Prunus pumila L.

Treesearch

Don C. Bragg

2002-01-01

Sand cherry, also called beach plum, "cerise de sable" (Fernald 1923), or dwarf American cherry, is a diffusely branched, low growing (0.5 to 3 m tall, depending on variety and habitat) to sometimes decumbent or prostrate shrub (Fernald 1923, Gleason 1952, Lamson-Scribner 1891). Older stems develop a grayish, glabrous bark, while younger twigs are often...

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

Buck, E.C.; Cunnane, J.C.; Brown, N.R.

A combination of optical microscopy, scanning electron microscopy with backscattered electron detection (SEM/BSE), and analytical electron microscopy (AEM) is being used to determine the nature of uranium in soils from the Fernald Environmental Management Project. The information gained from these studies is being used to develop and test remediation technologies. Investigations using SEM have shown that uranium is contained within particles that are typically 1 to 100 {mu}m in diameter. Further analysis with AEM has shown that these uranium-rich regions are made up of discrete uranium-bearing phases. The distribution of these uranium phases was found to be inhomogeneous at themore » microscopic level.« less

Configuration management at an environmental restoration DOE facility (Fernald)

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

Beckett, C.; Pasko, W.; Kupinski, T.

This report contains information about a meeting held to discuss the decontamination and decommissioning of the Fernald site in Ohio. This site contains two major types of waste. First is the legacy waste. This waste consists of the wastes which were left over from production which is stored in various drums and containers across the site. Second is the waste generated from the remedial activities.

Automated container transportation using self-guided vehicles: Fernald site requirements

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

Hazen, F.B.

1993-09-01

A new opportunity to improve the safety and efficiency of environmental restoration operations, using robotics has emerged from advances in industry, academia, and government labs. Self-Guided Vehicles (SGV`s) have recently been developed in industry and early systems have already demonstrated much, though not all, of the functionality necessary to support driverless transportation of waste within and between processing facilities. Improved materials databases are being developed by at least two DOE remediation sites, the Fernald Environmental Management Project (FEME) in the State of Ohio and the Hanford Complex in the State of Washington. SGV`s can be developed that take advantage ofmore » the information in these databases and yield improved dispatch, waste tracking, report and shipment documentation. In addition, they will reduce the radiation hazard to workers and the risk of damaging containers through accidental collision. In this document, features of remediation sites that dictate the design of both the individual SGV`s and the collective system of SGV`s are presented, through the example of the site requirements at Fernald. Some concepts borrowed from the world of manufacturing are explained and then used to develop an integrated, holistic view of the remediation site as a pseudo-factory. Transportation methods at Fernald and anticipated growth in transport demand are analyzed. The new site-wide database under development at Fernald is presented so that advantageous and synergistic links between SGV`s and information systems can be analyzed. Details of the SGV development proposed are submitted, and some results of a recently completed state of the art survey for SGV use in this application are also presented.« less

Pilot study risk assessment for selected problems at the Fernald Environmental Management Project (FEMP)

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

Hamilton, L.D.; Meinhold, A.F.; Baxter, S.L.

1993-03-01

Two important environmental problems at the USDOE Fernald Environmental Management Project (FEMP) facility in Fernald, Ohio were studied in this human health risk assessment. The problems studied were radon emissions from the K-65 waste silos, and offsite contamination of ground water with uranium. Waste from the processing of pitchblende ore is stored in the K-65 silos at the FEMP. Radium-226 in the waste decays to radon gas which escapes to the outside atmosphere. The concern is for an increase in lung cancer risk for nearby residents associated with radon exposure. Monitoring data and a gaussian plume transport model were usedmore » to develop a source term and predict exposure and risk to fenceline residents, residents within 1 and 5 miles of the silos, and residents of Hamilton and Cincinnati, Ohio. Two release scenarios were studied: the routine release of radon from the silos and an accidental loss of one silo dome integrity. Exposure parameters and risk factors were described as distributions. Risks associated with natural background radon concentrations were also estimated.« less

Phytotoxic clerodane diterpenes from Salvia miniata Fernald (Lamiaceae).

PubMed

Bisio, Angela; Damonte, Gianluca; Fraternale, Daniele; Giacomelli, Emanuela; Salis, Annalisa; Romussi, Giovanni; Cafaggi, Sergio; Ricci, Donata; De Tommasi, Nunziatina

2011-02-01

Our ongoing research to identify natural growth inhibitors with diterpene and triterpene skeletons exuding from the surface of the aerial parts of Salvia species led us to study Salvia miniata Fernald. Ten clerodane diterpenoids were found, along with three known diterpenes. Most of the isolated compounds from S. miniata inhibited the germination of Papaver rhoeas L. and Avena sativa L. in Petri dish experiments. Parallel results have been obtained in experiments carried out to evaluate the subsequent growth of the seedlings of the target species in the presence of the tested compounds. Copyright © 2010 Elsevier Ltd. All rights reserved.

Authorized limits for Fernald copper ingots

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

Frink, N.; Kamboj, S.; Hensley, J.

This development document contains data and analysis to support the approval of authorized limits for the unrestricted release of 59 t of copper ingots containing residual radioactive material from the U.S. Department of Energy (DOE) Fernald Environmental Management Project (FEMP). The analysis presented in this document comply with the requirements of DOE Order 5400.5, {open_quotes}Radiation Protection of the Public and the Environment,{close_quotes} as well as the requirements of the proposed promulgation of this order as 10 CFR Part 834. The document was developed following the step-by-step process described in the Draft Handbook for Controlling Release for Reuse or Recycle Propertymore » Containing Residual Radioactive Material.« less

Occurrence of Schoenoplectus mucronatus at the U.S. Department of Energy Fernald Preserve

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

Homer, John; Decker, Ashlee; Bien, Stephanie

2010-01-01

Bog bulrush (Schoenoplectus mucronatus) is a perennial wetland species native to Africa, Asia, and Europe. Its documented occurrence in the United States includes California, Hawaii, Iowa, Kentucky, Missouri, New Jersey, New York, Pennsylvania, Washington, and Tennessee. This species spreads through seed, rhizomes, and stolons, and has shown resistance to certain herbicides. Online plant databases do not show the distribution of the species reaching into Ohio or Indiana; however, local experts have indicated that specimens are in both states. Various reports indicate that S. mucronatus is locally abundant but not yet widespread regionally. In recent years, S. mucronatus has become increasinglymore » abundant at the Fernald Preserve, a U.S. Department of Energy site in northwest Hamilton County, Ohio. The 425- hectare (1,050-acre) site has undergone extensive remediation and subsequent ecological restoration, and various wetlands have been constructed across the site. S. mucronatus was first observed at the Fernald Preserve in 2008, in one constructed basin. During monitoring in 2009, S. mucronatus was seen in 8 of 23 basins surveyed. This increase has raised concern that the species may become a regional problem. This poster aims to alert botanists and ecological restoration personnel of the species’ regional occurrence, and prompt discussion of its potential impacts and how it can be controlled.« less

Gynecological Care and Information

ERIC Educational Resources Information Center

Cibley, Leonard

1978-01-01

Based upon his experience as gynecologist at the Fernald School, the author suggests a set of criteria for establishing and running a gynecology program at an institution for the mentally retarded. (SBH)

Restoring public trust while tearing down site in rural Ohio

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

Schneider, Jerry; Wagner, Jeffrey; Connell, Judy

2007-07-01

In the mid-1980's, the impact of three decades of uranium processing near rural Fernald, Ohio, 18 miles northwest of Cincinnati, became the centre of national public controversy. When a series of incidents at the uranium foundry brought to light the years of contamination to the environment and surrounding farmland communities, local citizens' groups united and demanded a role in determining the plans for cleaning up the site. One citizens' group, Fernald Residents for Environmental Safety and Health (FRESH), formed in 1984 following reports that nearly 300 pounds of enriched uranium oxide had been released from a dust-collector system, and threemore » off-property wells south of the site were contaminated with uranium. For 22 years, FRESH monitored activities at Fernald and participated in the decision-making process with management and regulators. The job of FRESH ended on 19 January this year when the Fernald Site was declared clean of all nuclear contamination and open to public access. It marked the end of a remarkable turnaround in public confidence and trust that had attracted critical reports from around the world. When personnel from Fluor arrived in 1992, the management team thought it understood the issues and concerns of each stakeholder group, and was determined to implement the decommissioning scope of work aggressively, confident that stakeholders would agree with its plans. This approach resulted in strained relationships with opinion leaders during the early months of Fluor's contract. To forge better relationships, the U.S. Department of Energy (DOE) who owns the site, and Fluor embarked on three new strategies based on engaging citizens and interested stakeholder groups in the decision-making process. The first strategy was opening communication channels with site leadership, technical staff, and regulators. This strategy combined a strong public-information program with two-way communications between management and the community, soliciting and encouraging stakeholder participation early in the decision-making process. Fluor's public-participation strategy exceeded the 'check-the-box' approach common within the nuclear-weapons complex, and set a national standard that stands alone today. The second stakeholder-engagement strategy sprang from mending fences with the regulators and the community. The approach for disposing low-level waste was a 25-year plan to ship it off the site. Working with stakeholders, DOE and Fluor were able to convince the community to accept a plan to safely store waste permanently on site, which would save 15 years of cleanup and millions of dollars in cost. The third strategy addressed the potentially long delays in finalizing remedial action plans due to formal public comment periods and State and Federal regulatory approvals. Working closely with the U.S. and Ohio Environmental Protection Agencies (EPA) and other stakeholders, DOE and Fluor were able to secure approvals of five Records of Decision on time - a first for the DOE complex. Developing open and honest relationships with union leaders, the workforce, regulators and community groups played a major role in DOE and Fluor cleaning up and closing the site. Using lessons learned at Fernald, DOE was able to resolve challenges at other sites, including worker transition, labour disputes, and damaged relationships with regulators and the community. It took significant time early in the project to convince the workforce that their future lay in cleanup, not in holding out hope for production to resume. It took more time to repair relationships with Ohio regulators and the local community. Developing these relationships over the years required constant, open communications between site decision makers and stakeholders to identify issues and to overcome potential barriers. Fluor's open public-participation strategy resulted in stakeholder consensus of five remedial-action plans that directed Fernald cleanup. This strategy included establishing a public-participation program that emphasized a shared-decision making process and abandoned the government's traditional, non-participatory 'Decide, Announce, Defend' approach. Fernald's program became a model within the DOE complex for effective public participation. Fluor led the formation of the first DOE site-specific advisory board dedicated to remediation and closure. The board was successful at building consensus on critical issues affecting long-term site remediation, such as cleanup levels, waste disposal and final land use. Fluor created innovative public outreach tools, such as 'Cleanopoly', based on the Monopoly game, to help illustrate complex concepts, including risk levels, remediation techniques, and associated costs. These innovative tools helped DOE and Fluor gain stakeholder consensus on all cleanup plans. To commemorate the outstanding commitment of Fernald stakeholders to this massive environmental-restoration project, Fluor donated $20,000 to build the Weapons to Wetlands Grove overlooking the former 136-acre production area. The grove contains 24 trees, each dedicated to '[a] leader(s) behind the Fernald cleanup'. Over the years, Fluor, through the Fluor Foundation, also invested in educational and humanitarian projects, contributing nearly $2 million to communities in southwestern Ohio, Kentucky and Indiana. Further, to help offset the economic impact of the site's closing to the community, DOE and Fluor promoted economic development in the region by donating excess equipment and property to local schools and townships. This paper discusses the details of the public-involvement program - from inception through maturity - and presents some lessons learned that can be applied to other similar projects. (authors)« less

1995 annual epidemiologic surveillance report for Fernald Environmental Management Project

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

NONE

1995-12-31

The US Department of Energy's (DOE) commitment to assuring the health and safety of its workers includes the conduct of epidemiologic surveillance activities that provide an early warning system for health problems among workers. During the past several years, a number of DOE sites have participated in the Epidemiologic Surveillance Program. This program monitors illnesses and health conditions that result in an absence of five or more consecutive workdays, occupational injuries and illnesses, and disabilities and deaths among current workers. This report provides a summary of epidemiologic surveillance data collected from the Fernald Environmental Management Project (FEMP) from January 1,more » 1995 through December 31, 1995. The data were collected by a coordinator at FEMP and submitted to the Epidemiologic Surveillance Data Center, located at Oak Ridge Institute for Science and Education, where quality control procedures and data analyses were carried out.« less

Identification of a new species of Aphis (Hemiptera: Aphididae) based on distinct morphology

USDA-ARS?s Scientific Manuscript database

Aphis elena Lagos-Kutz and Voegtlin, sp. nov. (Hemiptera: Aphididae), is described from specimens collected in Illinois, USA, on the North American native plant, Pycnanthemum virginianum (L.) T. Dur. & B.D. Jacks. ex B.L. Rob. & Fernald (Family: Lamiaceae). Both apterous and alate viviparae are desc...

Effects of Vocabulary Size on Online Lexical Processing by Preschoolers

ERIC Educational Resources Information Center

Law, Franzo, II; Edwards, Jan R.

2015-01-01

This study was designed to investigate the relationship between vocabulary size and the speed and accuracy of lexical processing in preschoolers between the ages of 30 and 46 months using an automatic eye tracking task based on the looking-while-listening paradigm (Fernald, Zangl, Portillo, & Marchman, 2008) and mispronunciation paradigm…

Development in Children's Interpretation of Pitch Cues to Emotions

ERIC Educational Resources Information Center

Quam, Carolyn; Swingley, Daniel

2012-01-01

Young infants respond to positive and negative speech prosody (A. Fernald, 1993), yet 4-year-olds rely on lexical information when it conflicts with paralinguistic cues to approval or disapproval (M. Friend, 2003). This article explores this surprising phenomenon, testing one hundred eighteen 2- to 5-year-olds' use of isolated pitch cues to…

Hypertension and hematologic parameters in a community near a uranium processing facility

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

Wagner, Sara E., E-mail: swagner@uga.edu; Burch, James B.; South Carolina Statewide Cancer Prevention and Control Program, Columbia, SC

Background: Environmental uranium exposure originating as a byproduct of uranium processing can impact human health. The Fernald Feed Materials Production Center functioned as a uranium processing facility from 1951 to 1989, and potential health effects among residents living near this plant were investigated via the Fernald Medical Monitoring Program (FMMP). Methods: Data from 8216 adult FMMP participants were used to test the hypothesis that elevated uranium exposure was associated with indicators of hypertension or changes in hematologic parameters at entry into the program. A cumulative uranium exposure estimate, developed by FMMP investigators, was used to classify exposure. Systolic and diastolicmore » blood pressure and physician diagnoses were used to assess hypertension; and red blood cells, platelets, and white blood cell differential counts were used to characterize hematology. The relationship between uranium exposure and hypertension or hematologic parameters was evaluated using generalized linear models and quantile regression for continuous outcomes, and logistic regression or ordinal logistic regression for categorical outcomes, after adjustment for potential confounding factors. Results: Of 8216 adult FMMP participants 4187 (51%) had low cumulative uranium exposure, 1273 (15%) had moderate exposure, and 2756 (34%) were in the high (>0.50 Sievert) cumulative lifetime uranium exposure category. Participants with elevated uranium exposure had decreased white blood cell and lymphocyte counts and increased eosinophil counts. Female participants with higher uranium exposures had elevated systolic blood pressure compared to women with lower exposures. However, no exposure-related changes were observed in diastolic blood pressure or hypertension diagnoses among female or male participants. Conclusions: Results from this investigation suggest that residents in the vicinity of the Fernald plant with elevated exposure to uranium primarily via inhalation exhibited decreases in white blood cell counts, and small, though statistically significant, gender-specific alterations in systolic blood pressure at entry into the FMMP.« less

Radiological Monitoring Equipment For Real-Time Quantification Of Area Contamination In Soils And Facility Decommissioning

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

M. V. Carpenter; Jay A. Roach; John R Giles

2005-09-01

The environmental restoration industry offers several sys¬tems that perform scan-type characterization of radiologically contaminated areas. The Idaho National Laboratory (INL) has developed and deployed a suite of field systems that rapidly scan, characterize, and analyse radiological contamination in surface soils. The base system consists of a detector, such as sodium iodide (NaI) spectrometers, a global positioning system (GPS), and an integrated user-friendly computer interface. This mobile concept was initially developed to provide precertifica¬tion analyses of soils contaminated with uranium, thorium, and radium at the Fernald Closure Project, near Cincinnati, Ohio. INL has expanded the functionality of this basic system tomore » create a suite of integrated field-deployable analytical systems. Using its engineering and radiation measurement expertise, aided by computer hardware and software support, INL has streamlined the data acquisition and analysis process to provide real-time information presented on wireless screens and in the form of coverage maps immediately available to field technicians. In addition, custom software offers a user-friendly interface with user-selectable alarm levels and automated data quality monitoring functions that validate the data. This system is deployed from various platforms, depending on the nature of the survey. The deployment platforms include a small all-terrain vehicle used to survey large, relatively flat areas, a hand-pushed unit for areas where manoeuvrability is important, an excavator-mounted system used to scan pits and trenches where personnel access is restricted, and backpack- mounted systems to survey rocky shoreline features and other physical settings that preclude vehicle-based deployment. Variants of the base system include sealed proportional counters for measuring actinides (i.e., plutonium-238 and americium-241) in building demolitions, soil areas, roadbeds, and process line routes at the Miamisburg Closure Project near Dayton, Ohio. In addition, INL supports decontamination operations at the Oak Ridge National Laboratory.« less

Modifying the Monte Carlo Quiz to Increase Student Motivation, Participation, and Content Retention

ERIC Educational Resources Information Center

Simonson, Shawn R.

2017-01-01

Fernald developed the Monte Carlo Quiz format to enhance retention, encourage students to prepare for class, read with intention, and organize information in psychology classes. This author modified the Monte Carlo Quiz, combined it with the Minute Paper, and applied it to various courses. Students write quiz questions as part of the Minute Paper…

First Ade for the Man or Gril Who Dose not Spel Mutch: Fernald Revisited.

ERIC Educational Resources Information Center

Heinze, Betty L.

The tactile-kinesthetic approach to spelling provides a practical teaching device for use with both disabled learners and moderately poor spellers who need to learn a technical or professional vocabulary. This multisensory approach to learning teaches to the student's strengths and places emphasis on finger contact, muscle movement, saying and…

Real-Time Processing of Gender-Marked Articles by Native and Non-Native Spanish Speakers

ERIC Educational Resources Information Center

Lew-Williams, Casey; Fernald, Anne

2010-01-01

Three experiments using online-processing measures explored whether native and non-native Spanish-speaking adults use gender-marked articles to identify referents of target nouns more rapidly, as shown previously with 3-year-old children learning Spanish as L1 (Lew-Williams & Fernald, 2007). In Experiment 1, participants viewed familiar objects…

77 FR 46438 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-03

... Addition to the Special Exposure Cohort AGENCY: National Institute for Occupational Safety and Health... Fernald, Ohio, from January 1, 1968 through December 31, 1978, for a number of work days aggregating at..., Division of Compensation Analysis and Support, National Institute for Occupational Safety and Health (NIOSH...

Speed of Word Recognition and Vocabulary Knowledge in Infancy Predict Cognitive and Language Outcomes in Later Childhood

ERIC Educational Resources Information Center

Marchman, Virginia A.; Fernald, Anne

2008-01-01

The nature of predictive relations between early language and later cognitive function is a fundamental question in research on human cognition. In a longitudinal study assessing speed of language processing in infancy, Fernald, Perfors and Marchman (2006 ) found that reaction time at 25 months was strongly related to lexical and grammatical…

Developing public affairs counseling skills to support a public participation focus at Fernald

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

Hoopes, J.

To provide closer coordination between the Public Affairs Division and environmental restoration management and technical staff, the Fernald Environmental Restoration Management Corporation (FERMCO) matrixed Public Affairs staffers as counselors to project teams within FERMCO. Close coordination between technical staff and public affairs staff is essential for effective public communication in a public participation, environmental risk communication environment. Two-way symmetrical communication (public participation) represents a paradigm shift for public affairs staff who have developed skills primarily in a public information (asymmetrical communication) environment. While there has been much focus in the literature and workshops on management changes needed to support amore » public participation environment, less attention has been paid to identifying and developing the skills needed by public affairs professionals to support public participation. To support the new counseling role of public affairs staffers, FERMCO used a public affairs training consultant to design and deliver a workshop to initiate development of the skills needed for the public affairs counseling role. This paper describes FERMCO`s matrixed counseling program and the training to develop public affairs counseling skills for the public participation environment.« less

Antibacterial compounds from Salvia adenophora Fernald (Lamiaceae).

PubMed

Bisio, Angela; Schito, Anna Maria; Ebrahimi, Samad Nejad; Hamburger, Matthias; Mele, Giacomo; Piatti, Gabriella; Romussi, Giovanni; Dal Piaz, Fabrizio; De Tommasi, Nunziatina

2015-02-01

From the aerial parts of Salvia adenophora Fernald four derivatives of 12-oxo-phytodienoic acid (1-4) together with five clerodane diterpenoids (5, 6, 8-10), and one known diterpene (7) have been isolated. Compounds 1-6 and 8-10 are described for the first time. The structures were established by extensive 1D, 2D NMR and HRESI-TOFMS spectroscopic methods. Finally, the absolute configuration has been established by comparing of experimental and quantum chemical calculation of ECD spectra. Despite a total lack of antimicrobial activity of the plant extract, hinting to the existence of antagonistic interactions in the crude material, three oxylipins (2-4) displayed a promising inhibition on Gram-positive multidrug-resistant clinical strains including Staphylococcus aureus, Streptococcus agalactiae and, particularly, Staphylococcus epidermidis, while the compounds 9 and 10 revealed a specific and strain-dependent activity against S. epidermidis. Interestingly, the inhibition provided by these compounds was independent of the resistance patterns of these pathogens to classic antibiotics. No action was reported on Gram-negative strains nor on Candida albicans. These results confirm that clerodanes and, particularly, prostaglandin-like compounds can be considered as interesting antimicrobial agents deserving further study. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ecological life cycle of Chaerophyllum procumbens variety shortii (Apiacheae), a winter annual of the North American dedicuous forest

Treesearch

Carol C. Baskin; Tracy S. Hawkins; Jerry M. Baskin

2004-01-01

Numerous winter annuals occur in temperate eastern North America. Based on life cycle information and flowering period, the flora of northeastern USA and adjacent Canada described in Gray's Manual of Botany (Fernald 1950) contains 96 winter annuals (C. Baskin unpublished). This list includes native and introduced species in 57 genera and 23 families. The majority...

Research progress and harnessing method of soil and water loss in Pisha Sandstone region

NASA Astrophysics Data System (ADS)

Xiao, P. Q.; Yang, C. X.; Jing, C. R.

2018-05-01

Pisha Sandstone region is the most vulnerable and the most dramatic area of soil erosion, severe soil erosion on the ecological bases of China’s energy security constitutes a serious challenge. Research progress of soil erosion in pisha Sandstone region was reviewed based on the need of soil and water ecological construction in Pisha Sandstone region and harnessing the yellow river including soil erosion mechanism, soil erosion dynamic monitoring and soil erosion simulation assessments. Meanwhile, the latest progress of soil and water conservation measures was analyzed, and the existing problems and future harnessing measures of soil and water loss were discussed. This study is to explore the comprehensive management method and provide scientific theory for constructing soil and water conservation project in Pisha Sandstone region.

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

U.S. Department of Energy, Office of Health, Safety and Security, Office of Illness and Injury Prevention Programs

Annual Illness and Injury Surveillance Program report for 2003 for the Fernald Environmental Management Project. The U.S. Department of Energy’s (DOE) commitment to assuring the health and safety of its workers includes the conduct of epidemiologic surveillance activities that provide an early warning system for health problems among workers. The IISP monitors illnesses and health conditions that result in an absence of workdays, occupational injuries and illnesses, and disabilities and deaths among current workers.

A bill to amend the Energy Employees Occupational Illness Compensation Program Act of 2000 to provide compensation for certain persons injured in the course of employment at the Feed Materials Production Center (commonly referred to as "Fernald") or the Piqua Organic Moderated Reactor in Ohio.

THOMAS, 111th Congress

Sen. Brown, Sherrod [D-OH

2009-10-20

Senate - 10/20/2009 Read twice and referred to the Committee on Health, Education, Labor, and Pensions. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

To amend the Energy Employees Occupational Illness Compensation Program Act of 2000 to provide compensation for certain persons injured in the course of employment at the Feed Materials Production Center (commonly referred to as "Fernald") or the Piqua Organic Moderated Reactor in Ohio.

THOMAS, 111th Congress

Rep. Driehaus, Steve [D-OH-1

2009-11-03

House - 01/04/2010 Referred to the Subcommittee on Immigration, Citizenship, Refugees, Border Security, and International Law. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Final environmental assessment for the U.S. Department of Energy, Oak Ridge Operations receipt and storage of uranium materials from the Fernald Environmental Management Project site

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

NONE

Through a series of material transfers and sales agreements over the past 6 to 8 years, the Fernald Environmental Management Project (FEMP) has reduced its nuclear material inventory from 14,500 to approximately 6,800 metric tons of uranium (MTU). This effort is part of the US Department of energy`s (DOE`s) decision to change the mission of the FEMP site; it is currently shut down and the site is being remediated. This EA focuses on the receipt and storage of uranium materials at various DOE-ORO sites. The packaging and transportation of FEMP uranium material has been evaluated in previous NEPA and othermore » environmental evaluations. A summary of these evaluation efforts is included as Appendix A. The material would be packaged in US Department of Transportation-approved shipping containers and removed from the FEMP site and transported to another site for storage. The Ohio Field Office will assume responsibility for environmental analyses and documentation for packaging and transport of the material as part of the remediation of the site, and ORO is preparing this EA for receipt and storage at one or more sites.« less

The soil biota composition along a progressive succession of secondary vegetation in a karst area.

PubMed

Zhao, Jie; Li, Shengping; He, Xunyang; Liu, Lu; Wang, Kelin

2014-01-01

Karst ecosystems are fragile and are in many regions degraded by anthropogenic activities. Current management of degraded karst areas focuses on aboveground vegetation succession or recovery and aims at establishing a forest ecosystem. Whether progressive succession of vegetation in karst areas is accompanied by establishment of soil biota is poorly understood. In the present study, soil microbial and nematode communities, as well as soil physico-chemical properties were studied along a progressive succession of secondary vegetation (from grassland to shrubland to forest) in a karst area in southwest China. Microbial biomass, nematode density, ratio of fungal to bacterial biomass, nematode structure index, and nematode enrichment index decreased with the secondary succession in the plant community. Overall, the results indicated a pattern of declines in soil biota abundance and food web complexity that was associated with a decrease in soil pH and a decrease in soil organic carbon content with the progressive secondary succession of the plant community. Our findings suggest that soil biota amendment is necessary during karst ecosystem restoration and establishment and management of grasslands may be feasible in karst areas.

Centrifugal shot blasting. Innovative technology summary report

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

Not Available

1999-07-01

At the US Department of Energy (DOE) Fernald Environmental Management Project (FEMP), the Facilities Closure and Demolition Projects Integrated Remedial Design/Remedial Action (RD/RA) work plan calls for the removal of one inch (1 in) depth of concrete surface in areas where contamination with technetium-99 has been identified. This report describes a comparative demonstration between two concrete removal technologies: an innovative system using Centrifugal Shot Blasting (CSB) and a modified baseline technology called a rotary drum planer.

The Soil Biota Composition along a Progressive Succession of Secondary Vegetation in a Karst Area

PubMed Central

He, Xunyang; Liu, Lu; Wang, Kelin

2014-01-01

Karst ecosystems are fragile and are in many regions degraded by anthropogenic activities. Current management of degraded karst areas focuses on aboveground vegetation succession or recovery and aims at establishing a forest ecosystem. Whether progressive succession of vegetation in karst areas is accompanied by establishment of soil biota is poorly understood. In the present study, soil microbial and nematode communities, as well as soil physico-chemical properties were studied along a progressive succession of secondary vegetation (from grassland to shrubland to forest) in a karst area in southwest China. Microbial biomass, nematode density, ratio of fungal to bacterial biomass, nematode structure index, and nematode enrichment index decreased with the secondary succession in the plant community. Overall, the results indicated a pattern of declines in soil biota abundance and food web complexity that was associated with a decrease in soil pH and a decrease in soil organic carbon content with the progressive secondary succession of the plant community. Our findings suggest that soil biota amendment is necessary during karst ecosystem restoration and establishment and management of grasslands may be feasible in karst areas. PMID:25379741

SEISMIC PREDICTION USING UNATTACHED RADON DECAY PRODUCTS.

PubMed

Harley, Naomi H; Chittaporn, Passaporn; Fisenne, Isabel M

2017-11-01

Long-term measurements of the 222Rn concentration, 222Rn decay product activity, particle size distribution, and unattached, and attached 222Rn decay products, were made at two locations using the 22 y radon decay product 210Pb as their tracer. The particle size sampler collects both short lived 222Rn decay products that ultimately decay to 210Pb on the filters, and also airborne 210Pb. The measurements were made outdoors, at a suburban home and at Fernald, OH, a former uranium processing facility, on top of one of the two 226Ra storage silos containing 150 TBq 226Ra. The size distributions showed the unattached fractions, i.e. particle diameter 2-4 nm, to be 1.5% at the home and 14% at the silos. The unattached fraction of 218Po can be shown to be an immediate measure of the 222Rn concentration. The data indicates detection of the pressure driven 222Rn flow at the silo and with the enhanced measurement capability of a filtered air source versus the usual 222Rn gas measurement. It is proposed that real time measurements of unattached 218Po may be used to identify rapidly changing 222Rn concentrations associated with pressure driven soil air flow associated with seismic activity. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Processing of Lexical-Stress Cues by Young Children

PubMed Central

Quam, Carolyn; Swingley, Daniel

2014-01-01

Though infants learn an impressive amount about their native-language phonological system by the end of the first year of life, after the first year children still have much to learn about how acoustic dimensions cue linguistic categories in fluent speech. The present study investigates what children have learned about how the acoustic dimension of pitch indicates the location of the stressed syllable in familiar words. Preschoolers (2.5–5 years) and adults were tested on their ability to use lexical-stress cues to identify familiar words. Both age groups saw pictures of a bunny and a banana, and heard versions of “bunny” and “banana” in which stress was either indicated normally with convergent cues (pitch, duration, amplitude, and vowel quality), or was manipulated such that only pitch differentiated the words’ initial syllables. Adults (n=48) used both the convergent cues, and the isolated pitch cue, to identify the target words as they unfolded. Children (n=206) used the convergent stress cues, but not pitch alone, in identifying words. We discuss potential reasons for children’s difficulty exploiting isolated pitch cues to stress, despite children’s early sensitivity to pitch in language (e.g., Fernald, 1992). These findings contribute to a view in which phonological development progresses toward the adult state well past infancy. PMID:24705094

Office of Inspector General audit report on credit card usage at the Ohio Field Office and the Fernald and Miamisburg Environmental Management Projects

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

NONE

1999-03-01

In 1994 the Department of Energy (Department) obtained the services of Rocky Mountain BankCard System, through the use of a General Services Administration contract, as a means for the Department and its contractors to make small purchases. The use of credit cards was expected to simplify small purchase procedures and improve cash management. The Ohio Field Office (Field Office) uses the credit card system and oversees usage by its area offices. Contractors under the Field Office also use the credit card system to make small purchases. The Office of Inspector General (OIG) has issued one audit report concerning the usemore » of credit cards. In April 1996, the OIG issued Report WR-B-96-06, Audit of Bonneville Power Administration`s Management of Information Resources. The audit concluded that improvements could be made in implementing credit card and property procedures in Bonneville`s management of computer-related equipment. Specifically, many credit card purchases were made by employees whose authority to buy was not properly documented, and the purchasing files often lacked invoices that would show what was purchased. Additionally, some cardholders split purchases to avoid credit card limits. The objective of this audit was to determine whether the Field Office, Fernald and Miamisburg Environmental Management Projects, Fluor Daniel, and B and W were using credit cards for the appropriate purposes and within the limitations established by Federal and Departmental regulations.« less

Shifts of tundra bacterial and archaeal communities along a permafrost thaw gradient in Alaska.

PubMed

Deng, Jie; Gu, Yunfu; Zhang, Jin; Xue, Kai; Qin, Yujia; Yuan, Mengting; Yin, Huaqun; He, Zhili; Wu, Liyou; Schuur, Edward A G; Tiedje, James M; Zhou, Jizhong

2015-01-01

Understanding the response of permafrost microbial communities to climate warming is crucial for evaluating ecosystem feedbacks to global change. This study investigated soil bacterial and archaeal communities by Illumina MiSeq sequencing of 16S rRNA gene amplicons across a permafrost thaw gradient at different depths in Alaska with thaw progression for over three decades. Over 4.6 million passing 16S rRNA gene sequences were obtained from a total of 97 samples, corresponding to 61 known classes and 470 genera. Soil depth and the associated soil physical-chemical properties had predominant impacts on the diversity and composition of the microbial communities. Both richness and evenness of the microbial communities decreased with soil depth. Acidobacteria, Verrucomicrobia, Alpha- and Gamma-Proteobacteria dominated the microbial communities in the upper horizon, whereas abundances of Bacteroidetes, Delta-Proteobacteria and Firmicutes increased towards deeper soils. Effects of thaw progression were absent in microbial communities in the near-surface organic soil, probably due to greater temperature variation. Thaw progression decreased the abundances of the majority of the associated taxa in the lower organic soil, but increased the abundances of those in the mineral soil, including groups potentially involved in recalcitrant C degradation (Actinomycetales, Chitinophaga, etc.). The changes in microbial communities may be related to altered soil C sources by thaw progression. Collectively, this study revealed different impacts of thaw in the organic and mineral horizons and suggests the importance of studying both the upper and deeper soils while evaluating microbial responses to permafrost thaw. © 2014 John Wiley & Sons Ltd.

Wetlands Research Program. Corps of Engineers Wetlands Delineation Manual. Appendix C. Sections 1 and 2. Region 2 - Southeast.

DTIC Science & Technology

1987-01-01

cycZophylZa’Fernald Bacopa B 3. innominata (Gomez Maza) Alain Bacopa OBL B. monnieri (L.) Wettst. Coast bacopa OBL 3. repens (Swartz) Wettgt. Creeping bacopa ...OBL B. rctundifoiia (Michx.) Wettst. Roundleaf bacopa OBL Baiduina atropur’purea Harper Balduina FACW B. uniflora Nutt. One-flowered balduina FACW... Bacopa OBL Batis maritima Saltwort OBL .B.’., 5erchemia scanden8 Rattan vine FACW " " Fetula nigra River birch OBL -.. ¢2 ". FAC FA 3.eThre3er4Ztu

Status of Environmental Management Initiatives to Accelerate the Reduction of Environmental Risks and Challenges Posed by the Legacy of the Cold War

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

None

2009-01-01

Fifty years of nuclear weapons production and energy research in the United States during the Cold War generated large amounts of radioactive wastes, spent nuclear fuel (SNF), excess plutonium and uranium, thousands of contaminated facilities, and contaminated soil and groundwater. During most of that half century, the Nation did not have the environmental regulatory structure or nuclear waste cleanup technologies that exist today. The result was a legacy of nuclear waste that was stored and disposed of in ways now considered unacceptable. Cleaning up and ultimately disposing of these wastes is the responsibility of the U.S. Department of Energy (DOE).more » In 1989, DOE established the Office of Environmental Management (EM) to solve the large scale and technically challenging risks posed by the world's largest nuclear cleanup. This required EM to build a new nuclear cleanup infrastructure, assemble and train a technically specialized workforce, and develop the technologies and tools required to safely decontaminate, disassemble, stabilize, disposition, and remediate unique radiation hazards. The sites where nuclear activities produced legacy waste and contamination include the original Manhattan Project sites--Los Alamos, New Mexico; Hanford, Washington; and Oak Ridge, Tennessee--as well as major Cold War sites, such as Savannah River Site, South Carolina; the Idaho National Laboratory, Idaho; Rocky Flats Plant, Colorado; and Fernald, Ohio. Today EM has responsibility for nuclear cleanup activities at 21 sites covering more than two million acres in 13 states, and employs more than 30,000 Federal and contractor employees, including scientists, engineers and hazardous waste technicians. This cleanup poses unique, technically complex problems, which must be solved under the most hazardous of conditions, and which will require billions of dollars a year for several more decades. The EM program focus during its first 10 years was on managing the most urgent risks and maintaining safety at each site while negotiating state and Federal environmental compliance agreements. The program also concentrated on characterizing waste and nuclear materials and assessing the magnitude and extent of environmental contamination. By the late 1990s, EM had made significant progress in identifying and characterizing the extent of contamination and cleanup required and began transitioning from primarily a characterization and stabilization program to an active cleanup and closure program. During that time, EM formulated multi-year cleanup and closure plans, which contributed to cleanup progress; however, reducing the overall environmental risk associated with the cleanup program remained a challenge. In response, the Secretary of Energy directed a review of the EM program be undertaken. The resulting 'Top-to Bottom Review' re-directed the program focus from managing risks to accelerating the reduction of these risks.« less

[Research Progress in Technology of Using Soil Micro-organisms to Generate Electricity and Its Potential Applications].

PubMed

Deng, Huan; Xue, Hong-jing; Jiang, Yun-bin; Zhong, Wen-hui

2015-10-01

Microbial fuel cells ( microbial fuel cells, MFCs) are devices in which micro-organisms convert chemical energy into electrical power. Soil has electrogenic bacteria and organic substrates, thus can generate electrical current in MFCs. Soil MFCs can be operated and applied to real-time and continuously monitor soil pollution, remove soil pollutants and to reduce methane emitted from flooded rice paddy, without energy consumption and the application of chemical reagents to the soil. Instead, the operation of soil MFCs generates small amount of electrical power. Therefore, soil MFCs are useful in the development of environment-friendly technology for monitoring and remediating soil pollution, which have potential value for applications in the domain of environmental science and engineering. However, much of advanced technology hasn't been applied into soil MFCs since the studies on soil MFCs was not started until recently. This paper summarized the research progress in related to soil MFCs combining with the frontier of MFCs technology, and brought forward the possible direction in studies on soil MFCs.

Efforts to Improve Efficiency of Extraction Well Operation at the Fernald Preserve, Harrison, Ohio – 16177

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

Glassmeyer, Cathy; Hooten, Gwen; Hertel, Bill

The Fernald Preserve, a former uranium processing facility that produced high-purity uranium metal products during the Cold War, is located in southwest Ohio. The facility became a US Department of Energy Office of Legacy Management (LM) site in November 2006, following completion of the Comprehensive Environmental Response, Compensation, and Liability Act environmental remediation and site restoration (with the exception of groundwater). When the site was turned over to LM, approximately 76.5 ha of the Great Miami Aquifer remained contaminated with uranium above the final remediation level of 30 μg/L. Here, uranium contamination is being removed from groundwater in the Greatmore » Miami Aquifer through a pump-and-treat operation, which is predicted to continue until 2033. Twenty extraction wells pump about 30 million liters per day. Operation of the system is impacted by iron in the groundwater that promotes iron fouling of the well pumps, motors, and screens. The design of the well field evolved over 21 years and reflected a conservative system that could respond to a wide range of pumping conditions. For instance, some of the extraction wells were sized with pumps and motors that would allow the well to pump up to 1890 L/min (500 gpm) if warranted. The added flexibility, though, came at the cost of operational efficiency. We describe the efforts that have been taken by LM since the Fernald site was transferred to LM to mitigate the operational impacts from the iron fouling aquifer conditions and improve the efficiency of the well-field operation. Variable-frequency drives were installed at six wells to replace flow control valves. Several wells with oversized pumps and motors were changed from 24-hour per day operation to 8-hour per day operation to allow the pumps to operate closer to their design flow rates. Pumps and motors were “right-sized” at many wells to improve pumping efficiency. The process used to rehabilitate (or clean) well screens was improved, and a process was developed to clean pumps without having to pull them from the well. To reduce pressure drops, improvements were also made to the configuration of the discharge piping. A new control system was installed for each well to allow local control and local tracking of energy used. The amount of energy used daily compared to number of gallons pumped provides a method to assess pump performance and determine when action is necessary to restore well pump efficiency. Additionally, the metrics being employed to help quantify well-field efficiency improvements are described, and the benefits achieved by proactively managing the pump-and-treat operation are presented.« less

[Hydrological characteristics of calcareous soil with contrasting architecture on dolomite slope of Northwest Guangxi].

PubMed

Zhang, Xing; Wang, Ke Lin; Fu, Zhi Yong; Chen, Hong Song; Zhang, Wei; Shi, Zhi Hua

2017-07-18

The traditional hydrology method, stable hydrogen and oxygen isotope technology, and rainfall simulation method were combined to investigate the hydrological function of small experimental plots (2 m×1.2 m) of contrasting architecture in Northwest Guangxi dolomite area. There were four typical catenary soils along the dolomite peak-cluster slope, which were the whole-sand, up-loam and down-sand, the whole loam, up-clay and down-sand soil types, respectively. All the experimental plots generated little amounts of overland runoff and had a high surface infiltration rate, ranging from 41 to 48 mm·h -1 , and the interflow and deep percolation were the dominant hydrological progress. The interflow was classified into interflow in soil clay A and C according to soil genetic layers. For interflow in soil clay A, matrix flow was generated from the whole-sand, up-loam and down-sand, up-clay and down-sand soil types, but preferential flow dominated in the whole-loam soil type. As for interflow in soil clay C, preferential flow dominated in the whole-loam, up-clay and down-sand, up-loam and down-sand soil types. The soils were shallow yet continuously distributed along the dolomite slope. The difference of hydrological characteristics in soil types with different architectures mainly existed in the runoff generation progress of each interface underground. It proved that the a 3-D perspective was needed to study the soil hydrological functions on dolomite slope of Northwest Guangxi, and a new way paying more attention on underground hydrological progress should be explored to fully reveal the near-surface hydrological processes on karst slope.

Dependence of soil respiration on soil temperature and soil moisture in successional forests in Southern China

USGS Publications Warehouse

Tang, X.-L.; Zhou, G.-Y.; Liu, S.-G.; Zhang, D.-Q.; Liu, S.-Z.; Li, Ji; Zhou, C.-Y.

2006-01-01

The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (±SD) soil respiration rate in the DNR forests was (9.0 ± 4.6) Mg CO2-C/hm2per year, ranging from (6.1 ± 3.2) Mg CO2-C/hm2per year in early successional forests to (10.7 ± 4.9) Mg CO2-C/hm2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities.

