch, P.; Beese, F.

    1996-11-01

    Agricultural practices are assumed to contribute significantly to the increase in atmospheric N{sub 2}O concentrations observed in the last decades, and they might influence the consumption of atmospheric CH{sub 4}. We report on measurements of N{sub 2}O and CH{sub 4} exchange of a pasture soil, as influenced by droppings of a grazing cattle (Bos taurus) herd. Nitrous oxide and methane fluxes in pasture soil were largely determined by the emission rates from cattle excrement with dung patches being hot spots of CH{sub 4} production and urine-affected areas showing extremely high N{sub 2}O release rates. Methane emissions from dung patches (0.778 g CH{sub 4}-C per animal and day) were insignificant when compared with those from the rumen of the cattle. Total N{sub 2}O-N losses from the droppings were equivalent to 3.2% of the nitrogen excreted. Based on global data of total nitrogen excretion by dairy cattle, non-dairy cattle, buffalo (Syncerus caffer), and bison during grazing, we estimate the global N{sub 2}O emission from this source to be {approximately}1.18 teragrams N{sub 2}O-N per year, indicating that grazing cattle excretory products are one of the most important sources of atmospheric nitrous oxide. Our work suggests that these sources have been drastically underestimated. 27 refs., 2 figs., 2 tabs.

  7. Climate variability rather than overstocking causes recent large scale cover changes of Tibetan pastures

    NASA Astrophysics Data System (ADS)

    Lehnert, L. W.; Wesche, K.; Trachte, K.; Reudenbach, C.; Bendix, J.

    2016-04-01

    The Tibetan Plateau (TP) is a globally important “water tower” that provides water for nearly 40% of the world’s population. This supply function is claimed to be threatened by pasture degradation on the TP and the associated loss of water regulation functions. However, neither potential large scale degradation changes nor their drivers are known. Here, we analyse trends in a high-resolution dataset of grassland cover to determine the interactions among vegetation dynamics, climate change and human impacts on the TP. The results reveal that vegetation changes have regionally different triggers: While the vegetation cover has increased since the year 2000 in the north-eastern part of the TP due to an increase in precipitation, it has declined in the central and western parts of the TP due to rising air temperature and declining precipitation. Increasing livestock numbers as a result of land use changes exacerbated the negative trends but were not their exclusive driver. Thus, we conclude that climate variability instead of overgrazing has been the primary cause for large scale vegetation cover changes on the TP since the new millennium. Since areas of positive and negative changes are almost equal in extent, pasture degradation is not generally proceeding.

  8. Meat goat kids finished on alfalfa, red clover or orchardgrass pastures: carcass merit and meat quality.

    PubMed

    Turner, K E; Cassida, K A; Zerby, H N

    2014-12-01

    This experiment was conducted in 2005-2007 to evaluate carcass and chevon (goat meat) quality parameters when meat-goat kids (n=72) were finished on alfalfa (Medicago sativa L; ALF); red clover (Trifolium pratense L.; RCG); or orchardgrass (Dactylis glomerata L.; OGR) pastures. Carcass conformation score was greater (P=0.08) when meat-goat kids were finished on ALF compared to OGR with RCG intermediate. Chevon meat samples from goats finished on the three pasture treatments did not differ in ash, intramuscular fat, or crude protein content or in concentrations of omega6 and omega3 fatty acids, or the omega6 to omega3 ratio. Goats finished on OGR had higher (P<0.001) 18:1 trans-11 fatty acids (FA) compared to ALF or RCG. Overall, meat-goat kids finished on ALF, RCG, or ORG produced desirable carcass weights for most niche markets in the USA. Chevon is a low-fat meat option with high desirable fatty acids for human diets. PMID:25089787

  9. Potential for reduced methane and carbon dioxide emissions from livestock and pasture management in the tropics

    PubMed Central

    Thornton, Philip K.; Herrero, Mario

    2010-01-01

    We estimate the potential reductions in methane and carbon dioxide emissions from several livestock and pasture management options in the mixed and rangeland-based production systems in the tropics. The impacts of adoption of improved pastures, intensifying ruminant diets, changes in land-use practices, and changing breeds of large ruminants on the production of methane and carbon dioxide are calculated for two levels of adoption: complete adoption, to estimate the upper limit to reductions in these greenhouse gases (GHGs), and optimistic but plausible adoption rates taken from the literature, where these exist. Results are expressed both in GHG per ton of livestock product and in Gt CO2-eq. We estimate that the maximum mitigation potential of these options in the land-based livestock systems in the tropics amounts to approximately 7% of the global agricultural mitigation potential to 2030. Using historical adoption rates from the literature, the plausible mitigation potential of these options could contribute approximately 4% of global agricultural GHG mitigation. This could be worth on the order of $1.3 billion per year at a price of $20 per t CO2-eq. The household-level and sociocultural impacts of some of these options warrant further study, however, because livestock have multiple roles in tropical systems that often go far beyond their productive utility. PMID:20823225

  10. Eddy covariance methane flux measurements over a grazed pasture: effect of cows as moving point sources

    NASA Astrophysics Data System (ADS)

    Felber, R.; Münger, A.; Neftel, A.; Ammann, C.

    2015-02-01

    Methane (CH4) from ruminants contributes one third to global agricultural greenhouse gas emissions. Eddy covariance (EC) technique has been extensively used at various flux sites to investigate carbon dioxide exchange of ecosystems. Since the development of fast CH4 analysers the instrumentation at many flux sites have been amended for these gases. However the application of EC over pastures is challenging due to the spatial and temporal uneven distribution of CH4 point sources induced by the grazing animals. We applied EC measurements during one grazing season over a pasture with 20 dairy cows (mean milk yield: 22.7 kg d-1) managed in a rotational grazing system. Individual cow positions were recorded by GPS trackers to attribute fluxes to animal emissions using a footprint model. Methane fluxes with cows in the footprint were up to two orders of magnitude higher than ecosystem fluxes without cows. Mean cow emissions of 423 ± 24 g CH4 head-1 d-1 (best guess of this study) correspond well to animal respiration chamber measurements reported in the literature. However a systematic effect of the distance between source and EC tower on cow emissions was found which is attributed to the analytical footprint model used. We show that the EC method allows to determine CH4 emissions of grazing cows if the data evaluation is adjusted for this purpose and if some cow distribution information is available.

  11. Climate variability rather than overstocking causes recent large scale cover changes of Tibetan pastures

    PubMed Central

    Lehnert, L. W.; Wesche, K.; Trachte, K.; Reudenbach, C.; Bendix, J.

    2016-01-01

    The Tibetan Plateau (TP) is a globally important “water tower” that provides water for nearly 40% of the world’s population. This supply function is claimed to be threatened by pasture degradation on the TP and the associated loss of water regulation functions. However, neither potential large scale degradation changes nor their drivers are known. Here, we analyse trends in a high-resolution dataset of grassland cover to determine the interactions among vegetation dynamics, climate change and human impacts on the TP. The results reveal that vegetation changes have regionally different triggers: While the vegetation cover has increased since the year 2000 in the north-eastern part of the TP due to an increase in precipitation, it has declined in the central and western parts of the TP due to rising air temperature and declining precipitation. Increasing livestock numbers as a result of land use changes exacerbated the negative trends but were not their exclusive driver. Thus, we conclude that climate variability instead of overgrazing has been the primary cause for large scale vegetation cover changes on the TP since the new millennium. Since areas of positive and negative changes are almost equal in extent, pasture degradation is not generally proceeding. PMID:27073126

  12. Multivariate statistical techniques for the assessment of seasonal variations in surface water quality of pasture ecosystems.