Seasonal Variation in Soil Microbial Biomass, Bacterial Community Composition and Extracellular Enzyme Activity in Relation to Soil Respiration in a Northern Great Plains Grassland

NASA Astrophysics Data System (ADS)

Wilton, E.; Flanagan, L. B.

2014-12-01

Soil respiration rate is affected by seasonal changes in temperature and moisture, but is this a direct effect on soil metabolism or an indirect effect caused by changes in microbial biomass, bacterial community composition and substrate availability? In order to address this question, we compared continuous measurements of soil and plant CO2 exchange made with an automatic chamber system to analyses conducted on replicate soil samples collected on four dates during June-August. Microbial biomass was estimated from substrate-induced respiration rate, bacterial community composition was determined by 16S rRNA amplicon pyrosequencing, and β-1,4-N-acetylglucosaminidase (NAGase) and phenol oxidase enzyme activities were assayed fluorometrically or by absorbance measurements, respectively. Soil microbial biomass declined from June to August in strong correlation with a progressive decline in soil moisture during this time period. Soil bacterial species richness and alpha diversity showed no significant seasonal change. However, bacterial community composition showed a progressive shift over time as measured by Bray-Curtis dissimilarity. In particular, the change in community composition was associated with increasing relative abundance in the alpha and delta classes, and declining abundance of the beta and gamma classes of the Proteobacteria phylum during June-August. NAGase showed a progressive seasonal decline in potential activity that was correlated with microbial biomass and seasonal changes in soil moisture. In contrast, phenol oxidase showed highest potential activity in mid-July near the time of peak soil respiration and ecosystem photosynthesis, which may represent a time of high input of carbon exudates into the soil from plant roots. This input of exudates may stimulate the activity of phenol oxidase, a lignolytic enzyme involved in the breakdown of soil organic matter. These analyses indicated that seasonal change in soil respiration is a complex interaction between temporal changes in soil environmental factors and biological changes in the plant and microbial community that affect soil respiratory metabolism.

Recent progress in the imaging of soil processes at the microscopic scale, and a look ahead

NASA Astrophysics Data System (ADS)

Garnier, Patricia; Baveye, Philippe C.; Pot, Valérie; Monga, Olivier; Portell, Xavier

2016-04-01

Over the last few years, tremendous progress has been achieved in the visualization of soil structures at the microscopic scale. Computed tomography, based on synchrotron X-ray beams or table-top equipment, allows the visualization of pore geometry at micrometric resolution. Chemical and microbiological information obtainable in 2D cuts through soils can now be interpolated, with the support of CT-data, to produce 3-dimensional maps. In parallel with these analytical advances, significant progress has also been achieved in the computer simulation and visualization of a range of physical, chemical, and microbiological processes taking place in soil pores. In terms of water distribution and transport in soils, for example, the use of Lattice-Boltzmann models as well as models based on geometric primitives has been shown recently to reproduce very faithfully observations made with synchrotron X-ray tomography. Coupling of these models with fungal and bacterial growth models allows the description of a range of microbiologically-mediated processes of great importance at the moment, for example in terms of carbon sequestration. In this talk, we shall review progress achieved to date in this field, indicate where questions remain unanswered, and point out areas where further advances are expected in the next few years.

Soil Respiration at Dominant Patch Types within a Managed Northern Wisconsin Landscape

Treesearch

Eug& #233; nie Euskirchen; Jiquan Chen; Eric J. Gustafson; Siyan Ma; Siyan Ma

2003-01-01

Soil respiration (SR), a substantial component of the forest carbon budget, has been studied extensively at the ecosystem, regional, continental, and global scales, but little progress has been made toward understanding SR over managed forest landscapes. Soil respiration is often influenced by soil temperature (Ts), soil moisture (Ms...

Soil respiration at dominant patch types within a managed northern Wisconsin landscape

Treesearch

Eugenie S. Euskirchen; Jiquan Chen; Eric J. Gustafson; Siyan Ma

2003-01-01

Soil respiration (SR), a substantial component of the forest carbon budget, has been studied extensively at the ecosystem, regional, continental, and global scales, but little progress has been made toward understanding SR over managed forest landscapes. Soil respiration is often influenced by soil temperature (Ts), soil moisture (Ms...

STRATEGIES IN SOIL PROTECTION - MISSIONS AND VISIONS

EPA Science Inventory

The focus of this paper is the progress to reach our present understandings of the needs and methods for "Soil protection." Soil is critical to human life, needed for production of foods safe for lifetime consumption. Soils must be protected for support of human societies. Until...

Safety Oversight of Decommissioning Activities at DOE Nuclear Sites

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

Zull, Lawrence M.; Yeniscavich, William

2008-01-15

The Defense Nuclear Facilities Safety Board (Board) is an independent federal agency established by Congress in 1988 to provide nuclear safety oversight of activities at U.S. Department of Energy (DOE) defense nuclear facilities. The activities under the Board's jurisdiction include the design, construction, startup, operation, and decommissioning of defense nuclear facilities at DOE sites. This paper reviews the Board's safety oversight of decommissioning activities at DOE sites, identifies the safety problems observed, and discusses Board initiatives to improve the safety of decommissioning activities at DOE sites. The decommissioning of former defense nuclear facilities has reduced the risk of radioactive materialmore » contamination and exposure to the public and site workers. In general, efforts to perform decommissioning work at DOE defense nuclear sites have been successful, and contractors performing decommissioning work have a good safety record. Decommissioning activities have recently been completed at sites identified for closure, including the Rocky Flats Environmental Technology Site, the Fernald Closure Project, and the Miamisburg Closure Project (the Mound site). The Rocky Flats and Fernald sites, which produced plutonium parts and uranium materials for defense needs (respectively), have been turned into wildlife refuges. The Mound site, which performed R and D activities on nuclear materials, has been converted into an industrial and technology park called the Mound Advanced Technology Center. The DOE Office of Legacy Management is responsible for the long term stewardship of these former EM sites. The Board has reviewed many decommissioning activities, and noted that there are valuable lessons learned that can benefit both DOE and the contractor. As part of its ongoing safety oversight responsibilities, the Board and its staff will continue to review the safety of DOE and contractor decommissioning activities at DOE defense nuclear sites.« less

Systemic Lupus Erythematosus is Associated with Uranium Exposure in a Community Living Near a Uranium Processing Plant: A Nested Case-Control Study

PubMed Central

Lu-Fritts, Pai-Yue; Kottyan, Leah C.; James, Judith A.; Xie, Changchung; Buckholz, Jeanette M.; Pinney, Susan M.; Harley, John B.

2014-01-01

Objective Explore the hypothesis that cases of SLE will be found more frequently in community members with high prior uranium exposure in the Fernald Community Cohort (FCC). Methods A nested case control study was performed. The FCC is a volunteer population that lived near a uranium ore processing plant in Fernald, Ohio, USA during plant operation and members were monitored for 18 years. Uranium plant workers were excluded. SLE cases were identified using American College of Rheumatology classification criteria, laboratory testing, and medical record review. Each case was matched to four age-, race-, and sex-matched controls. Sera from potential cases and controls were screened for autoantibodies. Cumulative uranium particulate exposure was calculated using a dosimetry model. Logistic regression with covariates was used to calculate odds ratios (OR) with 95% confidence intervals (CI). Results The FCC includes 4,187 individuals with background uranium exposure, 1,273 with moderate exposure, and 2,756 with higher exposure. SLE was confirmed in 23 of 31 individuals with a lupus ICD9 code, and in 2 of 43 other individuals prescribed hydroxychloroquine. The female:male ratio was 5.25:1. Of the 25 SLE cases, 12 were in the higher exposure group. SLE was associated with higher uranium exposure (OR 3.92, 95% CI 1.131-13.588, p = 0.031). Conclusion High uranium exposure is associated with SLE relative to matched controls in this sample of uranium exposed individuals. Potential explanations for this relationship include possible autoimmune or estrogen effects of uranium, somatic mutation, epigenetic effects, or effects of some other unidentified accompanying exposure. PMID:25103365

IMPROVED RISK ASSESSMENT AND REMEDIATION OF SOIL METALS BASED ON BIOAVAILABILITY MEASUREMENTS

EPA Science Inventory

Heavy metals in soils can comprise risk through plant uptake or soil ingestion. Recent research results and progress in understandings of risks and methods for soil metal remediation will be presented. Beneficial use of composts/bosolids plus limestone to remediate metal killed e...

Soil & Tillage Research: Publication history and assessment of progress

USDA-ARS?s Scientific Manuscript database

The journal, Soil and Tillage Research, is concerned with the changes in physical, chemical and biological properties and processes of the soil environment brought about by soil tillage and field traffic, their effects on both below- and above-ground environmental quality, crop establishment, root d...

Monitoring Transcriptomic Changes in Soil-Grown Roots and Shoots of Arabidopsis thaliana Subjected to a Progressive Drought Stress.

PubMed

Bashir, Khurram; Rasheed, Sultana; Matsui, Akihiro; Iida, Kei; Tanaka, Maho; Seki, Motoaki

2018-01-01

Numerous experiments have been performed in Arabidopsis to monitor changes in gene expression that occur in response to a variety of abiotic and biotic stresses, different growth conditions, and at various developmental stages. In addition, gene expression patterns have also been characterized among wild-type and mutant genotypes. Despite these numerous reports, transcriptional changes occurring in roots of soil-grown plants subjected to a progressive drought stress have remained undocumented. To fill this gap, we established a system that allows one to establish water-deficit conditions and to collect root and shoot samples with minimal damage to the root system. Arabidopsis plants are grown in a ceramic-based granular soil and subjected to progressive drought stress by withholding water. Root and shoot samples were collected separately, RNA was purified, and a microarray analysis of drought-stressed roots and shoots was performed at 0, 1, 3, 5, 7, and 9 days after the onset of drought stress treatment. Here, we describe the detailed protocol used to analyze the transcriptomic changes occurring in roots and shoots of soil-grown Arabidopsis subjected to a progressive drought stress.

Phytoremediation of Soil Trace Elements

USDA-ARS?s Scientific Manuscript database

This chapter summarizes research progress in development of phytoremediation technologies. Some soils have become contaminated by trace elements enough to kill plants, inhibit soil organisms, and/or threaten wildlife, humans or the environment. Traditional remediation by dig and haul methods are v...

Similarities in chemical composition of soil organic matter across a millennia-old paddy soil chronosequence as revealed by advanced solid-state NMR spectroscopy

USDA-ARS?s Scientific Manuscript database

Soil organic matter (SOM) accumulation in paddy soils has aroused considerable attention due to its vital significance in global food, energy, climate, and environmental issues. Considerable progress has been made toward the understanding of changes in the quantity of SOM in paddy soils over a mille...

Review of progress in soil inorganic carbon research

NASA Astrophysics Data System (ADS)

Bai, S. G.; Jiao, Y.; Yang, W. Z.; Gu, P.; Yang, J.; Liu, L. J.

2017-12-01

Soil inorganic carbon is one of the main carbon banks in the near-surface environment, and is the main form of soil carbon library in arid and semi-arid regions, which plays an important role in the global carbon cycle. This paper mainly focuses on the inorganic dynamic process of soil inorganic carbon in soil environment in arid and semi-arid regions, and summarized the composition and source of soil inorganic carbon, influence factors and soil carbon sequestration.

WASTE CONDITIONING FOR TANK HEEL TRANSFER

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

M.A. Ebadian, Ph.D.

1999-01-01

This report summarizes the research carried out at Florida International University's Hemispheric Center for Environmental Technology (FIU-HCET) for the fiscal year 1998 (FY98) under the Tank Focus Area (TFA) project ''Waste Conditioning for Tank Slurry Transfer.'' The objective of this project is to determine the effect of chemical and physical properties on the waste conditioning process and transfer. The focus of this research consisted in building a waste conditioning experimental facility to test different slurry simulants under different conditions, and analyzing their chemical and physical properties. This investigation would provide experimental data and analysis results that can make the tankmore » waste conditioning process more efficient, improve the transfer system, and influence future modifications to the waste conditioning and transfer system. A waste conditioning experimental facility was built in order to test slurry simulants. The facility consists of a slurry vessel with several accessories for parameter control and sampling. The vessel also has a lid system with a shaft-mounted propeller connected to an air motor. In addition, a circulation system is connected to the slurry vessel for simulant cooling and heating. Experimental data collection and analysis of the chemical and physical properties of the tank slurry simulants has been emphasized. For this, one waste slurry simulant (Fernald) was developed, and another two simulants (SRS and Hanford) obtained from DOE sites were used. These simulants, composed of water, soluble metal salts, and insoluble solid particles, were used to represent the actual radioactive waste slurries from different DOE sites. The simulants' chemical and physical properties analyzed include density, viscosity, pH, settling rate, and volubility. These analyses were done to samples obtained from different experiments performed at room temperature but different mixing time and strength. The experimental results indicate that the viscosity of the slurries follow the Bingham plastic model, especially when the solids concentration is increased. At low concentrations slurries may behave as Newtonian fluids. The three simulants follow a similar settling rate behavior. This behavior can be explained as a combination of one or more decreasing exponential curves. This means that the particle settling rate of the simulants decreases exponentially as time increases. The pH range for the three simulants was from 8 to 13 at all concentrations. The SRS simulant showed the highest pH, around 12; the other two simulants, Hanford and Fernald, had about the same pH range, from 3 to 9. When comparing volubility of the three simulants at the same concentration, SRS simulant showed higher volubility, followed by the Hanford simulant and the Fernald simulant, in that order. Further work is scheduled for next year (FY99) in this project, when other parameters like simulants particle size distribution, particle shape, and crystallization behavior will be studied. The same tests performed this period also will be performed at different temperatures for data comparison.« less

Severe soil frost reduced losses of carbon and nitrogen from the forest floor during simulated snowmelt: A laboratory experiment

Treesearch

Andrew B. Reinmann; Pamela H. Templer; John L. Campbell

2012-01-01

Considerable progress has been made in understanding the impacts of soil frost on carbon (C) and nitrogen (N) cycling, but the effects of soil frost on C and N fluxes during snowmelt remain poorly understood. We conducted a laboratory experiment to determine the effects of soil frost on C and N fluxes from forest floor soils during snowmelt. Soil cores were collected...

Creep behavior of soil nail walls in high plasticity index (PI) soils : project summary.

DOT National Transportation Integrated Search

2015-08-31

Soil nailing is a convenient and economic : stabilization method for the reinforcement of existing : excavations by installing threaded steel bars into cuts : or slopes as wall construction progresses from top : down (Figure 1). An aspect of particul...

STRATEGIES IN SOIL PROTECTION - MISSIONS AND VISIONS

EPA Science Inventory

The focus of this paper is the progress to reach our present understandings of the needs and methods for "Soil protection." Sloil is critical to human life, needed for production of foods safe for lifetime consumption. Soils must be protected for support of human societies. Unti...

Aliphatic and aromatic plant biopolymer dynamics in soil particles isolated from sequential density fractionation

NASA Astrophysics Data System (ADS)

Caldwell, B.; Filley, T.; Sollins, P.; Lajtha, K.; Swanston, C.; Kleber, M.; Kramer, M.

2007-12-01

A recent multi-layer-based soil organic matter-mineral interaction mechanistic model to describe the nature of soil organic matter-mineral surface mechanism for soil organic matter stabilization predicts that proteinaceous and aliphatic materials establish the core of strong binding-interactions upon which other organic matter is layered. A key methodology providing data underpinning this hypothesis is sequential density fractionation where soil is partitioned into particles of increasing density with the assumption that a partial control on organic matter distribution through density series is the thickness of its layering. Four soils of varying mineralogy and texture were investigated for their biopolymer, isotopic, and mineralogical properties. Light fractions (<1.8 g/cm3), although dominanted by organic detritus, did not always contain the highest concentration of lignin and substituted fatty acids from cutin and suberin while heavier fractions, 1.8-2.6 g/cm3, exhibited a progressive decrease in concentration in plant derived biopolymers with density. Extractable lignin phenols exhibited a progressive oxidation state with density. The concentration of biopolymers roughly mirrored the C:N ratio of soil particles which dropped consistently with increasing particle density. Although, in all soils, both lignin phenols and SFA concentration generally decreased with increasing density the ratio SFA/lignin varied with density and depending upon the soil. All soils, except the oxisol, exhibited an increase in SFA with respect to lignin suggesting a selective stabilization of those material with respect to lignin. In the oxisol, which showed little variation in its hematite dominated mineralogy across density, SFA/lignin remained constant, potentially indicating a greater capacity to stabilize lignin in that system. Interestingly, the lignin oxidation state increased with density in the oxisol. Given the variation in soil character, the consistency in these trends it suggests a general phenomenon of progressive decay in plant derived material with thinness of mineral coating but an overall relative increase in aliphatic character-all consistent with the multi-layer model.

Role of the interface between distributed fibre optic strain sensor and soil in ground deformation measurement

NASA Astrophysics Data System (ADS)

Zhang, Cheng-Cheng; Zhu, Hong-Hu; Shi, Bin

2016-11-01

Recently the distributed fibre optic strain sensing (DFOSS) technique has been applied to monitor deformations of various earth structures. However, the reliability of soil deformation measurements remains unclear. Here we present an integrated DFOSS- and photogrammetry-based test study on the deformation behaviour of a soil foundation model to highlight the role of strain sensing fibre-soil interface in DFOSS-based geotechnical monitoring. Then we investigate how the fibre-soil interfacial behaviour is influenced by environmental changes, and how the strain distribution along the fibre evolves during progressive interface failure. We observe that the fibre-soil interfacial bond is tightened and the measurement range of the fibre is extended under high densities or low water contents of soil. The plastic zone gradually occupies the whole fibre length when the soil deformation accumulates. Consequently, we derive a theoretical model to simulate the fibre-soil interfacial behaviour throughout the progressive failure process, which accords well with the experimental results. On this basis, we further propose that the reliability of measured strain can be determined by estimating the stress state of the fibre-soil interface. These findings may have important implications for interpreting and evaluating fibre optic strain measurements, and implementing reliable DFOSS-based geotechnical instrumentation.

State of the Art in Large-Scale Soil Moisture Monitoring

NASA Technical Reports Server (NTRS)

Ochsner, Tyson E.; Cosh, Michael Harold; Cuenca, Richard H.; Dorigo, Wouter; Draper, Clara S.; Hagimoto, Yutaka; Kerr, Yan H.; Larson, Kristine M.; Njoku, Eni Gerald; Small, Eric E.;

Analytical aspects of diterpene alkaloid poisoning with monkshood.

PubMed

Colombo, Maria Laura; Bugatti, Carlo; Davanzo, Franca; Persico, Andrea; Ballabio, Cinzia; Restani, Patrizia

2009-11-01

A sensitive and specific method for aconitine extraction from biological samples was developed. Aconitine, the main toxic alkaloid from plants belonging to Aconitum species (family Ranunculaceae), was determined in plant material by an external standard method, and by a standard addition calibration method in biological fluids. Described here is one fatal case and five intoxications of accidental aconitine poisoning following the ingestion of aconite mistaken for an edible grass, Aruncus dioicus (Walt.) Fernald, "mountain asparagus", and Cicerbita alpina (L.) Wallroth. The aconitine content in urine was in the range 2.94 microg/mL (dead patient)-0.20 microg/mL (surviving patients), which was almost two to four times higher than that in plasma.

Effects of a selenium-laden soil amendment on grapevine metabolism and progression of Pierce’s disease

USDA-ARS?s Scientific Manuscript database

Selenium containing soil amendments might be beneficial to growers as selenium may increase resistance to certain plant pathogens and pests. Therefore, grapevines growing in soil with different amounts of selenium-laden amendment were evaluated for metabolism and susceptibility to Pierce’s disease (...

Degradation of the Herbicide Metolachlor in Drummer Soil Under Different Redox Conditions

USDA-ARS?s Scientific Manuscript database

Understanding the role of microorganisms and effect of soil environmental conditions on herbicide fate is critical for stewardship of herbicide use in cropping systems. As compared to the modernized perceptions of soil redox status, diminutive progress has been made in characterizing the impact of a...

Effect of climate on the storage and turnover of carbon in soils

NASA Technical Reports Server (NTRS)

Trumbore, Susan; Chadwick, Oliver; Amundson, Ronald; Brasher, Benny

1994-01-01

Climate is, in many instances, the dominant variable controlling the storage of carbon in soils. It has proven difficult, however, to determine how soil properties influenced by climate, such as soil temperature and soil moisture, actually operate to determine the rates of accumulation and decomposition of soil organic matter. Our approach has been to apply a relatively new tool, the comparison of C-14 in soil organic matter from pre- and post-bomb soils, to quantify carbon turnover rates along climosequences. This report details the progress made toward this end by work under this contract.

The contentious nature of soil organic matter.

PubMed

Lehmann, Johannes; Kleber, Markus

2015-12-03

The exchange of nutrients, energy and carbon between soil organic matter, the soil environment, aquatic systems and the atmosphere is important for agricultural productivity, water quality and climate. Long-standing theory suggests that soil organic matter is composed of inherently stable and chemically unique compounds. Here we argue that the available evidence does not support the formation of large-molecular-size and persistent 'humic substances' in soils. Instead, soil organic matter is a continuum of progressively decomposing organic compounds. We discuss implications of this view of the nature of soil organic matter for aquatic health, soil carbon-climate interactions and land management.

Role of macropore flow in the transport of Escherichia coli cells in undisturbed cores of a brown leached soil.

PubMed

Martins, Jean M F; Majdalani, Samer; Vitorge, Elsa; Desaunay, Aurélien; Navel, Aline; Guiné, Véronique; Daïan, Jean François; Vince, Erwann; Denis, Hervé; Gaudet, Jean Paul

2013-02-01

The objective of this work was to evaluate the transport of Escherichia coli cells in undisturbed cores of a brown leached soil collected at La Côte St André (France). Two undisturbed soil cores subjected to repeated injections of bacterial cells and/or bromide tracer were used to investigate the effect of soil hydrodynamics and ionic strength on cell mobility. Under the tested experimental conditions, E. coli cells were shown to be transported at the water velocity (retardation factor close to 1) and their retention appeared almost insensitive to water flow and ionic strength variations, both factors being known to control bacterial transport in model saturated porous media. In contrast, E. coli breakthrough curves evolved significantly along with the repetition of the cell injections in each soil core, with a progressive acceleration of their transport. The evolution of E. coli cells BTCs was shown to be due to the evolution of the structure of soil hydraulic pathways caused by the repeated water infiltrations and drainage as may occur in the field. This evolution was demonstrated through mercury intrusion porosimetry (MIP) performed on soil aggregates before and after the repeated infiltrations of bacteria. MIP revealed a progressive and important reduction of the soil aggregate porosity, n, that decreased from approximately 0.5 to 0.3, along with a decrease of the soil percolating step from 27 to 2 μm. From this result a clear compaction of soil aggregates was evidenced that concerned preferentially the pores larger than 2 μm equivalent diameter, i.e. those allowing bacterial cell passage. Since no significant reduction of the global soil volume was observed at the core scale, this aggregate compaction was accompanied by macropore formation that became progressively the preferential hydraulic pathway in the soil cores, leading to transiently bi-modal bacterial BTCs. The evolution of the soil pore structure induced a modification of the main hydrodynamic processes, evolving from a matrix-dominant transfer of water and bacteria to a macropore-dominant transfer. This work points out the importance of using undisturbed natural soils to evaluate the mobility of bacteria in the field, since the evolving hydrodynamic properties of soils appeared to dominate most physicochemical factors.

The structure of fungal biomass and diversity of cultivated micromycetes in Antarctic soils (progress and Russkaya Stations)

NASA Astrophysics Data System (ADS)

Marfenina, O. E.; Nikitin, D. A.; Ivanova, A. E.

2016-08-01

The distribution of the fungal biomass and diversity of cultivated microscopic fungi in the profiles of some soils from East (Progress Station, valleys of the Larsemann Hills oasis) and West (Russkaya Station, the Marie Byrd Land) Antarctica regions were studied. The structure of the biomass (spore/mycelium and live cells/dead cells) was analyzed by fluorescence microscopy with staining using a set of coloring agents: calcofluor white, ethidium bromide, and fluorescein diacetate. The species composition of the cultivated microscopic fungi was determined on Czapek's medium. The fungal biomass in the soils studied is not high (on the average, 0.3 mg/g of soil); the greatest biomass (0.6 mg/g) was found in the soil samples with plant residues. The fungal biomass is mainly (to 70%) represented by small (to 2.5 μm) spores. About half of the fungal biomass is composed of living cells. There are differences in the distribution of the fungal biomass within the profiles of different primitive soils. In the soil samples taken under mosses and lichens, the maximal biomass was registered in the top soil horizons. In the soils with the peat horizon under stone pavements, the greatest fungal biomass was registered in the subsurface horizons. Thirty-eight species of cultivated microscopic fungi were isolated from the soils studied. Species of the genus Penicillium and Phoma herbarum predominated.

Does sediment geochemistry (based on selective extractions of Al and Fe and REE) provide a record of soil evolution?

NASA Astrophysics Data System (ADS)

Mourier, B.; Poulenard, J.; Blarquez, O.; Williamson, D.; Arnaud, F.; Carcaillet, C.

2009-04-01

Soil is a natural body occurring at the interface between the lithosphere, atmosphere and biosphere. As a result, the physical and chemical properties of soils evolve with time, and the reconstruction of their history represents a key to understand past environmental changes. Palaeolimnological techniques such as sediment geochemistry can be used to investigate changes in catchment history by providing information about soil development. However, due to the lack of conservative pedosignatures (soil proxies), only few paleoecological studies have attempted to reconstruct the history of soil genesis using geochemical analyses of lacustrine sediments. Here we present a multidisciplinary study which aims to use pedosignatures, defined by a previous soil study, in order to characterize the history of soil genesis, podzolization and chemical weathering processes in two sediment sequences. Moreover, we aim to compare the timing of soil evolution with other paleoenvironmental markers (macroremains, charcoals…) in order to infer the role of climate, vegetation and possible human activities as forcing factors. In a first step, the geochemical investigation of eight subalpine soil profiles from the inner Alps allowed to define relevant proxies of two major soil processes. Parent material normalized REE patterns provide a precise tracer of chemical weathering whereas the proportions of secondary Al- and Fe-bearing phases provide a tracer of the podzolisation process. Then, the same tracers were assessed on two lacustrine and peat sediment sequences (Loup and Thyl lakes) from the subalpine domain. The proxy records, spanning ca. 4.500 yr at the Thyl lake and ca. 13.500 yr at the Loup lake, indicate that both progressive and regressive pedogenesis occurred after the deglaciation. The Thyl record is highly contrasted: the progressive setting of the mixed cembra pine ecosystem is associated to the podzolisation process (secondary Al- and Fe-bearing phases are maximal) and the increase of chemical weathering (enrichments of specific REE's fractions) that lasted totally ca. 1500 to 2000 years. Then, these progressive pathways are followed by abrupt and rapid secondary processes that could result from drastic transformation of the plant cover. The flat normalized REE patterns associated with low secondary Al and Fe values suggest a decrease of chemical weathering and podzolization. Moreover, the higher variability in cembra pine and the enrichment in sedge and other herbs remains in the lake suggest the setting of semi-open vegetation associated to the evidence of regressive soil processes. On the other hand, Loup environment and soil history are characterized by a progressive and stable evolution leading to present day old growing forests and Podzol soil type. Whereas the major sedimentological changes are sensitive to climate, the soil proxy records may be more triggered by the natural dynamic of the plant cover. At this site, human disturbances seem to have lower importance than at the Thyl site.

Research progress of on-the-go soil parameter sensors based on NIRS

NASA Astrophysics Data System (ADS)

An, Xiaofei; Meng, Zhijun; Wu, Guangwei; Guo, Jianhua

2014-11-01

Both the ever-increasing prices of fertilizer and growing ecological concern over chemical run-off into sources of drinking water have brought the issues of precision agriculture and site-specific management to the forefront of present technological development within agriculture and ecology. Soil is an important and basic element in agriculture production. Acquisition of soil information plays an important role in precision agriculture. The soil parameters include soil total nitrogen, phosporus, potassium, soil organic matter, soil moisture, electrical conductivity and pH value and so on. Field rapid acquisition to all the kinds of soil physical and chemical parameters is one of the most important research directions. And soil parameter real-time monitoring is also the trend of future development in precision agriculture. While developments in precision agriculture and site-specific management procedures have made significant in-roads on these issues and many researchers have developed effective means to determine soil properties, routinely obtaining robust on-the-go measurements of soil properties which are reliable enough to drive effective fertilizer application remains a challenge. NIRS technology provides a new method to obtain soil parameter with low cost and rapid advantage. In this paper, research progresses of soil on-the-go spectral sensors at domestic and abroad was combed and analyzed. There is a need for the sensing system to perform at least six key indexes for any on-the-go soil spectral sensor to be successful. The six indexes are detection limit, specificity, robustness, accuracy, cost and easy-to-use. Both the research status and problems were discussed. Finally, combining the national conditions of china, development tendency of on-the-go soil spectral sensors was proposed. In the future, on-the-go soil spectral sensors with reliable enough, sensitive enough and continuous detection would become popular in precision agriculture.

Adoption of Soil Health Improvement Strategies by Australian Farmers: I. Attitudes, Management and Extension Implications

ERIC Educational Resources Information Center

Bennett, J. McL.; Cattle, S. R.

2013-01-01

Purpose: There is inconsistency in the design, understanding, implementation and monitoring of soil health programmes. Despite mounting scientific evidence for the credibility of certain soil health indicators, an increase in the reporting of programme benefits, and progress in communicating these benefits, many farmers remain hesitant to…

Adoption of Soil Health Improvement Strategies by Australian Farmers: II. Impediments and Incentives

ERIC Educational Resources Information Center

Bennett, J. McL.; Cattle, S. R.

2014-01-01

Purpose: Many farmers remain hesitant to implement structured management plans and strategies tailored to address soil health, irrespective of mounting scientific evidence for the credibility of certain soil health indicators, an increase in the reporting of program benefits and progress in communicating these benefits. Hence, the purpose of this…

Soil moisture retrieval in forest biomes: field experiment focus for SMAP 2018-2020 and beyond

USDA-ARS?s Scientific Manuscript database

The Soil Moisture Active Passive (SMAP) project has made excellent progress in addressing the requirements and science goals of the primary mission. The primary mission baseline requirement is estimates of global surface soil moisture with an error of no greater than 4% volumetric (one sigma) exclud...

Soil properties and aspen development five years after compaction and forest floor removal

Treesearch

Douglas M. Stone; John D. Elioff

1998-01-01

Forest management activities that decrease soil porosity and remove organic matter have been associated with declines in site productivity. In the northern Lake States region, research is in progress in the aspen (Populus tremuloides Michx. and P. grandidentata Michx.) forest type to determine effects of soil compaction and organic...

Semiannual progress report, April - September 1991

NASA Technical Reports Server (NTRS)

1991-01-01

Research conducted during the past year in the climate and modeling programs has concentrated on the development of appropriate atmospheric and upper ocean models, and preliminary applications of these models. Principal models are a one-dimensional radiative-convective model, a three dimensional global climate model, and an upper ocean model. Principal applications have been the study of the impact of CO2, aerosols, and the solar constant on climate. Progress was made in the 3-D model development towards physically realistic treatment of these processes. In particular, a map of soil classifications on 1 degree by 1 degree resolution has now been digitized, and soil properties have been assigned to each soil type. Using this information about soil properties, a method has been developed to simulate the hydraulic behavior of the soils of the world. This improved treatment of soil hydrology, together with the seasonally varying vegetation cover, will provide a more realistic study of the role of the terrestrial biota in climate change. A new version of the climate model was created which follows the isotopes of water and sources of water throughout the planet.

An application of the NCRP screening techniques to atmospheric radon releases from the former Feed Materials Production Center near Fernald, Ohio

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

Miller, C.W.

1999-11-01

The National Council on Radiation Protection and Measurements has published a series of screening models for releases of radionuclides to the environment. These models have been used to prioritize radionuclides being considered in environmental dose reconstructions. The NCRP atmospheric models are also accepted by the U.S. Nuclear Regulatory Commission for demonstrating compliance with the constraint on releases of airborne radioactive materials to the environment from licenses other than power reactors. This study tested the NCRP atmospheric techniques by comparing annual average predicted air concentrations of radon with measured radon concentrations at 14 locations 43 m to 598 m downwind ofmore » the former US Department of Energy Feed Materials Production Center (FMPC) near Fernald, Ohio, for the period 2 July 1985 to 2 July 1986. Predictions were made using five different sets of meteorological data as input: (1) NCRP default values; (2) composite FMPC site data; (3) data from the Greater Cincinnati Airport; (4) data from the Dayton, Ohio, airport; and (5) data collected at Miami University, located near Oxford, Ohio. Following are the respective medians and ranges of the ratio of the predicted to observed annual radon air concentrations for each of these sources of meterological data: (1) 5.2, 0.9--54; (2) 1.4, 0.1--8.2; (3) 0.7, 0.1--7.2; (4) 0.7, 0.1--8.4; and (5) 0.6, 0.1--10. The stated goal of the NCRP models is to predict doses that do not underpredict actual doses by greater than a factor of 10. In this comparison, all of the meteorological data produced air concentration predictions that meet this criteria. However, to ensure that final doses meet this criterion, one would need to carefully evaluate all assumptions used to calculate dose from each of these air concentrations.« less

An application of the NCRP screening techniques to atmospheric radon releases from the former feed materials production center near Fernald, Ohio. National Council on Radiation Protection and Measurements.

PubMed

Miller, C W

1999-11-01

The National Council on Radiation Protection and Measurements has published a series of screening models for releases of radionuclides to the environment. These models have been used to prioritize radionuclides being considered in environmental dose reconstructions. The NCRP atmospheric models are also accepted by the U.S. Nuclear Regulatory Commission for demonstrating compliance with the constraint on releases of airborne radioactive materials to the environment from licensees other than power reactors. This study tested the NCRP atmospheric techniques by comparing annual average predicted air concentrations of radon with measured radon concentrations at 14 locations 43 m to 598 m downwind of the former U.S. Department of Energy Feed Materials Production Center (FMPC) near Fernald, Ohio, for the period 2 July 1985 to 2 July 1986. Predictions were made using five different sets of meteorological data as input: (1) NCRP default values; (2) composite FMPC site data; (3) data from the Greater Cincinnati Airport; (4) data from the Dayton, Ohio, airport; and (5) data collected at Miami University, located near Oxford, Ohio. Following are the respective medians and ranges of the ratio of the predicted to observed annual radon air concentrations for each of these sources of meteorological data: (1) 5.2, 0.9-54; (2) 1.4, 0.1-8.2; (3) 0.7, 0.1-7.2; (4) 0.7, 0.1-8.4; and (5) 0.6, 0.1-10. The stated goal of the NCRP models is to predict doses that do not underpredict actual doses by greater than a factor of 10. In this comparison, all of the meteorological data produced air concentration predictions that meet this criteria. However, to ensure that final doses meet this criterion, one would need to carefully evaluate all assumptions used to calculate dose from each of these air concentrations.

Endophytic fungi and soil microbial community characteristics over different years of phytoremediation in a copper tailings dam of Shanxi, China.

PubMed

Tong, Jia; Miaowen, Cao; Juhui, Jing; Jinxian, Liu; Baofeng, Chai

2017-01-01

We conducted a survey of native grass species infected by endophytic fungi in a copper tailings dam over progressive years of phytoremediation. We investigated how endophytic fungi, soil microbial community structure and soil physiochemical properties and enzymatic activity varied in responses to heavy metal pollution over different stages of phytoremediation. endophyte infection frequency increased with years of phytoremediation. Rates of endophyte infection varied among different natural grass species in each sub-dam. Soil carbon content and soil enzymatic activity gradually increased through the years of phytoremediation. endophyte infection rates of Bothriochloa ischaemum and Festuca rubra were positively related to levels of cadmium (Cd) pollution levels, and fungal endophytes associated with Imperata cylindrical and Elymus dahuricus developed tolerance to lead (Pb). The structure and relative abundance of bacterial communities varied little over years of phytoremediation, but there was a pronounced variation in soil fungi types. Leotiomycetes were the dominant class of resident fungi during the initial phytoremediation period, but Pezizomycetes gradually became dominant as the phytoremediation period progressed. Fungal endophytes in native grasses as well as soil fungi and soil bacteria play different ecological roles during phytoremediation processes. Copyright © 2016 Elsevier B.V. All rights reserved.

Mineral cycling in soil and litter arthropod food chains. Three-year progress report, February 1, 1984-January 31, 1987

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

Crossley, D.A. Jr.

1986-08-29

This report summarizes progress in a three-year research project on the influence of soil arthropods (mites, collembolans, insects, millipedes and others) upon decomposition rates and nutrient dynamics in decaying vegetable matter. Research has concentrated on two aspects of elemental dynamics in decomposing organic matter: Effects of arthropods on rates of decomposition and nutrient loss (mineralization of carbon and other elements), and arthropod stimulation of microbial immobilization of nutrient elements during decomposition.

Compilation of 1986 annual reports of the Navy ELF (extremely low frequency) communications system ecological-monitoring program. Volume 2. Tabs D-G. Annual progress report, January-December 1986

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

Not Available

1987-07-01

The U.S. Navy is conducting a long-term program to monitor for possible effects from the operation of its Extremely Low Frequency (ELF) Communications System to resident biota and their ecological relationships. This report documents progress of the following studies: Soil Amoeba; Soil and Litter Arthropoda and Earthworm Studies; Biological Studies on Pollinating insects: Megachilid Bees; and Small Vertebrates: Small Mammals and Nesting Birds.

Selective progressive response of soil microbial community to wild oat roots.

PubMed

DeAngelis, Kristen M; Brodie, Eoin L; DeSantis, Todd Z; Andersen, Gary L; Lindow, Steven E; Firestone, Mary K

2009-02-01

Roots moving through soil induce physical and chemical changes that differentiate rhizosphere from bulk soil, and the effects of these changes on soil microorganisms have long been a topic of interest. The use of a high-density 16S rRNA microarray (PhyloChip) for bacterial and archaeal community analysis has allowed definition of the populations that respond to the root within the complex grassland soil community; this research accompanies compositional changes reported earlier, including increases in chitinase- and protease-specific activity, cell numbers and quorum sensing signal. PhyloChip results showed a significant change compared with bulk soil in relative abundance for 7% of the total rhizosphere microbial community (147 of 1917 taxa); the 7% response value was confirmed by16S rRNA terminal restriction fragment length polymorphism analysis. This PhyloChip-defined dynamic subset was comprised of taxa in 17 of the 44 phyla detected in all soil samples. Expected rhizosphere-competent phyla, such as Proteobacteria and Firmicutes, were well represented, as were less-well-documented rhizosphere colonizers including Actinobacteria, Verrucomicrobia and Nitrospira. Richness of Bacteroidetes and Actinobacteria decreased in soil near the root tip compared with bulk soil, but then increased in older root zones. Quantitative PCR revealed rhizosphere abundance of beta-Proteobacteria and Actinobacteria at about 10(8) copies of 16S rRNA genes per g soil, with Nitrospira having about 10(5) copies per g soil. This report demonstrates that changes in a relatively small subset of the soil microbial community are sufficient to produce substantial changes in functions observed earlier in progressively more mature rhizosphere zones.

Progress report: effects of subsoiling study, Milford Ranger District, Plumas National Forest

Treesearch

John T. Kliejunas; William J. Otrosina

1997-01-01

Subsoiling is becoming a standard practice to alleviate detrimental soil compaction following biomass harvesting in eastside pine and mixed conifer forests in California. Compaction of soil following the harvesting can be detrimental to growth of residuals, to establishment of natural regeneration, and may change long-term soil productivity. The short and long-term...

Phytoremediation of heavy metal polluted soils and water: Progresses and perspectives*

PubMed Central

Lone, Mohammad Iqbal; He, Zhen-li; Stoffella, Peter J.; Yang, Xiao-e

2008-01-01

Environmental pollution affects the quality of pedosphere, hydrosphere, atmosphere, lithosphere and biosphere. Great efforts have been made in the last two decades to reduce pollution sources and remedy the polluted soil and water resources. Phytoremediation, being more cost-effective and fewer side effects than physical and chemical approaches, has gained increasing popularity in both academic and practical circles. More than 400 plant species have been identified to have potential for soil and water remediation. Among them, Thlaspi, Brassica, Sedum alfredii H., and Arabidopsis species have been mostly studied. It is also expected that recent advances in biotechnology will play a promising role in the development of new hyperaccumulators by transferring metal hyperaccumulating genes from low biomass wild species to the higher biomass producing cultivated species in the times to come. This paper attempted to provide a brief review on recent progresses in research and practical applications of phytoremediation for soil and water resources. PMID:18357623

Characterization of microbial 'hot spots' in soils": Where are we, and where are we going?

NASA Astrophysics Data System (ADS)

Baveye, Philippe C.

2015-04-01

Fifty years ago, microbiologists realized that significant progress in our understanding of microbial processes in soils required being able to measure various physical, chemical, and microbial parameters at the scale of microorganisms, i.e., at micrometric or even submicrometric scales, and to identify areas of particularly high microbial activity. Back then, this was only a dream, severely hampered by the crudeness of our measuring instruments. In the intervening years, however, amazing technological progress has transformed that old dream into reality. We are now able to quantify the physical and (bio)chemical environment of soil microorganisms at spatial scales that are commensurate with bacterial cells. In this invited presentation, I will provide an overview of the significant progress achieved in this field over the last few years, and mention a number of further technological advances that are likely to profoundly influence the nature of the research over the next decade. Technology must however remain a means to an end, and therefore it is important to firmly keep in mind that the goal of the research on understanding better how soil processes work at the microscale is to be ultimately in a position to predict the behavior of soils at scales that matter to society at large, for example in terms of food security or global climate change. In that context, part of the research has to focus on how we can upscale information about soil microbial hotspots to macroscopic scales and beyond. I will discuss where we stand on this crucial question, which remains largely open at the moment.

The response of soil CO2 fluxes to progressively excluding vertebrate and invertebrate herbivores depends on ecosystem type

Treesearch

Anita C. Risch; Alan G. Haynes; Matt D. Busse; Flurin Filli; Martin Schütz

2013-01-01

Grasslands support large populations of herbivores and store up to 30% of the world’s soil carbon (C). Thus, herbivores likely play an important role in the global C cycle. However, most studies on how herbivory impacts the largest source of C released from grassland soils—soil carbon dioxide (CO2) emissions—only considered the role of large...

Speciation of lipids and humus-like colloidal compounds in a forest soil reclaimed with municipal solid waste compost.

PubMed

Zancada, M Cristina; Almendros, Gonzalo; Sanz, Jesús; Román, Román

2004-02-01

The progressive transformations of lipid and humus-like fractions in soil after massive input (400 Mg ha(-1)) of urban waste have been studied during an 87-week experiment in field plots of a degraded Calcic Regosol in Central Spain. Structural changes in the macromolecular fractions were small when compared with the qualitative and quantitative changes in lipid composition. The intense depletion of the lipid fraction with time and the decrease of the humic acid to fulvic acid ratio were the most significant quantitative indices of the compost transformation in soil. Changes in soil lipid fractions were especially noted in relation to their speciation status and distribution patterns (carbon preference index and relative chain length). Three subfractions were considered: (I) direct extraction with petroleum ether, (II) liquid-liquid extraction after soil treatment with 2 M H3PO4 and (III) after soil treatment with 0.1 M NaOH. Although lipid concentration tends to decrease with time, lipids in the fraction tightly bonded to soil (III) remained qualitatively and quantitatively constant in the course of the field experiment. Gas chromatographic-mass spectrometric analyses showed that the more stable the association of lipid to the soil matrix, the fewer the changes observed in the distribution pattern of the fatty acids during the progressive transformation stages.

High temperature causes negative whole-plant carbon balance under mild drought.

PubMed

Zhao, Junbin; Hartmann, Henrik; Trumbore, Susan; Ziegler, Waldemar; Zhang, Yiping

2013-10-01

Theoretically, progressive drought can force trees into negative carbon (C) balance by reducing stomatal conductance to prevent water loss, which also decreases C assimilation. At higher temperatures, negative C balance should be initiated at higher soil moisture because of increased respiratory demand and earlier stomatal closure. Few data are available on how these theoretical relationships integrate over the whole plant. We exposed Thuja occidentalis to progressive drought under three temperature conditions (15, 25, and 35°C), and measured C and water fluxes using a whole-tree chamber design. High transpiration rates at higher temperatures led to a rapid decline in soil moisture. During the progressive drought, soil moisture-driven changes in photosynthesis had a greater impact on the whole-plant C balance than respiration. The soil moisture content at which whole-plant C balance became negative increased with temperature, mainly as a result of higher respiration rates and an earlier onset of stomatal closure under a warmer condition. Our results suggest that the effect of drought on whole-plant C balance is highly temperature-dependent. High temperature causes a negative C balance even under mild drought and may increase the risk of C starvation. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

DYNAMICS OF MINERAL STRUCTURES AND THE FATE OF METALS IN SOILS AND SEDIMENTS

EPA Science Inventory

Significant progress has been made in elucidating sorption reactions that control the partitioning of metals from solution to mineral surfaces in contaminated soil/sediment systems. Surface complexation models have been developed to quantify the forward reaction with reasonable ...

Research progress on expansive soil cracks under changing environment.

PubMed

Shi, Bei-xiao; Zheng, Cheng-feng; Wu, Jin-kun

2014-01-01

Engineering problems shunned previously rise to the surface gradually with the activities of reforming the natural world in depth, the problem of expansive soil crack under the changing environment becoming a control factor of expansive soil slope stability. The problem of expansive soil crack has gradually become a research hotspot, elaborates the occurrence and development of cracks from the basic properties of expansive soil, and points out the role of controlling the crack of expansive soil strength. We summarize the existing research methods and results of expansive soil crack characteristics. Improving crack measurement and calculation method and researching the crack depth measurement, statistical analysis method, crack depth and surface feature relationship will be the future direction.

Fundamental Properties of Soils for Complex Dynamic Loadings: Dynamic Constitutive Modeling of Sandy Soils.

DTIC Science & Technology

1983-04-01

1.0 INTRODUCTION AND SCOPE 1 2.0 PROGRESS SUMMARY 3 2.1 Soil Element Model Development 3 2.2 U.S. Any Engineer Waterways Experiment Station (WES...LABORATORY BEHAVIOR OF SAND 8 3.1 Introduction 8 3.2 Material Description 8 3.3 Laboratory Tests Performed 9 3.4 Laboratory Test Results 14 4.0 MODELING THE... INTRODUCTION AND SCOPE The subject of this annual report is constitutive modeling of cohesionless soil, for both laboratory standard static test conditions

RAWP Progress Report August 19, 2011 - Combined

EPA Pesticide Factsheets

Combines cover letter and Progress Report #2 as required in Residential Soil Remedial Action Work Plan (RAWP)-Phase 1, with the Analytical Laboratory Report of Walter Coke Inc site in Birmingham AL, August 16, 2011, prepared by TestAmerica Laboratories.

Geochemical evidence for African dust and volcanic ash inputs to terra rossa soils on carbonate reef terraces, northern Jamaica, West Indies

USGS Publications Warehouse

Muhs, D.R.; Budahn, J.R.

2009-01-01

The origin of red or reddish-brown, clay-rich, "terra rossa" soils on limestone has been debated for decades. A traditional qualitative explanation for their formation has been the accumulation of insoluble residues as the limestone is progressively dissolved over time. However, this mode of formation often requires unrealistic or impossible amounts of carbonate dissolution. Therefore, where this mechanism is not viable and where local fluvial or colluvial inputs can be ruled out, an external source or sources must be involved in soil formation. On the north coast of the Caribbean island of Jamaica, we studied a sequence of terra rossa soils developed on emergent limestones thought to be of Quaternary age. The soils become progressively thicker, redder, more Fe- and Al-rich and Si-poor with elevation. Furthermore, although kaolinite is found in all the soils, the highest and oldest soils also contain boehmite. Major and trace element geochemistry shows that the host limestones and local igneous rocks are not likely source materials for the soils. Other trace elements, including the rare earth elements (REE), show that tephra from Central American volcanoes is not a likely source either. However, trace element geochemistry shows that airborne dust from Africa plus tephra from the Lesser Antilles island arc are possible source materials for the clay-rich soils. A third, as yet unidentified, source may also contribute to the soils. We hypothesize that older, more chemically mature Jamaican bauxites may have had a similar origin. The results add to the growing body of evidence of the importance of multiple parent materials, including far-traveled dust, to soil genesis.

REMEDIATING TNT-CONTAMINATED SOIL BV SOIL WASHING AND FENTON OXIDATION. (R825549C043)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

DECONTAMINATION OF DDT-POLLUTED SOIL BY SOIL WASHING/CLOUD POINT EXTRACTION (R822832)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

THE INFLUENCE OF MINERAL REACTIONS ON THE ENVIRONMENTAL FATE OF METALS IN SOILS AND SEDIMENTS

EPA Science Inventory

Significant progress has been made in elucidating sorption reactions that control the partitioning of metals from solution to mineral surfaces in contaminated soil/sediment systems. Surface complexation models have been developed to quantify the forward reaction, however, these ...

Development in Children’s Interpretation of Pitch Cues to Emotions

PubMed Central

Quam, Carolyn; Swingley, Daniel

2012-01-01

Young infants respond to positive and negative speech prosody (Fernald, 1993), yet 4-year-olds rely on lexical information when it conflicts with paralinguistic cues to approval or disapproval (Friend, 2003). This article explores this surprising phenomenon, testing 118 2- to 5-year-olds’ use of isolated pitch cues to emotions in interactive tasks. Only 4- to 5-year-olds consistently interpreted exaggerated, stereotypically happy or sad pitch contours as evidence that a puppet had succeeded or failed to find his toy (Experiment 1) or was happy or sad (Experiments 2, 3). Two- and three-year-olds exploited facial and body-language cues in the same task. The authors discuss the implications of this late-developing use of pitch cues to emotions, relating them to other functions of pitch. PMID:22181680

Evaluating the effect of microalgal biomass on soil-plant-water systems

USDA-ARS?s Scientific Manuscript database

Exploring all possible applications of microalgal biomass is crucial to strengthen the current algal industry and reducing the environmental impacts of agriculture is a major global challenge. Microalgae can play a progressive role as they have the potential to improve soil structure, reduce erosion...

AIR PERMEABILITY IN UNDISTURBED VOLCANIC ASH SOILS: PREDICTIVE MODEL TEST AND SOIL STRUCTURE FINGERPRINT. (R825433)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Recent Progress in Measuring and Modeling Patterns of Biomass and Soil Carbon Pools Across the Amazon Basin

NASA Technical Reports Server (NTRS)

Potter, Christopher; Malhi, Yadvinder

2004-01-01

Ever more detailed representations of above-ground biomass and soil carbon pools have been developed during the LBA project. Environmental controls such as regional climate, land cover history, secondary forest regrowth, and soil fertility are now being taken into account in regional inventory studies. This paper will review the evolution of measurement-extrapolation approaches, remote sensing, and simulation modeling techniques for biomass and soil carbon pools, which together help constrain regional carbon budgets and enhance in our understanding of uncertainty at the regional level.

MODELING DIFFUSION AND REACTION IN SOILS: X. A UNIFYING MODEL FOR SOLUTE AND GAS DIFFUSIVITY IN UNSATURATED SOIL. (R825433)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Soil erodibility for water erosion: A perspective and Chinese experiences

USDA-ARS?s Scientific Manuscript database

Erodibility is a key indicator to evaluate soil’s susceptibility to erosion and crucial for predicting and evaluating soil loss and its environmental effects. This review aims to synthesize almost a century’s worth of research progress on the concept, indicators, and spatio-temporal variations of so...

SOIL-WATER PARTITIONING AND MASS TRANSFER KINETICS OF 2,4,6 TNT IN HIGHLY CONTAMINATED SOIL. (R825513C013)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Nutrient response of Bacopa monnieri (water hyssop) to varying degrees of soil saturation

USDA-ARS?s Scientific Manuscript database

Tissue concentrations of N and P were measured in Bacopa monnieri subjected to four progressive levels of flooding: well-drained Control, Intermittently Flooded, Partially Flooded, and Continuously Flooded. Soil redox potential (Eh) decreased in all flooded treatments at 30 cm depth, becoming anoxic...

GAS DIFFUSIVITY IN UNDISTURBED VOLCANIC ASH SOILS: TEST OF SOIL-WATER-CHARACTERISTIC-BASED PREDICTION MODELS. (R825433)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Compilation of 1985 annual reports of the Navy elf (extremely low frequency) communications system ecological monitoring program. Volume 2. Tabs D-G. Annual progress report, January-December 1985

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

Band, R.N.; Snider, R.J.; Snider, R.M.

1986-07-01

This volume consists of the following reports: Soil Amoeba; Soil and Litter Arthropoda and Earthworm Studies; Biological Studies on Pollinating Insects: Megachilid Bees; Small Vertebrates: Small Mammals and Nesting Birds.

BIOAVAILABILITY OF ARSENIC IN CATTLE DIPPING VAT SITE SOILS AS A FUNCTION OF SOIL CHEMISTRY. (R830842)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

CONSIDERATION OF SOIL PROPERTIES IN ASSESSMENT OF HUMAN HEALTH RISK FROM EXPOSURE TO ARSENICAL PESTICIDE APPLIED SOILS. (R830842)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

On the structural factors of soil humic matter related to soil water repellence in fire-affected soils

NASA Astrophysics Data System (ADS)

Almendros, G.; González-Vila, F. J.; González-Pérez, J. A.; Knicker, H.; De la Rosa, J. M.; Dettweiler, C.; Hernández, Z.

2012-04-01

In order to elucidate the impact of forest fires on physical and chemical properties of the soils as well as on the chemical composition of the soil organic matter, samples from two Mediterranean soils with contrasted characteristics and vegetation (O horizon, Lithic Leptosols under Quercus ilex and Pinus pinaster) and one agricultural soil (Ap horizon, Luvisol) were heated at 350 °C in laboratory conditions for three successive steps up to 600 s. The C- and N-depletion in the course of the heating showed small changes up to an oxidation time of 300 s. On the other side, and after 600 s, considerable C-losses (between 21% in the Luvisol and 50% in the Leptosols) were observed. The relatively low N-depletion ca. 4% (Luvisol) and 21% (Leptosol under pine) suggested preferential loss of C and the subsequent relative enrichment of nitrogen. Paralleling the progressive depletion of organic matter, the Leptosols showed a significant increase of both pH and electrical conductivity. The former change paralleled the rapid loss of carboxyl groups, whereas the latter point to the relative enrichment of ash with a bearing on the concentration of inorganic ions, which could be considered a positive effect for the post-fire vegetation. The quantitative and qualitative analyses by solid-state 13C NMR spectra of the humic fractions in the samples subjected to successive heating times indicate significant concentration of aromatic structures newly-formed in the course of the dehydration and cyclization of carbohydrates (accumulation of black carbon-type polycyclic aromatic structures), and probably lipids and peptides. The early decarboxylation, in addition to the depletion of O-alkyl hydrophilic constituents and further accumulation of secondary aromatic structures resulted in the dramatic increase in the soil water drop penetration time. It was confirmed that this enhancement of the soil hydrophobicity is not related to an increased concentration of soil free lipid, but is explained by changes in the surface properties of the macromolecular soil humic fractions. It is worthy to mention that whereas in mineral soils a considerable chemical alteration of the organic matter occurred only after a heating time >300 s, in the case of organic soils large transformations occur after 90 s. This could suggest the extent to which the soil mineral phase protects the organic matter during the fire event. The composition of the soil lipid assemblages showed very significant qualitative and quantitative changes: the maxima of the alkyl homologous series shifted towards short-chain compounds (indicating thermal breakdown of long-chain alkyl compounds). Additional progressive changes of the Carbon Preference Indexes (relative abundance of odd- versus even-C numbered alkyl molecules, which tended to one) were observed such as the progressive smoothing of the biogenic signature of the alkyl series, probably simultaneous to a re-compartmentalization of lipid species within soil microaggregates.

Research Progress of Artificial Forest in the Remediation of Heavy Metal Contaminated Soils

NASA Astrophysics Data System (ADS)

Jiafang, MA; Guangtao, MENG; Liping, HE; Guixiang, LI

2017-01-01

(1) Remediation of soil contaminated by heavy metals has become a hot topic in the world, and phytoremediation technology is the most widely used. (2) In addition to traditional economic benefits, ecological benefits of artificial forest have been more and more important, which are very helpful to soil polluted with heavy metals in the environment. (3) The characteristics of heavy metal pollution of soil and plantations of repair mechanism have been reviewed, and the current mining areas, wetlands, urban plantations on heavy metal elements have enriched the research results. The purpose is to find a new path for governance of heavy metal soil pollution.

Soil health paradigms and implications for disease management.

PubMed

Larkin, Robert P

2015-01-01

Soil health has been defined as the capacity of soil to function as a vital living system to sustain biological productivity, maintain environmental quality, and promote plant, animal, and human health. Building and maintaining soil health are essential to agricultural sustainability and ecosystem function. Management practices that promote soil health, including the use of crop rotations, cover crops and green manures, organic amendments, and conservation tillage, also have generally positive effects on the management of soilborne diseases through a number of potential mechanisms, including increasing soil microbial biomass, activity, and diversity, resulting in greater biological suppression of pathogens and diseases. However, there also may be particular disease issues associated with some soil health management practices. In this review, research and progress made over the past twenty years regarding soil health, sustainability, and soil health management practices, with an emphasis on their implications for and effects on plant disease and disease management strategies, are summarized.

Quantifying the dilution of the radiocesium contamination in Fukushima coastal river sediment (2011-2015)

NASA Astrophysics Data System (ADS)

Evrard, Olivier; Laceby, J. Patrick; Onda, Yuichi; Wakiyama, Yoshifumi; Jaegler, Hugo; Lefèvre, Irène

2016-10-01

Fallout from the Fukushima Dai-ichi nuclear power plant accident resulted in a 3000-km2 radioactive contamination plume. Here, we model the progressive dilution of the radiocesium contamination in 327 sediment samples from two neighboring catchments with different timing of soil decontamination. Overall, we demonstrate that there has been a ~90% decrease of the contribution of upstream contaminated soils to sediment transiting the coastal plains between 2012 (median - M - contribution of 73%, mean absolute deviation - MAD - of 27%) and 2015 (M 9%, MAD 6%). The occurrence of typhoons and the progress of decontamination in different tributaries of the Niida River resulted in temporary increases in local contamination. However, the much lower contribution of upstream contaminated soils to coastal plain sediment in November 2015 demonstrates that the source of the easily erodible, contaminated material has potentially been removed by decontamination, diluted by subsoils, or eroded and transported to the Pacific Ocean.

ALTERED SOIL-SOIL WATER INTERACTION INFERRED FROM STREAM WATER CHEMISTRY AT AN ARTIFICIALLY ACIDIFIED WATERSHED AT BEAR BROOK WATERSHED, MAINE. (R825762)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

ALTERED SOIL-SOIL WATER INTERACTIONS INFERRED FROM STREAMWATER CHEMISTRY AT AN ARTIFICALLY ACIDIFIED WATERSHED AT BEAR BROOK WATERSHED, MAINE USA. (R825762)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Changes in soil amino composition and microbial N acquisition strategies in response to woody plant invasion of grasslands

USDA-ARS?s Scientific Manuscript database

Changes in land cover have the potential to alter nutrient cycling through changes in carbon input chemistry, microbial community structure, and even soil structure. In the Rio Grande plains region of southern Texas, overgrazing and fire suppression have resulted in progressive encroachment of N-fix...

Evaluating Snowmelt Runoff Processes Using Stable Isotopes in a Permafrost Hillslope

NASA Astrophysics Data System (ADS)

Carey, S. K.

2004-05-01

Conceptual understanding of runoff generation in permafrost regions have been derived primarily from hydrometric information, with isotope and hydrochemical data having only limited application in delineating sources and pathways of water. Furthermore, when stable isotope data are used to infer runoff processes, it often provides conflicting results from hydrometric measurements. In a small subarctic alpine catchment within the Wolf Creek Research Basin, Yukon, Canada, experiments were conducted during the melt period of 2002 and 2003 to trace the stable isotopic signature (d18O) of meltwater from a melting snowpack into permafrost soils and laterally to the stream to identify runoff processes and evaluate sources of error for traditional hydrograph separation studies in snowmelt-dominated permafrost basins. Isotopic variability in the snowpack was recorded at 0.1 m depth intervals during the melt period and compared with the meltwater isotopic signature at the snowpack base collected in lysimeters. Throughout the melt period in both years, there was an isotopic enrichment of meltwater as the season progressed. A downslope transect of wells and piezometers were used to evaluate the influence of infiltrating meltwater and thawing ground on the subsurface d18O signature. As melt began, meltwater infiltrated the frozen porous organic layer, leading to liquid water saturation in the unsaturated pore spaces. Water sampled during this initial melt stage show soil water d18O mirroring that of the meltwater signal. As the melt season progressed, frozen soil began to melt, mixing enriched pre-melt soil water with meltwater. This mixing increased the overall value of d18O obtained from the soil, which gradually increased as thaw progressed. At the end of snowmelt, soil water had a d18O value similar to values from the previous fall, suggesting that much of the initial snowmelt water had been flushed from the hillslope. Results from the hillslope scale are compared with two-component hydrograph separations and sources of error are discussed.

Study of environmental biodegradation of LDPE films in soil using optical and scanning electron microscopy.

PubMed

Mumtaz, Tabassum; Khan, M R; Hassan, Mohd Ali

2010-07-01

An outdoor soil burial test was carried out to evaluate the degradation of commercially available LDPE carrier bags in natural soil for up to 2 years. Biodegradability of low density polyethylene films in soil was monitored using both optical and scanning electron microscopy (SEM). After 7-9 months of soil exposure, microbial colonization was evident on the film surface. Exposed LDPE samples exhibit progressive changes towards degradation after 17-22 months. SEM images reveal signs of degradation such as exfoliation and formation of cracks on film leading to disintegration. The possible degradation mode and consequences on the use and disposal of LDPE films is discussed. Copyright 2010 Elsevier Ltd. All rights reserved.

Soil networks become more connected and take up more carbon as nature restoration progresses.

PubMed

Morriën, Elly; Hannula, S Emilia; Snoek, L Basten; Helmsing, Nico R; Zweers, Hans; de Hollander, Mattias; Soto, Raquel Luján; Bouffaud, Marie-Lara; Buée, Marc; Dimmers, Wim; Duyts, Henk; Geisen, Stefan; Girlanda, Mariangela; Griffiths, Rob I; Jørgensen, Helene-Bracht; Jensen, John; Plassart, Pierre; Redecker, Dirk; Schmelz, Rűdiger M; Schmidt, Olaf; Thomson, Bruce C; Tisserant, Emilie; Uroz, Stephane; Winding, Anne; Bailey, Mark J; Bonkowski, Michael; Faber, Jack H; Martin, Francis; Lemanceau, Philippe; de Boer, Wietse; van Veen, Johannes A; van der Putten, Wim H

2017-02-08

Soil organisms have an important role in aboveground community dynamics and ecosystem functioning in terrestrial ecosystems. However, most studies have considered soil biota as a black box or focussed on specific groups, whereas little is known about entire soil networks. Here we show that during the course of nature restoration on abandoned arable land a compositional shift in soil biota, preceded by tightening of the belowground networks, corresponds with enhanced efficiency of carbon uptake. In mid- and long-term abandoned field soil, carbon uptake by fungi increases without an increase in fungal biomass or shift in bacterial-to-fungal ratio. The implication of our findings is that during nature restoration the efficiency of nutrient cycling and carbon uptake can increase by a shift in fungal composition and/or fungal activity. Therefore, we propose that relationships between soil food web structure and carbon cycling in soils need to be reconsidered.

Incorporating a Soil Science Artifact into a University ePortfolio Assessment Tool

ERIC Educational Resources Information Center

Mikhailova, Elena; Werts, Joshua; Post, Christopher; Ring, Gail

2014-01-01

The ePortfolio is a useful educational tool that is utilized in many educational institutions to showcase student accomplishments and provide students with an opportunity to reflect on their educational progress. The objective of this study was to develop and test an artifact from an introductory soil science course to be included in the…

Evaluation Criteria and Results of Full Scale Testing of Bridge Abutment Made from Reinforced Soil

NASA Astrophysics Data System (ADS)

Hildebrand, Maciej; Rybak, Jarosław

2017-10-01

Structures made of reinforced soil can be evaluated for their safety based on a load testing. Measurement results are essentially evaluated by displacements of surcharge (mainly in vertical direction) and facing elements (mainly in horizontal direction). Displacements are within several tenths to several millimetres and they can be taken by common geodetic equipment. Due to slow soil consolidation (progress of displacements) under constant load, observations should be made over several days or even weeks or months. A standard procedure of heating of geotextiles, used in laboratory conditions to simulate long term behaviour cannot be used in a natural scale. When the load is removed, the soil unloading occurs. Both the progress of displacements and soil unloading after unloading of the structure are the key presumptions for evaluating its safety (stability). Assessment of measuring results must be preceded by assuming even the simplest model of the structure, so as it could be possible to estimate the expected displacements under controlled load. In view of clearly random nature of soil parameters of retaining structure composed of reinforced soil and due to specific erection technology of reinforced soil structure, the assessment of its condition is largely based on expert’s judgment. It is an essential and difficult task to interpret very small displacements which are often enough disturbed by numerous factors like temperature, insolation, precipitation, vehicles, etc. In the presented paper, the authors tried to establish and juxtapose some criteria for a load test of a bridge abutment and evaluate their suitability for decision making. Final remarks are based on authors experience from a real full scale load test.

Use of Magnetic Parameters to Asses Soil Erosion Rates on Agricultural Site

NASA Astrophysics Data System (ADS)

Petrovsky, E.; Kapicka, A.; Dlouha, S.; Jaksik, O.; Grison, H.; Kodesova, R.

2014-12-01

A detailed field study on a small test site of agricultural land situated in loess region in Southern Moravia (Czech Republic) and laboratory analyses were carried out in order to test the applicability of magnetic methods in assessing soil erosion. Haplic Chernozem, the original dominant soil unit in the area, is nowadays progressively transformed into different soil units along with intense soil erosion. As a result, an extremely diversified soil cover structure has developed due to the erosion. The site was characterized by a flat upper part while the middle part, formed by a substantive side valley, is steeper. We carried out field measurements of magnetic susceptibility on a regular grid, resulting in 101 data points. The bulk soil material for laboratory investigation was gathered from all the grid points. Values of the magnetic susceptibility are spatially distributed depending on the terrain. Higher values were measured in the flat upper part (where the original top horizon remained). The lowest values of were obtained on the steep valley sides. Here the original topsoil was eroded and mixed by tillage with the soil substrate (loess). A soil profile unaffected by erosion was investigated in detail. The vertical distribution of magnetic susceptibility along this "virgin" profile was measured in laboratory on the samples collected with 2-cm spacing. The undisturbed profile shows several soil horizons. Horizons Ac and A show a slight increase in magnetic susceptibility up to a depth of about 70 cm. Horizon A/Ck is characterized by a decrease in susceptibility, and the underlying C horizon (h > 103 cm) has a very low value of magnetic susceptibility. The differences between the values of susceptibility in the undisturbed soil profile and the magnetic signal after uniform mixing the soil material as a result of tillage and erosion are fundamental for the estimation of soil loss in the studied test field. Using the uneroded profile from the studied locality as a basis for examining the changes in cultivated soils, tillage homogenization model can be applied to predict changes in the surface soil magnetism with progressive soil erosion. The model is very well applicable at the studied site. Acknowledgement: This study was supported by NAZV Agency of the Ministry of Agriculture of the Czech Republic through grant No QJ1230319.

The effect of vapor transport of acidic aerosols on salt speciation in Antarctic soils collected near the polar plateau

NASA Astrophysics Data System (ADS)

Graly, J. A.; Licht, K.; Kaplan, M. R.; Druschel, G.

2017-12-01

Vapor is the primary phase in which water is transported through soils where temperatures rarely, if ever, reach the melting point. In terrestrial settings, such as Antarctica, these cold, dry soils accumulate appreciable quantities of salts, primarily derived from atmospheric aerosols. Past studies have often analyzed the transport of salts to depth using solubility parameters, which assumes liquid water can percolate through porous media. We analyzed the distribution of salts in an Antarctic blue ice moraine, located near the polar plateau (84˚S, 163˚E). Here moraine soils are progressively older with distance from active ice, the oldest soils dating to several hundred ka. Changes in salt content were analyzed both with depth and with soil age. Of atmospheric salts analyzed, chloride and fluoride salts are fluxed to greatest depth, followed by nitrate salts. Sulfate and borate salts are both relatively immobile in the soil and are not detected below the top several cm. This distribution runs counter to the solubility of the salt species, with borate having high solubility and fluoride and nitrate both being relatively insoluble. Instead, the vapor pressures of the acids from which the salts form correspond very strongly with the relative abundance of the salts at depth. This suggests that percolation of liquid water plays a minimal role in moving salts to depth. Instead salts move to depth as vapors of acidic aerosols. With soil age, surface concentrations of the more mobile salts (nitrate, chloride, and fluoride) show logarithmic or power-law increases in concentrations, whereas boron and sulfate increase linearly. This is consistent with the former's progressive flux to depth. An exception to this pattern occurs in a few of the oldest soils, where substantially higher concentrations of the mobile salts are found in the top soils. This suggests that the direction of net vapor flux may reverse once sufficient salt concentration is developed at depth, though further measurements are needed to test this hypothesis.

Beneficial uses program. Progress report, period ending June 30, 1979

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

Not Available

1979-10-01

Progress in research on the irradiation of sewage sludge, the potential use of dried sewage sludge as animal feed or soil conditioners, the inactivation of rotavirus in sewage sludge, fruit fly control by the irradiation of citrus fruits, and the production of /sup 137/Cs source pellets is reported. (LCL)

Soils of Walker Branch Watershed

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

Lietzke, D.A.

1994-03-01

The soil survey of Walker Branch Watershed (WBW) utilized the most up-to-date knowledge of soils, geology, and geohydrology in building the soils data base needed to reinterpret past research and to begin new research in the watershed. The soils of WBW were also compared with soils mapped elsewhere along Chestnut Ridge on the Oak Ridge Reservation to (1) establish whether knowledge obtained elsewhere could be used within the watershed, (2) determine whether there were any soils restricted to the watershed, and (3) evaluate geologic formation lateral variability. Soils, surficial geology, and geomorphology were mapped at a scale of 1:1,200 usingmore » a paper base map having 2-ft contour intervals. Most of the contours seemed to reasonably represent actual landform configurations, except for dense wooded areas. For example, the very large dolines or sinkholes were shown on the contour base map, but numerous smaller ones were not. In addition, small drainageways and gullies were often not shown. These often small but important features were located approximately as soil mapping progressed.« less

The Global Soil Partnership

NASA Astrophysics Data System (ADS)

Montanarella, Luca

2015-07-01

The Global Soil Partnership (GSP) has been established, following an intensive preparatory work of the Food and Agriculture Organization of the United Nations (FAO) in collaboration with the European Commission (EC), as a voluntary partnership coordinated by the FAO in September 2011 [1]. The GSP is open to all interested stakeholders: Governments (FAO Member States), Universities, Research Organizations, Civil Society Organizations, Industry and private companies. It is a voluntary partnership aiming towards providing a platform for active engagement in sustainable soil management and soil protection at all scales: local, national, regional and global. As a “coalition of the willing” towards soil protection, it attempts to make progress in reversing soil degradation with those partners that have a genuine will of protecting soils for our future generations. It openly aims towards creating an enabling environment, despite the resistance of a minority of national governments, for effective soil protection in the large majority of the countries that are genuinely concerned about the rapid depletion of their limited soil resources.

Education in Soil Science: the Italian approach

NASA Astrophysics Data System (ADS)

Benedetti, Anna; Canfora, Loredana; Dazzi, Carmelo; Lo Papa, Giuseppe

2017-04-01

The Italian Society of Soil Science (SISS) was founded in Florence on February 18th, 1952. It is an association legally acknowledged by Decree of the President of the Italian Republic in February 1957. The Society is member of the International Union of Soil Sciences (IUSS) of the European Confederation of Soil Science Societies (ECSSS) and collaborates with several companies, institutions and organizations having similar objectives or policy aspects. SISS promotes progress, coordination and dissemination of soil science and its applications encouraging relationships and collaborations among soil lovers. Within the SISS there are Working Groups and Technical Committees for specific issues of interest. In particular: • the Working Group on Pedotechniques; • the Working Group on Hydromorphic and Subaqueous Soils and • the Technical Committee for Soil Education and Public Awareness. In this communication we wish to stress the activities developed since its foundation by SISS to spread soil awareness and education in Italy through this last Technical Committee, focusing also the aspect concerning grants for young graduates and PhD graduates to stimulate the involvement of young people in the field of soil science. Keywords: SISS, soil education and awareness.

Interaction Effect between Phosphorus and Zinc on their Availability in Soil in Relation to their Contents in Stevia (Stevia rebaudiana)

PubMed Central

Das, Kuntal; Dang, Raman; Shivananda, T. N.; Sur, Pintu

2005-01-01

A greenhouse experiment was conducted at the Indian Institute of Horticultural Research (IIHR), Bangalore to study the interaction effect between phosphorus and zinc on their availability in soil in relation to their contents in stevia (Stevia rebaudiana). The results show that the amount of available P and Zn content in soil has been found to increase initially and, thereafter, the amount of the same decreased with the progress of plant growth up to 60 days irrespective of treatments. The amount of P and Zn in soils showed an increase with their separate applications either as soil or foliar spray while that of the same value significantly decreased both in soils and plants due to their combined applications, suggesting a mutual antagonistic effect between Zn and P affecting each other's availability in soil and content in the stevia plant. PMID:15980919

Investing in soils as an infrastructure to maintain and enhance food water and carbon services

NASA Astrophysics Data System (ADS)

Davies, Jessica

2017-04-01

Soils are a life support system for global society and our planet. In addition to providing the vast majority of our food; soils regulate water quality and quantity reducing the risk of floods, droughts and pollution; and as the largest store of carbon in the earth system they are critical to climate change. By providing these multiple essential services, soils act a natural form of infrastructure that is critical to supporting both rural and urban communities and economies. Can natural infrastructure and natural capital concepts be used to motivate and enable investment and regulation of soils for purposes such as soil carbon sequestration? What scientific knowledge and tools would we need to support soil infrastructure decision making - in policy arenas and elsewhere? This poster will present progress from a new research project supported by the UK research council (EP/N030532/1) that addresses these questions.

Investigation of 4-year-old stabilised/solidified and accelerated carbonated contaminated soil.

PubMed

Antemir, A; Hills, C D; Carey, P J; Magnié, M-C; Polettini, A

2010-09-15

The investigation of the pilot-scale application of two different stabilisation/solidification (S/S) techniques was carried out at a former fireworks and low explosives manufacturing site in SE England. Cores and granular samples were recovered from uncovered accelerated carbonated (ACT) and cement-treated soils (S/S) after 4 years to evaluate field-performance with time. Samples were prepared for microstructural examination and leaching testing. The results indicated that the cement-treated soil was progressively carbonated over time, whereas the mineralogy of the carbonated soil remained essentially unchanged. Distinct microstructures were developed in the two soils. Although Pb, Zn and Cu leached less from the carbonated soil, these metals were adequately immobilised by both treatments. Geochemical modeling of pH-dependent leaching data suggested that the retention of trace metals resulted from different immobilisation mechanisms operating in the two soils examined. Copyright 2010 Elsevier B.V. All rights reserved.

From peds to paradoxes: Linkages between soil biota and their influences on ecological processes

Treesearch

David C. Coleman

2008-01-01

Soils and their biota have been studied by a variety of observational and experimental methods that have allowed biologists to infer their structural and functional interactions. Viewing progress made over the last 10 years, it is apparent that an increasing diversity of analytical and chemical methods are providing much more detailed information about feeding...

Progress in the Use of Rapid Molecular Techniques to Detect Life Forms in Soil: Implications for Interplanetary Astrobiology Missions

NASA Technical Reports Server (NTRS)

Warmflash, D.; Larios-Sanz, M.; Fox, G. E.; McKay, D. S.

2002-01-01

To demonstrate the feasibility of two promising technologies, we have applied Enzyme-Linked Immunosorbent Assay (ELISA) as well as probes that target the 16S rRNA molecule to search for life in terrestrial soil samples, known to contain numerous life forms. Additional information is contained in the original extended abstract.

Spatial variation of corn canopy temperature as dependent upon soil texture and crop rooting characteristics

NASA Technical Reports Server (NTRS)

Choudhury, B. J.

1983-01-01

A soil plant atmosphere model for corn (Zea mays L.) together with the scaling theory for soil hydraulic heterogeneity are used to study the sensitivity of spatial variation of canopy temperature to field averaged soil texture and crop rooting characteristics. The soil plant atmosphere model explicitly solves a continuity equation for water flux resulting from root water uptake, changes in plant water storage and transpirational flux. Dynamical equations for root zone soil water potential and the plant water storage models the progressive drying of soil, and day time dehydration and night time hydration of the crop. The statistic of scaling parameter which describes the spatial variation of soil hydraulic conductivity and matric potential is assumed to be independent of soil texture class. The field averaged soil hydraulic characteristics are chosen to be representative of loamy sand and clay loam soils. Two rooting characteristics are chosen, one shallow and the other deep rooted. The simulation shows that the range of canopy temperatures in the clayey soil is less than 1K, but for the sandy soil the range is about 2.5 and 5.0 K, respectively, for the shallow and deep rooted crops.

Quantifying the dilution of the radiocesium contamination in Fukushima coastal river sediment (2011–2015)

PubMed Central

Evrard, Olivier; Laceby, J. Patrick; Onda, Yuichi; Wakiyama, Yoshifumi; Jaegler, Hugo; Lefèvre, Irène

2016-01-01

Fallout from the Fukushima Dai-ichi nuclear power plant accident resulted in a 3000-km2 radioactive contamination plume. Here, we model the progressive dilution of the radiocesium contamination in 327 sediment samples from two neighboring catchments with different timing of soil decontamination. Overall, we demonstrate that there has been a ~90% decrease of the contribution of upstream contaminated soils to sediment transiting the coastal plains between 2012 (median – M – contribution of 73%, mean absolute deviation – MAD – of 27%) and 2015 (M 9%, MAD 6%). The occurrence of typhoons and the progress of decontamination in different tributaries of the Niida River resulted in temporary increases in local contamination. However, the much lower contribution of upstream contaminated soils to coastal plain sediment in November 2015 demonstrates that the source of the easily erodible, contaminated material has potentially been removed by decontamination, diluted by subsoils, or eroded and transported to the Pacific Ocean. PMID:27694832

Progress Towards Identifying and Quantifying the Organic Ice Nucleating Particles in Soils and Aerosols

NASA Astrophysics Data System (ADS)

Hill, T. C. J.; DeMott, P. J.; Fröhlich-Nowoisky, J.; Tobo, Y.; Suski, K. J.; Levin, E. J.; Kreidenweis, S. M.; Franc, G. D.

2014-12-01

Soil and plant surfaces emit ice nucleating particles (INP) to the atmosphere, especially when disturbed by wind, harvesting, rain or fire. Organic (biogenic) INP are abundant in most soils and dominate the population that nucleate >-15°C. For example, the sandy topsoil of sagebrush shrubland, a widespread ecotype prone to wind erosion after fire, contains ~106 organic INP g-1 at -6°C. The relevance of organic INP may also extend to colder temperatures than previously thought: Particles of soil organic matter (SOM) have been shown to be more important than mineral particles for the ice nucleating ability of agricultural soil dusts to -34°C. While the abundance of ice nucleation active (INA) bacteria on plants has been established, the identity of the organic INP in and emitted by soils remains a 40-year-old mystery. The need to understand their production and release is highlighted by recent findings that INA bacteria (measured with qPCR) account for few, if any, of the warm-temperature organic INP that predominate in boundary layer aerosols and snow; organic INP lofted with soil dusts seem a likely source. The complexity of SOM hinders its investigation. It contains decomposing plant materials, a diverse microbial and microfaunal community, humus, and inert organic matter. All are biochemically complex and all may contain ice nucleating constituents, either by design or by chance. Indeed the smoothness of the INP temperature spectra of soils is indicative of numerous, overlapping distributions of INP. We report recent progress in identifying and quantifying the organic INP in soils and boundary layer aerosols representative of West Central U.S. ecosystems, and how their characteristics may affect their dispersal. Chemical, enzymatic and DNA-based tests were used to assess contributions of INP from plant tissues, INA bacteria, INA fungi, organic crystals, monolayers of aliphatic alcohols, carbohydrates, and humic substances, while heat- and peroxide-based tests were used to estimate total organic INP abundance.

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

Jacobs, G.K.

ORNL, through The Consortium for Research on Enhancing Carbon Sequestration in Terrestrial Ecosystems (CSiTE), collaborated with The Village Botanica, Inc. (VB) on a project investigating carbon sequestration in soils and commercial products from a new sustainable crop developed from perennial Hibiscus spp. Over 500 pre-treated samples were analyzed for soil carbon content. ORNL helped design a sampling scheme for soils during the planting phase of the project. Samples were collected and prepared by VB and analyzed for carbon content by ORNL. The project did not progress to a Phase II proposal because VB declined to prepare the required proposal.

[Strategies and mechanisms of soil springtails in adapting lower temperature environment: research progress].

PubMed

Liu, Jing; Wang, Yun-Biao; Wu, Dong-Hui

2012-12-01

Low temperature and drought are the main environmental factors threatening the animals living in arctic area and cold temperate regions. To adapt the severe environment, the animals should adopt appropriate strategies. As a group of arthopods with freeze-avoiding strategy, soil springtails have the similar ecological mechanisms and modes of cold resistance/tolerance as insects, manifesting in the cold acclimation and drought tolerance to decrease the damage of ice crystal formation. During cold acclimation, there are a rapid increase of glycerol, a rapid decrease of fucose and glucose, and the production of anti-freeze proteins (AFP) , and exists the inter-transformation of different kinds of lipids to improve the flow of cell membrane to protect the cell from low temperature injury. In addition, soil springtails have their own specific modes and mechanisms to tolerate low temperature stress, mainly the vertical migration under the protection of snow cover and the excretion of ice nucleator from haemolymph, illustrating that it's of significance to research the cryobiology of soil springtails. This paper summarized the modes and mechanisms of soil springtails in tolerating low temperature environment, reviewed the research progress on the eco-physiology of the springtails, discussed the existing problems of the researches on the low temperature tolerance of the springtails, and prospected the research directions of the springtails low temperature ecology under the background of global change.

Rich in life but poor in data: the known knowns and known unknowns of modelling how soil biology drives soil structure

NASA Astrophysics Data System (ADS)

Hallett, Paul; Ogden, Mike

2015-04-01

Soil biology has a fascinating capacity to manipulate pore structure by altering or overcoming hydrological and mechanical properties of soil. Many have postulated, quite rightly, that this capacity of soil biology to 'engineer' its habitat drives its diversity, improves competitiveness and increases resilience to external stresses. A large body of observational research has quantified pore structure evolution accompanied by the growth of organisms in soil. Specific compounds that are exuded by organisms or the biological structures they create have been isolated and found to correlate well with observed changes to pore structure or soil stability. This presentation will provide an overview of basic mechanical and hydrological properties of soil that are affected by biology, and consider missing data that are essential to model how they impact soil structure evolution. Major knowledge gaps that prevent progress will be identified and suggestions will be made of how research in this area should progress. We call for more research to gain a process based understanding of structure formation by biology, to complement observational studies of soil structure before and after imposed biological activity. Significant advancement has already been made in modelling soil stabilisation by plant roots, by combining data on root biomechanics, root-soil interactions and soil mechanical properties. Approaches for this work were developed from earlier materials science and geotechnical engineering research, and the same ethos should be adopted to model the impacts of other biological compounds. Fungal hyphae likely reinforce soils in a similar way to plant roots, with successful biomechanical measurements of these micron diameter structures achieved with micromechanical test frames. Extending root reinforcement models to fungi would not be a straightforward exercise, however, as interparticle bonding and changes to pore water caused by fungal exudates could have a major impact on structure formation and stability. Biological exudates from fungi, bacteria or roots have been found to decrease surface tension and increase viscosity of pore water, with observed impacts to soil strength and water retention. Modelling approaches developed in granular mechanics and geotechnical engineering could be built upon to incorporate biological transformations of hydrological and mechanical properties of soil. With new testing approaches, adapted from materials science, pore scale hydromechanical impacts from biological exudates can be quantified. The research can be complemented with model organisms with differences in biological structures (e.g. root hair mutants), exudation or other properties. Coupled with technological advances that provide 4D imaging of soil structure at relatively rapid capture rates, the potential opportunities to disentangle and model how biology drives soil structure evolution and stability are vast. By quantifying basic soil hydrological and mechanical processes that are driven by soil biology, unknown unknowns may also emerge, providing new insight into how soils function.