    PubMed

    Ajorlo, Majid; Abdullah, Ramdzani B; Yusoff, Mohd Kamil; Halim, Ridzwan Abd; Hanif, Ahmad Husni Mohd; Willms, Walter D; Ebrahimian, Mahboubeh

    2013-10-01

    This study investigates the applicability of multivariate statistical techniques including cluster analysis (CA), discriminant analysis (DA), and factor analysis (FA) for the assessment of seasonal variations in the surface water quality of tropical pastures. The study was carried out in the TPU catchment, Kuala Lumpur, Malaysia. The dataset consisted of 1-year monitoring of 14 parameters at six sampling sites. The CA yielded two groups of similarity between the sampling sites, i.e., less polluted (LP) and moderately polluted (MP) at temporal scale. Fecal coliform (FC), NO3, DO, and pH were significantly related to the stream grouping in the dry season, whereas NH3, BOD, Escherichia coli, and FC were significantly related to the stream grouping in the rainy season. The best predictors for distinguishing clusters in temporal scale were FC, NH3, and E. coli, respectively. FC, E. coli, and BOD with strong positive loadings were introduced as the first varifactors in the dry season which indicates the biological source of variability. EC with a strong positive loading and DO with a strong negative loading were introduced as the first varifactors in the rainy season, which represents the physiochemical source of variability. Multivariate statistical techniques were effective analytical techniques for classification and processing of large datasets of water quality and the identification of major sources of water pollution in tropical pastures. PMID:23604787

  13. Identifying risk factors associated with lameness in pasture-based dairy herds.

    PubMed

    Ranjbar, S; Rabiee, A R; Gunn, A; House, J K

    2016-09-01

    Lameness is a significant welfare concern for dairy farmers and a major contributing economic loss to the dairy industry. Information is limited on environmental and managerial risk factors associated with lameness in Australian dairy herds. The objective of this study was to explore and quantify the environmental and management risk factors associated with lameness in pasture-based dairy herds. A cross-sectional study was conducted in 63 pasture-based dairy herds between 2011 and 2014, where all lactating cows were locomotion scored (scale 1-4) during a single visit. Environmental and management variables, such as length of main track and animal handling practices, were recorded during the visit. The prevalence of lameness was measured for each farm and associated risk factors were analyzed using a Generalized Linear Model, where farm was the unit of analysis. Estimated average prevalence of lameness was 18.9% (range 5 to 44.5%). The prevalence of lameness was associated with the amount of rainfall during the 30 d before the farm assessment, smoothness of concrete surface and available space per cow in the holding yard, and length of feed-pad available per cow. Inappropriate handling of cows on the track (e.g., causing sideways pushing among cows) was also a contributing risk factor to high prevalence of lameness in these dairy herds. The findings of this study suggest that by managing several environmental and farming practices, producers can reduce the prevalence of lameness, leading to improved productivity of their herds. PMID:27394954

  14. Climate variability rather than overstocking causes recent large scale cover changes of Tibetan pastures.

    PubMed

    Lehnert, L W; Wesche, K; Trachte, K; Reudenbach, C; Bendix, J

    2016-01-01

    The Tibetan Plateau (TP) is a globally important "water tower" that provides water for nearly 40% of the world's population. This supply function is claimed to be threatened by pasture degradation on the TP and the associated loss of water regulation functions. However, neither potential large scale degradation changes nor their drivers are known. Here, we analyse trends in a high-resolution dataset of grassland cover to determine the interactions among vegetation dynamics, climate change and human impacts on the TP. The results reveal that vegetation changes have regionally different triggers: While the vegetation cover has increased since the year 2000 in the north-eastern part of the TP due to an increase in precipitation, it has declined in the central and western parts of the TP due to rising air temperature and declining precipitation. Increasing livestock numbers as a result of land use changes exacerbated the negative trends but were not their exclusive driver. Thus, we conclude that climate variability instead of overgrazing has been the primary cause for large scale vegetation cover changes on the TP since the new millennium. Since areas of positive and negative changes are almost equal in extent, pasture degradation is not generally proceeding. PMID:27073126

  15. From rags to riches: the story of carbon, nutrients and pasture with dairy compost application

    NASA Astrophysics Data System (ADS)

    Drake, Jess; Cavagnaro, Tim; Patti, Tony; Wilkinson, Kevin; McDonald, Declan; Johnston, Priscilla; Wilson, Katrina; Rose, Mick; Jackson, Roy

    2014-05-01

    Around the world, dairy farmers are transforming dairy waste to compost for land application. In southeastern Australia, farmers are using composted dairy waste to increase production and reduce costs. In addition, the farmers are considering the benefits of compost for increasing sequestration of soil carbon, and on-farm nutrient retention. The "Carbon Farming Initative" in Australia is exploring the option to allow farmers to trade Carbon Credits for carbon stored in the soil. Compost also retains vital nutrients, such as N, on farm rather than importing N in the form of mineral fertilisers. Composting also reduces greenhouse gas emissions, such as CH4, compared to when stored in effluent ponds. This project will investigate if dairy compost applied to pasture improves carbon sequestration, nutrient retention and pasture production. In this project dairy compost, made from dairy effluent, feedpad waste, spoilt sillage and wood mulch, was applied onto a 1Ha field and companion plots at a rate of 0, 3, 6 and 12 t/ha. The field plot is open to grazing and normal farm management practices. The companion plots are being subjected to simulated grazing (mowing). The trials, currently underway will run for 18 months. Along with preliminary soil carbon results, this work will also include preliminary data for total and plant available nutrients, and farm biomass production. The outcomes of this research, and benefits it finds for "Carbon Farming" and nutrient retention has practical, policy and economic applications for world wide markets.

  16. Niche overlap and species assemblage dynamics in an ageing pasture gradient in north-western France

    NASA Astrophysics Data System (ADS)

    Decaëns, T.; Margerie, P.; Renault, J.; Bureau, F.; Aubert, M.; Hedde, M.

    2011-05-01

    This study aims at describing the mechanisms of earthworm species assemblages in a temperate grassland ageing gradient. Earthworms were sampled by a combination of formaldehyde extraction and hand sorting. Density data were analysed by combining correspondence analysis (CA) and null model analyses of niche overlap patterns and morphological trait dispersion. The first axis of the CA arranged samples according to the pasture ageing gradient and separated "pioneer" (CA1-) from "old pasture" (CA1+) species assemblages. The second axis segregated two different assemblages (CA2- and CA2+) that were consistently represented along the ageing gradient and was assumed to represent intra-plot assemblage heterogeneity. Niche overlap according to soil organic C, C:N ratio and root biomass was higher than expected by chance (EBC) in most assemblages, and was higher when calculated for the whole regional species pool than for local assemblages. Morphological dispersion was random or lower than expected by chance for the regional species pool and both CA1- and CA1+, and higher than expected by chance for both CA2- and CA2+. These results indicate that: (1) habitat and dispersal constraints act as filters by allowing only those species with similar prerequisite traits into assemblages; (2) inter-specific competition limit composition in a further step by calling for a minimal level of overdispersion in morphological traits.