Influence of Robinia pseudoacacia short rotation coppice on soil physical properties

NASA Astrophysics Data System (ADS)

Xavier, Morvan; Isabelle, Bertrand; Gwenaelle, Gibaud

2015-04-01

Human activities can lead to the degradation of soil physical properties. For instance, machinery traffic across the land can induce the development of compacted areas at the wheel tracks. It leads to a decrease in porosity which results in a decrease of the hydraulic conductivity, and therefore, prevents water infiltration and promotes surface runoff. Land use, soil management and soil cover also have a significant influence on soil physical properties (Kodesova et al., 2011). In the arable land, surface runoff and soil erosion are enhanced by the absence of soil cover for part of the year and by the decrease of aggregate stability due to a decline of soil organic matter. In that context, few studies focused on the effects of a Robinia pseudoacacia short rotation coppice (SRC) on soil physical properties. Therefore, this study aims to determine the effect of the conversion of a grassland in a SRC on soil physical properties. These properties have also been compared to those of arable land and natural forest. For that, in several plots of the experimental farm of Grignon (30 km west of Paris, France), different measurements were performed: i) soil water retention on a pressure plate apparatus for 7 water potential between 0 and 1500 kPa, ii) bulk density using the method for gravelly and rocky soil recommended by the USDA, iii) aggregate stability using the method described in Le Bissonnais (1996), and iv) soil hydraulic conductivity using a Guelph permeameter. All these measurements were performed on the same soil type and on different land uses: arable land (AL), grassland (GL), natural forest (NF) and short rotation coppice (SRC) of Robinia pseudoacacia planted 5 years ago. Soil water retention measurements are still under progress and will be presented in congress. Bulk density measurements of the AL, GL and SRC are not significantly different. They ranged from 1.32 to 1.42. Only the NF measurements are significantly lower than the other (0.97). Aggregate stability measurements showed that the SRC soil had the most stable aggregates compared to the other land uses. SRC also had the highest infiltration rates (656 mm.h-1) compared to NF (54 mm.h-1), GL (23 mm.h-1) and AL (8 mm.h-1). Analyses and explanation of these results are still under progress and will be presented in congress. Kodesova, R., Jirku, V., Kodes, V., Muhlhanselova, M., Nikodem, A., Žigová, A., 2011. Soil structure and soil hydraulic properties of Haplic Luvisol used as arable land and grassland. Soil and Tillage Research 111 (2), pp. 154-161. Le Bissonnais Y., 1996. Aggregate stability and assessment of soil crustability and erodibility: I theory and methodology. European Journal of Soil Science 47, 425-437.

Ecological risks of DOE`s programmatic environmental restoration alternatives

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

Not Available

1994-06-01

This report assesses the ecological risks of the Department of Energy`s (DOE) Environmental Restoration Program. The assessment is programmatic in that it is directed at evaluation of the broad programmatic alternatives outlined in the DOE Implementation Plan. It attempts to (1) characterize the ecological resources present on DOE facilities, (2) describe the occurrence and importance of ecologically significant contamination at major DOE facilities, (3) evaluate the adverse ecological impacts of habitat disturbance caused by remedial activities, and (4) determine whether one or another of the programmatic alternatives is clearly ecologically superior to the others. The assessment focuses on six representativemore » facilities: the Idaho National Engineering Laboratory (INEL); the Fernald Environmental Management Project (FEMP); the Oak Ridge Reservation (ORR), including the Oak Ridge National Laboratory (ORNL), Y-12 plant, and K-25 plant; the Rocky Flats Plant; the Hanford Reservation; and the Portsmouth Gaseous Diffusion Plant.« less

Development in children's interpretation of pitch cues to emotions.

PubMed

Quam, Carolyn; Swingley, Daniel

2012-01-01

Young infants respond to positive and negative speech prosody (A. Fernald, 1993), yet 4-year-olds rely on lexical information when it conflicts with paralinguistic cues to approval or disapproval (M. Friend, 2003). This article explores this surprising phenomenon, testing one hundred eighteen 2- to 5-year-olds' use of isolated pitch cues to emotions in interactive tasks. Only 4- to 5-year-olds consistently interpreted exaggerated, stereotypically happy or sad pitch contours as evidence that a puppet had succeeded or failed to find his toy (Experiment 1) or was happy or sad (Experiments 2, 3). Two- and 3-year-olds exploited facial and body-language cues in the same task. The authors discuss the implications of this late-developing use of pitch cues to emotions, relating them to other functions of pitch. © 2011 The Authors. Child Development © 2011 Society for Research in Child Development, Inc.

Human impacts on soil carbon dynamics of deep-rooted Amazonian forests and effect of land use change on the carbon cycle in Amazon soils

NASA Technical Reports Server (NTRS)

Nepstad, Daniel; Stone, Thomas; Davidson, Eric; Trumbore, Susan E.

1992-01-01

The main objective of these NASA-funded projects is to improve our understanding of land-use impacts on soil carbon dynamics in the Amazon Basin. Soil contains approximately one half of tropical forest carbon stocks, yet the fate of this carbon following forest impoverishment is poorly studied. Our mechanistics approach draws on numerous techniques for measuring soil carbon outputs, inputs, and turnover time in the soils of adjacent forest and pasture ecosystems at our research site in Paragominas, state of Para, Brazil. We are scaling up from this site-specific work by analyzing Basin-wide patterns in rooting depth and rainfall seasonality, the two factors that we believe should explain much of the variation in tropical soil carbons dynamics. In this report, we summarize ongoing measurements at our Paragominas study site, progress in employing new field data to understand soil C dynamics, and some surprising results from our regional, scale-up work.

A general overview of the history of soil science

NASA Astrophysics Data System (ADS)

Brevik, Eric C.; Cerdà, Artemi

2017-04-01

Human knowledge of soil has come a long way since agriculture began about 9000 BCE, when finding the best soils to grow crops in was largely based on a trial and error approach. Many innovations to manage and conserve soil, such as the plow, irrigation techniques, terraces, contour tillage, and even the engineering of artificial soils, were developed between 9000 BCE and 1500 CE. Scientific methods began to be employed in the study of soils during the Renaissance and many famous scientists addressed soil issues, but soil science did not evolve into an independent scientific field of study until the 1880s. In the early days of the study of soil as a science, soil survey activities provided one of the major means of advancing the field. As the 20th century progressed, advances in soil biology, chemistry, genesis, management, and physics allowed the use of soil information to expand beyond agriculture to environmental issues, human health, land use planning, and many other areas. The development of soil history as a subfield of the discipline in the latter part of the 20th century has promise to help advance soil science through a better understanding of how we have arrived at the major theories that shape the modern study of soil science.

Airstream fractionation of vesicular-arbuscular mycorrhizal fungi: concentration and enumeration of propagules.

PubMed

Tommerup, I C

1982-09-01

Spores and fragments of vesicular-arbuscular mycorrhizal fungi in dry soils were concentrated up to 100-fold when the soils were partitioned by fluidization and elutriation with a series of upward airstreams at progressively increasing velocities. The propagules were transported with the finer soil particles according to their equivalent spherical diameters. The system was used to predict the transport of propagules by wind. Concentrated propagules were rapidly separated from the soil particles in each soil fraction by an aqueous flotation method. The technique is proposed as a quantitative method for estimating the numbers of spores and fragments of mycorrhizae. The scheme includes a viability test that was used to differentiate between potentially infective propagules and those that were either dormant or incapable of regrowth.

Soil erosion at agricultural land in Moravia loess region estimated by using magnetic properties

NASA Astrophysics Data System (ADS)

Kapicka, Ales; Dlouha, Sarka; Petrovsky, Eduard; Jaksik, Ondrej; Grison, Hana; Kodesova, Radka

2014-05-01

A detailed field study on a small test site of agricultural land situated in loess region in Southern Moravia (Czech Republic) and subsequent laboratory analyses have been carried out in order to test the applicability of magnetic methods for the estimation of soil erosion. Chernozem, the original dominant soil unit in the wider area, is nowadays progressively transformed into different soil units along with intensive soil erosion. As a result, an extremely diversified soil cover structure has resulted from the erosion. The site was characterized by a flat upper part while the middle part, formed by a substantive side valley, is steeper (up to 15°). We carried out field measurements of magnetic susceptibility on a regular grid, resulting in 101 data points. The bulk soil material for laboratory investigation was gathered from all the grid points. We found a strong correlation between the volume magnetic susceptibility (field measurement) and mass specific magnetic susceptibility measured in the laboratory (R2 = 0.80). Values of the magnetic susceptibility are spatially distributed depending on the terrain. Higher values were measured in the flat upper part (where the original top horizon remained). The lowest values of magnetic susceptibility were obtained on the steep valley sides. Here the original topsoil was eroded and mixed by tillage with the soil substrate (loess). The soil profile that was unaffected by erosion was investigated in detail. The vertical distribution of magnetic susceptibility along this "virgin" profile was measured in laboratory on the samples from layers along the whole profile with 2-cm spacing. The undisturbed profile shows several soil horizons. Horizons Ac and A show a slight increase in magnetic susceptibility up to a depth of about 70 cm. Horizon A/Ck is characterized by a decrease in susceptibility, and the underlying C horizon (h > 103 cm) has a very low value of magnetic susceptibility. The differences between the values of susceptibility in the undisturbed soil profile and the magnetic signal after uniform mixing the soil material as a result of tillage and erosion are fundamental for the estimation of soil loss in the studied test field. Using the uneroded profile from the studied locality as a basis for examining the changes in cultivated soils, tillage homogenization model can be applied to predict changes in the surface soil magnetism with progressive soil erosion. The model is very well applicable at the studied site. Acknowledgement: This study was supported by NAZV Agency of the Ministry of Agriculture of the Czech Republic through grant No QJ1230319

Soil biology research across latitude, elevation and disturbance gradients: A review of forest studies from Puerto Rico during the past 25 years

Treesearch

Grizelle González; D. Lodge

2017-01-01

Progress in understanding changes in soil biology in response to latitude, elevation and disturbance gradients has generally lagged behind studies of above-ground plants and animals owing to methodological constraints and high diversity and complexity of interactions in below-ground food webs. New methods have opened research opportunities in below-ground systems,...

Effects of timber harvesting on the lag time of a Caspar Creek watershed...a study in progress

Treesearch

Karen D. Hardison

1982-01-01

Researchers are not agreed on the effects of logging on lag time. Numerous studies have shown that the use of heavy equipment in logging operations can cause soil compaction. Also, associated roads alter natural drainage patterns by concentrating runoff and interrupting subsurface flow. As a result these researchers say, less infiltration into the soil takes place...

Radioecology of natural systems in Colordao. Fourteenth annual progress report, May 1, 1975--July 31, 1976. [Pu diffusion in terrestrial ecosystems at Rocky Flats Plant

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

Whicker, F.W.

1976-08-01

This report summarizes project activities during the period May 1, 1975 through July 31, 1976. The major study on the distribution and levels of Pu in major components of the terrestrial ecosystem at Rocky Flats was completed. Supportive studies on the ecology and pathology of small mammals and their role in Pu transport were essentially completed as well. Detailed studies on mule deer food habits, population dynamics, and movements at Rocky Flats are progressing. These studies are designed to measure the potential of mule deer in transporting Pu to uncontrolled areas. Alpha autoradiographic studies designed to measure Pu particle sizemore » and distribution and spatial patterns in soil were initiated. Field and greenhouse transport pathways from soil to vegetation are in progress and some early results reported. The status of studies on seasonal kinetics of Cs in a montane lake and stable lead geochemistry in an alpine lake watershed are also reported.« less

Effect of DCB extraction on Mossbauer and spectral data for a Hawaiian palagonitic soil (PN-9): Iden tification of pigmentary phases

NASA Technical Reports Server (NTRS)

Morris, Richard V.; Golden, D. C.; Bell, J. F., III; Lauer, H. V., Jr.; Adams, J. B.

1992-01-01

The study of palagonitic soils is an active area of research in martian geoscience because the spectral and magnetic properties of a subset are spectral and/or magnetic analogues of martian bright regions. An understanding of the composition, distribution, and mineralogy of ferric-bearing phases for palagonitic soils forms, through spectral and magnetic data, a basis for inferring the nature of ferric-bearing phases on Mars. Progress has been made in this area, but the data set is incomplete, especially with respect to the nature of pigmenting phases. The purpose of this study is to identify the nature of the pigment for Hawaiian palagonitic soil PN-9 by using extraction procedures to selectively remove iron oxide phases. This soil was collected at the same locale as samples Hawaii 34 and VOL02. All three soils are good spectral analogues for martian bright regions.

[Effects of climate change on forest soil organic carbon storage: a review].

PubMed

Zhou, Xiao-yu; Zhang, Cheng-yi; Guo, Guang-fen

2010-07-01

Forest soil organic carbon is an important component of global carbon cycle, and the changes of its accumulation and decomposition directly affect terrestrial ecosystem carbon storage and global carbon balance. Climate change would affect the photosynthesis of forest vegetation and the decomposition and transformation of forest soil organic carbon, and further, affect the storage and dynamics of organic carbon in forest soils. Temperature, precipitation, atmospheric CO2 concentration, and other climatic factors all have important influences on the forest soil organic carbon storage. Understanding the effects of climate change on this storage is helpful to the scientific management of forest carbon sink, and to the feasible options for climate change mitigation. This paper summarized the research progress about the distribution of organic carbon storage in forest soils, and the effects of elevated temperature, precipitation change, and elevated atmospheric CO2 concentration on this storage, with the further research subjects discussed.

[Progress in improvement of continuous monoculture cropping problem in Panax ginseng by controlling soil-borne disease management].

PubMed

Wang, Rui; Dong, Lin-Lin; Xu, Jiang; Chen, Jun-Wen; Li, Xi-Wen; Chen, Shi-Lin

2016-11-01

The continuous monoculture cropping problem severely has hindered the land resource of Panax ginseng cultivation and threatened the sustainable development of ginseng industry. There are comprehensive factors causing the continuous monoculture cropping problem, such as deterioration of soil physical and chemical properties, accumulation of allelochemical, increase of pesticide residue and heavy metal, imbalance of rhizospheric micro-ecosystem, and increase of soil-borne diseases. Among soil-borne disease was one of the key factors. More than 40 soil-borne diseases have been reported in the ginseng cultivation, especially, the diseases were more serious in the ginseng replanting land. Here main soil-borne diseases and their prevention way have been summarized, and we try to provide the effective improvement strategy of continuous monoculture cropping problem focusing on the disease control and offer reference for overcoming the ginseng continuous monoculture cropping problem. Copyright© by the Chinese Pharmaceutical Association.

Dynamic Analysis of Soil Erosion in Songhua River Watershed

NASA Astrophysics Data System (ADS)

Zhang, Yujuan; Li, Xiuhai; Wang, Qiang; Liu, Jiang; Liang, Xin; Li, Dan; Ni, Chundi; Liu, Yan

2018-01-01

In this paper, based on RS and GIS technology and Revised Universal Soil Loss Equation (RUSLE), the soil erosion dynamic changes during the two periods of 1990 and 2010 in Bin County was analyzed by using the Landsat TM data of the two periods, so as to reveal the soil erosion spatial distribution pattern and spatial and temporal dynamic evolution rule in the region. The results showed that: the overall patterns of soil erosion were basically the same in both periods, mainly featuring slight erosion and mild erosion, with the area proportions of 80.68% and 74.71% respectively. The slight and extremely intensive erosion changing rates showed a narrowing trend; mild, moderate and intensive erosion was increasing, with a trend of increased soil erosion; mild and intensive erosion were developing towards moderate erosion and moderate and extremely intensive erosion were progressing towards intensive erosion.

Abacus to determine soils salinity in presence of saline groundwater in arid zones case of the region of Ouargla

NASA Astrophysics Data System (ADS)

Fergougui, Myriam Marie El; Benyamina, Hind; Boutoutaou, Djamel

2018-05-01

In order to remedy the limit of salt intake to the soil surface, it is necessary to study the causes of the soil salinity and find the origin of these salts. The arid areas in the region of Ouargla lie on excessively mineralized groundwater whose level is near the soil surface (0 - 1.5 m). The topography and absence of a reliable drainage system led to the rise of the groundwater beside the arid climatic conditions contributed to the salinization and hydromorphy of the soils. The progress and stabilization of cultures yields in these areas can only occur if the groundwater is maintained (drained) to a depth of 1.6 m. The results of works done to the determination of soil salinity depend mainly on the groundwater's salinity, its depth and the climate.

Rheological properties of soil: a review

NASA Astrophysics Data System (ADS)

Zhu, Guangli; Zhu, Long; Yu, Chao

2017-05-01

Recently rheological methods have been applied to investigate the mechanical properties of soil micro-structure. Rheological techniques have a number of quantitative physically based measurements and offer a better understanding of how soil micro-structure behaves when subject to stress. Rheological material is refers to deformation properties similar to the solid and flow properties similar to the liquid of bound water and colloidal substances under stress. Soil rheology is divided into fluid rheology and plasticity rheology. Fluid rheology is produced by rheological material. Plasticity rheology mainly refers to the sliding and peristaltic between soil solid particles under shear stress. It is generally believed that the soft soil rheology mainly belongs to fluid rheology, while the rheology of sand and other coarse grained soil mainly belongs to plasticity rheology. Thus, rheology mechanisms of soft soil and sand are different. This paper introduces the methods of the research progress on the rheology of soil, in the soil rheological mechanism, rheological model and rheological numerical aspects of the research at home and abroad were summarized and analysed, discussed the problems existed in related research, and puts forward some suggestions for the future study on the rheology of soil.

Progress towards more uniform assessment and reporting of soil disturbance for operations, research, and sustainability protocols.

Treesearch

Michael P. Curran; Richard E. Miller; Steven W. Howes; Douglas G. Maynard; Thomas A. Terry; Ronald L. Heninger; Thomas Niemann; Ken van Rees; Robert F. Powers; Stephen H. Schoenholtz

2005-01-01

International protocols, such as those of the Montreal Process (MP), specify desired outcomes without specifying the process and components required to attain those outcomes. We suggest that the process and its components are critical to achieve desired outcomes. We discuss recent progress in northwestern North America, on three topics that will facilitate development...

Root-soil air gap and resistance to water flow at the soil-root interface of Robinia pseudoacacia.

PubMed

Liu, X P; Zhang, W J; Wang, X Y; Cai, Y J; Chang, J G

2015-12-01

During periods of water deficit, growing roots may shrink, retaining only partial contact with the soil. In this study, known mathematical models were used to calculate the root-soil air gap and water flow resistance at the soil-root interface, respectively, of Robinia pseudoacacia L. under different water conditions. Using a digital camera, the root-soil air gap of R. pseudoacacia was investigated in a root growth chamber; this root-soil air gap and the model-inferred water flow resistance at the soil-root interface were compared with predictions based on a separate outdoor experiment. The results indicated progressively greater root shrinkage and loss of root-soil contact with decreasing soil water potential. The average widths of the root-soil air gap for R. pseudoacacia in open fields and in the root growth chamber were 0.24 and 0.39 mm, respectively. The resistance to water flow at the soil-root interface in both environments increased with decreasing soil water potential. Stepwise regression analysis demonstrated that soil water potential and soil temperature were the best predictors of variation in the root-soil air gap. A combination of soil water potential, soil temperature, root-air water potential difference and soil-root water potential difference best predicted the resistance to water flow at the soil-root interface. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Advance in researches on vegetation cover and management factor in the soil erosion prediction model].

PubMed

Zhang, Yan; Yuan, Jianping; Liu, Baoyuan

2002-08-01

Vegetation cover and land management are the main limiting factors of soil erosion, and quantitative evaluation on the effect of different vegetation on soil erosion is essential to land use and soil conservation planning. The vegetation cover and management factor (C) in the universal soil loss equation (USLE) is an index to evaluate this effect, which has been studied deeply and used widely. However, the C factor study is insufficient in China. In order to strengthen the research of C factor, this paper reviewed the developing progress of C factor, and compared the methods of estimating C value in different USLE versions. The relative studies in China were also summarized from the aspects of vegetation canopy coverage, soil surface cover, and root density. Three problems in C factor study were pointed out. The authors suggested that cropland C factor research should be furthered, and its methodology should be unified in China to represent reliable C values for soil loss prediction and conservation planning.

Prediction of soil stability and erosion in semiarid regions using numerical hydrological model (MCAT) and airborne hyperspectral imagery

NASA Astrophysics Data System (ADS)

Brook, Anna; Wittenberg, Lea

2015-04-01

Long-term environmental monitoring is addressed to identify physical and biological changes and progresses taking place in the ecosystem. This basic action of landscape monitoring is an essential part of the systematic long-term surveillance, aiming to evaluate, assess and predict the spatial change and progresses. Indeed, it provides a context for wide range of diverse studies and research frameworks from regional or global scale. Spatial-temporal trends and changes at various scales (massive to less certain) require establishing consistent baseline data over time. One of the spatial cases of landscape monitoring is dedicated to soil formation and pedological progresses. It is previously acknowledged that changes in soil affect the functionality of the environment, so monitoring changes recently become important cause considerable resources in areas such as environmental management, sustainability services, and protecting the environment healthy. Given the above, it can be concluded that monitoring changes in the base for sustainable development. The hydrological response of bare soils and watersheds in semiarid regions to intense rainfall events is known to be complex due to multiply physical and structural impacts and feedbacks. As a result, the comprehensive evaluations of mathematical models including detailed consideration of uncertainties in the modeling of hydrological and environmental systems are of increasing importance. The presented method incorporates means of remote sensing data, hydrological and climate data and implementing dedicated and integrative Monte Carlo Analysis Toolbox (MCAT) model for semiarid region. Complexity of practical models to represent spatial systems requires an extensive understanding of the spatial phenomena, while providing realistic balance of sensitivity and corresponding uncertainty levels. Nowadays a large number of dedicated mathematical models applied to assess environmental hydrological process. Among the most promising models is the MCAT, which is a MATLAB library of visual and numerical analysis tools for the evaluation of hydrological and environmental models. The model applied in this paper presents an innovative infrastructural system for predicting soil stability and erosion impacts. This integrated model is applicable to mixed areas with spatially varying soil properties, landscape, and land-cover characteristics. Data from a semiarid site in southern Israel was used to evaluate the model and analyze fundamental erosion mechanisms. The findings estimate the sensitivity of the suggested model to the physical parameters and encourage the use of hyperspectral remote sensing imagery (HSI). The proposed model is integrated according to the following stages: 1. The soil texture, aggregation, soil moisture estimated via airborne HSI data, including soil surface clay and calcium carbonate erosions; 2. The mechanical stability of soil assessed via pedo-transfer function corresponding to load dependent changes in soil physical properties due to pre-compression stress (set of equations study shear strength parameters take into account soil texture, aggregation, soil moisture and ecological soil variables); 3. The precipitation-related runoff model program (RMP) satisfactorily reproduces the observed seasonal mean and variation of surface runoff for the current climate simulation; 4. The Monte Carlo Analysis Toolbox (MCAT), a library of visual and numerical analysis tools for the evaluation of hydrological and environmental models, is proposed as a tool for integrate all the approaches to an applicable model. The presented model overcomes the limitations of existing modeling methods by integrating physical data produced via HSI and yet stays generic in terms of space and time independency.

Impacts of terracing on soil erosion control and crop yield in two agro-ecological zones of Rwanda

NASA Astrophysics Data System (ADS)

Rutebuka, Jules; Ryken, Nick; Uwimanzi, Aline; Nkundwakazi, Olive; Verdoodt, Ann

2017-04-01

Soil erosion remains a serious limiting factor to the agricultural production in Rwanda. Terracing has been widely adopted in many parts of the country in the past years, but its effectiveness is not yet known. Besides the standard radical (bench) terraces promoted by the government, also progressive terraces (with living hedges) become adopted mainly by the farmers. The aim of this study was to measure short-term (two consecutive rainy seasons 2016A and 2016B) run-off and soil losses for existing radical (RT) and progressive (PT) terraces versus non-protected (NP) fields using erosion plots installed in two agro-ecological zones, i.e. Buberuka highlands (site Tangata) and Eastern plateau (site Murehe) and determine their impacts on soil fertility and crop production. The erosion plot experiment started with a topsoil fertility assessment and during the experiment, maize was grown as farmer's cropping preference in the area. Runoff data were captured after each rainfall event and the collected water samples were dried to determine soil loss. Both erosion control measures reduced soil losses in Tangata, with effectiveness indices ranging from 43 to 100% when compared to the NP plots. RT showed the highest effectiveness, especially in season A. In Murehe, RT minimized runoff and soil losses in both seasons. Yet, the PT were largely inefficient, leading to soil losses exceeding those on the NP plots (ineffectiveness index of -78% and -65% in season A and B, respectively). Though topsoil fertility assessment in the erosion plots showed that the soil quality parameters were significantly higher in RT and NP plots compared to the PT plots on both sites, maize grain yield was not correlated with the physical effectiveness of the erosion control measures. Finally, the effectiveness of soil erosion control measures as well as their positive impacts on soil fertility and production differ not only by terracing type but also by agro-ecological zone and the management or maintenance adopted by farmers. Terracing should be complemented by continuous fertility amendments (organic material inputs), use of improved agronomic and management practices considering agro-ecological zone conditions. In general, radical terracing was found to be the most effective soil erosion control measure on both sites.

Optimizing root system architecture in biofuel crops for sustainable energy production and soil carbon sequestration.

PubMed

To, Jennifer Pc; Zhu, Jinming; Benfey, Philip N; Elich, Tedd

2010-09-08

Root system architecture (RSA) describes the dynamic spatial configuration of different types and ages of roots in a plant, which allows adaptation to different environments. Modifications in RSA enhance agronomic traits in crops and have been implicated in soil organic carbon content. Together, these fundamental properties of RSA contribute to the net carbon balance and overall sustainability of biofuels. In this article, we will review recent data supporting carbon sequestration by biofuel crops, highlight current progress in studying RSA, and discuss future opportunities for optimizing RSA for biofuel production and soil carbon sequestration.

Winter survival of microbial contaminants in soil: an in situ verification.

PubMed

Bucci, Antonio; Allocca, Vincenzo; Naclerio, Gino; Capobianco, Giovanni; Divino, Fabio; Fiorillo, Francesco; Celico, Fulvio

2015-01-01

The aim of the research was to evaluate, at site scale, the influence of freezing and freeze/thaw cycles on the survival of faecal coliforms and faecal enterococci in soil, in a climate change perspective. Before the winter period and during grazing, viable cells of faecal coliforms and faecal enterococci were detected only in the first 10 cm below ground, while, after the winter period and before the new seasonal grazing, a lower number of viable cells of both faecal indicators was detected only in some of the investigated soil profiles, and within the first 5 cm. Taking into consideration the results of specific investigations, we hypothesise that the non-uniform spatial distribution of grass roots within the studied soil can play an important role in influencing this phenomenon, while several abiotic factors do not play any significant role. Taking into account the local trend in the increase of air temperature, a different distribution of microbial pollution over time is expected in spring waters, in future climate scenarios. The progressive increase in air temperature will cause a progressive decrease in freeze/thaw cycles at higher altitudes, minimising cold shocks on microbial cells, and causing spring water pollution also during winter. Copyright © 2014. Published by Elsevier B.V.

The effect of soil on human health: an overview.

PubMed

Steffan, J J; Brevik, E C; Burgess, L C; Cerdà, A

2018-01-01

Soil has a considerable effect on human health, whether those effects are positive or negative, direct or indirect. Soil is an important source of nutrients in our food supply and medicines such as antibiotics. However, nutrient imbalances and the presence of human pathogens in the soil biological community can cause negative effects on health. There are also many locations where various elements or chemical compounds are found in soil at toxic levels, because of either natural conditions or anthropogenic activities. The soil of urban environments has received increased attention in the last few years, and they too pose a number of human health questions and challenges. Concepts such as soil security may provide a framework within which issues on soil and human health can be investigated using interdisciplinary and transdisciplinary approaches. It will take the contributions of experts in several different scientific, medical and social science fields to address fully soil and human health issues. Although much progress was made in understanding links between soil and human health over the last century, there is still much that we do not know about the complex interactions between them. Therefore, there is still a considerable need for research in this important area.

Semi-Quantitative Evaluation of Secondary Carbonates via Portable X-ray Fluorescence Spectrometry

NASA Astrophysics Data System (ADS)

Chakraborty, Somsubhra; Weindorf, David; Weindorf, Camille; Duda, Bogdan; Pennington, Sarah; Ortiz, Rebekah

2017-04-01

Secondary calcium carbonate commonly occurs in subsoils of semi-arid soils worldwide. In US Soil Taxonomy, such horizons are frequently described as Bk, Bkk, Bkm, Bkkm, or Ck horizons at variable stages of development. Specifically, the Soil Survey Staff uses a qualitative scale of one through six to indicate differential developmental stages. However, considerable disagreement exists even among experienced soil scientists. Evaluating 75 soil samples from across four US states, a portable X-ray fluorescence (PXRF) spectrometer was used to quantify the total soil Ca content and compare it to average developmental stage scores as determined by a panel of Soil Survey Staff personnel. Samples were evaluated both as intact aggregates as well as ground (<2 mm), homogenized powders. PXRF readings of total soil Ca concentration steadily increased under both conditions as developmental stage progressed. However, minimal difference was observed between stage five and six carbonate accumulation. Stage three showed the widest variability in total soil Ca. Given than PXRF cannot distinguish between primary and secondary CaCO3 in soils, interpretation by the analyst remains essential. Nonetheless, PXRF provides an important tool for assessing carbonate laden subsoils providing elemental differentiation beyond that perceived by the human eye.

Empirical estimates to reduce modeling uncertainties of soil organic carbon in permafrost regions: a review of recent progress and remaining challenges

USGS Publications Warehouse

Mishra, U.; Jastrow, J.D.; Matamala, R.; Hugelius, G.; Koven, C.D.; Harden, Jennifer W.; Ping, S.L.; Michaelson, G.J.; Fan, Z.; Miller, R.M.; McGuire, A.D.; Tarnocai, C.; Kuhry, P.; Riley, W.J.; Schaefer, K.; Schuur, E.A.G.; Jorgenson, M.T.; Hinzman, L.D.

2013-01-01

The vast amount of organic carbon (OC) stored in soils of the northern circumpolar permafrost region is a potentially vulnerable component of the global carbon cycle. However, estimates of the quantity, decomposability, and combustibility of OC contained in permafrost-region soils remain highly uncertain, thereby limiting our ability to predict the release of greenhouse gases due to permafrost thawing. Substantial differences exist between empirical and modeling estimates of the quantity and distribution of permafrost-region soil OC, which contribute to large uncertainties in predictions of carbon–climate feedbacks under future warming. Here, we identify research challenges that constrain current assessments of the distribution and potential decomposability of soil OC stocks in the northern permafrost region and suggest priorities for future empirical and modeling studies to address these challenges.

Involvement of the European Confederation of the Soil Science Societies in soil protection policy development

NASA Astrophysics Data System (ADS)

Boivin, Pascal

2017-04-01

The European Confederation of the Soil Science Societies (ECSSS) was founded not only to organize the Eurosoil congress, but also to continuously support and promote the soil causes in the European area. A work is in progress to define the best way to achieve this goal, with integrating voices of the European structures and networks, and the national societies. One of the major objectives is to develop a modern approach of soil protection, including leading experimentations shared with all the members, and active lobbying. Such an approach requires the buildup of an efficient interface with policy makers, stake holders, engineering and science, which should be concretized in a new the dimension of the Eurosoil congress. This communication will sketch the on-going work, with reviewing the perspectives, conditions, strengths, questions and difficulties identified.

Making time for soil: Technoscientific futurity and the pace of care.

PubMed

de la Bellacasa, Maria Puig

2015-10-01

The dominant drive for understanding soil has been to pace its fertility with human demand. Today, warnings about soil's exhaustion and endangered ecology raise concerns marked by fears of gloomy environmental futures, prompting scientists and soil practitioners urgently to develop better ways of taking care of soils. Yet the pace required by ecological soil care could be at odds with the predominant temporal orientation of technoscientific intervention, which is driven by an inherently progressivist, productionist and restless mode of futurity. Through a conceptual and historical approach to the soil sciences and other domains of soil knowledge, this article looks for soil ontologies and relations to soil care that are obscured by the predominant timescape. Contemporary discussions of the future of the soil sciences expose tensions between 'progress as usual'--by intensifying productivity--and the need to protect the pace of soil renewal. The intimate relation of soil science with productionism is being interrogated, as ecology attempts to engage with soil as a living community rather than a receptacle for crops. In this context, and beyond science, the 'foodweb' model of soil ecology has become a figure of alternative human-soil relations that involve environmental practitioners in the soil community. Reading these ways of making time for soil as a form of 'care time' helps to reveal a diversity of more-than-human interdependent temporalities, disrupting the anthropocentric appeal of predominant timescales of technoscientific futurity and their reductive notion of innovation.

Soil erodibility for water erosion: A perspective and Chinese experiences

NASA Astrophysics Data System (ADS)

Wang, Bin; Zheng, Fenli; Römkens, Mathias J. M.; Darboux, Frédéric

2013-04-01

Knowledge of soil erodibility is an essential requirement for erosion prediction, conservation planning, and the assessment of sediment related environmental effects of watershed agricultural practices. This paper reviews the status of soil erodibility evaluations and determinations based on 80 years of upland area erosion research mainly in China and the USA. The review synthesizes the general research progress made by discussing the basic concepts of erodibility and its evaluation, determination, and prediction as well as knowledge of its spatio-temporal variations. The authors found that soil erodibility is often inappropriately or inaccurately applied in describing soil loss caused by different soil erosion component processes and mechanisms. Soil erodibility indicators were related to intrinsic soil properties and exogenic erosional forces, measurements, and calculations. The present review describes major needs including: (1) improved definition of erodibility, (2) modified erodibility determinations in erosion models, especially for specific geographical locations and in the context of different erosion sub-processes, (3) advanced methodologies for quantifying erodibilities of different soil erosion sub-processes, and (4) a better understanding of the mechanism that causes temporal variations in soil erodibility. The review also provides a more rational basis for future research on soil erodibility and supports predictive modeling of soil erosion processes and the development of improved conservation practices.

[Research progress on wind erosion control with polyacrylamide (PAM).

PubMed

Li, Yuan Yuan; Wang, Zhan Li

2016-03-01

Soil wind erosion is one of the main reasons for soil degradation in the northwest region of China. Polyacrylamide (PAM), as an efficient soil amendment, has gained extensive attention in recent years since it is effective in improving the structure of surface soil due to its special physical and chemical properties. This paper introduced the physical and chemical properties of PAM, reviewed the effects of PAM on soil wind erosion amount and threshold wind velocity, as well as the effect differences of PAM in soil wind erosion control under conditions of various methods and doses. Its effect was proved by comparing with other materials in detail. Furthermore, we analyzed the mecha-nism of wind erosion control with PAM according to its influence on soil physical characteristics. Comprehensive analysis showed that, although some problems existed in wind erosion control with (PAM), PAM as a sand fixation agent, can not only enhance the capacity of the soil resis-tance to wind erosion, but also improve soil physical properties to form better soil conditions. Besides, we proposed that combination of PAM and plant growth would increase the survival rate of plants greatly, control soil wind erosion in wind-erosive areas, and improve the quality of the ecological environment construction. Thus, PAM has practically important significance and wide application prospect in controlling soil wind erosion.

Soils as relative-age dating tools

USGS Publications Warehouse

Markewich, Helaine Walsh; Pavich, Milan J.; Wysocki, Douglas A.

2017-01-01

Soils develop at the earth's surface via multiple processes that act through time. Precluding burial or disturbance, soil genetic horizons form progressively and reflect the balance among formation processes, surface age, and original substrate composition. Soil morphology provides a key link between process and time (soil age), enabling soils to serve as both relative and numerical dating tools for geomorphic studies and landscape evolution. Five major factors define the contemporary state of all soils: climate, organisms, topography, parent material, and time. Soils developed on similar landforms and parent materials within a given landscape comprise what we term a soil/landform/substrate complex. Soils on such complexes that differ in development as a function of time represent a soil chronosequence. In a soil chronosequence, time constitutes the only independent formation factor; the other factors act through time. Time dictates the variations in soil development or properties (field or laboratory measured) on a soil/landform/substrate complex. Using a dataset within the chronosequence model, we can also formulate various soil development indices based upon one or a combination of soil properties, either for individual soil horizons or for an entire profile. When we evaluate soil data or soil indices mathematically, the resulting equation creates a chronofunction. Chronofunctions help quantify processes and mechanisms involved in soil development, and relate them mathematically to time. These rigorous kinds of comparisons among and within soil/landform complexes constitute an important tool for relative-age dating. After determining one or more absolute ages for a soil/landform complex, we can calculate quantitative soil formation, and or landform-development rates. Multiple dates for several complexes allow rate calculations for soil/landform-chronosequence development and soil-chronofunction calibration.

Examining diel patterns of soil and xylem moisture using electrical resistivity imaging

NASA Astrophysics Data System (ADS)

Mares, Rachel; Barnard, Holly R.; Mao, Deqiang; Revil, André; Singha, Kamini

2016-05-01

The feedbacks among forest transpiration, soil moisture, and subsurface flowpaths are poorly understood. We investigate how soil moisture is affected by daily transpiration using time-lapse electrical resistivity imaging (ERI) on a highly instrumented ponderosa pine and the surrounding soil throughout the growing season. By comparing sap flow measurements to the ERI data, we find that periods of high sap flow within the diel cycle are aligned with decreases in ground electrical conductivity and soil moisture due to drying of the soil during moisture uptake. As sap flow decreases during the night, the ground conductivity increases as the soil moisture is replenished. The mean and variance of the ground conductivity decreases into the summer dry season, indicating drier soil and smaller diel fluctuations in soil moisture as the summer progresses. Sap flow did not significantly decrease through the summer suggesting use of a water source deeper than 60 cm to maintain transpiration during times of shallow soil moisture depletion. ERI captured spatiotemporal variability of soil moisture on daily and seasonal timescales. ERI data on the tree showed a diel cycle of conductivity, interpreted as changes in water content due to transpiration, but changes in sap flow throughout the season could not be interpreted from ERI inversions alone due to daily temperature changes.

An Overview of Soils and Human Health - Research Trends and Future Needs

NASA Astrophysics Data System (ADS)

Brevik, Eric C.; Burgess, Lynn C.; Steffan, Joshua J.; Cerdà, Artemi

2017-04-01

Soils have significant impact on human health, whether those influences are positive or negative, direct or indirect. Soils are a significant source of nutrients in our food supply and medications such as antibiotics. However, nutrient imbalances and the presence of human pathogens in the soil biological community can cause negative impacts on health. There are also many locations where various elements or chemical compounds are found in soils at toxic levels, due to either natural conditions or anthropogenic activities. The soils of urban environments have received increased attention in the last few years, and they too pose a number of human health questions and challenges. Concepts such as soil security may provide a framework within which soils and human health issues can be investigated using interdisciplinary and transdisciplinary approaches, as it will take the contributions of experts in a number of different scientific, medical, and social science fields to fully address soils and human health issues. While much progress was made in understanding links between soils and human health over the last century, there is still much we do not know and the interactions between soils and human health are extremely complex. Therefore, there is still significant need for research in this important area.

A systemic approach for modeling soil functions

NASA Astrophysics Data System (ADS)

Vogel, Hans-Jörg; Bartke, Stephan; Daedlow, Katrin; Helming, Katharina; Kögel-Knabner, Ingrid; Lang, Birgit; Rabot, Eva; Russell, David; Stößel, Bastian; Weller, Ulrich; Wiesmeier, Martin; Wollschläger, Ute

2018-03-01

The central importance of soil for the functioning of terrestrial systems is increasingly recognized. Critically relevant for water quality, climate control, nutrient cycling and biodiversity, soil provides more functions than just the basis for agricultural production. Nowadays, soil is increasingly under pressure as a limited resource for the production of food, energy and raw materials. This has led to an increasing demand for concepts assessing soil functions so that they can be adequately considered in decision-making aimed at sustainable soil management. The various soil science disciplines have progressively developed highly sophisticated methods to explore the multitude of physical, chemical and biological processes in soil. It is not obvious, however, how the steadily improving insight into soil processes may contribute to the evaluation of soil functions. Here, we present to a new systemic modeling framework that allows for a consistent coupling between reductionist yet observable indicators for soil functions with detailed process understanding. It is based on the mechanistic relationships between soil functional attributes, each explained by a network of interacting processes as derived from scientific evidence. The non-linear character of these interactions produces stability and resilience of soil with respect to functional characteristics. We anticipate that this new conceptional framework will integrate the various soil science disciplines and help identify important future research questions at the interface between disciplines. It allows the overwhelming complexity of soil systems to be adequately coped with and paves the way for steadily improving our capability to assess soil functions based on scientific understanding.

Landuse legacies of old-field succession and soil structure at the Calhoun Criticl Zone Observatory in SC, USA.

NASA Astrophysics Data System (ADS)

Brecheisen, Z. S.; Richter, D. D., Jr.; Callaham, M.; Carrera-Martinez, R.; Heine, P.

2017-12-01

The pre-colonial Southern Piedmont was an incredibly stable CZ with erosion rates between 0.35-3m/Myr on a 4th order interfluve. With soils and saprolite weathered up to 30m in total depth bedrock with multi-million year residence times under continual forest cover prior to widespread agricultural disturbance. With this biogeomorphic stability came time for soil macroporosity and soil structure to be established and maintained by the activities of soil fauna, plant root growth and death, and tree-fall tip-up events serving to continually mix and aerate the soil. Greatly accelerated surficial agricultural erosion (ca. 1750-1930) has fundamentally altered the Calhoun Critical Zone Observatory forest community dynamics aboveground and the soil structure, hydrology, and biogeochemistry belowground. The arrival of the plow to the Southern Piedmont marked the destruction of soil structure, macropore networks, and many of the macroinvertebrate soil engineers. This transformation came via forest clearing, soil tilling, compaction, and wholesale soil erosion, with the region having lost an estimated average of 18cm of soil across the landscape. In the temporal LULC progression from hardwood forests, to cultivated farms, to reforestation, secondary forest soil structure is expected to remain altered compared to the reference hardwood ecosystems. The research presented herein seeks to quantify CZ soil structure regeneration in old-field pine soil profiles' Ksat, aggregation, texture, macro-invertebrates, and direct measurements of topsoil porosity using X-ray computed tomography analysis on 15cm soil cores.