  17. Halogen Biogeochemistry of Invasive Perennial Pepperweed (Lepidium latifolium) in a Peatland Pasture

    NASA Astrophysics Data System (ADS)

    Khan, M. H.; Whelan, M.; Rhew, R. C.

    2011-12-01

    Exotic invasive plants pose one of the greatest threats to native plant populations and communities, especially in the California floristic province. Many invasive plant species thrive on disturbed lands and alter the biogeochemical cycles of their ecosystem once established. In the Sacramento-San Joaquin Delta of California, large islands have been formed from the drainage of peatlands, now surrounded by levees and sectioned with drainage channels. One of these tracts, Sherman Island, is a heavily impacted pasture peatland that has a large coverage of perennial pepperweed (Lepidium latifolium), an invasive plant that is widespread in the western United States and Canada. Like other members of the Brassicaceae family, L. latifolium has the capacity to produce methyl halides, halogenated compounds that destroy stratospheric ozone. In 2009-10, we conducted a yearlong study of methyl bromide (CH3Br) and methyl chloride (CH3Cl) fluxes at Sherman Island, using both field flux chambers and laboratory soil core incubations. A stable isotope tracer technique was employed to simultaneously quantify gross production and consumption rates, along with net fluxes. Methyl halide emission rates from this pasture were comparable to coastal salt marshes, with L. latifolium plants as the primary source and soils providing a minor contribution. Meanwhile, gross consumption of methyl halides in the soils were strongly affected by soil moisture and temperature. The temporal variability of fluxes was dominated overall by gross production, with plant biochemistry and environmental factors both playing important roles in regulating emissions.

  18. The Value of Forest and Pasture to Water Supply in Kona, HI

    NASA Astrophysics Data System (ADS)

    Brauman, K. A.; Daily, G. C.; Freyberg, D. L.

    2007-12-01

    By quantifying the supply and value of ecosystem services flowing from private land, we can provide a mechanism for sustaining ecosystem services by compensating landowners for their supply. In order for compensation to occur, however, both suppliers and users of ecosystem services require information about the way different land management scenarios will affect ecosystem service flows. This case study in Kona, HI, takes advantage of the direct link between upland water source areas and municipal drinking water users in Kailua-Kona to explore the value of one type of hydrologic service. By quantifying the difference in aquifer recharge under paired forest and pasture sites, we assess the impact of each land-cover type on the volume of water potentially available to municipal water users. We use a water balance approach - measuring rainfall interception and water use by plants, then calculating the balance to be aquifer recharge because of the absence of surface runoff. We aim to integrate these biophysical measurements with information, including costs of pumping, well construction, and land-cover maintenance, provided by the water utility and landowners to ascertain the value of forest and pasture to water supply. By determining the value to water users in Kailua-Kona of the increase or decrease in water quantity that would result from upland land-cover change, we aim both to protect drinking water quantity and to help landowners offset financial pressure to convert their land.

  19. Greener Pastures

    ERIC Educational Resources Information Center

    Buchanan, Bruce

    2005-01-01

    Rural districts usually have a tough time attracting new teachers; but one in North Carolina is defying the odds. Teacher recruitment and retention is the number one challenge of John Parker, Roanoke Rapids Graded School District superintendent. Until recently, Roanoke Rapids had a 13 percent faculty turnover rate--not unusual among rural schools.…

  20. Greener Pastures

    ERIC Educational Resources Information Center

    Kennedy, Mike

    2007-01-01

    Education administrators do not have to be deeply committed to the ecology movement to see the value of conserving energy and providing more environmentally friendly facilities. Reducing energy costs frees up funds for learning programs. Providing more healthful facilities can help students and teachers ward off illness and disease and perform…

  1. Carcass parameters and meat quality in meat-goat kids finished on chicory, birdsfoot trefoil, or red clover pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted in 2009-2010 to assess carcass parameters and chevon (goat meat) quality when meat-goat kids (n = 72) were finished on pastures of red clover (Trifolium pratense L.; RCL), birdsfoot trefoil (Lotus corniculatus L.; BFT), or chicory (Cichorium intybus L.; CHIC). Final body we...

  2. Performance and carcass parameters when meat goats were finished on chicory, birdsfoot trefoil, or red clover pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The meat goat industry is growing rapidly in the eastern U.S., particularly on small farms, to supply ethnic market demands. Body weight (BW), average daily gain (ADG), and carcass parameters were determined when meat goat kids were finished on pastures of chicory (Cichorium intybus L.; CHIC), bird...

  3. Influence of flue gas desulfurization gypsum on reducing soluble phosphorus in successive runoff events from a coastal plain bermudagrass pasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Controlling the potential threat that pasture systems which have been intensively fertilized with poultry litter (PL) pose to accelerate eutrophication of surface waters has become a major issue in the southeastern U.S. Gypsum has been identified as a promising management tool for ameliorating the ...

  4. Runoff water quality during drought in a zero-order Georgia Piedmont pasture: nitrogen and total organic carbon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Approximately 11% of the Southern Piedmont (1.8 million ha) is used for pasture and hay production. These systems are mostly under low-input management. Cattle manure can lead to enrichment of surface soils with nutrients raising concerns about water quality. We present 11 years (1999-2009) of hydro...

  5. Genome Sequence of Bradyrhizobium stylosanthis Strain BR 446T, a Nitrogen-Fixing Symbiont of the Legume Pasture Stylosanthes guianensis

    PubMed Central

    Delamuta, Jakeline Renata Marçon; Ribeiro, Renan Augusto; Gomes, Douglas Fabiano; Souza, Renata Carolini; Chueire, Ligia Maria Oliveira

    2016-01-01

    Bradyrhizobium stylosanthis BR 446T is a nitrogen-fixing symbiont of the tropical legume pasture Stylosanthes guianensis. Its draft genome contains 8,801,717 bp and 8,239 coding sequences (CDSs). Several putative genes that might confer high competitiveness and saprophytic capacity under the stressful conditions of tropical soils were identified in the genome. PMID:27365354

  6. Genome Sequence of Bradyrhizobium stylosanthis Strain BR 446T, a Nitrogen-Fixing Symbiont of the Legume Pasture Stylosanthes guianensis.

    PubMed

    Delamuta, Jakeline Renata Marçon; Ribeiro, Renan Augusto; Gomes, Douglas Fabiano; Souza, Renata Carolini; Chueire, Ligia Maria Oliveira; Hungria, Mariangela

    2016-01-01

    Bradyrhizobium stylosanthis BR 446(T) is a nitrogen-fixing symbiont of the tropical legume pasture Stylosanthes guianensis Its draft genome contains 8,801,717 bp and 8,239 coding sequences (CDSs). Several putative genes that might confer high competitiveness and saprophytic capacity under the stressful conditions of tropical soils were identified in the genome. PMID:27365354

  7. Spatial distribution of soil phosphorus and herbage mass in beef cattle pastures: Effects of slope aspect and slope position

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Characterizing and assessing spatial distribution of soil phosphorus and herbage mass in relation to landscape properties, land use, or landscape positions is important for understanding how pasture sustainability can be managed and improved properly. Our reason for conducting this study was to det...

  8. Integrating pasture-based livestock production with annual crop production on the Great Plains to reduce loss of grassland wildlife

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tallgrass prairie has been replaced by corn and soybeans and mixed-grass prairie is being replaced by various annual crops. Annual crop fields support vegetarian diets but not much wildlife. Alternatively, integrating pastured livestock farming with annual crops can provide wildlife habitat. For ...

  9. Effect of supplement type on ruminal fermentation of an orchardgrass-based pasture diet during continuous culture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A dual-flow continuous culture fermenter system was used to investigate the effect of supplemental crude protein (CP) level on digestion and ruminal fermentation of a vegetative orchardgrass (Dactylis glomerata L.) pasture-based diet. Treatments were: 10, 12, 14, and 16% supplemental CP fed at a rat...

  10. Effect of Herbage Depletion on the Grazing Dynamics and Short-Term Intake Rate of Steers Grazing Wheat Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reduction of herbage mass may not accurately predict herbage intake rate, as it does not incorporate aspects of availability and accessibility of preferred plant parts. There is little research attempting to understand cattle foraging strategies during pasture depletion. This study aimed to assess g...

  11. Runoff Water Quality During Drought in a Zero-Order Georgia Piedmont Pasture: Nitrogen and Total Organic Carbon

    EPA Science Inventory

    Approximately 11% of the Southern Piedmont (1.8 million ha) is used for pasture and hay production, mostly under low-input management. Few studies have investigated in the region long-term nitrogen and carbon losses in surface runoff, which can be significant. We present 1999 to ...

  12. Nitrogen in soils, plants, surface water and shallow groundwater in a bahiagrass pasture of southern Florida, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Better understanding of soil N dynamics and other crop nutrient changes in pasture-based cow-calf management systems should allow us to better predict potential impact on adjacent surface and ground waters. Despite substantial measurements using both laboratory and field techniques, little is known ...

  13. Nutritional composition of the meat of Hereford and Braford steers finished on pastures or in a feedlot in southern Brazil.

    PubMed

    Freitas, A K de; Lobato, J F P; Cardoso, L L; Tarouco, J U; Vieira, R M; Dillenburg, D R; Castro, I

    2014-01-01

    Chemical and mineral composition and the intramuscular fatty acid (IMF) profile of the Longissimus dorsi muscle (LM) of 60 purebred Hereford, 1/4 Braford and 3/8 Braford steers finished either in a feedlot or on improved pastures of the Pampa biome were evaluated. Pastures were improved with the introduction of Lolium multiflorum, Trifolium repens, and Lotus corniculatus. On average, beef from pasture-fed steers presented higher concentrations of the fatty acids C18:3n-3 (P<0.001), C20:3n-3 (P=0.035), total n-3 (P<0.001) and lower n-6/n-3 ratio (P<0.001) in the IMF, and higher Mg and lower K content in muscle relative to those finished in the feedlot. C12:0 concentration in IMF was higher (P=0.027) for 3/8 Braford than the purebred Hereford steers, whereas purebred Herefords presented lower C14:1 (P=0.003) and higher C18:0 (P=0.022) concentrations than the two Braford groups. The meat composition of purebred Hereford and Braford steers was not substantially different; however, beef produced exclusively on improved pastures presented higher concentration of components that are considered beneficial to human health, such as n-3 fatty acids, and a lower n-6/n-3 ratio. PMID:23954275

  14. Composition and quality differences between the longissimus and infraspinatus muscles for several groups of pasture-finished cattle.

    PubMed

    Purchas, R W; Zou, M

    2008-10-01

    Samples of longissimus (LT) and infraspinatus (IS) muscles from five contrasting groups of pasture-finished cattle (n=7/group) were assessed for quality and composition characteristics in order to determine whether features of pasture-finished beef reported previously apply across different muscles and different classes of cattle. The cattle were not raised together or slaughtered at the same time. Wagyu-cross steers had the highest intramuscular fat levels, particularly in the LT, followed by Angus steers, Charolais-cross steers and Belgian Blue-cross steers, with the lowest levels for Friesian bulls. Relative to the LT, the IS muscle had longer sarcomeres, higher cooking losses, higher concentrations of vitamin E, and lower myofibrillar fragmentation indexes, while its ultimate pH was slightly higher but less variable. Beef from Wagyu-cross steers had the highest chroma values and the lowest shear values, while Friesian bull beef was darkest and least tender. Intramuscular fatty acid composition and concentrations of bioactive compounds such as coenzyme Q(10) and carnosine, were similar to those reported previously for cattle finished on New Zealand pastures although taurine levels were lower. Generally concentrations of bioactive compounds differed more between muscles and groups than between cattle finished on pasture or grain as reported previously. PMID:22063355

  15. Alternative mating tactics in the yellow dung fly: resolving mechanisms of small-male advantage off pasture.

    PubMed

    Gress, Brian E; Waltzer, Ryan J; Lüpold, Stefan; Droge-Young, Elizabeth M; Manier, Mollie K; Pitnick, Scott

    2014-01-01

    Recent work suggests that the yellow dung fly mating system may include alternative patroller-competitor mating tactics in which large males compete for gravid females on dung, whereas small, non-competitive males search for females at foraging sites. Small males obtain most matings off pasture, yet the behavioural mechanism(s) giving rise to this pattern are unknown. We investigated the male and female behaviours that determine mating success in this environment by conducting field mating experiments and found small males to benefit from several attributes specific to the off-pasture mating environment. First, small males from foraging sites exhibited higher mating propensity, indicating that large males away from dung may be depleted of energy and/or sperm. Second, small males were more discriminating, being significantly less likely to attempt with non-gravid females, which are absent on dung but common off pasture. Third, non-gravid females were generally more likely to actively struggle and reject mating attempts; however, such behaviours occurred disproportionately more often with large males. Female Scathophaga stercoraria thus appear to preferentially mate with small males when off pasture. These findings challenge assumptions about male-female interactions in systems with alternative mating tactics and reveal hidden processes that may influence selection patterns in the field. PMID:24225455

  16. Survey of Total Mixed Ration Use on Pasture-based Dairy Farms in Pennsylvania and New York

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A survey was conducted to collect information on the use of a TMR on thirteen pasture-based dairy farms in New York and Pennsylvania with the objectives of monitoring TMR ingredient and nutrient content and summarizing what and how decisions are being made in relation to TMR formulation throughout t...

  17. Use of cuticular wax alkanes to estimate digestibility and intake of cows as pasture with a view to estimating efficiency.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determination of feed efficiency requires estimates of intake and digestibility of the diet, but they are difficult to measure on pasture. The objective of this research was to determine if plants cuticular alkanes were suitable as markers to estimate intake and diet digestibility of grazing cows wi...

  18. Inputs and losses by surface runoff and subsurface leaching for pastures managed by continuous or rotational stocking

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pasture management practices can affect forage quality and production, and animal health and production as well as impacting surface and ground water quality. In a 5-yr study, conducted at the North Appalachian Experimental Watershed near Coshocton, Ohio, we compared the effects of two contrasting g...