Quantification of the inevitable: the influence of soil macrofauna on soil water movement in rehabilitated open-cut mine land

NASA Astrophysics Data System (ADS)

Arnold, S.; Williams, E. R.

2015-08-01

Recolonisation of soil by macrofauna (especially ants and termites) in rehabilitated open-cut mine sites is inevitable. In these highly disturbed landscapes, soil invertebrates play a major role in soil development (macropore configuration, nutrient cycling, bioturbation, etc.) and can influence hydrological processes such as infiltration and seepage. Understanding and quantifying these ecosystem processes is important in rehabilitation design, establishment and subsequent management to ensure progress to the desired end-goal, especially in waste cover systems designed to prevent water reaching and transporting underlying hazardous waste materials. However, soil macrofauna are typically overlooked during hydrological modelling, possibly due to uncertainties on the extent of their influence, which can lead to failure of waste cover systems or rehabilitation activities. We propose that scientific experiments under controlled conditions are required to quantify (i) macrofauna - soil structure interactions, (ii) functional dynamics of macrofauna taxa, and (iii) their effects on macrofauna and soil development over time. Such knowledge would provide crucial information for soil water models, which would increase confidence in mine waste cover design recommendations and eventually lead to higher likelihood of rehabilitation success of open-cut mining land.

Microbial chlorination of organic matter in forest soil: investigation using 36Cl-chloride and its methodology.

PubMed

Rohlenová, J; Gryndler, M; Forczek, S T; Fuksová, K; Handova, V; Matucha, M

2009-05-15

Chloride, which comes into the forest ecosystem largely from the sea as aerosol (and has been in the past assumed to be inert), causes chlorination of soil organic matter. Studies of the chlorination showed that the content of organically bound chlorine in temperate forest soils is higher than that of chloride, and various chlorinated compounds are produced. Our study of chlorination of organic matter in the fermentation horizon of forest soil using radioisotope 36Cl and tracer techniques shows that microbial chlorination clearly prevails over abiotic, chlorination of soil organic matter being enzymatically mediated and proportional to chloride content and time. Long-term (>100 days) chlorination leads to more stable chlorinated substances contained in the organic layer of forest soil (overtime; chlorine is bound progressively more firmly in humic acids) and volatile organochlorines are formed. Penetration of chloride into microorganisms can be documented by the freezing/thawing technique. Chloride absorption in microorganisms in soil and in litter residues in the fermentation horizon complicates the analysis of 36Cl-chlorinated soil. The results show that the analytical procedure used should be tested for every soil type under study.

Ecosystem services driven by the diversity of soil biota - understanding and management in agriculture - The Biodiversa SoilMan-Project

NASA Astrophysics Data System (ADS)

Potthoff, Martin; Pérès, Guénola; Taylor, Astrid; Schrader, Stefan; Landa, Blanca; Nicolai, Annegret; Sandor, Mignon; Öptik, Maarja; Gema, Guzmán; Bergmann, Holger; Cluzeau, Daniel; Banse, Martin; Bengtsson, Jan; Guernion, Muriel; Zaller, Johann; Roslin, Tomas; Scheu, Stefan; Gómez Calero, José Alfonso

2017-04-01

Soil biota diversity is ensuring primary production in terrestrial ecosystems and agricultural productivity. Water and nutrient cycling, soil formation and aggregation, decomposition and carbon sequestration as well as control of pest organisms are important functions in soil that are driven by biota and biota interactions. In agricultural systems these functions support and regulate ecosystem services directed to agricultural production and agricultural sustainability. A main goal of future cropping systems will be to maintain or raise agricultural productivity while keeping production sustainable in spite of increasing food demands and ongoing soil degradation caused by inappropriate soil management practices. Farm based tools that farmers use to engineer soils for plant production depend as soil management factors on decisions by farmers, which are triggered by regional traditions, knowledge and also by agriculture policies as a governance impact. However, biological impacts on soil fertility and soil health are often neglected or overseen when planning and shaping soil management in annual cropping systems or perennial systems like vineyards. In order to get progress in conservation farming and in agricultural sustainability not only knowledge creation is in need, but also a clash of perspectives has to be overcome within the societies (generals public, farmers associations, NGOs) The talk will present the conception of the recently startet SoilMan-project and summaries selected results from current and recent European research projects.

Humic substances interfere with detection of pathogenic prion protein

USGS Publications Warehouse

Smith, Christen B.; Booth, Clarissa J.; Wadzinski, Tyler J.; Legname, Giuseppe; Chappell, Rick; Johnson, Christopher J.; Pedersen, Joel A.

2014-01-01

Studies examining the persistence of prions (the etiological agent of transmissible spongiform encephalopathies) in soil require accurate quantification of pathogenic prion protein (PrPTSE) extracted from or in the presence of soil particles. Here, we demonstrate that natural organic matter (NOM) in soil impacts PrPTSE detection by immunoblotting. Methods commonly used to extract PrPTSE from soils release substantial amounts of NOM, and NOM inhibited PrPTSE immunoblot signal. The degree of immunoblot interference increased with increasing NOM concentration and decreasing NOM polarity. Humic substances affected immunoblot detection of prion protein from both deer and hamsters. We also establish that after interaction with humic acid, PrPTSE remains infectious to hamsters inoculated intracerebrally, and humic acid appeared to slow disease progression. These results provide evidence for interactions between PrPTSE and humic substances that influence both accurate measurement of PrPTSE in soil and disease transmission.

Completing below-ground carbon budgets for pastures, recovering forests, and mature forests of Amazonia

NASA Technical Reports Server (NTRS)

Davidson, Eric A.; Nepstad, Daniel C.; Trumbore, Susan E.

1995-01-01

This progress report covers the following efforts initiated for the year: year-round monthly soil CO2 flux measurements were started in both primary and secondary forests and in managed and degraded pastures; root sorting and weighing has begun and all four ecosystems at Paragominas have been analyzed through samples; regional modeling of soil water dynamics and minimum rooting depth has been done and the RADAMBRASIL soils database has been digitized and a 20 year record of the precipitation for the region has been produced, along with a hydrological ('bucket-tipping') model that will run within a GIS framework; prototype tension lysimeters have been designed and installed in soil pits to begin assessing the importance of DOC as a source of organic matter in deep soils; and many publications, listed in this document, have resulted from this year's research. Two of the papers published are included with this annual report document.

Examination of the behavior of gravity quay wall against liquefaction under the effect of wall width and soil improvement.

PubMed

Firoozi, Ali Akbar; Taha, Mohd Raihan; Mir Moammad Hosseini, S M; Firoozi, Ali Asghar

2014-01-01

Deformation of quay walls is one of the main sources of damage to port facility while liquefaction of backfill and base soil of the wall are the main reasons for failures of quay walls. During earthquakes, the most susceptible materials for liquefaction in seashore regions are loose saturated sand. In this study, effects of enhancing the wall width and the soil improvement on the behavior of gravity quay walls are examined in order to obtain the optimum improved region. The FLAC 2D software was used for analyzing and modeling progressed models of soil and loading under difference conditions. Also, the behavior of liquefiable soil is simulated by the use of "Finn" constitutive model in the analysis models. The "Finn" constitutive model is especially created to determine liquefaction phenomena and excess pore pressure generation.

Examination of the Behavior of Gravity Quay Wall against Liquefaction under the Effect of Wall Width and Soil Improvement

PubMed Central

Taha, Mohd Raihan; Mir Moammad Hosseini, S. M.

2014-01-01

Deformation of quay walls is one of the main sources of damage to port facility while liquefaction of backfill and base soil of the wall are the main reasons for failures of quay walls. During earthquakes, the most susceptible materials for liquefaction in seashore regions are loose saturated sand. In this study, effects of enhancing the wall width and the soil improvement on the behavior of gravity quay walls are examined in order to obtain the optimum improved region. The FLAC 2D software was used for analyzing and modeling progressed models of soil and loading under difference conditions. Also, the behavior of liquefiable soil is simulated by the use of “Finn” constitutive model in the analysis models. The “Finn” constitutive model is especially created to determine liquefaction phenomena and excess pore pressure generation. PMID:25126595

Area G perimeter surface-soil and single-stage water sampling: Environmental surveillance for fiscal year 95. Progress report

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

Childs, M.; Conrad, R.

1997-09-01

ESH-19 personnel collected soil and single-stage water samples around the perimeter of Area G at Los Alamos National Laboratory (LANL) during FY 95 to characterize possible radionuclide movement out of Area G through surface water and entrained sediment runoff. Soil samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241, and cesium-137. The single-stage water samples were analyzed for tritium and plutonium isotopes. All radiochemical data was compared with analogous samples collected during FY 93 and 94 and reported in LA-12986 and LA-13165-PR. Six surface soils were also submitted for metal analyses. These data were included with similar data generatedmore » for soil samples collected during FY 94 and compared with metals in background samples collected at the Area G expansion area.« less

Efficient Meshfree Large Deformation Simulation of Rainfall Induced Soil Slope Failure

NASA Astrophysics Data System (ADS)

Wang, Dongdong; Li, Ling

2010-05-01

An efficient Lagrangian Galerkin meshfree framework is presented for large deformation simulation of rainfall-induced soil slope failure. Detailed coupled soil-rainfall seepage equations are given for the proposed formulation. This nonlinear meshfree formulation is featured by the Lagrangian stabilized conforming nodal integration method where the low cost nature of nodal integration approach is kept and at the same time the numerical stability is maintained. The initiation and evolution of progressive failure in the soil slope is modeled by the coupled constitutive equations of isotropic damage and Drucker-Prager pressure-dependent plasticity. The gradient smoothing in the stabilized conforming integration also serves as a non-local regularization of material instability and consequently the present method is capable of effectively capture the shear band failure. The efficacy of the present method is demonstrated by simulating the rainfall-induced failure of two typical soil slopes.

Soil and public health: invisible bridges

NASA Astrophysics Data System (ADS)

Pachepsky, Yakov

2017-04-01

Public health institutions, as ancient as civilizations itself, are intrinsically connected with soils. The massive body of the empirical knowledge about this connection has been accumulated. Recently unraveling the underlying mechanisms of this link has begun, and many of them appear to have the microbiological origin. The impressive progress in understanding the nexus between soil and health has been achieved by experimentation with preserved soil microbial systems functioning along with the metagenomic characterization. The objective of this work is to present an overview of some recent onsets. In the food safety arena, survival of human pathogens in soils has been related to the degree of soil eutrophication and/or related structure of soil microbial communities. Soil microbial systems affect the affinity of plants to internalizing pathogenic organisms. Pharmaceutical arsenals benefit from using field soil environment for developing antibiotics. Enzyme production by soil bacteria is used as the signal source for drug activation. Sanitary functions of sols are dependent on soil microbial system workings. The healthy living can be enhanced by the human immune system training received from direct contact with soils. The hygiene hypothesis considers the microbial input due to exposure to soil as the essential ecosystem service. The invisible links between soil and public health result in large-scale consequences. Examples of concurrent degradation of soil and public health are worth scrutinizing. Public health records can provide valuable sources of 'soil-public health' interactions. It may be worthwhile to examine current assessments of soil health from the public health standpoint. Soil management can be an efficient instrument of public health control.

Medium-term evolution of water repellency and aggregate stability in Mediterranean calcareous soils after wildfire

NASA Astrophysics Data System (ADS)

Gordillo-Rivero, Ángel; García-Moreno, Jorge; Zavala, Lorena M.; Jordán, Antonio; Granged, Arturo JP; Gil, Juan

2013-04-01

Wildfires are a common feature of Mediterranean ecosystems due to environmental factors and anthropic influence, especially in those areas where land use change and the development of touristic infrastructures are more intense. Wildfires induce a series of soil changes affecting their physical and chemical properties and the hydrological and erosive response. Two of the properties that are commonly affected by burning are soil water repellency (WR) and aggregate stability (AS). Both properties play an important role in the hydrological response of soils and other processes, and may be used as indices for assessing burn severity (Gordillo-Rivero et al., 2013). OBJECTIVES The field study was carried out between August 2006 (date of burning) and August 2011 with the following objectives: [i] to study the changes in SWR and AS immediately after fire and in the medium-term (6 years after burning) and its distribution within aggregate size fractions (<2, 1-2, 0.5-1 and 0.25-0.5 mm), [ii] to assess the relationships between postfire AS and WR, and [iii] to investigate interactions between AS and WR and different factors (site, time since burning, lithology and vegetation type) in calcareous Mediterranean soils. METHODS Five areas affected by wildfires during summer 2006 were selected for this research. Vegetation was characterized by grassland and Mediterranean shrubland. Soils were calcareous, with loam to clayey texture. As shown from adjacent areas, soils were wettable or slightly water-repellent immediately before burning. Soil WR and AS were measured in soil samples (0-15 mm deep) in fine earth (<2 mm) and aggregate sieve fractions (1-2, 0.5-1 and 0.25-0.5 mm). WR was assessed using the WDPT test, and AS was determined as the percentage of stable aggregates after laboratory rainfall simulation. RESULTS Both properties showed different tendencies in different aggregate size fractions. Results showed that soil WR was induced in wettable soils or enhanced in slightly or moderately water-repellent soils after moderate severity burning. WR increased after fire especially in the finer fractions (0.25-0.5 mm) immediately after fire, and WR from finer aggregates (0.5-1 and 0.25-0.5 mm) varied or remained stable during the studied period, but did not contribute to general soil WR assessed in the fine earth fraction. AS increased significantly after the fire and was progressively reduced during the experimental period. Both properties returned progressively to pre-fire conditions during the study period. Soil resilience to low-moderate severity burning in the study area was very high. REFERENCES Gordillo-Rivero, A.J., García-Moreno, J., Jordán, A., Zavala, L.M. 2013. Monitoring fire impacts in soil water repellency and structure stability during 6 years. FLAMMA, 4(2):71-75.

A Carbon Monitoring System Approach to US Coastal Wetland Carbon Fluxes: Progress Towards a Tier II Accounting Method with Uncertainty Quantification

NASA Astrophysics Data System (ADS)

Windham-Myers, L.; Holmquist, J. R.; Bergamaschi, B. A.; Byrd, K. B.; Callaway, J.; Crooks, S.; Drexler, J. Z.; Feagin, R. A.; Ferner, M. C.; Gonneea, M. E.; Kroeger, K. D.; Megonigal, P.; Morris, J. T.; Schile, L. M.; Simard, M.; Sutton-Grier, A.; Takekawa, J.; Troxler, T.; Weller, D.; Woo, I.

2015-12-01

Despite their high rates of long-term carbon (C) sequestration when compared to upland ecosystems, coastal C accounting is only recently receiving the attention of policy makers and carbon markets. Assessing accuracy and uncertainty in net C flux estimates requires both direct and derived measurements based on both short and long term dynamics in key drivers, particularly soil accretion rates and soil organic content. We are testing the ability of remote sensing products and national scale datasets to estimate biomass and soil stocks and fluxes over a wide range of spatial and temporal scales. For example, the 2013 Wetlands Supplement to the 2006 IPCC GHG national inventory reporting guidelines requests information on development of Tier I-III reporting, which express increasing levels of detail. We report progress toward development of a Carbon Monitoring System for "blue carbon" that may be useful for IPCC reporting guidelines at Tier II levels. Our project uses a current dataset of publically available and contributed field-based measurements to validate models of changing soil C stocks, across a broad range of U.S. tidal wetland types and landuse conversions. Additionally, development of biomass algorithms for both radar and spectral datasets will be tested and used to determine the "price of precision" of different satellite products. We discuss progress in calculating Tier II estimates focusing on variation introduced by the different input datasets. These include the USFWS National Wetlands Inventory, NOAA Coastal Change Analysis Program, and combinations to calculate tidal wetland area. We also assess the use of different attributes and depths from the USDA-SSURGO database to map soil C density. Finally, we examine the relative benefit of radar, spectral and hybrid approaches to biomass mapping in tidal marshes and mangroves. While the US currently plans to report GHG emissions at a Tier I level, we argue that a Tier II analysis is possible due to national maps of wetland area and soil carbon, as well as sediment accretion and sea-level rise correlations and wetland area change data. The uncertainty analyses performed nationally and in six regionally-representative "sentinel sites" will be an important guide for future efforts towards more accurate and complete wetland C inventories.

Plant stimulation of soil microbial community succession: how sequential expression mediates soil carbon stabilization and turnover

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

Firestone, Mary

2015-03-31

It is now understood that most plant C is utilized or transformed by soil microorganisms en route to stabilization. Hence the composition of microbial communities that mediate decomposition and transformation of root C is critical, as are the metabolic capabilities of these communities. The change in composition and function of the C-transforming microbial communities over time in effect defines the biological component of soil C stabilization. Our research was designed to test 2 general hypotheses; the first two hypotheses are discussed first; H1: Root-exudate interactions with soil microbial populations results in the expression of enzymatic capacities for macromolecular, complex carbonmore » decomposition; and H2: Microbial communities surrounding roots undergo taxonomic succession linked to functional gene activities as roots grow, mature, and decompose in soil. Over the term of the project we made significant progress in 1) quantifying the temporal pattern of root interactions with the soil decomposing community and 2) characterizing the role of root exudates in mediating these interactions.« less

Quantification of the inevitable: the influence of soil macrofauna on soil water movement in rehabilitated open-cut mined lands

NASA Astrophysics Data System (ADS)

Arnold, S.; Williams, E. R.

2016-01-01

Recolonisation of soil by macrofauna (especially ants, termites and earthworms) in rehabilitated open-cut mine sites is inevitable and, in terms of habitat restoration and function, typically of great value. In these highly disturbed landscapes, soil invertebrates play a major role in soil development (macropore configuration, nutrient cycling, bioturbation, etc.) and can influence hydrological processes such as infiltration, seepage, runoff generation and soil erosion. Understanding and quantifying these ecosystem processes is important in rehabilitation design, establishment and subsequent management to ensure progress to the desired end goal, especially in waste cover systems designed to prevent water reaching and transporting underlying hazardous waste materials. However, the soil macrofauna is typically overlooked during hydrological modelling, possibly due to uncertainties on the extent of their influence, which can lead to failure of waste cover systems or rehabilitation activities. We propose that scientific experiments under controlled conditions and field trials on post-mining lands are required to quantify (i) macrofauna-soil structure interactions, (ii) functional dynamics of macrofauna taxa, and (iii) their effects on macrofauna and soil development over time. Such knowledge would provide crucial information for soil water models, which would increase confidence in mine waste cover design recommendations and eventually lead to higher likelihood of rehabilitation success of open-cut mining land.

[Soil seed bank research of China mining areas: necessity and challenges].

PubMed

Chang, Qing; Zhang, Da-Wei; Li, Xue; Peng, Jian; Guan, Ai-Nong; Liu, Xiao-Si

2011-05-01

Soil seed bank consists of all living seeds existed in soil and its surface litter, especially in topsoil, and can reflect the characteristics of regional biodiversity. As the base of vegetation restoration and potential greening material, topsoil and its seed bank are the limited and non-renewable resources in mining areas. The study of soil seed bank has become one of the hotspots in the research field of vegetation restoration and land reclamation in China mining areas. Owing to the special characteristics of mining industry, the soil seed bank study of mining areas should not only concern with the seed species, quantities, and their relations with ground surface vegetation, but also make use of the research results on the soil seed bank of other fragile habitats. Besides, a breakthrough should be sought in the thinking ways and research approach. This paper analyzed the particularity of mining area's soil seek bank research, summarized the research progress in the soil seed bank of mining areas and other fragile habitats, and put forward the challenges we are facing with. It was expected that this paper could help to reinforce the soil seed bank research of China mining areas, and provide scientific guidelines for taking great advantage of the significant roles of soil seed bank in land reclamation and vegetation restoration in the future.

The 1981 Environmental Quality Index.

ERIC Educational Resources Information Center

National Wildlife, 1981

1981-01-01

Describes trends in the state of the nation's wildlife, minerals, air, water, forests, living space, and soil resources. Positive gains in 1980 are offset by threats to the progress made during the past decade. (WB)

Part V--Sorption of pharmaceuticals and personal care products.

PubMed

Pan, Bo; Ning, Ping; Xing, Baoshan

2009-01-01

Pharmaceuticals and personal care products (PPCPs) including antibiotics, endocrine-disrupting chemicals, and veterinary pharmaceuticals are emerging pollutants, and their environmental risk was not emphasized until a decade ago. These compounds have been reported to cause adverse impacts on wildlife and human. However, compared to the studies on hydrophobic organic contaminants (HOCs) whose sorption characteristics is reviewed in Part IV of this review series, information on PPCPs is very limited. Thus, a summary of recent research progress on PPCP sorption in soils or sediments is necessary to clarify research requirements and directions. We reviewed the research progress on PPCP sorption in soils or sediments highlighting PPCP sorption different from that of HOCs. Special function of humic substances (HSs) on PPCP behavior is summarized according to several features of PPCP-soil or sediment interaction. In addition, we discussed the behavior of xenobiotic chemicals in a three-phase system (dissolved organic matter (DOM)-mineral-water). The complexity of three-phase systems was also discussed. Nonideal sorption of PPCPs in soils or sediments is generally reported, and PPCP sorption behavior is relatively a more complicated process compared to HOC sorption, such as the contribution of inorganic fractions, fast degradation and metabolite sorption, and species-specific sorption mechanism. Thus, mechanistic studies are urgently needed for a better understanding of their environmental risk and for pollution control. Recent research progress on nonideal sorption has not been incorporated into fate modeling of xenobiotic chemicals. A major reason is the complexity of the three-phase system. First of all, lack of knowledge in describing DOM fractionation after adsorption by mineral particles is one of the major restrictions for an accurate prediction of xenobiotic chemical behavior in the presence of DOM. Secondly, no explicit mathematical relationship between HS chemical-physical properties, and their sorption characteristics has been proposed. Last but not least, nonlinear interactions could exponentially increase the complexity and uncertainties of environmental fate models for xenobiotics. Discussion on proper simplification of fate modeling in the framework of nonlinear interactions is still unavailable. Although the methodologies and concepts for studying HOC environmental fate could be adopted for PPCP study, their differences should be highly understood. Prediction of PPCP environmental behavior needs to combine contributions from various fractions of soils or sediments and the sorption of their metabolites and different species. More detailed studies on PPCP sorption in separated soil or sediment fractions are needed in order to propose a model predicting PPCP sorption in soils or sediments based on soil or sediment properties. The information on sorption of PPCP metabolites and species and the competition between them is still not enough to be incorporated into any predictive models.

[Deposition and burial of organic carbon in coastal salt marsh: research progress].

PubMed

Cao, Lei; Song, Jin-Ming; Li, Xue-Gang; Yuan, Hua-Mao; Li, Ning; Duan, Li-Qin

2013-07-01

Coastal salt marsh has higher potential of carbon sequestration, playing an important role in mitigating global warming, while coastal saline soil is the largest organic carbon pool in the coastal salt marsh carbon budget. To study the carbon deposition and burial in this soil is of significance for clearly understanding the carbon budget of coastal salt marsh. This paper summarized the research progress on the deposition and burial of organic carbon in coastal salt marsh from the aspects of the sources of coastal salt marsh soil organic carbon, soil organic carbon storage and deposition rate, burial mechanisms of soil organic carbon, and the relationships between the carbon sequestration in coastal salt marsh and the global climate change. Some suggestions for the future related researches were put forward: 1) to further study the underlying factors that control the variability of carbon storage in coastal salt marsh, 2) to standardize the methods for measuring the carbon storage and the deposition and burial rates of organic carbon in coastal salt marsh, 3) to quantify the lateral exchange of carbon flux between coastal salt marsh and adjacent ecosystems under the effects of tide, and 4) to approach whether the effects of global warming and the increased productivity could compensate for the increase of the organic carbon decomposition rate resulted from sediment respiration. To make clear the driving factors determining the variability of carbon sequestration rate and how the organic carbon storage is affected by climate change and anthropogenic activities would be helpful to improve the carbon sequestration capacity of coastal salt marshes in China.

Recovery from chronic and snowmelt acidification: Long-term trends in stream and soil water chemistry at the Hubbard Brook Experimental Forest, New Hampshire, USA

Treesearch

Colin B. Fuss; Charles T. Driscoll; John L. Campbell

2015-01-01

Atmospheric acid deposition of sulfate and nitrate has declined markedly in the northeastern United States due to emissions controls. We investigated long-term trends in soil water (1984–2011) and stream water (1982–2011) chemistry along an elevation gradient of a forested watershed to evaluate the progress of recovery of drainage waters from acidic deposition at the...

Compilation of 1986 annual reports of the Navy ELF (Extremely Low Frequency) communications system ecological monitoring program, volume 2

NASA Astrophysics Data System (ADS)

1987-07-01

The U.S. Navy is conducting a long-term program to monitor for possible effects from the operation of its Extremely Low Frequency (ELF) Communications System to resident biota and their ecological relationships. This report documents progress of the following studies: soil amoeba; soil and litter arthropoda and earthworm studies; biological studies on pollinating insects: megachilid bees; and small vertebrates: small mammals and nesting birds.

Seasonal changes in depth of water uptake for encroaching trees Juniperus virginiana and Pinus ponderosa and two dominant C4 grasses in a semiarid grassland.

PubMed

Eggemeyer, Kathleen D; Awada, Tala; Harvey, F Edwin; Wedin, David A; Zhou, Xinhua; Zanner, C William

2009-02-01

We used the natural abundance of stable isotopic ratios of hydrogen and oxygen in soil (0.05-3 m depth), plant xylem and precipitation to determine the seasonal changes in sources of soil water uptake by two native encroaching woody species (Pinus ponderosa P. & C. Lawson, Juniperus virginiana L.), and two C(4) grasses (Schizachyrium scoparium (Michx.) Nash, Panicum virgatum L.), in the semiarid Sandhills grasslands of Nebraska. Grass species extracted most of their water from the upper soil profile (0.05-0.5 m). Soil water uptake from below 0.5 m depth increased under drought, but appeared to be minimal in relation to the total water use of these species. The grasses senesced in late August in response to drought conditions. In contrast to grasses, P. ponderosa and J. virginiana trees exhibited significant plasticity in sources of water uptake. In winter, tree species extracted a large fraction of their soil water from below 0.9 m depth. In spring when shallow soil water was available, tree species used water from the upper soil profile (0.05-0.5 m) and relied little on water from below 0.5 m depth. During the growing season (May-August) significant differences between the patterns of tree species water uptake emerged. Pinus ponderosa acquired a large fraction of its water from the 0.05-0.5 and 0.5-0.9 m soil profiles. Compared with P. ponderosa, J. virginiana acquired water from the 0.05-0.5 m profile during the early growing season but the amount extracted from this profile progressively declined between May and August and was mirrored by a progressive increase in the fraction taken up from 0.5-0.9 m depth, showing plasticity in tracking the general increase in soil water content within the 0.5-0.9 m profile, and being less responsive to growing season precipitation events. In September, soil water content declined to its minimum, and both tree species shifted soil water uptake to below 0.9 m. Tree transpiration rates (E) and water potentials (Psi) indicated that deep water sources did not maintain E which sharply declined in September, but played an important role in the recovery of tree Psi. Differences in sources of water uptake among these species and their ecological implications on tree-grass dynamics and soil water in semiarid environments are discussed.

Adsorption properties of subtropical and tropical variable charge soils: Implications from climate change and biochar amendment

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

Xu, Ren-Kou; Qafoku, Nikolla; Van Ranst, Eric

2016-01-25

This review paper attempts to summarize the progress made in research efforts conducted over the last years to study the surface chemical properties of the tropical and subtropical soils, usually called variable charge soils, and the way they response to different management practices. The paper is composed of an introductory section that provides a brief discussion on the surface chemical properties of these soils, and five other review sections. The focus of these sections is on the evolution of surface chemical properties during the development of the variable charge properties (second section), interactions between oppositely charged particles and the resultingmore » effects on the soil properties and especially on soil acidity (third section), the surface effects of low molecular weight organic acids sorbed to mineral surfaces and the chemical behavior of aluminum (fourth section), and the crop straw derived biochar induced changes of the surface chemical properties of these soils (fifth section). A discussion on the effect of climate change variables on the properties of the variable charge soils is included at the end of this review paper (sixth section).« less

Soil Properties Analysis of the Phoenix Landing Site Based on Trench Characteristics and Robotic Arm Forces

NASA Astrophysics Data System (ADS)

Shaw, A.; Arvidson, R.; Bonitz, R.; Carsten, J.; Keller, H.; Lemmon, M.; Mellon, M. T.; Robinson, M.; Trebi-Ollennu, A.; Volpe, R.

2008-12-01

The Phoenix Mars lander has had access to polygonal terrain; specifically, two polygons and a trough. Slopes in the trenches and dump piles created from the interaction of the Phoenix robotic arm (RA) with the soil around its landing site are similar to those seen on previous missions, such as the MER and Viking missions. This indicates similar cohesion and angle of internal friction to previous landing sites. For example, trench slopes typically range from 44-72° and dump pile slopes range from 20-30°. There are at least two very different types of materials at the site: a layer of soil which goes down to several centimeters below the surface and, below that, a layer of icy soil. The RA can easily dig through the top layer of soil, often using 20-30N force. However, when it encounters icy soil, the RA requires tens of scrapes with the lower tungsten carbide blade on its scoop to progress even a few millimeters. To verify soil property parameters, we analyze the normal and shear stresses exerted on the soil by digging, scraping, and rasping with the RA.

Microbial Community Dynamics in Soil Depth Profiles Over 120,000 Years of Ecosystem Development

PubMed Central

Turner, Stephanie; Mikutta, Robert; Meyer-Stüve, Sandra; Guggenberger, Georg; Schaarschmidt, Frank; Lazar, Cassandre S.; Dohrmann, Reiner; Schippers, Axel

2017-01-01

Along a long-term ecosystem development gradient, soil nutrient contents and mineralogical properties change, therefore probably altering soil microbial communities. However, knowledge about the dynamics of soil microbial communities during long-term ecosystem development including progressive and retrogressive stages is limited, especially in mineral soils. Therefore, microbial abundances (quantitative PCR) and community composition (pyrosequencing) as well as their controlling soil properties were investigated in soil depth profiles along the 120,000 years old Franz Josef chronosequence (New Zealand). Additionally, in a microcosm incubation experiment the effects of particular soil properties, i.e., soil age, soil organic matter fraction (mineral-associated vs. particulate), O2 status, and carbon and phosphorus additions, on microbial abundances (quantitative PCR) and community patterns (T-RFLP) were analyzed. The archaeal to bacterial abundance ratio not only increased with soil depth but also with soil age along the chronosequence, coinciding with mineralogical changes and increasing phosphorus limitation. Results of the incubation experiment indicated that archaeal abundances were less impacted by the tested soil parameters compared to Bacteria suggesting that Archaea may better cope with mineral-induced substrate restrictions in subsoils and older soils. Instead, archaeal communities showed a soil age-related compositional shift with the Bathyarchaeota, that were frequently detected in nutrient-poor, low-energy environments, being dominant at the oldest site. However, bacterial communities remained stable with ongoing soil development. In contrast to the abundances, the archaeal compositional shift was associated with the mineralogical gradient. Our study revealed, that archaeal and bacterial communities in whole soil profiles are differently affected by long-term soil development with archaeal communities probably being better adapted to subsoil conditions, especially in nutrient-depleted old soils. PMID:28579976

Pompton Lakes Photo Gallery

EPA Pesticide Factsheets

This gallery provides representative photographs of the soil removal and dredging operations within the Pompton Lake Study Area (PLSA) performed starting in 2016 through the present. It will be periodically updated in conjunction with the progress of the

Lithologic Control on the Form of Soil Mantled Hillslopes

NASA Astrophysics Data System (ADS)

Johnstone, S. A.; Hilley, G. E.

2014-12-01

Slopes on steady-state soil-mantled hillslopes tend to increase downslope in a way that balances local transport capacity with the sediment supplied from progressively larger source areas. Most predictions for the transport of soil depend purely on topographic slope and constants. Thus, soil mantled topography should evolve toward smooth forms in which soils act to buffer these forms from the underlying geologic structure. However, in the Gabilan Mesa, CA, oscillations in the slope of soil-mantled hillslopes mirror oscillations in the underlying stratigraphy. Using field measurements of stratigraphy and soil depths, topographic analysis, and numerical modeling, we demonstrate that variations in rock type can impact the form of soil-mantled hillslopes. Specifically, variations in the properties of underlying rocks may yield different soil thicknesses. Balancing transport rates across these variations in thickness requires slopes to change when soil transport depends on both soil thickness and slope. A compilation of published data on the variation in activity with depth of various transport processes provides the basis for a geomorphic transport law (GTL) that generalizes the depth dependence of various transport processes. While this GTL is explicitly depth dependent, it is also capable of describing situations in which hillslope transport is relatively insensitive to variations in thickness and therefore essentially equivalent to existing formulations. We use dimensional analysis and numerical modeling to demonstrate the conditions under which transport on soil mantled slopes, and consequently topographic forms, may be sensitive to variations in soil thickness and therefore lithology.

Drought causes substantial reductions in non-isothermal soil strength

NASA Astrophysics Data System (ADS)

Vahedifard, F.; Robinson, J. D.; Love, C. A.; AghaKouchak, A.

2016-12-01

The stability and settlement of natural slopes and engineering structures are governed primarily by the shear strength of foundation soil. Understanding soil-atmosphere interactions and their impacts on shear strength is imperative to evaluating drought impacts on the resilience of our infrastructure. This understanding is also important for assessing a variety of emerging science and engineering problems in a changing climate including analyzing existing and new infrastructures, landslides, soil carbon sequestration, land management, and managing traction and tillage in agriculture. While progress has been made in understanding shear strength response to soil moisture changes, the impacts of concurrent soil moisture and temperature changes on shear strength remain uncertain from a regional-scale perspective. Here we present a methodological framework based on various soil types, temperatures, and moistures, and surface fluxes, to quantify a non-isothermal soil shear strength. We employ a non-isothermal soil strength analysis (NISSA) to explore the extent to which elevated soil temperatures and low moistures, along with abnormal surface fluxes, during California's record-setting 2012 - 2015 drought reduced the soil's shear strength. Our results suggest that the prolonged California drought reduced the shear strength of fine-grained soil as much as 95%. In contrast, the NISSA suggests that drought impacts on coarse-grained soil were not as significant. These opposing behaviors are attributed to the existence and absence of intermolecular physico-chemical forces in fine- and coarse-grained soils, respectively. The outlined framework offers a unique avenue to explore how soil shear strength is likely to behave under extreme drought conditions.

Geotechnical Characteristics and Stability Analysis of Rock-Soil Aggregate Slope at the Gushui Hydropower Station, Southwest China

PubMed Central

Shi, Chong; Xu, Fu-gang

2013-01-01

Two important features of the high slopes at Gushui Hydropower Station are layered accumulations (rock-soil aggregate) and multilevel toppling failures of plate rock masses; the Gendakan slope is selected for case study in this paper. Geological processes of the layered accumulation of rock and soil particles are carried out by the movement of water flow; the main reasons for the toppling failure of plate rock masses are the increasing weight of the upper rock-soil aggregate and mountain erosion by river water. Indoor triaxial compression test results show that, the cohesion and friction angle of the rock-soil aggregate decreased with the increasing water content; the cohesion and the friction angle for natural rock-soil aggregate are 57.7 kPa and 31.3° and 26.1 kPa and 29.1° for saturated rock-soil aggregate, respectively. The deformation and failure mechanism of the rock-soil aggregate slope is a progressive process, and local landslides will occur step by step. Three-dimensional limit equilibrium analysis results show that the minimum safety factor of Gendakan slope is 0.953 when the rock-soil aggregate is saturated, and small scale of landslide will happen at the lower slope. PMID:24082854

Microbial activity and community diversity in a variable charge soil as affected by cadmium exposure levels and time*

PubMed Central

Shentu, Jia-li; He, Zhen-li; Yang, Xiao-e; Li, Ting-qiang

2008-01-01

Effects of cadmium (Cd) on microbial biomass, activity and community diversity were assessed in a representative variable charge soil (Typic Aquult) using an incubation study. Cadmium was added as Cd(NO3)2 to reach a concentration range of 0~16 mg Cd/kg soil. Soil extractable Cd generally increased with Cd loading rate, but decreased with incubation time. Soil microbial biomass was enhanced at low Cd levels (0.5~1 mg/kg), but was inhibited consistently with increasing Cd rate. The ratio of microbial biomass C/N varied with Cd treatment levels, decreasing at low Cd rate (<0.7 mg/kg available Cd), but increasing progressively with Cd loading. Soil respiration was restrained at low Cd loading (<1 mg/kg), and enhanced at higher Cd levels. Soil microbial metabolic quotient (MMQ) was generally greater at high Cd loading (1~16 mg/kg). However, the MMQ is also affected by other factors. Cd contamination reduces species diversity of soil microbial communities and their ability to metabolize different C substrates. Soils with higher levels of Cd contamination showed decreases in indicator phospholipids fatty acids (PLFAs) for Gram-negative bacteria and actinomycetes, while the indicator PLFAs for Gram-positive bacteria and fungi increased with increasing levels of Cd contamination. PMID:18357628

Geotechnical characteristics and stability analysis of rock-soil aggregate slope at the Gushui Hydropower Station, southwest China.

PubMed

Zhou, Jia-wen; Shi, Chong; Xu, Fu-gang

2013-01-01

Two important features of the high slopes at Gushui Hydropower Station are layered accumulations (rock-soil aggregate) and multilevel toppling failures of plate rock masses; the Gendakan slope is selected for case study in this paper. Geological processes of the layered accumulation of rock and soil particles are carried out by the movement of water flow; the main reasons for the toppling failure of plate rock masses are the increasing weight of the upper rock-soil aggregate and mountain erosion by river water. Indoor triaxial compression test results show that, the cohesion and friction angle of the rock-soil aggregate decreased with the increasing water content; the cohesion and the friction angle for natural rock-soil aggregate are 57.7 kPa and 31.3° and 26.1 kPa and 29.1° for saturated rock-soil aggregate, respectively. The deformation and failure mechanism of the rock-soil aggregate slope is a progressive process, and local landslides will occur step by step. Three-dimensional limit equilibrium analysis results show that the minimum safety factor of Gendakan slope is 0.953 when the rock-soil aggregate is saturated, and small scale of landslide will happen at the lower slope.

Performance of soil-applied FeEDDHA isomers in delivering Fe to soybean plants in relation to the moment of application.

PubMed

Schenkeveld, Walter D C; Reichwein, Arjen M; Bugter, Marcel H J; Temminghoff, Erwin J M; van Riemsdijk, Willem H

2010-12-22

FeEDDHA (iron(3+) ethylenediamine-N,N'-bis(hydroxyphenylacetic acid) products are commonly applied to mend and prevent Fe deficiency chlorosis in soil-grown crops. Plants mainly take up Fe in the progressed vegetative and in the reproductive stages. This study examined which of the principal constituents of FeEDDHA products (the isomers racemic o,o-FeEDDHA, meso o,o-FeEDDHA, and o,p-FeEDDHA), most effectively meets the Fe requirements of soybean plants (Glycine max (L.) Merr.) grown on calcareous soil in the aforementioned growth stages. FeEDDHA isomers were applied once, separately or in mixtures, at t = 0, in the progressed vegetative stage or in the reproductive stage. o,p-FeEDDHA did not significantly contribute to Fe uptake in either growth stage. Both racemic and meso o,o-FeEDDHA were effective in supplying plants with Fe, approximately to the same extent. The moment of application had a significant effect on yield and FeEDDHA pore water concentrations at harvest, but not on Fe uptake. To optimize yield while minimizing FeEDDHA dosage, FeEDDHA is best applied to soybean plants prior to the onset of chorosis.

Nitrogen dynamics in flooded soil systems: an overview on concepts and performance of models

PubMed Central

Nurulhuda, Khairudin; Gaydon, Donald S; Jing, Qi; Zakaria, Mohamad P; Struik, Paul C

2017-01-01

Abstract Extensive modelling studies on nitrogen (N) dynamics in flooded soil systems have been published. Consequently, many N dynamics models are available for users to select from. With the current research trend, inclined towards multidisciplinary research, and with substantial progress in understanding of N dynamics in flooded soil systems, the objective of this paper is to provide an overview of the modelling concepts and performance of 14 models developed to simulate N dynamics in flooded soil systems. This overview provides breadth of knowledge on the models, and, therefore, is valuable as a first step in the selection of an appropriate model for a specific application. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:28940491

Assessing and monitoring soil quality at agricultural waste disposal areas-Soil Indicators

NASA Astrophysics Data System (ADS)

Doula, Maria; Kavvadias, Victor; Sarris, Apostolos; Lolos, Polykarpos; Liakopoulou, Nektaria; Hliaoutakis, Aggelos; Kydonakis, Aris

2014-05-01

The necessity of elaborating indicators is one of the priorities identified by the United Nations Convention to Combat Desertification (UNCCD). The establishment of an indicator monitoring system for environmental purposes is dependent on the geographical scale. Some indicators such as rain seasonality or drainage density are useful over large areas, but others such as soil depth, vegetation cover type, and land ownership are only applicable locally. In order to practically enhance the sustainability of land management, research on using indicators for assessing land degradation risk must initially focus at local level because management decisions by individual land users are taken at this level. Soils that accept wastes disposal, apart from progressive degradation, may cause serious problems to the surrounding environment (humans, animals, plants, water systems, etc.), and thus, soil quality should be necessarily monitored. Therefore, quality indicators, representative of the specific waste type, should be established and monitored periodically. Since waste composition is dependent on their origin, specific indicators for each waste type should be established. Considering agricultural wastes, such a specification, however, could be difficult, since almost all agricultural wastes are characterized by increased concentrations of the same elements, namely, phosphorous, nitrogen, potassium, sulfur, etc.; contain large amounts of organic matter; and have very high values of chemical oxygen demand (COD), biochemical oxygen demand (BOD), and electrical conductivity. Two LIFE projects, namely AgroStrat and PROSODOL are focused on the identification of soil indicators for the assessment of soil quality at areas where pistachio wastes and olive mill wastes are disposed, respectively. Many soil samples were collected periodically for 2 years during PROSODOL and one year during AgroStrat (this project is in progress) from waste disposal areas and analyzed for 23 parameters. Results indicate that there are soil parameters that can be used as indictors to assess soil quality at such areas. For the two cases, i.e pistachio wastes and olive oil mill wastes, different soil parameters were identified as potential indicators. In specific, for OMW the proposed indicators are: organic matter, electrical conductivity, total N, total polyphenols, exchangeable K, DTPA-available Fe, available P and pH (for the cases of acid soils). For pistachio wastes, it seems that the most appropriate indictors are: organic matter, electrical conductivity, exchangeable Mg, DTPA-available Fe, DTPA-available Cu, available B. A monitoring system was developed which may assist authorities and policy makers to continuously monitor the disposal areas or areas where wastes are used for fertilization/irrigation. For this, soil parameters were mapped with respect to the depth, date and temporal variations of their spatial distribution (spatial surfaces). Interpolated surfaces based on the Inverse Distance Weighted method (IDW) were created and integrated within a geospatial web based map application tool.