  19. Use of Ground-Based LiDAR to Assess Potential Sediment Loss from Stream Banks in Grazed Pastures.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Animal grazing on lands near streams has the potential to contribute sediment and nutrients to surface waters. To minimize the impact, we must understand the effects of grazing systems on stream bank erosion. In this study, we used six 12-ha grass pastures that were each bisected by a 141-m stream s...

  20. Can live weight be used as a proxy for enteric methane emissions from pasture-fed sheep?

    PubMed Central

    Moorby, J. M.; Fleming, H. R.; Theobald, V. J.; Fraser, M. D.

    2015-01-01

    To test the hypothesis that sheep live weight (LW) could be used to improve enteric methane (CH4) emission calculations, mature ewes of 4 different breeds representative of the UK sheep industry were studied: Welsh Mountain, Scottish Blackface, Welsh Mule and Texel (n = 8 per breed). The ewes were housed and offered ad libitum access to fresh cut pasture of three different types, varying in digestibility: (a) a relatively high digestibility monoculture of perennial ryegrass (Lolium perenne), (b) a medium digestibility permanent pasture comprising a range of grass species, and (c) a relatively low digestibility native grassland pasture comprising mainly Molinia caerulea. Individual LW, feed dry matter intake (DMI), and CH4 emissions in chambers were measured. The linear functional relationship between DMI and CH4 emissions was positive (r = 0.77) with little breed effect. The relationships between LW and DMI, and LW and CH4 emissions were also positive but weaker, regardless of pasture type. It is concluded that change to LW was a poor indicator of DMI and has limited value in the prediction of enteric CH4 emissions from mature ewes. PMID:26647754

  1. Alternative mating tactics in the yellow dung fly: resolving mechanisms of small-male advantage off pasture

    PubMed Central

    Gress, Brian E.; Waltzer, Ryan J.; Lüpold, Stefan; Droge-Young, Elizabeth M.; Manier, Mollie K.; Pitnick, Scott

    2014-01-01

    Recent work suggests that the yellow dung fly mating system may include alternative patroller–competitor mating tactics in which large males compete for gravid females on dung, whereas small, non-competitive males search for females at foraging sites. Small males obtain most matings off pasture, yet the behavioural mechanism(s) giving rise to this pattern are unknown. We investigated the male and female behaviours that determine mating success in this environment by conducting field mating experiments and found small males to benefit from several attributes specific to the off-pasture mating environment. First, small males from foraging sites exhibited higher mating propensity, indicating that large males away from dung may be depleted of energy and/or sperm. Second, small males were more discriminating, being significantly less likely to attempt with non-gravid females, which are absent on dung but common off pasture. Third, non-gravid females were generally more likely to actively struggle and reject mating attempts; however, such behaviours occurred disproportionately more often with large males. Female Scathophaga stercoraria thus appear to preferentially mate with small males when off pasture. These findings challenge assumptions about male–female interactions in systems with alternative mating tactics and reveal hidden processes that may influence selection patterns in the field. PMID:24225455

  2. Biosolids and dredged materials: alternative sources of nutrients for crop productivity and sustainability of pasture-based agroecosystem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domestic sewage sludge or “biosolids” and lake-dredged materials are examples of materials that can be used to cut fertilizer costs in pasture-based animal agriculture. Sustainable biosolids and lake-dredged materials management is based upon controlling and influencing the quantity, quality and cha...

  3. Rapid changes in microbial biomass and aggregate size distribution in response to changes in organic matter management in grass pasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adding high quantities of organic matter can increase carbon (C) inputs to soil and help maintain soil structure. This study investigated short-term effects of application of different levels of composted dairy manure (CDM) versus interseeding a legume into grass pasture on aggregate stability and s...

  4. Broiler Litter Application Method and Runoff Timing Effects on Nutrient and Escherichia coli Losses from Tall Fescue Pasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    More than 85% of broiler (chicken, Gallus gallus domesticus) litter applied in the U.S. is being applied to pasture lands year-round. Runoff from litter-applied land has the potential to transport nutrients and pathogenic microorganisms to nearby surface water. Many studies have indicated the advant...

  5. Comparison of the in vitro digestion of raw pasture milk and commercial HTST and UHT pasteurized milk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumption of raw milk from pasture-fed cows, typically purchased at local farms, is steadily increasing in the US because many consumers believe that high-temperature short-time (HTST) or ultrahigh temperature (UHT) pasteurization affects the digestibility of milk proteins and thus the bioavailabi...

  6. Chaparral Herbicide Application for Suppression of Seedhead Emergence in Tall Fescue Pastures and Possible Alleviation of Fescue Toxicosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chaparral® herbicide has shown in small-plot experiments to suppress seed head emergence in tall fescue. A two-yr grazing experiment is being conducted with steers grazed on endophyte-infected tall fescue pastures that are either treated or untreated with Chaparral® herbicide. The objective of the...

  7. Effects of grazing stockpilied endophyte-infected tall fescue pastures on growth and physiological indices of dairy heifers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tall fescue (Lolium arundinaceum [Schreb.] S. J. Darbyshire) is a cool-season grass grown on over 20 million acres of pasture land and hayfields in the Midwestern and Southeastern United States. A grazing trial was conducted to determine the effects of stockpiled tall fescue on the physiological and...

  8. Can live weight be used as a proxy for enteric methane emissions from pasture-fed sheep?

    PubMed

    Moorby, J M; Fleming, H R; Theobald, V J; Fraser, M D

    2015-01-01

    To test the hypothesis that sheep live weight (LW) could be used to improve enteric methane (CH4) emission calculations, mature ewes of 4 different breeds representative of the UK sheep industry were studied: Welsh Mountain, Scottish Blackface, Welsh Mule and Texel (n = 8 per breed). The ewes were housed and offered ad libitum access to fresh cut pasture of three different types, varying in digestibility: (a) a relatively high digestibility monoculture of perennial ryegrass (Lolium perenne), (b) a medium digestibility permanent pasture comprising a range of grass species, and (c) a relatively low digestibility native grassland pasture comprising mainly Molinia caerulea. Individual LW, feed dry matter intake (DMI), and CH4 emissions in chambers were measured. The linear functional relationship between DMI and CH4 emissions was positive (r = 0.77) with little breed effect. The relationships between LW and DMI, and LW and CH4 emissions were also positive but weaker, regardless of pasture type. It is concluded that change to LW was a poor indicator of DMI and has limited value in the prediction of enteric CH4 emissions from mature ewes. PMID:26647754

  9. Impacts of Rotational Grazing on Soil Carbon in Native Grass-Based Pastures in Southern Australia

    PubMed Central

    Sanderman, Jonathan; Reseigh, Jodie; Wurst, Michael; Young, Mary-Anne; Austin, Jenet

    2015-01-01

    Rotational grazing management strategies have been promoted as a way to improve the sustainability of native grass-based pasture systems. From disturbance ecology theory, rotational grazing relative to continuous grazing can increase pasture productivity by allowing vegetation to recover after short intense grazing periods. This project sought to assess whether soil organic carbon (SOC) stocks would also increase with adoption of rotational grazing management. Twelve pairs of rotationally and continuously grazed paddocks were sampled across a rainfall gradient in South Australia. Pasture productivity approximated as the normalized difference vegetation index (NDVI) was on average no different between management categories, but when the data from all sites were aggregated as log response ratios (rotational/continuous) a significant positive trend of increasing NDVI under rotational grazing relative to continuous grazing was found (R2 = 0.52). Mean SOC stocks (0–30 cm) were 48.3 Mg C ha-1 with a range of 20–80 Mg C ha-1 across the study area with no differences between grazing management categories. SOC stocks were well correlated with rainfall and temperature (multiple linear regression R2 = 0.61). After removing the influence of climate on SOC stocks, the management variables, rest periods, stocking rate and grazing days, were found to be significantly correlated with SOC, explaining 22% of the variance in SOC, but there were still no clear differences in SOC stocks at paired sites. We suggest three reasons for the lack of SOC response. First, changes in plant productivity and turnover in low-medium rainfall regions due to changes in grazing management are small and slow, so we would only expect at best small incremental changes in SOC stocks. This is compounded by the inherent variability within and between paddocks making detection of a small real change difficult on short timescales. Lastly, the management data suggests that there is a gradation in

  10. Mountain pastures of Qilian Shan: plant communities, grazing impact and degradation status (Gansu province, NW China)

    NASA Astrophysics Data System (ADS)

    Baranova, Alina; Schickhoff, Udo; Shunli, Wang; Ming, Jin

    2015-04-01

    Qilian Mountains are the water source region for the low arid reaches of HeiHe river basin (Gansu province, NW China). Due to overstocking and overgrazing during the last decades adverse ecological ef¬fects, in particular on soil properties and hydrological cycle, are to be expected in growing land areas. Vegetation cover is very important to prevent erosion process and to sustain stable subsurface runoff and ground water flow. The aim of this research is to identify plant communities, detecting grazing-induced and spatially differentiated changes in vegetation patterns, and to evaluate status of pasture land degradation.The study area is located in the spring/autumn pasture area of South Qilian Mountains between 2600-3600 m a.s.l., covering five main vegetation types: spruce forest, alpine shrubland, shrubby grassland, mountain grassland, degraded mountain grassland. In order to analyze gradual changes in vegetation patterns along altitudinal and grazing gradients and to classify related plant communities, quantitative and qualitative relevé data were collected (coverage, species composition, abundance of unpalatable plants, plant functional types, etc.). Vegetation was classified using hierarchical cluster analyses. Indirect Detrended Correspondence Analysis (DCA) was used to analyze variation in relationships between vegetation, environmental factors, and grazing impact. According to DCA results, distribution of the plant communities was strongly affected by altitude and exposition. Grassland floristic gradients showed greater dependence on grazing impact, which correlated contrarily with soil organic content, soil moisture and pH. Highest numbers of species richness and alpha diversity were detected in alpine shrubland vegetation type. Comparing the monitoring data for the recent nine years, a trend of deterioration, species successions and shift in dominant species becomes obvious. Species indicating degrading site environmental conditions were identified

  11. Pasture degradation modifies soil organic matter properties and biochemical functioning in Tibetan grasslands

    NASA Astrophysics Data System (ADS)

    Spielvogel, Sandra; Steingräber, Laura; Schleuß, Per; Kuzyakov, Yakov; Guggenberger, Georg

    2015-04-01

    Kobresia pastures of the Tibetan Plateau represent the world's largest alpine ecosystem. Moderate husbandry on Kobresia pastures is beneficial for the storage of soil organic carbon (OC), nitrogen (N) and other nutrients and prevents erosion by establishment of sedge-turf root mats with high OC allocation rates below ground. However, undisturbed root mats are affected by freezing and thawing processes, which cause initial ice cracks. As a consequence decomposition of root mat layers will be accelerated and current sedentarization programs with concomitant increased grazing intensity may additionally enhance root mat degradation. Finally, cracks are enlarged by water and wind erosion as well as pika activities until bare soil surface areas without root mat horizons occur. The aim of this study was to understand the impact of the root mat layer on soil organic carbon stabilization and microbial functioning depending on soil depths and to predict future changes (OC, N and nutrient losses, soil microbial functioning in SOM transformation) by overgrazing and climate change. We investigated the mineral soil below Kobresia root mats along a false time degradation sequence ranging from stage 1 (intact root mat) to stage 4 (mats with large cracks and bare soil patches). Vertical gradients of δ13C values, neutral sugar, cutin and suberin contents as well as microbial biomass estimated by total phospholipid fatty acid (PLFA), microbial community composition (PLFA profiles) and activities of six extracellular enzymes involved in the C, N, and P cycle were assessed. Soil OC and N contents as well as C/N ratios indicate an increasing illuviation of topsoil material into the subsoil with advancing root mat degradation. This was confirmed by more negative δ13C values as well as significantly (p ≤ 0.05) increasing contributions of cutin derived hydroxy fatty acids to OC in the subsoils from degradation stages 1 to 4. PLFA profiles were surprisingly similar in the subsoils of

  12. Genetic and environmental variation in methane emissions of sheep at pasture.

    PubMed

    Robinson, D L; Goopy, J P; Hegarty, R S; Oddy, V H; Thompson, A N; Toovey, A F; Macleay, C A; Briegal, J R; Woodgate, R T; Donaldson, A J; Vercoe, P E

    2014-10-01

    A total of 2,600 methane (CH4) and 1,847 CO2 measurements of sheep housed for 1 h in portable accumulation chambers (PAC) were recorded at 5 sites from the Australian Sheep CRC Information Nucleus, which was set up to test leading young industry sires for an extensive range of current and novel production traits. The final validated dataset had 2,455 methane records from 2,279 animals, which were the progeny of 187 sires and 1,653 dams with 7,690 animals in the pedigree file. The protocol involved rounding up animals from pasture into a holding paddock before the first measurement on each day and then measuring in groups of up to 16 sheep over the course of the day. Methane emissions declined linearly (with different slopes for each site) with time since the sheep were drafted into the holding area. After log transformation, estimated repeatability (rpt) and heritability (h(2)) of liveweight-adjusted CH4 emissions averaged 25% and 11.7%, respectively, for a single 1-h measurement. Sire × site interactions were small and nonsignificant. Correlations between EBV for methane emissions and Sheep Genetics Australia EBV for production traits were used as approximations to genetic correlations. Apart from small positive correlations with weaning and yearling weights (r = 0.21-0.25, P < 0.05), there were no significant relationships between production trait and methane EBV (calculated from a model adjusting for liveweight by fitting separate slopes for each site). To improve accuracy, future protocols should use the mean of 2 (rpt = 39%, h(2) = 18.6%) or 3 (rpt = 48%, h(2) = 23.2%) PAC measurements. Repeat tests under different pasture conditions and time of year should also be considered, as well as protocols measuring animals directly off pasture instead of rounding them up in the morning. Reducing the time in the PAC from 1 h to 40 min would have a relatively small effect on overall accuracy and partly offset the additional time needed for more tests per animal. Field

  13. Impacts of Rotational Grazing on Soil Carbon in Native Grass-Based Pastures in Southern Australia.

    PubMed

    Sanderman, Jonathan; Reseigh, Jodie; Wurst, Michael; Young, Mary-Anne; Austin, Jenet