Geochemical and radiological characterization of soils from former radium processing sites

USGS Publications Warehouse

Landa, E.R.

1984-01-01

Soil samples were collected from former radium processing sites in Denver, CO, and East Orange, NJ. Particle-size separations and radiochemical analyses of selected samples showed that while the greatest contents of both 226Ra and U were generally found in the finest (< 45 ??m) fraction, the pattern was not always of progressive increase in radionuclide content with decreasing particle size. Leaching tests on these samples showed a large portion of the 225Ra and U to be soluble in dilute hydrochloric acid. Radon-emanation coefficients measured for bulk samples of contaminated soil were about 20%. Recovery of residual uranium and vanadium, as an adjunct to any remedial action program, appears unlikely due to economic considerations.

Review in Strengthening Technology for Phytoremediation of Soil Contaminated by Heavy Metals

NASA Astrophysics Data System (ADS)

Wu, Chishan; Zhang, Xingfeng; Deng, Yang

2017-07-01

In view of current problems of phytoremediation technology, this paper summarizes research progress for phytoremediation technology of heavy metal contaminated soil. When the efficiency of phytoremediation may not meet the demand in practice of contaminated soil or water. Effective measures should be taken to improve the plant uptake and translocation. This paper focuses on strengthening technology mechanism, which can not only increase the biomass of plant and hyperaccumulators, but also enhance the tolerance and resistance to heavy metals, and application effect of phytoremediation, including agronomic methods, earthworm bioremediation and chemical induction technology. In the end of paper, deficiencies of each methods also be discussed, methods of strengthening technology for phytoremediation need further research.

Reproducible research in vadose zone sciences

USDA-ARS?s Scientific Manuscript database

A significant portion of present-day soil and Earth science research is computational, involving complex data analysis pipelines, advanced mathematical and statistical models, and sophisticated computer codes. Opportunities for scientific progress are greatly diminished if reproducing and building o...

Priorities for research in soil ecology

PubMed Central

Eisenhauer, Nico; Antunes, Pedro M.; Bennett, Alison E.; Birkhofer, Klaus; Bissett, Andrew; Bowker, Matthew A.; Caruso, Tancredi; Chen, Baodong; Coleman, David C.; de Boer, Wietse; de Ruiter, Peter; DeLuca, Thomas H.; Frati, Francesco; Griffiths, Bryan S.; Hart, Miranda M.; Hättenschwiler, Stephan; Haimi, Jari; Heethoff, Michael; Kaneko, Nobuhiro; Kelly, Laura C.; Leinaas, Hans Petter; Lindo, Zoë; Macdonald, Catriona; Rillig, Matthias C.; Ruess, Liliane; Scheu, Stefan; Schmidt, Olaf; Seastedt, Timothy R.; van Straalen, Nico M.; Tiunov, Alexei V.; Zimmer, Martin; Powell, Jeff R.

2017-01-01

The ecological interactions that occur in and with soil are of consequence in many ecosystems on the planet. These interactions provide numerous essential ecosystem services, and the sustainable management of soils has attracted increasing scientific and public attention. Although soil ecology emerged as an independent field of research many decades ago, and we have gained important insights into the functioning of soils, there still are fundamental aspects that need to be better understood to ensure that the ecosystem services that soils provide are not lost and that soils can be used in a sustainable way. In this perspectives paper, we highlight some of the major knowledge gaps that should be prioritized in soil ecological research. These research priorities were compiled based on an online survey of 32 editors of Pedobiologia – Journal of Soil Ecology. These editors work at universities and research centers in Europe, North America, Asia, and Australia.The questions were categorized into four themes: (1) soil biodiversity and biogeography, (2) interactions and the functioning of ecosystems, (3) global change and soil management, and (4) new directions. The respondents identified priorities that may be achievable in the near future, as well as several that are currently achievable but remain open. While some of the identified barriers to progress were technological in nature, many respondents cited a need for substantial leadership and goodwill among members of the soil ecology research community, including the need for multi-institutional partnerships, and had substantial concerns regarding the loss of taxonomic expertise. PMID:29129942

Priorities for research in soil ecology.

PubMed

Eisenhauer, Nico; Antunes, Pedro M; Bennett, Alison E; Birkhofer, Klaus; Bissett, Andrew; Bowker, Matthew A; Caruso, Tancredi; Chen, Baodong; Coleman, David C; de Boer, Wietse; de Ruiter, Peter; DeLuca, Thomas H; Frati, Francesco; Griffiths, Bryan S; Hart, Miranda M; Hättenschwiler, Stephan; Haimi, Jari; Heethoff, Michael; Kaneko, Nobuhiro; Kelly, Laura C; Leinaas, Hans Petter; Lindo, Zoë; Macdonald, Catriona; Rillig, Matthias C; Ruess, Liliane; Scheu, Stefan; Schmidt, Olaf; Seastedt, Timothy R; van Straalen, Nico M; Tiunov, Alexei V; Zimmer, Martin; Powell, Jeff R

2017-07-01

The ecological interactions that occur in and with soil are of consequence in many ecosystems on the planet. These interactions provide numerous essential ecosystem services, and the sustainable management of soils has attracted increasing scientific and public attention. Although soil ecology emerged as an independent field of research many decades ago, and we have gained important insights into the functioning of soils, there still are fundamental aspects that need to be better understood to ensure that the ecosystem services that soils provide are not lost and that soils can be used in a sustainable way. In this perspectives paper, we highlight some of the major knowledge gaps that should be prioritized in soil ecological research. These research priorities were compiled based on an online survey of 32 editors of Pedobiologia - Journal of Soil Ecology. These editors work at universities and research centers in Europe, North America, Asia, and Australia.The questions were categorized into four themes: (1) soil biodiversity and biogeography, (2) interactions and the functioning of ecosystems, (3) global change and soil management, and (4) new directions. The respondents identified priorities that may be achievable in the near future, as well as several that are currently achievable but remain open. While some of the identified barriers to progress were technological in nature, many respondents cited a need for substantial leadership and goodwill among members of the soil ecology research community, including the need for multi-institutional partnerships, and had substantial concerns regarding the loss of taxonomic expertise.

Regularized finite element modeling of progressive failure in soils within nonlocal softening plasticity

NASA Astrophysics Data System (ADS)

Huang, Maosong; Qu, Xie; Lü, Xilin

2017-11-01

By solving a nonlinear complementarity problem for the consistency condition, an improved implicit stress return iterative algorithm for a generalized over-nonlocal strain softening plasticity was proposed, and the consistent tangent matrix was obtained. The proposed algorithm was embodied into existing finite element codes, and it enables the nonlocal regularization of ill-posed boundary value problem caused by the pressure independent and dependent strain softening plasticity. The algorithm was verified by the numerical modeling of strain localization in a plane strain compression test. The results showed that a fast convergence can be achieved and the mesh-dependency caused by strain softening can be effectively eliminated. The influences of hardening modulus and material characteristic length on the simulation were obtained. The proposed algorithm was further used in the simulations of the bearing capacity of a strip footing; the results are mesh-independent, and the progressive failure process of the soil was well captured.

Can differences in root responses to soil drying and compaction explain differences in performance of trees growing on landfill sites?

PubMed

Liang, Jiansheng; Zhang, Jianhua; Chan, Gilbert Y. S.; Wong, M. H.

1999-07-01

Two tropical woody species, Acacia confusa Merrill and Litsea glutinosa (Lour.) C.B. Robinson, were grown under controlled conditions in PVC pipes filled with John Innes No. 2 soil. To investigate root distribution, physiological characteristics and hydraulic conductivity, four soil treatments were imposed-well-watered and noncompacted (control), well-watered and compacted; unwatered and noncompacted, and unwatered and compacted. In L. glutinosa, rooting depth and root elongation were severely restricted when soil bulk density increased from around 1.12 to 1.62 g cm(-3), whereas soil compaction had little effect on these parameters in A. confusa. As soil drying progressed, root water potential and osmotic potential declined more slowly in L. glutinosa than in A. confusa. Both the soil drying and compaction treatments significantly stimulated the accumulation of root abscisic acid (ABA) in both species. Soil drying damaged the root cell membrane of A. confusa, but had little influence on the root cell membrane of L. glutinosa. Soil drying had a greater effect on root hydraulic conductivity (L(p)) in L. glutinosa than in A. confusa, whereas the effect of soil compaction on L(p) was less in L. glutinosa than in A. confusa. Soil drying enhanced the effects of soil compaction on root L(p). We conclude that soil drying and compaction have large species-specific effects on the distribution, growth and physiology of roots. The relationships of these root properties to the species' ability to tolerate unfavorable soil conditions were examined.

Linking Carbon Flux Dynamics and Soil Structure in Dryland Soils

NASA Astrophysics Data System (ADS)

DeCarlo, K. F.; Caylor, K. K.

2016-12-01

Biological sources in the form of microbes and plants play a fundamental role in determining the magnitude of carbon flux. However, the geophysical structure of the soil (which the carbon must pass through before entering the atmosphere) often serves as a constraining entity, which has the potential to serve as instigators or mitigators of those carbon and hydrologic flux processes. We characterized soil carbon dynamics in three dryland soil systems: bioturbated soils, biocompacted soils, and undisturbed soils. Carbon fluxes were characterized using a closed-system respiration chamber, with CO2 concentration differences measured using an infrared gas analyzer (IRGA). Structure of the soil systems, with a focus on the macro-crack structure, were characterized using a combined resin-casting/X-ray imaging technique. Results show fundamental differences in carbon dynamics between the different soil systems/structures: control soils have gaussian distributions of carbon flux that decrease with progressive drying of the soil, while biocompacted soils exhibit exponentially distributed fluxes that do not regularly decrease with increased drying of the soil. Bioturbated soils also exhibit an exponential distribution of carbon flux, though at a much higher magnitude. These differences are evaluated in the context of the underlying soil structure: while the control soils exhibit a shallow and narrow crack structure, the biocompacted soils exhibit a "systematic" crack network with moderate cracking intensity and large depth. The deep crack networks of the biocompacted soils may serve to physically enhance an otherwise weak source of carbon via advection and/or convection, inducing fluxes that are equal or greater than an otherwise carbon-rich soil. The bioturbated soils exhibit a "surficial" crack network that is shallow but extensive, but additionally have deep holes known to convectively vent carbon, which may explain their periodically large carbon fluxes. Our results suggest that variability in soil structure, as well as carbon source, plays a fundamental role in carbon flux dynamics, and the importance of evaluating biological carbon source and geophysical soil structure in a dryland environment.

Determination of Martian soil mineralogy and water content using the Thermal Analyzer for Planetary Soils (TAPS)

NASA Technical Reports Server (NTRS)

Gooding, James L.; Ming, Douglas W.; Allton, Judith H.; Byers, Terry B.; Dunn, Robert P.; Gibbons, Frank L.; Pate, Daniel B.; Polette, Thomas M.

1992-01-01

Physical and chemical interactions between the surface and atmosphere of Mars can be expected to embody a strong cause-and-effect relationship with the minerals comprising the martian regolith. Many of the minerals in soils and sediments are probably products of chemical weathering (involving surface/atmosphere or surface/hydrosphere reactions) that could be expected to subsequently influence the sorption of atmospheric gases and water vapor. Therefore, identification of the minerals in martian surface soils and sediments is essential for understanding both past and present interactions between the Mars surface and atmosphere. Clearly, the most definitive mineral analyses would be achieved with well-preserved samples returned to Earth-based laboratories. In advance of a Mars sample return mission, however, significant progress could be made with in situ experiments that fill current voids in knowledge about the presence or abundance of key soil minerals such as clays (layered-structured silicates), zeolites, and various salts, including carbonates. TAPS is intended to answer that challenge by providing first-order identification of soil and sediment minerals.

A review of model applications for structured soils: b) Pesticide transport.

PubMed

Köhne, John Maximilian; Köhne, Sigrid; Simůnek, Jirka

2009-02-16

The past decade has seen considerable progress in the development of models simulating pesticide transport in structured soils subject to preferential flow (PF). Most PF pesticide transport models are based on the two-region concept and usually assume one (vertical) dimensional flow and transport. Stochastic parameter sets are sometimes used to account for the effects of spatial variability at the field scale. In the past decade, PF pesticide models were also coupled with Geographical Information Systems (GIS) and groundwater flow models for application at the catchment and larger regional scales. A review of PF pesticide model applications reveals that the principal difficulty of their application is still the appropriate parameterization of PF and pesticide processes. Experimental solution strategies involve improving measurement techniques and experimental designs. Model strategies aim at enhancing process descriptions, studying parameter sensitivity, uncertainty, inverse parameter identification, model calibration, and effects of spatial variability, as well as generating model emulators and databases. Model comparison studies demonstrated that, after calibration, PF pesticide models clearly outperform chromatographic models for structured soils. Considering nonlinear and kinetic sorption reactions further enhanced the pesticide transport description. However, inverse techniques combined with typically available experimental data are often limited in their ability to simultaneously identify parameters for describing PF, sorption, degradation and other processes. On the other hand, the predictive capacity of uncalibrated PF pesticide models currently allows at best an approximate (order-of-magnitude) estimation of concentrations. Moreover, models should target the entire soil-plant-atmosphere system, including often neglected above-ground processes such as pesticide volatilization, interception, sorption to plant residues, root uptake, and losses by runoff. The conclusions compile progress, problems, and future research choices for modelling pesticide displacement in structured soils.

Dynamic Succession of Soil Bacterial Community during Continuous Cropping of Peanut (Arachis hypogaea L.)

PubMed Central

Chen, Mingna; Li, Xiao; Yang, Qingli; Chi, Xiaoyuan; Pan, Lijuan; Chen, Na; Yang, Zhen; Wang, Tong; Wang, Mian; Yu, Shanlin

2014-01-01

Plant health and soil fertility are affected by plant–microbial interactions in soils. Peanut is an important oil crop worldwide and shows considerable adaptability, but growth and yield are negatively affected by continuous cropping. In this study, 16S rRNA gene clone library analyses were used to study the succession of soil bacterial communities under continuous peanut cultivation. Six libraries were constructed for peanut over three continuous cropping cycles and during its seedling and pod-maturing growth stages. Cluster analyses indicated that soil bacterial assemblages obtained from the same peanut cropping cycle were similar, regardless of growth period. The diversity of bacterial sequences identified in each growth stage library of the three peanut cropping cycles was high and these sequences were affiliated with 21 bacterial groups. Eight phyla: Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Gemmatimonadetes, Planctomycetes, Proteobacteria and Verrucomicrobia were dominant. The related bacterial phylotypes dynamic changed during continuous cropping progress of peanut. This study demonstrated that the bacterial populations especially the beneficial populations were positively selected. The simplification of the beneficial microbial communities such as the phylotypes of Alteromonadales, Burkholderiales, Flavobacteriales, Pseudomonadales, Rhizobiales and Rhodospirillales could be important factors contributing to the decline in peanut yield under continuous cropping. The microbial phylotypes that did not successively changed with continuous cropping, such as populations related to Rhizobiales and Rhodospirillales, could potentially resist stress due to continuous cropping and deserve attention. In addition, some phylotypes, such as Acidobacteriales, Chromatiales and Gemmatimonadales, showed a contrary tendency, their abundance or diversity increased with continuous peanut cropping progress. Some bacterial phylotypes including Acidobacteriales, Burkholderiales, Bdellovibrionales, and so on, also were affected by plant age. PMID:25010658

Development rates of Late Quaternary soils, Silver Lake Playa, California

USGS Publications Warehouse

Reheis, M.C.; Harden, J.W.; McFadden, L.D.; Shroba, R.R.

1989-01-01

Soils formed on alluvial fan deposits that range in age from about 35 000 to 200 yr BP near Silver Lake playa in the Mojave Desert permit study of the rates of soil development in an arid, hyperthermic climate. Field-described properties of soils were quantified and analyzed using a soil development index that combines properties and horizon thicknesses. Pedogenic CaCO3 (as indicated by color), pH increase, and dry consistence appear to change with age at linear rates, whereas rubification appears to change at a logarithmic rate. The linear rates are best attributed to the progressive accumulation of CaCO3- and salt-rich eolian dust derived from the playa and other mnore distant sources. The total-texture values of soils on fans older than 10 000 yr BP are similar, which suggests that playas in this area may have been wet enough to restrict the availability of fines from these sources for many thousands of years prior to 10 000 yr BP. Equations derived from regressions of soil age and properties can be used to estimate ages of undated, lithologically similar deposits in similar climates and geomorphic settings. -from Authors

Remediation of heavy metal contaminated soils by using Solanum nigrum: A review.

PubMed

Rehman, Muhammad Zia Ur; Rizwan, Muhammad; Ali, Shafaqat; Ok, Yong Sik; Ishaque, Wajid; Saifullah; Nawaz, Muhammad Farrakh; Akmal, Fatima; Waqar, Maqsooda

2017-09-01

Heavy metals are among the major environmental pollutants and the accumulation of these metals in soils is of great concern in agricultural production due to the toxic effects on crop growth and food quality. Phytoremediation is a promising technique which is being considered as an alternative and low-cost technology for the remediation of metal-contaminated soils. Solanum nigrum is widely studied for the remediation of heavy metal-contaminated soils owing to its ability for metal uptake and tolerance. S. nigrum can tolerate excess amount of certain metals through different mechanism including enhancing the activities of antioxidant enzymes and metal deposition in non-active parts of the plant. An overview of heavy metal uptake and tolerance in S. nigrum is given. Both endophytic and soil microorganisms can play a role in enhancing metal tolerance in S. nigrum. Additionally, optimization of soil management practices and exogenous application of amendments can also be used to enhance metal uptake and tolerance in this plant. The main objective of the present review is to highlight and discuss the recent progresses in using S. nigrum for remediation of metal contaminated soils. Copyright © 2017 Elsevier Inc. All rights reserved.

Review and Future Research Directions about Major Monitoring Method of Soil Erosion

NASA Astrophysics Data System (ADS)

LI, Yue; Bai, Xiaoyong; Tian, Yichao; Luo, Guangjie

2017-05-01

Soil erosion is a highly serious ecological problem that occurs worldwide. Hence,scientific methods for accurate monitoring are needed to obtain soil erosion data. At present,numerous methods on soil erosion monitoring are being used internationally. In this paper, wepresent a systematic classification of these methods based on the date of establishment andtype of approach. This classification comprises five categories: runoff plot method, erosion pinmethod, radionuclide tracer method, model estimation, and 3S technology combined method.The backgrounds of their establishment are briefly introduced, the history of their developmentis reviewed, and the conditions for their application are enumerated. Their respectiveadvantages and disadvantages are compared and analysed, and future prospects regarding theirdevelopment are discussed. We conclude that the methods of soil erosion monitoring in the past 100 years of their development constantly considered the needs of the time. According to the progress of soil erosion monitoring technology throughout its history, we predict that the future trend in this field would move toward the development of quantitative, precise, and composite methods. This report serves as a valuable reference for scientific and technological workers globally, especially those engaged in soil erosion research.

Geomorphic considerations for erosion prediction

USGS Publications Warehouse

Osterkamp, W.R.; Toy, T.J.

1997-01-01

Current soil-erosion prediction technology addresses processes of rainsplash, overland-flow sediment transport, and rill erosion in small watersheds. The effects of factors determining sediment yield from larger-scale drainage basins, in which sediment movement is controlled by the combined small-scale processes and a complex set of channel and other basin-scale sediment-delivery processes, such as soil creep, bioturbation, and accelerated erosion due to denudation of vegetation, have been poorly evaluated. General suggestions are provided for the development of erosion-prediction technology at the geomorphic or drainage-basin scale based on the separation of sediment-yield data for channel and geomorphic processes from those of field-scale soil loss. An emerging technology must consider: (1) the effects on sediment yield of climate, geology and soils, topography, biotic interactions with other soil processes, and land-use practices; (2) all processes of sediment delivery to a channel system; and (3) the general tendency in most drainage basins for progressively greater sediment storage in the downstream direction.

Apple replant disease: role of microbial ecology in cause and control.

PubMed

Mazzola, Mark; Manici, Luisa M

2012-01-01

Replant disease of apple is common to all major apple growing regions of the world. Difficulties in defining disease etiology, which can be exacerbated by abiotic factors, have limited progress toward developing alternatives to soil fumigation for disease control. However, the preponderance of data derived from studies of orchard soil biology employing multidisciplinary approaches has defined a complex of pathogens/parasites as causal agents of the disease. Approaches to manipulate microbial resources endemic to the orchard soil system have been proposed to induce a state of general soil suppressiveness to replant disease. Such a long-term strategy may benefit the existing orchard through extending the period of economic viability and reduce overall disease pressure to which young trees are exposed during establishment of successive plantings on the site. Alternatively, more near-term methods have been devised to achieve specific quantitative and qualitative changes in soil biology during the period of orchard renovation that may lead to effective disease suppression.

Soil Health Assessment Approaches and the Cornell Framework

NASA Astrophysics Data System (ADS)

van Es, Harold

2016-04-01

Soil health constraints beyond nutrient limitations and excesses currently limit agroecosystem productivity and sustainability, resilience to drought and extreme rainfall, and progress in soil and water conservation. With mounting pressure to produce food, feed, fiber, and even fuel for an increasing population, the concept of soil health is gaining national and international attention. Multiple regional, national, and global efforts are now leveraging that work to reach new stakeholder audiences, so that soil health management is expanding into mainstream agriculture. Each grower is generally faced with a unique situation in the choice of management options to address soil health constraints and each system affords its own set of opportunities or limitations to soil management. A more comprehensive understanding of soil health status can better guide farmers' management decisions. Until recently, there has not been a formalized decision making process for implementing a soil health management system that alleviates field-specific constrains identified through standard measurements and then maintains improved soil health. This presentation will discuss current US-based efforts related to soil health assessment, including efforts to build national consensus on appropriate methods for simple (inexpensive) and comprehensive tests. This includes the Cornell Soil Health Management Planning and Implementation Framework. The most relevant components of the framework are 1) measurement of indicators that represent critical soil processes, 2) scoring of measured values that allows for interpretation, and 3) linkage of identified constraints with management practices. Land managers can monitor changes over time through further assessment, and adapt management practices to achieve chosen goals. We will discuss the full tests and approaches for simplification.

[Priming effect of biochar on the minerialization of native soil organic carbon and the mechanisms: A review.

PubMed

Chen, Ying; Liu, Yu Xue; Chen, Chong Jun; Lyu, Hao Hao; Wa, Yu Ying; He, Li Li; Yang, Sheng Mao

2018-01-01

In recent years, studies on carbon sequestration of biochar in soil has been in spotlight owing to the specific characteristics of biochar such as strong carbon stability and well developed pore structure. However, whether biochar will ultimately increase soil carbon storage or promote soil carbon emissions when applied into the soil? This question remains controversial in current academic circles. Further research is required on priming effect of biochar on mineralization of native soil organic carbon and its mechanisms. Based on the analysis of biochar characteristics, such as its carbon composition and stability, pore structure and surface morphology, research progress on the priming effect of biochar on the decomposition of native soil organic carbon was reviewed in this paper. Furthermore, possible mechanisms of both positive and negative priming effect, that is promoting and suppressing the mineralization, were put forward. Positive priming effect is mainly due to the promotion of soil microbial activity caused by biochar, the preferential mineralization of easily decomposed components in biochar, and the co-metabolism of soil microbes. While negative priming effect is mainly based on the encapsulation and adsorption protection of soil organic matter due to the internal pore structure and the external surface of biochar. Other potential reasons for negative priming effect can be the stabilization resulted from the formation of organic-inorganic complex promoted by biochar in the soil, and the inhibition of activity of soil microbes and its enzymes by biochar. Finally, future research directions were proposed in order to provide theoretical basis for the application of biochar in soil carbon sequestration.

Control of embankment settlement field verification on PCPT prediction methods : tech summary.

DOT National Transportation Integrated Search

2011-07-01

Depending on loading and embankment height, the magnitude and progression of settlement can signifi cantly impact the safety and : serviceability of the infrastructures that are constructed on saturated fi ne-grained soils. Therefore, the constructio...

Searching for plant root traits to improve soil cohesion and resist soil erosion

NASA Astrophysics Data System (ADS)

De Baets, Sarah; Smyth, Kevin; Denbigh, Tom; Weldon, Laura; Higgins, Ben; Matyjaszkiewicz, Antoni; Meersmans, Jeroen; Chenchiah, Isaac; Liverpool, Tannie; Quine, Tim; Grierson, Claire

2017-04-01

Soil erosion poses a serious threat to future food and environmental security. Soil erosion protection measures are therefore of great importance for soil conservation and food security. Plant roots have proven to be very effective in stabilizing the soil and protecting the soil against erosion. However, no clear insights are yet obtained into the root traits that are responsible for root-soil cohesion. This is important in order to better select the best species for soil protection. Research using Arabidopsis mutants has made great progress towards explaining how root systems are generated by growth, branching, and responses to gravity, producing mutants that affect root traits. In this study, the performance of selected Arabidopsis mutants is analyzed in three root-soil cohesion assays. Measurements of detachment, uprooting force and soil detachment are here combined with the microscopic analysis of root properties, such as the presence, length and density of root hairs in this case. We found that Arabidopsis seedlings with root hairs (wild type, wer myb23, rsl4) were more difficult to detach from gel media than hairless (cpc try) or short haired (rsl4, rhd2) roots. Hairy roots (wild type, wer myb23) on mature, non-reproductive rosettes were more difficult to uproot from compost or clay soil than hairless roots (cpc try). At high root densities, erosion rates from soils with hairless roots (cpc try) were as much as 10 times those seen from soils occupied by roots with hairs (wer myb23, wild type). We find therefore root hairs play a significant role in root-soil cohesion and in minimizing erosion. This framework and associated suite of experimental assays demonstrates its ability to measure the effect of any root phenotype on the effectiveness of plant roots in binding substrates and reducing erosion.

ANZSoilML: An Australian - New Zealand standard for exchange of soil data

NASA Astrophysics Data System (ADS)

Simons, Bruce; Wilson, Peter; Ritchie, Alistair; Cox, Simon

2013-04-01

The Australian-New Zealand soil information exchange standard (ANZSoilML) is a GML-based standard designed to allow the discovery, query and delivery of soil and landscape data via standard Open Geospatial Consortium (OGC) Web Feature Services. ANZSoilML modifies the Australian soil exchange standard (OzSoilML), which is based on the Australian Soil Information Transfer and Evaluation System (SITES) database design and exchange protocols, to meet the New Zealand National Soils Database requirements. The most significant change was the removal of the lists of CodeList terms in OzSoilML, which were based on the field methods specified in the 'Australian Soil and Land Survey Field Handbook'. These were replaced with empty CodeLists as placeholders to external vocabularies to allow the use of New Zealand vocabularies without violating the data model. Testing of the use of these separately governed Australian and New Zealand vocabularies has commenced. ANZSoilML attempts to accommodate the proposed International Organization for Standardization ISO/DIS 28258 standard for soil quality. For the most part, ANZSoilML is consistent with the ISO model, although major differences arise as a result of: • The need to specify the properties appropriate for each feature type; • The inclusion of soil-related 'Landscape' features; • Allowing the mapping of soil surfaces, bodies, layers and horizons, independent of the soil profile; • Allowing specifying the relationships between the various soil features; • Specifying soil horizons as specialisations of soil layers; • Removing duplication of features provided by the ISO Observation & Measurements standard. The International Union of Soil Sciences (IUSS) Working Group on Soil Information Standards (WG-SIS) aims to develop, promote and maintain a standard to facilitate the exchange of soils data and information. Developing an international exchange standard that is compatible with existing and emerging national and regional standards is a considerable challenge. ANZSoilML is proposed as a profile of the more generalised SoilML model being progressed through the IUSS Working Group.

Global soil-climate-biome diagram: linking soil properties to climate and biota

NASA Astrophysics Data System (ADS)

Zhao, X.; Yang, Y.; Fang, J.

2017-12-01

As a critical component of the Earth system, soils interact strongly with both climate and biota and provide fundamental ecosystem services that maintain food, climate, and human security. Despite significant progress in digital soil mapping techniques and the rapidly growing quantity of observed soil information, quantitative linkages between soil properties, climate and biota at the global scale remain unclear. By compiling a large global soil database, we mapped seven major soil properties (bulk density [BD]; sand, silt and clay fractions; soil pH; soil organic carbon [SOC] density [SOCD]; and soil total nitrogen [STN] density [STND]) based on machine learning algorithms (regional random forest [RF] model) and quantitatively assessed the linkage between soil properties, climate and biota at the global scale. Our results demonstrated a global soil-climate-biome diagram, which improves our understanding of the strong correspondence between soils, climate and biomes. Soil pH decreased with greater mean annual precipitation (MAP) and lower mean annual temperature (MAT), and the critical MAP for the transition from alkaline to acidic soil pH decreased with decreasing MAT. Specifically, the critical MAP ranged from 400-500 mm when the MAT exceeded 10 °C but could decrease to 50-100 mm when the MAT was approximately 0 °C. SOCD and STND were tightly linked; both increased in accordance with lower MAT and higher MAP across terrestrial biomes. Global stocks of SOC and STN were estimated to be 788 ± 39.4 Pg (1015 g, or billion tons) and 63 ± 3.3 Pg in the upper 30-cm soil layer, respectively, but these values increased to 1654 ± 94.5 Pg and 133 ± 7.8 Pg in the upper 100-cm soil layer, respectively. These results reveal quantitative linkages between soil properties, climate and biota at the global scale, suggesting co-evolution of the soil, climate and biota under conditions of global environmental change.

Assessing soil and groundwater contamination in a metropolitan redevelopment project.

PubMed

Yun, Junki; Lee, Ju Young; Khim, Jeehyeong; Ji, Won Hyun

2013-08-01

The purpose of this study was to assess contaminated soil and groundwater for the urban redevelopment of a rapid transit railway and a new mega-shopping area. Contaminated soil and groundwater may interfere with the progress of this project, and residents and shoppers may be exposed to human health risks. The study area has been remediated after application of first remediation technologies. Of the entire area, several sites were still contaminated by waste materials and petroleum. For zinc (Zn) contamination, high Zn concentrations were detected because waste materials were disposed in the entire area. For petroleum contamination, high total petroleum hydrocarbon (TPH) and hydrocarbon degrading microbe concentrations were observed at the depth of 7 m because the underground petroleum storage tank had previously been located at this site. Correlation results suggest that TPH (soil) concentration is still related with TPH (groundwater) concentration. The relationship is taken into account in the Spearman coefficient (α).

Remote sensing research for agricultural applications. [San Joaquin County, California and Snake River Plain and Twin Falls area, Idaho

NASA Technical Reports Server (NTRS)

Colwell, R. N. (Principal Investigator); Wall, S. L.; Beck, L. H.; Degloria, S. D.; Ritter, P. R.; Thomas, R. W.; Travlos, A. J.; Fakhoury, E.

1984-01-01

Materials and methods used to characterize selected soil properties and agricultural crops in San Joaquin County, California are described. Results show that: (1) the location and widths of TM bands are suitable for detecting differences in selected soil properties; (2) the number of TM spectral bands allows the quantification of soil spectral curve form and magnitude; and (3) the spatial and geometric quality of TM data allows for the discrimination and quantification of within field variability of soil properties. The design of the LANDSAT based multiple crop acreage estimation experiment for the Idaho Department of Water Resources is described including the use of U.C. Berkeley's Survey Modeling Planning Model. Progress made on Peditor software development on MIDAS, and cooperative computing using local and remote systems is reported as well as development of MIDAS microcomputer systems.

Identifying calcium sources at an acid deposition-impacted spruce forest: A strontium isotope, alkaline earth element multi-tracer approach

USGS Publications Warehouse

Bullen, T.D.; Bailey, S.W.

2005-01-01

Depletion of calcium from forest soils has important implications for forest productivity and health. Ca is available to fine feeder roots from a number of soil organic and mineral sources, but identifying the primary source or changes of sources in response to environmental change is problematic. We used strontium isotope and alkaline earth element concentration ratios of trees and soils to discern the record of Ca sources for red spruce at a base-poor, acid deposition-impacted watershed. We measured 87Sr/86Sr and chemical compositions of cross-sectional stemwood cores of red spruce, other spruce tissues and sequential extracts of co-located soil samples. 87Sr/86Sr and Sr/Ba ratios together provide a tracer of alkaline earth element sources that distinguishes the plant-available fraction of the shallow organic soils from those of deeper organic and mineral soils. Ca/Sr ratios proved less diagnostic, due to within-tree processes that fractionate these elements from each other. Over the growth period from 1870 to 1960, 87Sr/86Sr and Sr/Ba ratios of stemwood samples became progressively more variable and on average trended toward values that considered together are characteristic of the uppermost forest floor. In detail the stemwood chemistry revealed an episode of simultaneous enhanced uptake of all alkaline earth elements during the growth period from 1930 to 1960, coincident with reported local and regional increases in atmospheric inputs of inorganic acidity. We attribute the temporal trends in stemwood chemistry to progressive shallowing of the effective depth of alkaline earth element uptake by fine roots over this growth period, due to preferential concentration of fine roots in the upper forest floor coupled with reduced nutrient uptake by roots in the lower organic and upper mineral soils in response to acid-induced aluminum toxicity. Although both increased atmospheric deposition and selective weathering of Ca-rich minerals such as apatite provide possible alternative explanations of aspects of the observed trends, the chemical buffering capacity of the forest floor-biomass pool limits their effectiveness as causal mechanisms. ?? Springer 2005.

X-ray digital imaging petrography of lunar mare soils: modal analyses of minerals and glasses

NASA Technical Reports Server (NTRS)

Taylor, L. A.; Patchen, A.; Taylor, D. H.; Chambers, J. G.; McKay, D. S.

1996-01-01

It is essential that accurate modal (i.e., volume) percentages of the various mineral and glass phases in lunar soils be used for addressing and resolving the effects of space weathering upon reflectance spectra, as well as for their calibration such data are also required for evaluating the resource potential of lunar minerals for use at a lunar base. However, these data are largely lacking. Particle-counting information for lunar soils, originally obtained to study formational processes, does not provide these necessary data, including the percentages of minerals locked in multi-phase lithic fragments and fused-soil particles, such as agglutinates. We have developed a technique for modal analyses, sensu stricto, of lunar soils, using digital imaging of X-ray maps obtained with an energy-dispersive spectrometer mounted on an electron microprobe. A suite of nine soils (90 to 150 micrometers size fraction) from the Apollo 11, 12, 15, and 17 mare sites was used for this study. This is the first collection of such modal data on soils from all Apollo mare sites. The abundances of free-mineral fragments in the mare soils are greater for immature and submature soils than for mature soils, largely because of the formation of agglutinitic glass as maturity progresses. In considerations of resource utilization at a lunar base, the best lunar soils to use for mineral beneficiation (i.e., most free-mineral fragments) have maturities near the immature/submature boundary (Is/FeO approximately or = 30), not the mature soils with their complications due to extensive agglutination. The particle data obtained from the nine mare soils confirm the generalizations for lunar soils predicted by L.A. Taylor and D.S. McKay (1992, Lunar Planet Sci. Conf. 23rd, pp. 1411-1412 [Abstract]).

BT TOXIN UPTAKE FROM SOIL BY PLANTS. (R826107)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

BIOENERGETICS AND BIOREMEDIATION OF CONTAMINATED SOIL. (R825549C034)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Accumulation of atmospheric sulfur in some Costa Rican soils

USGS Publications Warehouse

Bern, Carleton R.; Townsend, Alan R.

2013-01-01

Sulfur is one of the macronutrient elements whose sources to terrestrial ecosystems should shift from dominance by rock-weathering to atmospheric deposition as soils and underlying substrate undergo progressive weathering and leaching. However, the nature and timing of this transition is not well known. We investigated sources of sulfur to tropical rain forests growing on basalt-derived soils in the Osa Peninsula region of Costa Rica. Sulfur sources were examined using stable isotope ratios (δ34S) and compared to chemical indices of soil development. The most weathered soils, and the forests they supported, are dominated by atmospheric sulfur, while a less weathered soil type contains both rock-derived and atmospheric sulfur. Patterns of increasing δ34S with increasing soil sulfur concentration across the landscape suggest atmospheric sulfur is accumulating, and little rock-derived sulfur has been retained. Soil sulfur, minus adsorbed sulfate, is correlated with carbon and nitrogen, implying that sulfur accumulation occurs as plants and microbes incorporate sulfur into organic matter. Only the lower depth increments of the more weathered soils contained significant adsorbed sulfate. The evidence suggests a pattern of soil development in which sulfur-bearing minerals in rock, such as sulfides, weather early relative to other minerals, and the released sulfate is leached away. Sulfur added via atmospheric deposition is retained as organic matter accumulates in the soil profile. Adsorbed sulfate accumulates later, driven by changes in soil chemistry and mineralogy. These aspects of sulfur behavior during pedogenesis in this environment may hasten the transition to dominance by atmospheric sources.

Geochemical and radiological characterization of soils from former radium processing sites.

PubMed

Landa, E R

1984-02-01

Soil samples were collected from former radium processing sites in Denver, CO, and East Orange, NJ. Particle-size separations and radiochemical analyses of selected samples showed that while the greatest contents of both 226Ra and U were generally found in the finest (less than 45 micron) fraction, the pattern was not always of progressive increase in radionuclide content with decreasing particle size. Leaching tests on these samples showed a large portion of the 226Ra and U to be soluble in dilute hydrochloric acid. Radon-emanation coefficients measured for bulk samples of contaminated soil were about 20%. Recovery of residual uranium and vanadium, as an adjunct to any remedial action program, appears unlikely due to economic considerations.

[Testing and commercialization of a cotton stalk shredder and plow]. Technical progress report, October--December 1995

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

Thacker, G.W.

1996-01-27

This quarterly report describes work on Task 1: Field test and sell prototype to Ellis Equipment, Ltd; Task 2: Design, build, and field test two prototypes; and Task 3: Produce and sell Pegasus to farmers. The equipment has been built to shred stalks, deeply till the soil, and prepare seedbeds for cotton plants. The equipment has been field tested in Australia and is currently being field tested in California and Arizona. Unexpected problems appeared with hard dry soils and this report describes improvements made.

Progress Toward Cleanup of Operable Unit 1 Groundwater at the US DOE Mound, Ohio, Site: Success of a Phase-Combined Remedy – 15310

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

Hooten, Gwendolyn; Cato, Rebecca; Looney, Brian

2015-03-01

Operable Unit 1 (OU-1) soil and groundwater have been affected by volatile organic compounds (VOC) Present groundwater remedy is collection, treatment, and disposal (pump and treat [P&T]) Several combinations of technologies were used to address soil and groundwater contamination Monitored natural attenuation (MNA) is a viable alternative Majority of source term has been excavated VOC concentrations in groundwater have decreased Attenuation mechanisms have been observed in the subsurface at OU-1

Transport and fate of nitrate within soil units of glacial origin

NASA Astrophysics Data System (ADS)

Moore, Suzanna L.; Peterson, Eric W.

2007-08-01

Questions concerning the influence of soil type and crop cover on the fate and transport of nitrate (NO{3/-}) were examined. During a growing season, soils derived from glacial material underlying either corn or soybeans were sampled for levels of NO{3/-} within the pore water. Measured levels of NO{3/-} ranged from below detection limit to 14.9 g NO{3/-} per kilogram of soil (g/kg). In fields with the same crop cover, the silty-clayey soil exhibited a greater decrease in NO{3/-} levels with depth than the sandier soil. Crop uptake of NO{3/-} occurs within the root zone; however, the type of crop cover did not have a direct impact on the fate or transport during the growing season. The soils underlying soybeans had an increase in NO{3/-} levels following harvest, suggesting that the decomposition of the soybean roots contributed to the net gain of NO{3/-} in the shallow soil. For all of the soil types, conditions below 100 cm are conducive for microbial denitrification, with both a high water saturation level (>60%) and moderate organic carbon content (1-2%). At depths below 100 cm, temporal differences in NO{3/-} levels of over a magnitude, up to a 95% reduction, were recorded in the soil units as the growing season progressed. Physical properties that control the transport of NO{3/-} or denitrification have a larger influence on NO{3/-} levels than crop type.

A soil water based index as a suitable agricultural drought indicator

NASA Astrophysics Data System (ADS)

Martínez-Fernández, J.; González-Zamora, A.; Sánchez, N.; Gumuzzio, A.

2015-03-01

Currently, the availability of soil water databases is increasing worldwide. The presence of a growing number of long-term soil moisture networks around the world and the impressive progress of remote sensing in recent years has allowed the scientific community and, in the very next future, a diverse group of users to obtain precise and frequent soil water measurements. Therefore, it is reasonable to consider soil water observations as a potential approach for monitoring agricultural drought. In the present work, a new approach to define the soil water deficit index (SWDI) is analyzed to use a soil water series for drought monitoring. In addition, simple and accurate methods using a soil moisture series solely to obtain soil water parameters (field capacity and wilting point) needed for calculating the index are evaluated. The application of the SWDI in an agricultural area of Spain presented good results at both daily and weekly time scales when compared to two climatic water deficit indicators (average correlation coefficient, R, 0.6) and to agricultural production. The long-term minimum, the growing season minimum and the 5th percentile of the soil moisture series are good estimators (coefficient of determination, R2, 0.81) for the wilting point. The minimum of the maximum value of the growing season is the best estimator (R2, 0.91) for field capacity. The use of these types of tools for drought monitoring can aid the better management of agricultural lands and water resources, mainly under the current scenario of climate uncertainty.