    2015-01-01

    Rotational grazing management strategies have been promoted as a way to improve the sustainability of native grass-based pasture systems. From disturbance ecology theory, rotational grazing relative to continuous grazing can increase pasture productivity by allowing vegetation to recover after short intense grazing periods. This project sought to assess whether soil organic carbon (SOC) stocks would also increase with adoption of rotational grazing management. Twelve pairs of rotationally and continuously grazed paddocks were sampled across a rainfall gradient in South Australia. Pasture productivity approximated as the normalized difference vegetation index (NDVI) was on average no different between management categories, but when the data from all sites were aggregated as log response ratios (rotational/continuous) a significant positive trend of increasing NDVI under rotational grazing relative to continuous grazing was found (R2 = 0.52). Mean SOC stocks (0-30 cm) were 48.3 Mg C ha-1 with a range of 20-80 Mg C ha-1 across the study area with no differences between grazing management categories. SOC stocks were well correlated with rainfall and temperature (multiple linear regression R2 = 0.61). After removing the influence of climate on SOC stocks, the management variables, rest periods, stocking rate and grazing days, were found to be significantly correlated with SOC, explaining 22% of the variance in SOC, but there were still no clear differences in SOC stocks at paired sites. We suggest three reasons for the lack of SOC response. First, changes in plant productivity and turnover in low-medium rainfall regions due to changes in grazing management are small and slow, so we would only expect at best small incremental changes in SOC stocks. This is compounded by the inherent variability within and between paddocks making detection of a small real change difficult on short timescales. Lastly, the management data suggests that there is a gradation in

  14. Risk assessment of cattle handling on pasture using work environment screening tool.

    PubMed

    Geng, Qiuqing; Field, William E; Salomon, Eva

    2015-01-01

    Working with beef cattle in an open area or while on pasture has been shown to expose workers to a high risk of work-related injury. Prior research on this problem has been conducted using mail surveys, interviews, self-reporting of work practices and injury experiences, and summaries of published injury data, including media reports. Prior research on injury prevention has largely focused on worker education in a specific cultural or geographical setting. A pilot study was conducted to test the cross-cultural usability of the Working Environment Screening Tool in Agriculture (WEST-AG), a modification of the WEST, developed for Swedish industrial applications, to assess risk factors associated with farmers working with cattle being raised largely on pasture as compared with cattle raised in confined feeding operations. Swedish and English language versions of WEST-AG were developed and pilot-tested on a convenient sample of eight Swedish and eight Indiana farms that raise beef cattle primarily on pasture. On-site observations were conducted independently by Swedish and US agricultural safety professionals and documented using photography and a 15-risk-of-injury component on an 11-degree linear scale. Comparisons were made between independent observations documented from the Swedish and Indiana application of the WEST, including collective assessment of photographic record, and the results reported. Key findings included (a) a higher level of observed risks on Indiana farms studied as compared with their Swedish counterparts; (b) high levels of worker exposure to cattle, especially mature breeding bulls, on both sets of farms; (c) a higher frequency of self-reported farm-related injuries than anticipated on both Swedish and Indiana farms; (d) substantially different economic, social, cultural, and regulatory forces that influence small-operation Swedish and Indiana beef producers' decisions regarding adoption of safer work practices, including use of new and safer

  15. Milk fatty acid composition and cheese texture and appearance from cows fed hay or different grazing systems on upland pastures.

    PubMed

    Coppa, M; Ferlay, A; Monsallier, F; Verdier-Metz, I; Pradel, P; Didienne, R; Farruggia, A; Montel, M C; Martin, B

    2011-03-01

    The objective of this work was to compare milk fatty acid (FA) profile and texture and appearance of Cantal cheeses obtained from cows grazing 2 different upland grasslands: a highly diversified pasture (74 species) of area 12.5 ha managed under continuous mode (C), and a weakly diversified pasture (31 species) of area 7.7 ha (an old temporary grassland) managed under rotational mode (R). A control group of cows fed a hay-based diet (indoors, I) was used. Three equivalent groups of 12 Montbéliarde cows underwent the 3 treatments from May to September 2008. The cheeses were manufactured during 3 consecutive days in early June, early July, and late August (27 cheeses in all). The texture, appearance, and chemical composition of the cheeses were determined after 12 wk of ripening. Concentrations of total saturated FA and monounsaturated FA were higher and lower, respectively, in I milks compared with pasture milks. The concentrations of trans-11-C18:1 and cis-9-C18:1, and polyunsaturated FA as well as yellowness decreased during the season in C-derived milk but remained constant in R-derived milk, through a combined effect of grass development stage and the cows' grazing selection. The I cheeses were, on average, firmer, less creamy, less elastic, and less yellow than the pasture cheeses. Decreasing and increasing trends in texture firmness during the season were observed for C and R cheeses, respectively. The rind of the pasture-fed cow cheese had fewer, less intensely colored, and less prominent spots than did that of I cheeses. This difference was probably due to greater migration of fat to the rind during pressing because of the lower fat melting point of the pasture-fed cow cheeses, which had higher unsaturated FA content. The greater amounts of fat deposited on the rind of the pasture-fed cow cheeses may have partially inhibited the microbial activity responsible for rind appearance. Our trial underlines the importance of the effects of grazing management

  16. Conversion from forests to pastures in the Colombian Amazon leads to contrasting soil carbon dynamics depending on land management practices.

    PubMed

    Navarrete, Diego; Sitch, Stephen; Aragão, Luiz E O C; Pedroni, Lucio

    2016-10-01

    Strategies to mitigate climate change by reducing deforestation and forest degradation (e.g. REDD+) require country- or region-specific information on temporal changes in forest carbon (C) pools to develop accurate emission factors. The soil C pool is one of the most important C reservoirs, but is rarely included in national forest reference emission levels due to a lack of data. Here, we present the soil organic C (SOC) dynamics along 20 years of forest-to-pasture conversion in two subregions with different management practices during pasture establishment in the Colombian Amazon: high-grazing intensity (HG) and low-grazing intensity (LG) subregions. We determined the pattern of SOC change resulting from the conversion from forest (C3 plants) to pasture (C4 plants) by analysing total SOC stocks and the natural abundance of the stable isotopes (13) C along two 20-year chronosequences identified in each subregion. We also analysed soil N stocks and the natural abundance of (15) N during pasture establishment. In general, total SOC stocks at 30 cm depth in the forest were similar for both subregions, with an average of 47.1 ± 1.8 Mg C ha(-1) in HG and 48.7 ± 3.1 Mg C ha(-1) in LG. However, 20 years after forest-to-pasture conversion SOC in HG decreased by 20%, whereas in LG SOC increased by 41%. This net SOC decrease in HG was due to a larger reduction in C3-derived input and to a comparatively smaller increase in C4-derived C input. In LG both C3- and C4-derived C input increased along the chronosequence. N stocks were generally similar in both subregions and soil N stock changes during pasture establishment were correlated with SOC changes. These results emphasize the importance of management practices involving low-grazing intensity in cattle activities to preserve SOC stocks and to reduce C emissions after land-cover change from forest to pasture in the Colombian Amazon. PMID:26929394

  17. Additive effects of growth promoting technologies on performance of grazing steers and economics of the wheat pasture enterprise.

    PubMed

    Beck, P; Hess, T; Hubbell, D; Hufstedler, G D; Fieser, B; Caldwell, J

    2014-03-01

    This research was designed to evaluate the effect of monensin (Elanco Animal Health, Greenfield, IN) supplementation via mineral or pressed protein block with or without a growth-promoting implant on performance of steers grazing wheat pasture in Arkansas over 2 yr. Preconditioned steers (n = 360, BW = 238 ± 5.1 kg) grazed 15 1.6-ha wheat pastures in the fall (n = 60 steers each fall, stocking rate of 2.5 steers/ha) or 30 0.8-ha wheat pastures in the spring (n = 120 steers each spring, stocking rate of 5 steers/ha). Steers in each pasture were given free-choice access to nonmedicated mineral (CNTRL; MoorMan's WeatherMaster Range Minerals A 646AAA; ADM Alliance Nutrition, Inc., Quincy, IL), or were supplemented with monensin (Elanco Animal Health, Greenfield, IN) via mineral containing 1.78 g monensin/kg (RMIN; MoorMan's Grower Mineral RU-1620 590AR; ADM Alliance Nutrition, Inc.), or pressed protein block containing 0.33 g monensin/kg (RBLCK; MoorMan's Mintrate Blonde Block RU; ADM Alliance Nutrition, Inc.). Additionally, one-half of the steers in each pasture were implanted (IMPL) with 40 mg trenbolone acetate and 8 mg estradiol (Component TE-G with Tylan; Elanco Animal Health). There was no interaction (P ≥ 0.71) between supplement treatment and growth-promoting implants, and ADG for RMIN and RBLCK were increased (P < 0.01) over CNTRL by 0.07 to 0.09 kg/d, respectively. Implanting steers with Component TE-G increased (P < 0.01) ADG by 0.14 kg/d. The combination of these growth-promoting technologies are a cost-effective means of increasing beef production by 22% without increasing level of supplementation or pasture acreage. Utilizing ionophores and implants together for wheat pasture stocker cattle decreased cost of gain by 26%. Utilizing both IMPL and monensin increased net return by $30 to $54/steer for RMIN or $18 to $43/steer for RBLCK compared with UNIMPL CNTRL at Low and High values of BW gain, respectively. PMID:24492552

  18. Overcoming barriers to seedling regeneration during forest restoration on tropical pasture land and the potential value of woody weeds.

    PubMed

    Elgar, Amelia T; Freebody, Kylie; Pohlman, Catherine L; Shoo, Luke P; Catterall, Carla P

    2014-01-01

    Combating the legacy of deforestation on tropical biodiversity requires the conversion to forest of large areas of established pasture, where barriers to native plant regeneration include competition with pasture grasses and poor propagule supply (seed availability). In addition, initial woody plants that colonise pasture are often invasive, non-native species whose ecological roles and management in the context of forest regeneration are contested. In a restoration experiment at two 0.64 ha sites we quantified the response of native woody vegetation recruitment to (1) release from competition with introduced pasture grasses, and (2) local facilitation of frugivore-assisted seed dispersal provided by scattered woody plants and artificial bird perches. Herbicide pasture grass suppression during 20 months caused a significant but modest increase in density of native woody seedlings, together with abundant co-recruitment of the prominent non-native pioneer wild tobacco (Solanum mauritianum). Recruitment of native species was further enhanced by local structure in herbicide-treated areas, being consistently greater under live trees and dead non-native shrubs (herbicide-treated) than in open areas, and intermediate under bird perches. Native seedling recruitment comprised 28 species across 0.25 ha sampled but was dominated by two rainforest pioneers (Homalanthus novoguineensis, Polyscias murrayi). These early results are consistent with the expected increase in woody vegetation recruitment in response to release from competitive and dispersive barriers to rainforest regeneration. The findings highlight the need for a pragmatic consideration of the ecological roles of woody weeds and the potential roles of "new forests" more broadly in accelerating succession of humid tropical forest across large areas of retired agricultural land. PMID:24904602

  19. Remnant Pachira quinata pasture trees have greater opportunities to self and suffer reduced reproductive success due to inbreeding depression

    PubMed Central

    Rymer, P D; Sandiford, M; Harris, S A; Billingham, M R; Boshier, D H

    2015-01-01

    Habitat fragmentation is extensive throughout the world, converting natural ecosystems into fragments of varying size, density and connectivity. The potential value of remnant trees in agricultural landscapes as seed sources and in connecting fragments has formed a fertile area of debate. This study contrasted the mating patterns of bat-pollinated Pachira quinata trees in a continuous forest to those in pasture through microsatellite-based paternity analysis of progeny. The breeding system was determined by analysis of pollen tube growth and seed production from controlled pollinations. Fitness of selfed and outcrossed seed was compared by germination and seedling growth. There was more inbreeding within pasture trees (outcrossing=0.828±0.015) compared with forest trees (0.926±0.005). Pasture trees had fewer sires contributing to mating events, but pollen dispersal distances were greater than those in the forest. Paternity analysis showed variation in outcrossing rates among pasture trees with high proportions of external and self pollen sources detected. A leaky self-incompatibility system was found, with self pollen having reduced germination on stigmas and slower growth rate through the style. Controlled pollinations also showed a varied ability to self among trees, which was reflected in the selfing rates among pasture trees shown by the paternity analysis (0–80% selfing). Self pollination resulted in lower seed set, germination and seedling growth compared with outcrossing. While remnant trees in agricultural landscapes are involved in broader mating patterns, they show increased but varied levels of inbreeding, which result in reduced fitness. PMID:23963342

  20. Climate and topographic controls on simulated pasture production in a semiarid Mediterranean watershed with scattered tree cover

    NASA Astrophysics Data System (ADS)

    Lozano-Parra, J.; Maneta, M. P.; Schnabel, S.

    2014-04-01

    Natural grasses in semiarid rangelands constitute an effective protection against soil erosion and degradation, are a source of natural food for livestock and play a critical role in the hydrologic cycle by contributing to the uptake and transpiration of water. However, natural pastures are threatened by land abandonment and the consequent encroachment of shrubs and trees as well as by changing climatic conditions. In spite of their ecological and economic importance, the spatiotemporal variations of pasture production at the decadal-century scales over whole watersheds are poorly known. We used a physically based, spatially distributed ecohydrologic model applied to a 99.5 ha semiarid watershed in western Spain to investigate the sensitivity of pasture production to climate variability. The ecohydrologic model was run using a 300-year-long synthetic daily climate data set generated using a stochastic weather generator. The data set reproduced the range of climatic variations observed under the current climate. Results indicated that variation of pasture production largely depended on factors that also determined the availability of soil moisture such as the temporal distribution of precipitation, topography, and tree canopy cover. The latter is negatively related with production, reflecting the importance of rainfall and light interception, as well as water consumption by trees. Valley bottoms and flat areas in the lower parts of the catchment are characterized by higher pasture production but more interannual variability. A quantitative assessment of the quality of the simulations showed that ecohydrologic models are a valuable tool to investigate long-term (century scale) water and energy fluxes, as well as vegetation dynamics, in semiarid rangelands.