Physicochemical and biological quality of soil in hexavalent chromium-contaminated soils as affected by chemical and microbial remediation.

PubMed

Liao, Yingping; Min, Xiaobo; Yang, Zhihui; Chai, Liyuan; Zhang, Shujuan; Wang, Yangyang

2014-01-01

Chemical and microbial methods are the main remediation technologies for chromium-contaminated soil. These technologies have progressed rapidly in recent years; however, there is still a lack of methods for evaluating the chemical and biological quality of soil after different remediation technologies have been applied. In this paper, microbial remediation with indigenous bacteria and chemical remediation with ferrous sulphate were used for the remediation of soils contaminated with Cr(VI) at two levels (80 and 1,276 mg kg(-1)) through a column leaching experiment. After microbial remediation with indigenous bacteria, the average concentration of water-soluble Cr(VI) in the soils was reduced to less than 5.0 mg kg(-1). Soil quality was evaluated based on 11 soil properties and the fuzzy comprehensive assessment method, including fuzzy mathematics and correlative analysis. The chemical fertility quality index was improved by one grade using microbial remediation with indigenous bacteria, and the biological fertility quality index increased by at least a factor of 6. Chemical remediation with ferrous sulphate, however, resulted in lower levels of available phosphorus, dehydrogenase, catalase and polyphenol oxidase. The result showed that microbial remediation with indigenous bacteria was more effective for remedying Cr(VI)-contaminated soils with high pH value than chemical remediation with ferrous sulphate. In addition, the fuzzy comprehensive evaluation method was proven to be a useful tool for monitoring the quality change in chromium-contaminated soils.

Investigating the Relationship Between Soil Water Mobility and Stable Isotope Composition with Implications for the Ecohydrologic Separation Hypothesis

NASA Astrophysics Data System (ADS)

Shuler, J.; McNamara, J. P.; Benner, S. G.; Kohn, M. J.; Evans, S.

2017-12-01

The ecohydrologic separation (ES) hypothesis states that streams and plants return different soil water compartments to the atmosphere and that these compartments bear distinct isotopic compositions that can be used to infer soil water mobility. Recent studies have found isotopic evidence for ES in a variety of ecosystems, though interpretations of these data vary. ES investigations frequently suffer from low sampling frequencies as well as incomplete or missing soil moisture and matric potential data to support assumptions of soil water mobility. We sampled bulk soil water every 2-3 weeks in the upper 1 m of a hillslope profile from May 2016 to July 2017 in a semi-arid watershed outside Boise, ID. Twig samples of three plant species were also collected concurrently. Plant and soil water samples extracted via cryogenic vacuum distillation were analyzed for δ2H and δ18O composition. Soil moisture and soil matric potential sensors were installed at five and four depths in the profile, respectively. Shallow bulk soil water was progressively enriched in both isotopes over the growing season and plotted along a soil evaporation line in a plot of δ2H versus δ18O. Plant water during the growing season plotted below both the Local Meteoric Water Line and soil evaporation line. Plant water isotopic composition could not be traced to any source sampled in this study. Additionally, soil moisture and matric potential data revealed that soils were well-drained and that mobile soil water was unavailable throughout most of the growing season at the depths sampled. Soil water isotopic composition alone failed to predict mobility as observed in soil moisture and matric potential data. These results underscore the need for standard hydrologic definitions for the mobile and immobile compartments of soil water in future studies of the ES hypothesis and ecohydrologic processes in general.

Timing and magnitude of C partitioning through a young loblolly pine (Pinus taeda L.) stand using 13C labeling and shade treatments.

PubMed

Warren, J M; Iversen, C M; Garten, C T; Norby, R J; Childs, J; Brice, D; Evans, R M; Gu, L; Thornton, P; Weston, D J

2012-06-01

The dynamics of rapid changes in carbon (C) partitioning within forest ecosystems are not well understood, which limits improvement of mechanistic models of C cycling. Our objective was to inform model processes by describing relationships between C partitioning and accessible environmental or physiological measurements, with a special emphasis on short-term C flux through a forest ecosystem. We exposed eight 7-year-old loblolly pine (Pinus taeda L.) trees to air enriched with (13)CO(2) and then implemented adjacent light shade (LS) and heavy shade (HS) treatments in order to manipulate C uptake and flux. The impacts of shading on photosynthesis, plant water potential, sap flow, basal area growth, root growth and soil CO(2) efflux rate (CER) were assessed for each tree over a 3-week period. The progression of the (13)C label was concurrently tracked from the atmosphere through foliage, phloem, roots and surface soil CO(2) efflux. The HS treatment significantly reduced C uptake, sap flow, stem growth and fine root standing crop, and resulted in greater residual soil water content to 1 m depth. Soil CER was strongly correlated with sap flow on the previous day, but not the current day, with no apparent treatment effect on the relationship. Although there were apparent reductions in new C flux belowground, the HS treatment did not noticeably reduce the magnitude of belowground autotrophic and heterotrophic respiration based on surface soil CER, which was overwhelmingly driven by soil temperature and moisture. The (13)C label was immediately detected in foliage on label day (half-life = 0.5 day), progressed through phloem by Day 2 (half-life = 4.7 days), roots by Days 2-4, and subsequently was evident as respiratory release from soil which peaked between Days 3 and 6. The δ(13)C of soil CO(2) efflux was strongly correlated with phloem δ(13)C on the previous day, or 2 days earlier. While the (13)C label was readily tracked through the ecosystem, the fate of root C through respiratory, mycorrhizal or exudative release pathways was not assessed. These data detail the timing and relative magnitude of C flux through various components of a young pine stand in relation to environmental conditions.

Peat Land Oxidation Enhances Subsidence in the Venice Watershed

NASA Astrophysics Data System (ADS)

Gambolati, Giuseppe; Putti, Mario; Teatini, Pietro; Camporese, Matteo; Ferraris, Stefano; Stori, Giuseppe Gasparetto; Nicoletti, Vincenzo; Silvestri, Sonia; Rizzetto, Federica; Tosi, Luigi

2005-06-01

The southernmost part of the Venice Lagoon catchment was progressively reclaimed from marshland starting from the end of the 19th century and finishing in the late 1930s (Figure 1). As a major result, the area was turned into a fertile farmland. At present, the area is kept dry by a distributed drainage system that collects the water from a capillary network of ditches, and pumps it into the lagoon or the sea. By its very origin this area lies below sea level and progressively sinks mainly because of bio-oxidation of the histosols (soils with high organic content) that represent a large fraction of the outcropping soil in the area. The bio-oxidation process occurs in close connection with the agricultural practices and is currently responsible for a subsidence rate of between 1.5 and 2 cm/yr. The Venice Organic Soil Subsidence (VOSS) project was undertaken with the objective of understanding the process of land settlement in this area, quantifying past and present subsidence rates, and advancing possible remedial measures that would not penalize the current agricultural activities of the area. The study, conducted in close collaboration with the local Land Reclamation Authority (Consorzio di Bonifica) and the farmland owners, is focused on a hydrologically controlled catchment, the Zennare Basin (Venice, Italy).

Candidate soil indicators for monitoring the progress of constructed wetlands toward a natural state: a statistical approach

USGS Publications Warehouse

Stapanian, Martin A.; Adams, Jean V.; Fennessy, M. Siobhan; Mack, John; Micacchion, Mick

2013-01-01

A persistent question among ecologists and environmental managers is whether constructed wetlands are structurally or functionally equivalent to naturally occurring wetlands. We examined 19 variables collected from 10 constructed and nine natural emergent wetlands in Ohio, USA. Our primary objective was to identify candidate indicators of wetland class (natural or constructed), based on measurements of soil properties and an index of vegetation integrity, that can be used to track the progress of constructed wetlands toward a natural state. The method of nearest shrunken centroids was used to find a subset of variables that would serve as the best classifiers of wetland class, and error rate was calculated using a five-fold cross-validation procedure. The shrunken differences of percent total organic carbon (% TOC) and percent dry weight of the soil exhibited the greatest distances from the overall centroid. Classification based on these two variables yielded a misclassification rate of 11% based on cross-validation. Our results indicate that % TOC and percent dry weight can be used as candidate indicators of the status of emergent, constructed wetlands in Ohio and for assessing the performance of mitigation. The method of nearest shrunken centroids has excellent potential for further applications in ecology.

Challenges and opportunities for quantifying roots and rhizosphere interactions through imaging and image analysis.

PubMed

Downie, H F; Adu, M O; Schmidt, S; Otten, W; Dupuy, L X; White, P J; Valentine, T A

2015-07-01

The morphology of roots and root systems influences the efficiency by which plants acquire nutrients and water, anchor themselves and provide stability to the surrounding soil. Plant genotype and the biotic and abiotic environment significantly influence root morphology, growth and ultimately crop yield. The challenge for researchers interested in phenotyping root systems is, therefore, not just to measure roots and link their phenotype to the plant genotype, but also to understand how the growth of roots is influenced by their environment. This review discusses progress in quantifying root system parameters (e.g. in terms of size, shape and dynamics) using imaging and image analysis technologies and also discusses their potential for providing a better understanding of root:soil interactions. Significant progress has been made in image acquisition techniques, however trade-offs exist between sample throughput, sample size, image resolution and information gained. All of these factors impact on downstream image analysis processes. While there have been significant advances in computation power, limitations still exist in statistical processes involved in image analysis. Utilizing and combining different imaging systems, integrating measurements and image analysis where possible, and amalgamating data will allow researchers to gain a better understanding of root:soil interactions. © 2014 John Wiley & Sons Ltd.

Analysis of Soil Structure Turnover with Garnet Particles and X-Ray Microtomography

PubMed Central

Vogel, Hans-Jörg

2016-01-01

Matter turnover in soil is tightly linked to soil structure which governs the heterogeneous distribution of habitats, reaction sites and pathways in soil. Thereby, the temporal dynamics of soil structure alteration is deemed to be important for essential ecosystem functions of soil but very little is known about it. A major reason for this knowledge gap is the lack of methods to study soil structure turnover directly at microscopic scales. Here we devise a conceptual approach and an image processing workflow to study soil structure turnover by labeling some initial state of soil structure with small garnet particles and tracking their fate with X-ray microtomography. The particles adhere to aggregate boundaries at the beginning of the experiment but gradually change their position relative to the nearest pore as structure formation progresses and pores are destructed or newly formed. A new metric based on the contact distances between particles and pores is proposed that allows for a direct quantification of soil structure turnover rates. The methodology is tested for a case study about soil compaction of a silty loam soil during stepwise increase of bulk density (ρ = {1.1, 1.3, 1.5} g/cm3). We demonstrate that the analysis of mean contact distances provides genuinely new insights about changing diffusion pathways that cannot be inferred neither from conventional pore space attributes (porosity, mean pore size, pore connectivity) nor from deformation analysis with digital image correlation. This structure labeling approach to quantify soil structure turnover provides a direct analogy to stable isotope labeling for the analysis of matter turnover and can be readily combined with each other. PMID:27453995

Hydrological Impacts of Mesquite Encroachment in the Upper San Pedro Watershed

EPA Science Inventory

Invasion of mesquite into grassland occurs in water-limited ecosystems throughout the world. To assess hydrological consequences of mesquite invasion, the Soil and Water Assessment Tool (SWAT) was applied to simulate idealized progressive mesquite encroachments in the upper San P...

SOIL GAS OXYGEN TENSION AND PENTACHLOROPHENOL BIODEGRADATION. (R825549C051)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

MODELING PHYTOREMEDIATION FOR PETROLEUM CONTAMINATED SOIL: MODEL DEVELOPMENT. (R827015C018)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

IMAGING SOIL BACTERIA IN AN ENVIRONMENTAL SCANNING ELECTRON MICROSCOPE. (R827133)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

MICROBIAL RESPONSES TO NITROGEN ADDITIONS IN ALPINE TUNDRA SOILS (R823442)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

MODELS FOR LEACHING OF PESTICIDES IN SOILS AND GROUNDWATER. (R825433)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

DISTRIBUTION OF ARSENIC IN CHEMICALLY VARIANT DIPPING VAT SITE SOILS. (R830842)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Bioavailability of xenobiotics in the soil environment.

PubMed

Katayama, Arata; Bhula, Raj; Burns, G Richard; Carazo, Elizabeth; Felsot, Allan; Hamilton, Denis; Harris, Caroline; Kim, Yong-Hwa; Kleter, Gijs; Koedel, Werner; Linders, Jan; Peijnenburg, J G M Willie; Sabljic, Aleksandar; Stephenson, R Gerald; Racke, D Kenneth; Rubin, Baruch; Tanaka, Keiji; Unsworth, John; Wauchope, R Donald

2010-01-01

It is often presumed that all chemicals in soil are available to microorganisms, plant roots, and soil fauna via dermal exposure. Subsequent bioaccumulation through the food chain may then result in exposure to higher organisms. Using the presumption of total availability, national governments reduce environmental threshold levels of regulated chemicals by increasing guideline safety margins. However, evidence shows that chemical residues in the soil environment are not always bioavailable. Hence, actual chemical exposure levels of biota are much less than concentrations present in soil would suggest. Because "bioavailability" conveys meaning that combines implications of chemical sol persistency, efficacy, and toxicity, insights on the magnitude of a chemicals soil bioavailability is valuable. however, soil bioavailability of chemicals is a complex topic, and is affected by chemical properties, soil properties, species exposed, climate, and interaction processes. In this review, the state-of-art scientific basis for bioavailability is addressed. Key points covered include: definition, factors affecting bioavailability, equations governing key transport and distributive kinetics, and primary methods for estimating bioavailability. Primary transport mechanisms in living organisms, critical to an understanding of bioavailability, also presage the review. Transport of lipophilic chemicals occurs mainly by passive diffusion for all microorganisms, plants, and soil fauna. Therefore, the distribution of a chemical between organisms and soil (bioavailable proportion) follows partition equilibrium theory. However, a chemical's bioavailability does not always follow partition equilibrium theory because of other interactions with soil, such as soil sorption, hysteretic desorption, effects of surfactants in pore water, formation of "bound residue", etc. Bioassays for estimating chemical bioavailability have been introduced with several targeted endpoints: microbial degradation, uptake by higher plants and soil fauna, and toxicity to organisms. However, there bioassays are often time consuming and laborious. Thus, mild extraction methods have been employed to estimate bioavailability of chemicals. Mild methods include sequential extraction using alcohols, hexane/water, supercritical fluids (carbon dioxide), aqueous hydroxypropyl-beta-cyclodextrin extraction, polymeric TENAX beads extraction, and poly(dimethylsiloxane)-coated solid-phase microextraction. It should be noted that mild extraction methods may predict bioavailability at the moment when measurements are carried out, but not the changes in bioavailability that may occur over time. Simulation models are needed to estimate better bioavailability as a function of exposure time. In the past, models have progressed significantly by addressing each group of organisms separately: microbial degradation, plant uptake via evapotranspiration processes, and uptake of soil fauna in their habitat. This approach has been used primarily because of wide differences in the physiology and behaviors of such disparate organisms. However, improvement of models is badly needed, Particularly to describe uptake processes by plant and animals that impinge on bioavailability. Although models are required to describe all important factors that may affect chemical bioavailability to individual organisms over time (e.g., sorption/desorption to soil/sediment, volatilization, dissolution, aging, "bound residue" formation, biodegradation, etc.), these models should be simplified, when possible, to limit the number of parameters to the practical minimum. Although significant scientific progress has been made in understanding the complexities in specific methodologies dedicated to determining bioavailability, no method has yet emerged to characterized bioavailability across a wide range of chemicals, organisms, and soils/sediments. The primary aim in studying bioavailability is to define options for addressing bioremediation or environmental toxicity (risk assessment), and that is unlikely to change. Because of its importance in estimating research is needed to more comprehensively address the key environmental issue of "bioavailability of chemicals in soil/sediment."

Rehabilitation potential and practices of Colorado oil shale lands. Progress report, June 1, 1978--May 31, 1979

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

Cook, C.W.

The following document is a third-year progress report for the period June 1, 1978 to May 31, 1979. The overall objective of the project is to study the effects of seeding techniques, species mixtures, fertilizer, ecotypes, improved plant materials, mycorrhizal fungi, and soil microorganisms on the initial and final stages of reclamation obtained through seeding and subsequent succession on disturbed oil shale lands. Plant growth medias that are being used in field-established test plots include retorted shale, soil over retorted shale, subsoil materials, and surface disturbed topsoils. Because of the long-term nature of successional and ecologically oriented studies the projectmore » is just beginning to generate significant publications. Several of the studies associated with the project have some phases being conducted principally in the laboratories and greenhouses at Colorado State Univerisity. The majority of the research, however, is being conducted on a 20 hectare Intensive Study Site located near the focal points of oil shale activity in the Piceance Basin. The site is at an elevation of 2,042 m, receives approximately 30 to 55 cm of precipitation annually, and encompasses the plant communities most typical of the Piceance Basin. Most of the information contained in this report originated from the monitoring and sampling of research plots established in either the fall of 1976 or 1977. Therefore, data that have been obtained from the Intensive Study Site represent only first- or second-year results. However, many trends have been identified in thesuccessional process and the soil microorganisms and mycorrhizal studies continue to contribute significant information to the overall results. The phytosociological study has progressed to a point where field sampling is complete and the application and publication of this materials will be forthcoming in 1979.« less

Soil N retention and nitrate leaching in three types of dunes in the Mu Us desert of China.

PubMed

Jin, Zhao; Zhu, Yajuan; Li, Xiangru; Dong, Yunshe; An, Zhisheng

2015-09-15

A large reservoir of soil nitrate in desert subsoil zones has been demonstrated in previous studies; however, information on the subsoil nitrate reservoir and its distribution characteristics in the deserts of China is still limited. This study investigated the distribution patterns of soil total nitrogen (N), nitrate, ammonium, and stable isotopic ratios of (15)N (δ(15)N) in shallow (1 m) and subsoil (5 m) profiles in three types of dunes in the Mu Us desert of China. We found that soil N retention of the fixed and semi-fixed dunes followed a progressive nutrient depletion pattern in shallow soil profiles, whereas the subsoil nitrate of the fixed, semi-fixed and mobile dunes maintained a conservative accumulation pattern. The results indicate that the subsoil of the Mu Us desert may act as a reservoir of available nitrate. Furthermore, a soil δ(15)N analysis indicate that the nitrate content of the fixed dune is likely derived from soil nitrification, whereas the nitrate content in the mobile dune is derived from atmospheric nitrate deposition. Within the context of looming climate change and intensifying human activities, the subsoil nitrate content in the deserts of northern China could become mobilized and increase environmental risks to groundwater.

A reservoir for solar-wind-produced water in lunar soils

NASA Astrophysics Data System (ADS)

Taylor, L.; Liu, Y.; Zent, A.; Quinn, R.; Ichimura, A.

2012-09-01

Discoveries of new sources of WATER on the Moon are becoming more numerous as our research progresses. All these recent discoveries of different forms of H (OH, HOH, and H2O ice) on the Moon, both endogenic and exogenic, have reshaped our view of "water" ON and IN the Moon Despite these discoveries, a potential large reservoir, LUNAR SOIL, has been largely overlooked until recently [1-2]. This was the first report and confirmation of OH in micro-meteoriteformed, impact glass in lunar soils; so-called "agglutinates", with abundances of up to 500 ppmw H2O, presents a medium for the accumulation of H from all the various sources. And the Lunar Soil Characterization Consortium (LSCC) [3-5] has demonstrated that the impact-melt glass portion of the fine-grain sizes of the lunar soil contains upwards of 70-80 % of such water-bearing glass. This could make for lunar soil feedstock with upwards of ~0.1 wt% H2O, in addition to any water produced solarwind hydrogen reduction of ilmenite, etc. Therefore, thermal rendering of the fine-portions of the soil for solar-wind volatiles (e.g., H, He-3, C, N) will encounter additional quantities of water, exceeding those of the absorbed solar-wind.

Decontamination Systems Information and Research Program. Quarterly technical progress report, January 1--March 31, 1994

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

Not Available

1994-05-01

West Virginia University (WVU) and the US DOE Morgantown Energy Technology Center (METC) entered into a Cooperative Agreement on August 29, 1992 entitled ``Decontamination Systems Information and Research Programs.`` Stipulated within the Agreement is the requirement that WVU submit to METC a series of Technical Progress Reports on a quarterly basis. This report comprises the first Quarterly Technical Progress Report for Year 2 of the Agreement. This report reflects the progress and/or efforts performed on the sixteen (16) technical projects encompassed by the Year 2 Agreement for the period of January 1 through March 31, 1994. In situ bioremediation ofmore » chlorinated organic solvents; Microbial enrichment for enhancing in-situ biodegradation of hazardous organic wastes; Treatment of volatile organic compounds (VOCs) using biofilters; Drain-enhanced soil flushing (DESF) for organic contaminants removal; Chemical destruction of chlorinated organic compounds; Remediation of hazardous sites with steam reforming; Soil decontamination with a packed flotation column; Use of granular activated carbon columns for the simultaneous removal of organics, heavy metals, and radionuclides; Monolayer and multilayer self-assembled polyion films for gas-phase chemical sensors; Compact mercuric iodide detector technology development; Evaluation of IR and mass spectrometric techniques for on-site monitoring of volatile organic compounds; A systematic database of the state of hazardous waste clean-up technologies; Dust control methods for insitu nuclear and hazardous waste handling; Winfield Lock and Dam remediation; and Socio-economic assessment of alternative environmental restoration technologies.« less

Plant Adaptation to Acid Soils: The Molecular Basis for Crop Aluminum Resistance.

PubMed

Kochian, Leon V; Piñeros, Miguel A; Liu, Jiping; Magalhaes, Jurandir V

2015-01-01

Aluminum (Al) toxicity in acid soils is a significant limitation to crop production worldwide, as approximately 50% of the world's potentially arable soil is acidic. Because acid soils are such an important constraint to agriculture, understanding the mechanisms and genes conferring resistance to Al toxicity has been a focus of intense research interest in the decade since the last article on crop acid soil tolerance was published in this journal. An impressive amount of progress has been made during that time that has greatly increased our understanding of the diversity of Al resistance genes and mechanisms, how resistance gene expression is regulated and triggered by Al and Al-induced signals, and how the proteins encoded by these genes function and are regulated. This review examines the state of our understanding of the physiological, genetic, and molecular bases for crop Al tolerance, looking at the novel Al resistance genes and mechanisms that have been identified over the past ten years. Additionally, it examines how the integration of molecular and genetic analyses of crop Al resistance is starting to be exploited for the improvement of crop plants grown on acid soils via both molecular-assisted breeding and biotechnology approaches.

Research on the autumn irrigation schedule of Hetao Irrigation District of China

NASA Astrophysics Data System (ADS)

Han, Y.

2016-12-01

Salinization of soil has great influence on the function of crop land, leading to the crop failure to some extent. One of the inducement of salinization is that the water pressure of frozen soil is lower than that of unfrozen, salt is drew up to the frozen layer along with water during the freezing process. To prevent the salinization of soil, people carry out the autumn irrigation in Hetao Irrigation District which located is located in Bayannur City, Inner Mongolia, north of China. Autumn irrigation is an irrigation event before the freezing of soil, the function of autumn irrigation includes soil moisture conservation, loosening the soil and leaching the salt. Among all the crop models, none is designed to simulate the water and salt movement during freezing and thawing progress. So In this study, SWAP (Soil Water Atmosphere Plant) model is modified by adding the freezing and thawing module which enable the model to take into consideration the effect of freezing and thawing on water and salt movement. After validating the modified model using field data and lab test results, the model was used to simulate the results of various autumn irrigation schedules, exploring the influence of different autumn irrigation amounts on the water, salt and heat condition and transportation of soil. Finally, proper autumn irrigation schedule was obtained to instruct the production of Hetao Irrigation District.

Global Soil and Sediment transfer during the Anthropocene

NASA Astrophysics Data System (ADS)

Hoffmann, Thomas; Vanacker, Veerle; Stinchcombe, Gary; Penny, Dan; Xixi, Lu

2016-04-01

The vulnerability of soils to human-induced erosion and its downstream effects on fluvial and deltaic ecosystems is highly variable in space and time; dependent on climate, geology, the nature and duration of land use, and topography. Despite our knowledge of the mechanistic relationships between erosion, sediment storage, land-use and climate change, the global patterns of soil erosion, fluvial sediment flux and storage throughout the Holocene remain poorly understood. The newly launched PAGES working group GloSS aims to determine the sensitivity of soil resources and sediment routing systems to varying land use types during the period of agriculture, under contrasting climate regimes and socio-ecological settings. Successfully addressing these questions in relation to the sustainable use of soils, sediments and river systems requires an understanding of past human-landscape interactions. GloSS, therefore, aims to: Develop proxies for, or indices of, human impact on rates of soil erosion and fluvial sediment transfer that are applicable on a global scale and throughout the Holocene; Create a global database of long-term (102-104 years) human-accelerated soil erosion and sediment flux records; Identify hot spots of soil erosion and sediment deposition during the Anthropocene, and Locate data-poor regions where particular socio-ecological systems are not well understood, as strategic foci for future work. This paper will present the latest progress of the PAGES GloSS working group.

Chemical weathering rates of a soil chronosequence on granitic alluvium: III. Hydrochemical evolution and contemporary solute fluxes and rates

USGS Publications Warehouse

White, A.F.; Schulz, M.S.; Vivit, D.V.; Blum, A.E.; Stonestrom, David A.; Harden, J.W.

2005-01-01

Although long-term changes in solid-state compositions of soil chronosequences have been extensively investigated, this study presents the first detailed description of the concurrent hydrochemical evolution and contemporary weathering rates in such sequences. The most direct linkage between weathering and hydrology over 3 million years of soil development in the Merced chronosequence in Central California relates decreasing permeability and increasing hydrologic heterogeneity to the development of secondary argillic horizons and silica duripans. In a highly permeable, younger soil (40 kyr old), pore water solutes reflect seasonal to decadal-scale variations in rainfall and evapotranspiration (ET). This climate signal is strongly damped in less permeable older soils (250 to 600 kyr old) where solutes increasingly reflect weathering inputs modified by heterogeneous flow. Elemental balances in the soils are described in terms of solid state, exchange and pore water reservoirs and input/output fluxes from precipitation, ET, biomass, solute discharge and weathering. Solute mineral nutrients are strongly dependent on biomass variations as evidenced by an apparent negative K weathering flux reflecting aggradation by grassland plants. The ratios of solute Na to other base cations progressively increase with soil age. Discharge fluxes of Na and Si, when integrated over geologic time, are comparable to solid-state mass losses in the soils, implying similar past weathering conditions. Similarities in solute and sorbed Ca/Mg ratios reflect short-term equilibrium with the exchange reservoir. Long-term consistency in solute ratios, when contrasted against progressive decreases in solid-state Ca/Mg, requires an additional Ca source, probably from dry deposition. Amorphous silica precipitates from thermodynamically-saturated pore waters during periods of high evapotranspiration and result in the formation of duripans in the oldest soils. The degree of feldspar and secondary gibbsite and kaolinite saturation varies both spatially and temporally due to the seasonality of plant-respired CO2 and a decrease in organically complexed Al. In deeper pore waters, K-feldspar is in equilibrium and plagioclase is about an order of magnitude undersaturated. Hydrologic heterogeneity produces a range of weathering gradients that are constrained by solute distributions and matrix and macropore flow regimes. Plagioclase weathering rates, based on precipitation-corrected Na gradients, vary between 3 and 7 ?? 10-16 mol m-2 s-1. These rates are similar to previously determined solid-state rates but are several orders of magnitude slower than for experimental plagioclase dissolution indicating strong inhibitions to natural weathering, partly due to near-equilibrium weathering reactions. Copyright ?? 2005 Elsevier Ltd.

Soil physics: a Moroccan perspective

NASA Astrophysics Data System (ADS)

Lahlou, Sabah; Mrabet, Rachid; Ouadia, Mohamed

2004-06-01

Research on environmental pollution and degradation of soil and water resources is now of highest priority worldwide. To address these problems, soil physics should be conceived as a central core to this research. This paper objectives are to: (1) address the role and importance of soil physics, (2) demonstrate progress in this discipline, and (3) present various uses of soil physics in research, environment and industry. The study of dynamic processes at and within the soil vadose zone (flow, dispersion, transport, sedimentation, etc.), and ephemeral phenomena (deformation, compaction, etc.), form an area of particular interest in soil physics. Soil physics has changed considerably over time. These changes are due to needed precision in data collection for accurate interpretation of space and time variation of soil properties. Soil physics interacts with other disciplines and sciences such as hydro(geo)logy, agronomy, environment, micro-meteorology, pedology, mathematics, physics, water sciences, etc. These interactions prompted the emergence of advanced theories and comprehensive mechanisms of most natural processes, development of new mathematical tools (modeling and computer simulation, fractals, geostatistics, transformations), creation of high precision instrumentation (computer assisted, less time constraint, increased number of measured parameters) and the scale sharpening of physical measurements which ranges from micro to watershed. The environment industry has contributed to an enlargement of many facets of soil physics. In other words, research demand in soil physics has increased considerably to satisfy specific and environmental problems (contamination of water resources, global warming, etc.). Soil physics research is still at an embryonic stage in Morocco. Consequently, soil physicists can take advantage of developments occurring overseas, and need to build up a database of soil static and dynamic properties and to revise developed models to meet our conditions. Large, but special, investment is required to promote research programs in soil physics, which consider developments in this discipline and respect Moroccan needs. These programs will be highlighted herein.

Response of soil microbial activity and biodiversity in soils polluted with different concentrations of cypermethrin insecticide.

PubMed

Tejada, Manuel; García, Carlos; Hernández, Teresa; Gómez, Isidoro

2015-07-01

We performed a laboratory study into the effect of cypermethrin insecticide applied to different concentrations on biological properties in two soils [Typic Xerofluvent (soil A) and Xerollic Calciorthid (soil B)]. Two kg of each soil were polluted with cypermethrin at a rate of 60, 300, 600, and 1,200 g ha(-1) (C1, C2, C3, and C4 treatments). A nonpolluted soil was used as a control (C0 treatment). For all treatments and each experimental soil, soil dehydrogenase, urease, β-glucosidase, phosphatase, and arylsulphatase activities and soil microbial community were analysed by phospholipid fatty acids, which were measured at six incubation times (3, 7, 15, 30, 60, and 90 days). The behavior of the enzymatic activities and microbial population were dependent on the dose of insecticide applied to the soil. Compared with the C0 treatment, in soil A, the maximum inhibition of the enzymatic activities was at 15, 30, 45, and 90 days for the C1, C2, C3, and C4 treatments, respectively. However, in soil B, the maximum inhibition occurred at 7, 15, 30, and 45 days for the C1, C2, C3, and C4 treatments, respectively. These results suggest that the cypermethrin insecticide caused a negative effect on soil enzymatic activities and microbial diversity. This negative impact was greater when a greater dose of insecticide was used; this impact was also greater in soil with lower organic matter content. For both soils, and from these respective days onward, the enzymatic activities and microbial populations progressively increased by the end of the experimental period. This is possibly due to the fact that the insecticide or its breakdown products and killed microbial cells, subsequently killed by the insecticide, are being used as a source of energy or as a carbon source for the surviving microorganisms for cell proliferation.

Creating Common Ground: Activities of the Soil Health Dialog Workgroup

NASA Astrophysics Data System (ADS)

Lindbo, David L.; Moebius-Clune, Bianca; Hatfield, Jerry; Buckner, William; Conklin, Neil; McMahon, Sean; Haney, Richard; Muller, Paul; Martin, Larkin; Shaw, Richard; Eyrich, Ted; Martens, Klaas; Archuleta, Ray; Thompson, Mary

2014-05-01

The concept of Soil Health has come to forefront as a soil management concept for soil scientists, agronomists, producers, land-use planners, and environmental advocates. Although many see this simply as a way to increase organic matter in the soil it is much more than that and has implications to a broader management decisions. A diverse group of stake holders ranging from scientists to consultants, conventional to organic farmers, governmental to NGOs met to start a dialog about soil health with an overarching goal to adopt practices that will improve soil health across a wide area and for a wide variety of land uses. The group recognized the critical need for using soil health as a cornerstone of sustainable soil management. The group also realized that a consistent and coherent message about soil health needed to be developed that would be inclusive to all stake holders. Furthermore the group recognized that if soil health is to be promoted we all need to know and agree on how to measure it and interpret the results. The first outcome from the meeting was the creation of several teams comprised of individuals with the diverse interests as list above. The first was tasked to review and develop a definition of soil health. The first group, after much debate, decided on the adoption of the USDA-NRCS definition of Soil Health as the most effective way to begin. This definition was presented as a press release from the Farm Foundation in early December 2013 in conjunction with World Soil Day. The second group was tasked to review, develop or recommend standard measurement techniques to assess soil health. The methods group is in the process of reviewing methods and hopes to have a preliminary list out for broader review by mid-year. This presentation reviews current progress and asks for input from the Soil Science community at large.

Pile group program for full material modeling and progressive failure.

DOT National Transportation Integrated Search

2008-12-01

Strain wedge (SW) model formulation has been used, in previous work, to evaluate the response of a single pile or a group of piles (including its : pile cap) in layered soils to lateral loading. The SW model approach provides appropriate prediction f...

Progress in Working Towards a More Sustainable Agri-Food Industry

EPA Science Inventory

The human health and environmental issues related to food, feed, and bio-based systems, range widely from greenhouse gas emissions and energy use to land use, water availability, soil quality, water quality and quantity, biodi-versity losses, and chemical exposure. Threats that s...

TRACE ELEMENTS AND BENEFICIAL USE OF ORGANIC RESOURCES

EPA Science Inventory

This paper summarizes information on risk assessment for metals (Cd, Pb, As, Zn, Cu, Hg) in compost products used in agriculture or horticulture, and progress in research to develop and demonstrate the use of Tailor-Made Composts to remediate metal phytotoxic soils. Research has ...

LONG-TERM TNT SORPTION AND BOUND RESIDUE FORMATION IN SOIL. (R825549C043)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

ROLE OF LIPIDS IN PAH BINDING TO SOIL ORGANIC MATTER. (R825549C058)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

FIFTEEN YEARS OF VEGETATION AND SOIL DEVELOPMENT AFTER BRACKISH-WATER MARSH CREATION. (R826111)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

GENERALIZED MODEL FOR NOX AND N2O EMISSIONS FROM SOILS. (R824993)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

DEGRADATION OF ATRAZINE IN PESTICIDE-CONTAMINATED SOILS: PHYTOREMEDIATION POTENTIAL. (R825549C045)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

RAPID METHOD OF EXTRACTION (EXPRESSO) FOR DETERMINING AVAILABLE NITROGEN IN SOIL. (R826107)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

SOIL ORGANIC MATTER RECOVERY ON CONSERVATION RESERVE PROGRAM FIELDS IN SOUTHEASTERN WYOMING. (R824993)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

PHENOLOXIDASE-MEDIATED INTERACTIONS OF PHENOLS AND ANILINES WITH SOIL ORGANIC MATTER. (R826646)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

EXPERIMENTAL EVIDENCE AGAINST DIFFUSION CONTROL OF HG EVASION FROM SOILS. (R827622E02)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

COUPLING DIAZINON VOLATILIZATION AND WATER EVAPORATION IN UNSATURATED SOILS: I. WATER TRANSPORT. (R825433)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

CHELATING EXTRACTION OF COPPER FROM SOIL WITH S-CARBOXYMETHYLCYSTEINE. (R825549C052)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Ca cycling and isotopic fluxes in forested ecosystems in Hawaii

USGS Publications Warehouse

Wiegand, B.A.; Chadwick, O.A.; Vitousek, P.M.; Wooden, J.L.

2005-01-01

Biogeochemical processes fractionate Ca isotopes in plants and soils along a 4 million year developmental sequence in the Hawaiian Islands. We observed that plants preferentially take up 40Ca relative to 44Ca, and that biological fractionation and changes in the relative contributions from volcanic and marine sources produce a significant increase in 44Ca in soil exchangeable pools. Our results imply moderate fluxes enriched in 44Ca from strongly nutrient-depleted old soils, in contrast with high 40Ca fluxes in young and little weathered environments. In addition, biological fractionation controls divergent geochemical pathways of Ca and Sr in the plant-soil system. While Ca depletes progressively with increasing soil age, Sr/Ca ratios increase systematically. Sr isotope ratios provide a valuable tracer for provenance studies of alkaline earth elements in forested ecosystems, but its usefulness is limited when deciphering biogeochemical processes involved in the terrestrial Ca cycle. Ca isotopes in combination with Sr/ Ca ratios reveal more complex processes involved in the biogeochemistry of Ca and Sr. Copyright 2005 by the American Geophysical Union.

Aeolian dust nutrient contributions increase with substrate age in semi-arid ecosystems

NASA Astrophysics Data System (ADS)

Coble, A. A.; Hart, S. C.; Ketterer, M. E.; Newman, G. S.

2013-12-01

Rock-derived nutrients supplied by mineral weathering become depleted over time, and without an additional nutrient source the ecosystem may eventually regress or reach a terminal steady state. Previous studies have demonstrated that aeolian dust act as parent materials of soils and important nutrients to plants in arid regions, but the relative importance of these exogenous nutrients to the function of dry ecosystems during soil development is uncertain. Here, using strontium isotopes as a tracer and a well-constrained, three million year old substrate age gradient, we show that aeolian-derived nutrients become increasingly important to plant-available soil pools and tree (Pinus edulis) growth during the latter stages of soil development in a semi-arid climate. Furthermore, the depth of nutrient uptake increased on older substrates, suggesting that trees in arid regions acquire nutrients from greater depths as ecosystem development progresses presumably in response to nutrient depletion in the more weathered surface soils. Our results contribute to the unification of biogeochemical theory by demonstrating the similarity in roles of atmospheric nutrient inputs during ecosystem development across contrasting climates.

Ethiopia Schistosomiasis and Soil-Transmitted Helminthes Control Programme: Progress and Prospects.

PubMed

Negussu, Nebiyu; Mengistu, Birhan; Kebede, Biruck; Deribe, Kebede; Ejigu, Ephrem; Tadesse, Gemechu; Mekete, Kalkidan; Sileshi, Mesfin

2017-01-01

Schistosomiasis and soil-transmitted helminthes are among seventeen WHO prioritized neglected tropical diseases that infect humans. These parasitic infections can be treated using single-dose and safe drugs. Ethiopia successfully mapped the distribution of these infections nationwide. According to the mapping there are an estimated 37.3 million people living in schistosomiasis endemic areas, and 79 million in schistosomiasis and soil-transmitted helminthes endemic areas. The Federal Ministry of Health successfully scaled up Schistosomiasis and schistosomiasis and soil-transmitted helminthes intervention in endemic areas and treated over 19 million individuals in 2015. The Ministry of Health has made a huge effort to establish neglected tropical diseases, including schistosomiasis and soil-transmitted helminthes program in the health system which helped to map majority of the woredas and initiate nationwide intervention. The National control programme is designed to achieve elimination for those diseases as a major public health problem by 2020 and aim to attain transmission break by 2025. The programme focuses on reaching those school-aged children who are not attending school, integration between neglected tropical diseases programme, and further collaboration with the WASH actors.

Multivariate erosion risk assessment of lateritic badlands of Birbhum (West Bengal, India): A case study

NASA Astrophysics Data System (ADS)

Ghosh, Sandipan; Bhattacharya, Kamala

2012-12-01

Each geomorphic hazard involves a degree of risk which incorporates quantification of the probability that a hazard will be harmful. At present, the categorization of sub-watersheds into erosion risk is considered as the fundamental step to conserve the soil loss. Development of badlands over the laterites of Birbhum district is an indicative of excessive soil loss in the monsoonal wet-dry type of climate. Slope erosion and channel erosion have generated huge amount of sediment from the small watersheds during intense monsoonal rainfall (June-September). The adjoining areas of Rampurhat I Block, Birbhum (West Bengal) and Shikaripara Block, Dumka (Jharkhand) have lost the lateritic soil cover at a rate of 20-40 ton/ha/year (Sarkar et al. 2005). In order to estimate the progressive removal of soil particles from the gully-catchments of the above-mentioned area, different morphometric parameters, soil parameters, hydrologic parameters and empirical models are employed. Side by side, the study is carried out to categorize the gully-catchments into different magnitude of erosion risk using several multivariate statistical techniques.

Experimental warming and antecedent fire alter leaf element composition and increase soil C:N ratio in sub-alpine open heathland.

PubMed

White-Monsant, A C; Clark, G J; Ng Kam Chuen, M A G; Tang, C

2017-10-01

Plant communities in alpine ecosystems worldwide are being altered by climate warming. In the alpine open heathland of the Bogong High Plains, Australia, warming and fire have affected the growth and phenology of plants, and have recently been found to alter soil nutrient availability. We examined the effects of nine years of passive warming by open-top chambers and nine years post-fire on (i) the soluble and extractable nutrients and toxic elements available for plant uptake in the soil and (ii) on the element composition of leaves of seven dominant sub-alpine open heathland plants. Warming increased soil C, soil C:N, and decreased soil δ 13 C, indicating an accumulation of soil organic matter and C sequestration. Warming increased soil δ 15 N, indicating increased N mineralization, which concurred with the increased availability of NH 4 + (measured by ion-exchange membranes). Leaf element composition varied among the plant species in response to changes in soil element availabilities, suggesting the importance of species-specific knowledge. Warming decreased leaf N concentration and increased leaf C:N, generally in the plant community, and specifically in Asterolasia trymalioides, Carex breviculmis, Poa hiemata, and Rytidosperma nudiflorum. Warming increased soil P availability, but did not significantly affect leaf P in any species. Antecedent fire increased soil C:N, and decreased concentrations of Ca and Mg in Celmisia pugioniformis more than in the other species. The results suggest that warming and fire changed the nutrient composition of plants and increased soil C:N, which might lead to progressive N limitation in the alpine ecosystem. Copyright © 2017 Elsevier B.V. All rights reserved.

Statistical analyses of soil properties on a quaternary terrace sequence in the upper sava river valley, Slovenia, Yugoslavia

USGS Publications Warehouse

Vidic, N.; Pavich, M.; Lobnik, F.

1991-01-01

Alpine glaciations, climatic changes and tectonic movements have created a Quaternary sequence of gravely carbonate sediments in the upper Sava River Valley, Slovenia, Yugoslavia. The names for terraces, assigned in this model, Gu??nz, Mindel, Riss and Wu??rm in order of decreasing age, are used as morphostratigraphic terms. Soil chronosequence on the terraces was examined to evaluate which soil properties are time dependent and can be used to help constrain the ages of glaciofluvial sedimentation. Soil thickness, thickness of Bt horizons, amount and continuity of clay coatings and amount of Fe and Me concretions increase with soil age. The main source of variability consists of solutions of carbonate, leaching of basic cations and acidification of soils, which are time dependent and increase with the age of soils. The second source of variability is the content of organic matter, which is less time dependent, but varies more within soil profiles. Textural changes are significant, presented by solution of carbonate pebbles and sand, and formation is silt loam matrix, which with age becomes finer, with clay loam or clayey texture. The oldest, Gu??nz, terrace shows slight deviation from general progressive trends of changes of soil properties with time. The hypothesis of single versus multiple depositional periods of deposition was tested with one-way analysis of variance (ANOVA) on a staggered, nested hierarchical sampling design on a terrace of largest extent and greatest gravel volume, the Wu??rm terrace. The variability of soil properties is generally higher within subareas than between areas of the terrace, except for the soil thickness. Observed differences in soil thickness between the areas of the terrace could be due to multiple periods of gravel deposition, or to the initial differences of texture of the deposits. ?? 1991.

Natural remediation of an unremediated soil twelve years after a mine accident: trace element mobility and plant composition.

PubMed

Burgos, Pilar; Madejón, Paula; Madejón, Engracia; Girón, Ignacio; Cabrera, Francisco; Murillo, José Manuel

2013-01-15

The long-term influence of a mine spill in soil was studied 12 years after the Aznalcóllar accident. Soils where the pyritic sludge was not removed, a fenced plot established for research purposes (2000 m(2)) and soils where the process of remediation was accomplished successfully were sampled and studied in detail. Soils were characterized at different depths, down to 100 cm depth, determining chemical parameters and total concentrations of major and trace elements. Moreover plants colonizing remediated (RE) and non remediated (NRE) soils were also analysed attending their potential risk for herbivores. Strong acidification was observed in the NRE soil except in surface (0-10 cm). The progressive colonization of natural vegetation, more than 90% of the fenced plot covered by plants, could facilitate this increased pH values in the top soil (pH 6). In the NRE soil, the successive oxidation and hydrolysis of sulphide in the deposited sludge on the surface after the accident resulted in a re-dissolution of the most mobile element (Cd, Cu and Zn) and a penetration to deeper layers. Trace element concentrations in plants growing in the NRE soil showed normal contents for higher plants and tolerable for livestock. Nitrogen and mineral nutrients were of the same order in both soils, and also normal for high plants and adequate for animal nutrition. Despite of the natural remediation of the NRE soil, results demonstrate that the remediation tasks carried out in all the area, the Guadiamar Green Corridor at present, were necessary to avoid the leaching of the most mobile elements and minimize the risk of contamination of groundwater sources, many of them close to the Doñana National Park. Copyright © 2012 Elsevier Ltd. All rights reserved.

Geochemical and Isotopic (Sr, U) Tracing of Weathering Processes Controlling the Recent Geochemical Evolution of Soil Solutions in the Strengbach Catchment (Vosges, France)

NASA Astrophysics Data System (ADS)

Chabaux, F. J.; Prunier, J.; Pierret, M.; Stille, P.

2012-12-01

The characterization of the present-day weathering processes controlling the chemical composition of waters and soils in natural ecosystems is an important issue to predict and to model the response of ecosystems to recent environmental changes. It is proposed here to highlight the interest of a multi-tracer geochemical approach combining measurement of major and trace element concentrations along with U and Sr isotopic ratios to progress in this topic. This approach has been applied to the small granitic Strengbah Catchment, located in the Vosges Mountain (France), used and equipped as a hydro-geochemical observatory since 1986 (Observatoire Hydro-Géochimique de l'Environnement; http://ohge.u-strasbg.fr). This study includes the analysis of major and trace element concentrations and (U-Sr) isotope ratios in soil solutions collected within two soil profiles located on two experimental plots of this watershed, as well as the analysis of soil samples and vegetation samples from these two plots The depth variation of elemental concentration of soil solutions confirms the important influence of the vegetation cycling on the budget of Ca, K, Rb and Sr, whereas Mg and Si budget in soil solutions are quasi exclusively controlled by weathering processes. Variation of Sr, and U isotopic ratios with depth also demonstrates that the sources and biogeochemical processes controlling the Sr budget of soil solutions is different in the uppermost soil horizons and in the deeper ones, and clearly influence by the vegetation cycling.

Retrospective Analog Year Analyses Using NASA Satellite Precipitation and Soil Moisture Data to Improve USDA's World Agricultural Supply and Demand Estimates

NASA Technical Reports Server (NTRS)

Teng, William; Shannon, Harlan; Mladenova, Iliana; Fang, Fan

2010-01-01

A primary goal of the U.S. Department of Agriculture (USDA) is to expand markets for U.S. agricultural products and support global economic development. The USDA World Agricultural Outlook Board (WAOB) supports this goal by coordinating monthly World Agricultural Supply and Demand Estimates (WASDE) for the U.S. and major foreign producing countries. Because weather has a significant impact on crop progress, conditions, and production, WAOB prepares frequent agricultural weather assessments, in a GIS-based, Global Agricultural Decision Support Environment (GLADSE). The main goal of this project, thus, is to improve WAOB's estimates by integrating NASA remote sensing soil moisture observations and research results into GLADSE (See diagram below). Soil moisture is currently a primary data gap at WAOB.

Effects of topographical position on soil organic carbon and nitrogen in Mediterranean olive groves

NASA Astrophysics Data System (ADS)

Lozano-García, Beatriz; Parras-Alcántara, Luis

2014-05-01

INTRODUCTION The most important and extensive crops in the Mediterranean area are olive groves. Within the last 50 years, the surface occupied by olive groves has progressively increased in Spain including more complex topographies, with steeper slopes and higher altitudes. This situation has caused serious erosion problems; there is a huge range of studies assessing possible solutions to this problem and new tillage and management techniques have been developed (Lozano-García and Parras-Alcántara, 2013). However, topography has influence in soil properties too. The impact of the topographical position on soil properties, including soil organic carbon (SOC) and Nitrogen (N) stocks, and soil quality (expressed as Stratification Ratios-SRs) was evaluated in a Mediterranean olive grove with traditional tillage. MATERIAL AND METHODS The study was carried out in a rain-fed olive grove in Jaén managed with traditional tillage (with disc harrow 25 cm) and receiving mineral fertilization. Three topographical positions with the same aspect: summit, backslope and toeslope were chosen for evaluation. The soil samples were taken from four soil sections of 0.25 m (0-1 m) in order to establish a good comparison. Soil properties determined were: soil particle size, SOC and total Nitrogen (N). SOC and N stock, expressed for a specific depth in Mg ha-1. Stratification ratios (that can be used as an indicator of dynamic soil quality) for SOC and N at three different depths were calculated. The effect of topographical position on SOC and N stocks and other soil properties was analyzed using a ANOVA, followed by a Tuckey test. RESULTS SOC decreased with depth, in addition, the SOC and N content increased along the downslope direction (5.5, 6.5 and 7.1 g C kg-1; and 0.3, 0.8 and 0.9 g N kg-1 in the surface layer in the summit, backslope and toeslope respectively) as well as SOC stock considering the two first soil sections. The N stock varied significantly along the topographical positions, increasing from the summit to the toeslope (6.2, 8.6 and 10.6 Mg ha-1 in the summit, backslope and toeslope respectively), this may be due to the leaching effect suffered by urea. These increases along the downslope direction were due to erosion processes that occur along the toposequence, leading to organic matter losses (C and N) from the summit to the toeslope. As well, there was movement of the most erodible textural fraction (silt). All the SRs calculated were lower than 2. However, the lower values of SR were obtained in the summit, so the SRs confirm that the low values of SOC and N in this topographical position are progressively decreasing the soil quality in this position. Therefore, alternative management techniques that avoid soil erosion must be considered in order to increase the soil quality, especially in those topographical positions which suffer higher losses of SOC and N. REFERENCES Parras-Alcántara, L., Díaz-Jaimes, L., Lozano-García, B., 2013b. Organic farming affects C and N in soils under olive groves in Mediterranean areas. Land Degradation and Development (article in press) DOI: 10.1002/ldr.2231.

Observing and modeling links between soil moisture, microbes and CH4 fluxes from forest soils

NASA Astrophysics Data System (ADS)

Christiansen, Jesper; Levy-Booth, David; Barker, Jason; Prescott, Cindy; Grayston, Sue

2017-04-01

Soil moisture is a key driver of methane (CH4) fluxes in forest soils, both of the net uptake of atmospheric CH4 and emission from the soil. Climate and land use change will alter spatial patterns of soil moisture as well as temporal variability impacting the net CH4 exchange. The impact on the resultant net CH4 exchange however is linked to the underlying spatial and temporal distribution of the soil microbial communities involved in CH4 cycling as well as the response of the soil microbial community to environmental changes. Significant progress has been made to target specific CH4 consuming and producing soil organisms, which is invaluable in order to understand the microbial regulation of the CH4 cycle in forest soils. However, it is not clear as to which extent soil moisture shapes the structure, function and abundance of CH4 specific microorganisms and how this is linked to observed net CH4 exchange under contrasting soil moisture regimes. Here we report on the results from a research project aiming to understand how the CH4 net exchange is shaped by the interactive effects soil moisture and the spatial distribution CH4 consuming (methanotrophs) and producing (methanogens). We studied the growing season variations of in situ CH4 fluxes, microbial gene abundances of methanotrophs and methanogens, soil hydrology, and nutrient availability in three typical forest types across a soil moisture gradient in a temperate rainforest on the Canadian Pacific coast. Furthermore, we conducted laboratory experiments to determine whether the net CH4 exchange from hydrologically contrasting forest soils responded differently to changes in soil moisture. Lastly, we modelled the microbial mediation of net CH4 exchange along the soil moisture gradient using structural equation modeling. Our study shows that it is possible to link spatial patterns of in situ net exchange of CH4 to microbial abundance of CH4 consuming and producing organisms. We also show that the microbial community responds different to environmental change dependent on the soil moisture regime. These results are important to include in future modeling efforts to predict changes in soil-atmosphere exchange of CH4 under global change.

Next steps in the development of ecological soil clean-up values for metals.

PubMed

Wentsel, Randall; Fairbrother, Anne

2014-07-01

This special series in Integrated Environmental Assessment Management presents the results from 6 workgroups that were formed at the workshop on Ecological Soil Levels-Next Steps in the Development of Metal Clean-Up Values (17-21 September 2012, Sundance, Utah). This introductory article presents an overview of the issues assessors face when conducting risk assessments for metals in soils, key US Environmental Protection Agency (USEPA) documents on metals risk assessment, and discusses the importance of leveraging from recent major terrestrial research projects, primarily to address Registration, Evaluation, Authorization and Restriction of Chemical Substances (REACH) requirements in Europe, that have significantly advanced our understanding of the behavior and toxicity of metals in soils. These projects developed large data sets that are useful for the risk assessment of metals in soil environments. The workshop attendees met to work toward developing a process for establishing ecological soil clean-up values (Eco-SCVs). The goal of the workshop was to progress from ecological soil screening values (Eco-SSLs) to final clean-up values by providing regulators with the methods and processes to incorporate bioavailability, normalize toxicity thresholds, address food-web issues, and incorporate background concentrations. The REACH data sets were used by workshop participants as case studies in the development of the ecological standards for soils. The workshop attendees discussed scientific advancements in bioavailability, soil biota and wildlife case studies, soil processes, and food-chain modeling. In addition, one of the workgroups discussed the processes needed to frame the topics to gain regulatory acceptance as a directive or guidance by Canada, the USEPA, or the United States. © 2013 SETAC.

A comprehensive survey of soil acidobacterial diversity using pyrosequencing and clone library analyses

PubMed Central

Jones, Ryan T; Robeson, Michael S; Lauber, Christian L; Hamady, Micah; Knight, Rob; Fierer, Noah

2010-01-01

Acidobacteria are ubiquitous and abundant members of soil bacterial communities. However, an ecological understanding of this important phylum has remained elusive because its members have been difficult to culture and few molecular investigations have focused exclusively on this group. We generated an unprecedented number of acidobacterial DNA sequence data using pyrosequencing and clone libraries (39 707 and 1787 sequences, respectively) to characterize the relative abundance, diversity and composition of acidobacterial communities across a range of soil types. To gain insight into the ecological characteristics of acidobacterial taxa, we investigated the large-scale biogeographic patterns exhibited by acidobacterial communities, and related soil and site characteristics to acidobacterial community assemblage patterns. The 87 soils analyzed by pyrosequencing contained more than 8600 unique acidobacterial phylotypes (at the 97% sequence similarity level). One phylotype belonging to Acidobacteria subgroup 1, but not closely related to any cultured representatives, was particularly abundant, accounting for 7.4% of bacterial sequences and 17.6% of acidobacterial sequences, on average, across the soils. The abundance of Acidobacteria relative to other bacterial taxa was highly variable across the soils examined, but correlated strongly with soil pH (R = −0.80, P<0.001). Soil pH was also the best predictor of acidobacterial community composition, regardless of how the communities were characterized, and the relative abundances of the dominant Acidobacteria subgroups were readily predictable. Acidobacterial communities were more phylogenetically clustered as soil pH departed from neutrality, suggesting that pH is an effective habitat filter, restricting community membership to progressively more narrowly defined lineages as pH deviates from neutrality. PMID:19129864

Soil resources, land cover changes and rural areas: towards a spatial mismatch?

PubMed

Ferrara, Agostino; Salvati, Luca; Sabbi, Alberto; Colantoni, Andrea

2014-04-15

The present study analyzes the impact of long-term urban expansion on soil depletion in Emilia-Romagna, an agricultural-specialized region of northern Italy. Using settlement density maps at three points in time (1945, 1971 and 2001) dense and diffused urbanization trends were assessed and correlated with soil quality. Non-urbanized land decreased from 11.8% in 1945 to 6.3% in 2001. Urbanization dynamics between 1945 and 1971 reflect the increase of dense settlements around pre-existing urban centers. To the contrary, a discontinuous, low- and medium-density urban expansion along the road network and in the most fertile lowland areas was observed between 1971 and 2001. Overall, urbanization consumed soils with progressively higher quality. However, a diverging trend was observed in the two investigated time intervals: soil with high quality was occupied by compact and dense settlements during 1945-1971 and by discontinuous, medium- and low-density settlements during 1971-2001. These findings document the polarization in areas with low and high soil capital and may reflect disparities in agricultural production and increasing environmental degradation. Moreover, the analysis shows a diverging trend between land and soil consumption patterns suggesting that the edification of pervious land is an unreliable indicator of soil quality depletion. Taken together, the results of this study illustrate the (increasing) spatial mismatch between agricultural land and high-quality soils as a consequence of urbanization-driven landscape transformations and may inform measures to contain soil depletion driven by economic growth. Copyright © 2014 Elsevier B.V. All rights reserved.

In-situ Monitoring of Plant-microbe Communication to Understand the Influence of Soil Properties on Symbiotic Biological Nitrogen Fixation

NASA Astrophysics Data System (ADS)

Webster, T.; Del Valle, I.; Cheng, H. Y.; Silberg, J. J.; Masiello, C. A.; Lehmann, J.

2016-12-01

Plant-microbe signaling is important for many symbiotic and pathogenic interactions. While this signaling often occurs in soils, very little research has evaluated the role that the soil mineral and organic matter matrix plays in plant-microbe communication. One hurdle to these studies is the lack of simple tools for evaluating how soil mineral phases and organic matter influence the availability of plant-produced flavonoids that initiate the symbiosis between nitrogen-fixing bacteria and legumes. Because of their range of hydrophobic and electrostatic properties, flavonoids represent an informative class of signaling molecules. In this presentation, we will describe studies examining the bioavailable concentrations of flavonoids in soils using traditional techniques, such as high-pressure liquid chromatography and fluorescent microbial biosensors. Additionally, we will describe our progress developing a Rhizobium leguminosarum reporter that can be deployed into soils to report on flavonoid levels. This new microbial reporter is designed so that Rhizobium only generates a volatile gas signal when it encounters a defined concentration of flavonoids. By monitoring the output of this biosensor using gas chromatography-mass spectrometry during real time during soil incubations, we are working to establish the impact of soil organic matter, pH, and mineral phases on the reception of these signaling molecules. We expect that the findings from these studies will be useful for recommending soil management strategies that can enhance the communication between legumes and nitrogen fixing bacteria. This research highlights the importance of studying the role of soil as a mediator of plant-microbe communication.

Soil CO2 emissions from Northern Andean páramo ecosystems: effects of fallow agriculture.

PubMed

Cabaneiro, Ana; Fernandez, Irene; Pérez-Ventura, Luis; Carballas, Tarsy

2008-03-01

The effects of fallow agriculture on soil organic matter (SOM) dynamics and CO2 emissions were assessed in the tropical Andean páramo ecosystem. Possible changes during the cultivation-fallow cycle were monitored in four areas of the Quebrada Piñuelas valley (Venezuela). Uncultivated soils and plots at different stages of a complete cultivation--fallow cycle were incubated, and SOM mineralization kinetics was determined. Soils exhibited a low SOM mineralization activity, total CO2 evolved never reaching 3% of soil carbon, pointing to a stabilized SOM. Potential soil CO2 effluxes differed significantly according to their plot aspect: northeast (NE)-aspect soils presented higher CO2 effluxes than southwest (SW)-aspect soils. Soil CO2 emissions decreased after ploughing as compared to virgin páramo; low CO2 effluxes were still observed during cropping periods, increasing progressively to reach the highest values after 4-5 y of fallow. In all cases, experimental C mineralization data was fitted to a double exponential kinetic model. High soil labile C pool variability was observed, and two different trends were identified: NE-oriented soils showed more labile C and a wider range of values than SW-facing soils. Labile C positively correlated with CO2 effluxes and negatively with its instantaneous mineralization rate. The instantaneous mineralization rate of the recalcitrant C pool positively correlated with %C evolved as CO2 and negatively with soil C and Al2O3 contents, suggesting the importance of aluminum on SOM stability. The CO2 effluxes from these ecosystems, as well as the proportion of soil C released to the atmosphere, seem to depend not only on the size of the labile C pool but also on the accessibility of the more stabilized SOM. Therefore, fallow agriculture produces moderate changes in SOM quality and temporarily alters the CO2 emission capacity of these soils.

Considerations over the distribution of the organic matter in the soil cover of Transylvania Plain (Romania)

NASA Astrophysics Data System (ADS)

Cacovean, Horia; Man, Titus; Rusu, Teodor

2010-05-01

Considerations over the distribution of the organic matter in the soil cover of Transylvania Plain (Romania) Horea Cacovean*, Titus Man**, Teodor Rusu*** *OSPA-Cluj- 1Faglui street, Cluj Napoca, RO-40048, Romania- turda75@yahoo.com ** Faculty of Geographie, University of Babes-Bolyai, 5-7 Clinicilor street, Cluj Napoca, RO-400006, Romania *** Faculty of Agriculture, USAMV, 3-5 Calea Manastur street,Cluj Napoca, RO-400372, Romania Soil degradation has become a major concern in the Transylvania Plain. Erosion, landslides, salinization, gleysation, and loss of humus are the main forms of soil deterioration in that region. This factsheet deals with the role of organic matter in soil productivity and the effects of various management practices and abandonment of the lands on soil organic matter. Soils in Transylvania Plain are analyzed concerning the amount of humus they contain. The influence of soil texture, climatic variables, and soil management on the qualitative soil humus content was studied in the top 20 cm of different managed loess soils of more then 100 profiles along a climosequence in that region. Taken together, soil, landform, land use and vegetation data suggest: (1) summit positions are relatively stable with immobilizing humus environments; (2) the content of humus increase progressively down steep at the contact with the floodplains; 3) without the influx of organic materials, erodible backslopes may become humus depleted as it happen the poor inputs of grassland and forest litter are mixed with surface soil horizon; 4) influx of mixed sediment and organic materials from backslopes maintains concentrations of humus on footslopes and toeslopes. This influence was more pronounced in the heavy clayey soils, suggesting that the accumulation of humus was enhanced by organo-mineral interactions. Entrenchment of drainage ways can circumvent these translocation processes. The results underscore the importance of functional connectivity between upland hillslopes and alluvial soils.

Compilation of 1989 annual reports of the Navy ELF Communications System Ecological Monitoring Program. Volume 2. tabs C-F. Annual progress report, Jan-Dec 89

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

Not Available

1990-08-01

This is the eighth compilation of annual reports for the Navy's ELF Communications Systems Ecological Monitoring Program. The reports document the progress of eight studies performed during 1989 near the Naval Radio Transmitting Facility -- Republic, Michigan. The purpose of the monitoring is to determine whether electromagnetic fields produced by the ELF Communications System will affect resident biota or their ecological relationships. Soil Amoeba: Arthropoda and Earthworms: Pollinating Insects: Small Mammals and Nesting Birds.

RADIATION AND OTHER FACTORS INFLUENCING THE DISTRIBUTION OF ANIMALS. Progress Report and Renewal Proposal

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

Breckenridge, W.J.; Tester, J.R.

1962-01-01

Progress is reported for studies of environmental and radiation effects on three species of toads, Bufo americanus, B. cognatus and B. hemiophrys. Controlled surival tests in which tadpoles of B. americanus and B. hemiophrys were subjected to physical and chemical extremes indicated that B. hemiophrys is more resistant than B. americanus. The status of the subprojects on factors influencing toad survival during hibernatlon and irradistion of dormant toads is outlined. A soil simulator was built for studying the burrowing behavior of toads. (D.L.C.)

Real-time processing of gender-marked articles by native and non-native Spanish speakers

PubMed Central

Lew-Williams, Casey; Fernald, Anne

2010-01-01

Three experiments using online processing measures explored whether native and non-native Spanish-speaking adults use gender-marked articles to identify referents of target nouns more rapidly, as shown previously with 3-year-old children learning Spanish as L1 (Lew-Williams & Fernald, 2007). In Experiment 1, participants viewed familiar objects with names of either the same or different grammatical gender while listening to Spanish sentences referring to one object. L1 adults, like L1 children, oriented to the target more rapidly on different-gender trials, when the article was informative about noun identity; however, L2 adults did not. Experiments 2 and 3 controlled for frequency of exposure to article-noun pairs by using novel nouns. L2 adults could not exploit gender information when different article-noun pairs were used in teaching and testing. Experience-related factors may influence how L1 adults and children and L2 adults—who learned Spanish at different ages and in different settings—use grammatical gender in realtime processing. PMID:21076648

ELF Communications System, Ecological Monitoring Program: Summary of 1989 Progress

DTIC Science & Technology

1990-11-01

evenness, and richness were used to characterize colonization patterns. Processing rates were determined for both fresh and autumn- abscised leaves...Northern Journal of Applied Forestry, 5:14, 1988. 28. Connaughton, P. The effects of acid precipitation on nutrient levels in a forest soil and

CONSTANT SLOPE IMPEDANCE FACTOR MODEL FOR PREDICTING THE SOLUTE DIFFUSION COEFFICIENT IN UNSATURATED SOIL. (R825433)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

MODIFIED HALF-CELL METHOD FOR MEASURING THE SOLUTE DIFFUSION COEFFICIENTS IN UNDISTURBED, UNSATURATED SOIL. (R825433)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

EFFECT OF SOLUTE CONCENTRATION ON SORPTION OF POLYAROMATIC HYDROCARBONS IN SOIL: UPTAKE RATES. (R825959)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

SOIL FERTILITY LIMITS CARBON SEQUESTRATION BY FOREST ECOSYSTEMS IN A CO2-ENRICHED ATMOSPHERE. (R828785)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

A comparative study of aluminum and steel culverts : progress report no. 4.

DOT National Transportation Integrated Search

1971-01-01

The results of a comparative study of aluminum and steel culverts at six test sites throughout Virginia indicate that satisfactory durability can be expected of aluminum pipe under exposure to most of the soil and water conditions in the state. The p...

EFFECTS OF SOIL MOISTURE ON TEMPERATURES, WINDS, AND POLLUTANT CONCENTRATIONS IN LOS ANGELES. (R823186)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Remote sensing contribution to land surface hydrology

NASA Technical Reports Server (NTRS)

Salomonson, V. V.; Choudhury, B. J.

1990-01-01

Progress that has been made over the past decade in developing technology for hydrological observations from operational aircraft is described. Particular attention is given to research on soil moisture, snow cover, and vegetation. Future missions such as the ESA ERS-1 and Canada's Radarsat mission are considered.

TRANSPORT PROCESSES OF TNT FROM FLOODED HIGHLY CONTAMINATED SURFACE SOIL BEDS. (R825513C013)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

SOIL ORGANIC CARBON, NITROGEN, AND PHOSPHORUS AS INDICATORS OF RECOVERY IN RESTORED SPARTINA MARSHES. (R826111)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

CO-DEVELOPMENT OF WETLANDS SOILS AND BENTHIC INVERTEBRATE COMMUNITIES FOLLOWING SALT MARSH CREATION. (R826111)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

State of the Earth 1985.

ERIC Educational Resources Information Center

Brown, Lester; And Others

1985-01-01

Discusses soil erosion, drought, forest systems, overfishing, global climate change, hunger, population, energy, and building a sustainable society. Emphasizes the breakdown of natural systems in Africa. (Most of the material in this article was drawn from "State of the World 1985: A Worldwatch Institute Report on Progress Toward a…

Economic incentives to capture ecosystem services through increased temporal intensification of crop production

USDA-ARS?s Scientific Manuscript database

Land resources are becoming progressively more constrained with increasing demands for food, feed, fiber, and now fuel production. Developing strategies to intensify crop production without increasing the negative impacts on water, soil, and air resources are critical. Much of the best agricultural ...

CONTROLS ON ANNUAL EMISSIONS OF NITRIC OXIDE FROM SOILS OF THE COLORADO SHORTGRASS STEPPE. (R824993)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

FATE OF PYRENE IN CONTAMINATED SOIL AMENDED WITH ALTERNATE ELECTRON ACCEPTORS. (R825549C051)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

AEROBIC BIOTRANSFORMATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND ASSOCIATED METABOLITES IN SOIL. (R825549C051)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

A MATHEMATICAL MODEL OF PHYTOREMEDIATION FOR PETROLEUM CONTAMINATED SOIL: SENSITIVITY ANALYSIS. (R827015C018)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

EFFECTS OF NITROGEN ENRICHMENT, WILDFIRE, AND HARVESTING ON FOREST-SOIL CARBON AND NITROGEN. (R825762)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

ROLE OF ENTRAINERS IN SUPERCRITICAL FLUID EXTRACTION OF CHLORINATED AROMATICS FROM SOILS. (R825549C011)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

A SUPERCRITICAL FLUID EXTRACTION BASED CLOSED LOOP SYSTEM FOR DECONTAMINATION OF SOIL. (R825549C011)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

IMPACT OF THE PLANT RHIZOSPHERE AND AUGMENTATION ON REMEDIATION OF POLYCHLORINATED BIPHENYL CONTAMINATED SOIL. (R829404)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

PERSISTENCE OF TETRACHLORODIBENZO-P-DIOXIN IN SOIL: TIMES BEACH CASE STUDY. (R825549C032)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

MINERALIZATION AND UPTAKE OF A TRIAZINE PESTICIDE IN SOIL-PLANT SYSTEMS. (R825549C021)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

KINETICS OF TRICHLOROETHYLENE COMETABOLISM AND TOLUENE BIODEGRADATION: MODEL APPLICATION TO SOIL BATCH EXPERIMENTS. (R825433)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

INCREASE IN THE BIOAVAILABILITY OF AGED PHENANTHRENE IN SOILS BY COMPETITIVE DISPLACEMENT WITH PYRENE. (R825959)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

JUVENILE AMPHIBIANS DO NOT AVOID POTENTIALLY LETHAL LEVELS OF UREA ON SOIL SUBSTRATE. (U915529)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

USE OF SOIL AND WATER PROTECTION PRACTICES AMONG FARMERS IN THREE MIDWEST WATERSHEDS. (R825761)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

BIOAVAILABILITY OF ARSENIC AND PHOSPHORUS IN A SANDY SOIL AMENDED WITH WATER TREATMENT RESIDUALS. (R830842)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

HUMAN HEALTH RISK FROM EXPOSURE TO SOIL ARSENIC: DOES ONE SIZE FIT ALL? (R830842)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

The Redox Dynamics of Iron in a Seasonally Waterlogged Forest Soil (Chaux Forest, Eastern France) Traced with Rare Earth Element Distribution Patterns

NASA Astrophysics Data System (ADS)

Steinmann, M.; Floch, A. L.; Lucot, E.; Badot, P. M.

2014-12-01

The oxyhydroxides of iron are common soil minerals and known to control the availability of various major and trace elements essential for biogeochemical processes. We present a study from acidic natural forest soils, where reducing redox conditions due to seasonal waterlogging lead to the dissolution of Fe-oxyhydroxides, and to the release of Fe to soil water. In order to study in detail the mechanism of redox cycling of Fe, we used Rare Earth Element (REE) distribution patterns, because an earlier study has shown that they are a suitable tool to identify trace metal sources during soil reduction in wetland soils (Davranche et al., 2011). The REE patterns of soil leachates obtained with the modified 3-step BCR extraction scheme of Rauret et al., (1999) were compared with those of natural soil water. The adsorbed fractions (F1 leach), the reducible fraction of the deepest soil horizon H4 (F2 leach, 50-120 cm), and the oxidizable fractions of horizons H2 to H4 (F3 leachs, 24-120 cm) yielded REE patterns almost identical to soil water (see figure), showing that the REE and trace metal content of soil water was mainly derived from the F1 pool, and from the F2 and F3 pools of the clay mineral-rich deep soil horizons. In contrast, the F2 leach mobilized mainly Fe-oxyhydroxides associated with organic matter of the surface soil and yielded REE patterns significantly different from those of soil water. These results suggest that the trace metal content of soil water in hydromorphic soils is primarily controlled by the clay fraction of the deeper soil horizons and not by organic matter and related Fe-oxyhydroxides of the surface soil. Additional analyses are in progress in order to verify whether the REE and trace metals of the deeper soil horizons were directly derived from clay minerals or from associated Fe-oxyhydroxide coatings. Refs cited: Davranche et al. (2011), Chem. Geol. 284; Rauret et al. (1999), J. Environ. Monit. 1.

Research Progress of Building Materials Used in Construction Land

NASA Astrophysics Data System (ADS)

Niu, Yan

2018-01-01

Construction land preparation is an important aspect of land remediation project. The research of materials in the process of land improvement is the foundation and the core. Therefore, it is necessary to study the materials that may be involved in the process of building land preparation. In this paper, the research on the construction materials such as recycled concrete, geosynthetics, soil stabilizers, soil improvers, building insulation materials and inorganic fibrous insulation materials, which are commonly used in construction sites, is reviewed and discussed in this paper. Land remediation project involved in the construction of land materials to provide reference.

[Plant physiological and molecular biological mechanism in response to aluminium toxicity].

PubMed

Liu, Qiang; Zheng, Shaojian; Lin, Xianyong

2004-09-01

Aluminium toxicity is the major factor limiting crop growth on acid soils, which greatly affects the crop productivity on about 40% cultivated soils of the world and 21% of China. In the past decades, a lot of researches on aluminium toxicity and resistant mechanisms have been doing, and great progress was achieved. This paper dealt with the genetic differences in aluminium tolerance among plants, screening and selecting methods and technologies for identifying aluminium resistance in plants, and physiological and molecular mechanism resistance to aluminium toxicity. Some aspects needed to be further studied were also briefly discussed.

Dissolved Organic Carbon in Leachate after Application of Granular and Liquid N-P-K Fertilizers to a Sugarcane Soil.

PubMed

Pittaway, P A; Melland, A R; Antille, D L; Marchuk, S

2018-05-01

The progressive decline of soil organic matter (SOM) threatens the sustainability of arable cropping worldwide. Residue removal and burning, destruction of protected microsites, and the acceleration of microbial decomposition are key factors. Desorption of SOM by ammonia-based fertilizers from organomineral complexes in soil may also play a role. A urea- and molasses-based liquid fertilizer formulation and a urea-based granular formulation were applied at recommended and district practice rates, respectively, to soil leaching columns, with unfertilized columns used as controls. The chemistry of leachate collected from the columns, filled with two sandy soils differing in recent cropping history, was monitored over eight successive wet-dry drainage events. The pH, electrical conductivity, and concentration and species of N in leachate was compared with the concentration and aromaticity of dissolved organic C (DOC) to indicate if salt solutions derived from the two fertilizers extracted SOM from clay mineral sites. Cation exchange capacity and exchangeable cations in the soil were monitored at the start and end of the trial. Fertilizer application increased DOC in leachate up to 40 times above the control, but reduced aromaticity (specific ultraviolet light absorbance at 253.7 nm). Dissolved organic C was linearly proportional to leachate NH-N concentration. Exchangeable Ca and Mg in soil from fertilized columns at the end of both trials were significantly lower than in unfertilized soil, indicating that ammonium salt solutions derived from the fertilizers extracted cations and variably charged organic matter from soil mineral exchange sites. Desorption of organic matter and divalent cations from organomineral sites by ammonia-based fertilizers may be implicated in soil acidification. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Leachate characteristics as influenced by application of anaerobic baffled reactor effluent to three soils: a soil column study.

PubMed

Bame, I B; Hughes, J C; Titshall, L W; Buckley, C A

2013-11-01

A soil column study was undertaken in the laboratory with three contrasting soil types namely a sandy soil (Longlands (Typic Plinthaquult), E horizon), an organic soil (Inanda (Rhodic Hapludox), A horizon) and a clayey soil (Sepane (Aquic Haplustalf), A horizon). Anaerobic baffled reactor (ABR) effluent was leached through the soil and distilled water was concurrently used as a control. The effluent was slightly basic (pH 7.4-7.6), had heavy metal concentrations below permissible limits for irrigation purposes and contained plant nutrients such as P, S, Ca, Mg, and K. Results indicated that after application of 16 pore volumes, the concentrations of Ca(2+) and Mg(2+) were lower in the leachates than in the original effluent indicating adsorption by the soils and Mg(2+) was preferentially adsorbed to Ca(2+). Phosphorus was strongly adsorbed in all soils. While its adsorption in the Inanda could be attributed to organic matter and the presence of iron oxides and oxyhydroxides, the clay type and amount in the Sepane was likely responsible for P adsorption. The NO3(-)-N, which was initially low in the effluent, increased as leaching progressed while the NH4-N decreased. A chemical balance to ascertain loss or gain of major elements from the effluent application indicated P to be strongly immobilised from the effluent representing 41, 6 and 10 fold the fertilizer needs for maize in the Inanda, Longlands and Sepane, respectively. Results obtained indicated that the chemical composition of ABR effluent is significantly altered when leached through soils with distinct properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biogeochemistry of a temperate forest nitrogen gradient

USGS Publications Warehouse

Perakis, Steven S.; Sinkhorn, Emily R.

2011-01-01

Wide natural gradients of soil nitrogen (N) can be used to examine fundamental relationships between plant–soil–microbial N cycling and hydrologic N loss, and to test N-saturation theory as a general framework for understanding ecosystem N dynamics. We characterized plant production, N uptake and return in litterfall, soil gross and net N mineralization rates, and hydrologic N losses of nine Douglas-fir (Pseudotsuga menziesii) forests across a wide soil N gradient in the Oregon Coast Range (USA). Surface mineral soil N (0–10 cm) ranged nearly three-fold from 0.29% to 0.78% N, and in contrast to predictions of N-saturation theory, was linearly related to 10-fold variation in net N mineralization, from 8 to 82 kg N·ha−1·yr−1. Net N mineralization was unrelated to soil C:N, soil texture, precipitation, and temperature differences among sites. Net nitrification was negatively related to soil pH, and accounted for −1·yr−1. Aboveground net primary production per unit net N mineralization varied inversely with soil N, suggesting progressive saturation of plant N demands at high soil N. Hydrologic N losses were dominated by dissolved organic N at low-N sites, with increased nitrate loss causing a shift to dominance by nitrate at high-N sites, particularly where net nitrification exceeded plant N demands. With the exception of N mineralization patterns, our results broadly support the application of the N-saturation model developed from studies of anthropogenic N deposition to understand N cycling and saturation of plant and microbial sinks along natural soil N gradients. This convergence of behavior in unpolluted and polluted forest N cycles suggests that where future reductions in deposition to polluted sites do occur, symptoms of N saturation are most likely to persist where soil N content remains elevated.

Spatial and Temporal Patterns In Ecohydrological Separation

NASA Astrophysics Data System (ADS)

Jarvis, S. K.; Barnard, H. R.; Singha, K.; Harmon, R. E.; Szutu, D.

2017-12-01

The model of ecohydrological separation suggests that trees source water from a different subsurface pool than what is contributing to stream flow during dry periods, however diel fluctuations in stream flow and transpiration are tightly coupled. To better understand the mechanism of this coupling, this study examines spatiotemporal patterns in water isotopic relationships between tree, soil, and stream water. Preliminary analysis of data collected in 2015 show a trend in δ18O enrichment in xylem water, suggesting an increased reliance on enriched soil water not flowing to the stream as the growing season progresses, while xylem samples from 2016, a particularly wet year, do not have this trend. Variations in these temporal trends are explored with regard to distance from stream, aspect of hillslope, position in the watershed, size of the tree, and soil depth. Additionally, a near-stream site is examined at high resolution using water isotope data, sap flow, and electrical resistivity surveying to examine soil moisture and water use patterns across the riparian-hillslope transition.

Buckingham (1907): An appreciation

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

Narasimhan, T.N.

2004-11-17

Nearly a century ago, Edgar Buckingham (1907) published a seminal work on the movement of soil moisture which is part of the foundation of modern soil physics. It also constitutes a pioneering contribution in the study of multi-phase flow in porous media. A physicist, Buckingham took on an earth science issue of importance to society, and produced superb basic science as a byproduct. Buckingham impresses us with his ability to combine experiment and theory, and his capacity to intuitively explain difficult ideas to a wide audience. Science progresses both by gradual accretion of knowledge, and by sudden influx of ideas.more » Buckingham's contribution belongs in the latter category. After a brief, four-year rendezvous with soil science, he went on to pursue a long and distinguished career in physics with the National Bureau of Standards. This paper is an appreciation of Buckingham's contribution on soil moisture in the context of contemporary developments in diffusion theory, and the rapid growth of science in America at the turn of the twentieth century.« less

Nitrogen dynamics in flooded soil systems: an overview on concepts and performance of models.

PubMed

Nurulhuda, Khairudin; Gaydon, Donald S; Jing, Qi; Zakaria, Mohamad P; Struik, Paul C; Keesman, Karel J

2018-02-01

Extensive modelling studies on nitrogen (N) dynamics in flooded soil systems have been published. Consequently, many N dynamics models are available for users to select from. With the current research trend, inclined towards multidisciplinary research, and with substantial progress in understanding of N dynamics in flooded soil systems, the objective of this paper is to provide an overview of the modelling concepts and performance of 14 models developed to simulate N dynamics in flooded soil systems. This overview provides breadth of knowledge on the models, and, therefore, is valuable as a first step in the selection of an appropriate model for a specific application. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Biodegradability of regenerated cellulose films in soil

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

Zhang, L.; Liu, H.; Zheng, L.

1996-12-01

Regenerated cellulose films and a water-resistant film coated with thin Tung oil were prepared by using a cellulose cuoxam solution from pulps of cotton linter, cotton stalk, and wheat straw. They were buried in the soil to test biodegradability. The results showed that viscosity average molecular weight M{sub {eta}}, tensile strength {sigma}{sub b}, and the weight of the degraded films decreased sharply with the progress of degradation time, and the kinetics of decay were discussed. The degradation half-lives t{sub 1/2} of the films in soil at 10--20 C were given to be 30--42 days, and after 2 months the filmsmore » were decomposed into CO{sub 2} and water. The {alpha}-cellulose in soil was more readily biodegraded than hemicellulose, and regenerated cellulose film was more readily biodegraded than kraft paper. Nuclear magnetic resonance and scanning electron micrographs indicated that the biodegradation process of the films was performed through random breakdown of bonds of cellulose macromolecules resulting from the microorganism cleavage.« less

The Role of Compost in Stabilizing the Microbiological and Biochemical Properties of Zinc-Stressed Soil.

PubMed

Strachel, Rafał; Wyszkowska, Jadwiga; Baćmaga, Małgorzata

2017-01-01

The progressive development of civilization and intensive industrialization has contributed to the global pollution of the natural environment by heavy metals, especially the soil. Degraded soils generally contain less organic matter, and thus, their homeostasis is more often disturbed, which in turn manifests in changes in biological and physicochemical properties of the soil. Therefore, new possibilities and solutions for possible neutralization of these contaminations are sought, inter alia, through reclamation of degraded land. At present, the use of additives supporting the reclamation process that exhibit heavy metal-sorbing properties is becoming increasingly important in soil recovery. Research was conducted to determine the role of compost in stabilizing the microbial and biochemical balance of the soil due to the significant problem of heavy metal-contaminated areas. The study was conducted on loamy sand, to which zinc was applied at the following doses: 0, 250, 500, 750, 1000, and 1250 mg Zn 2+  kg -1 DM of soil. Compost was introduced to the appropriate objects calculated on the basis of organic carbon content in the amount of 0, 10, and 20 g C org  kg -1 DM of soil. The study was conducted over a period of 20 weeks, maintaining soil moisture at 50% capillary water capacity. Zinc significantly modified soil microbiome status. The abundance of microorganisms and their biological diversity and the enzymatic activity of the soil were affected. The negative effects of contaminating zinc doses were alleviated by the introduction of compost into the soil. Organic fertilization led to microbial growth intensification and increased biochemical activity of the soil already 2 weeks after compost application. These effects persisted throughout the experiment. Therefore, it can be stated that the use of compost is an appropriate method for restoring normal functions of soil ecosystems contaminated with zinc.

The diversity of methoxyphenols released by pyrolysis-gas chromatography as predictor of soil carbon storage.

PubMed

Jiménez-González, Marco A; Álvarez, Ana M; Carral, Pilar; González-Vila, Francisco J; Almendros, Gonzalo

2017-07-28

The variable extent to which environmental factors are involved in soil carbon storage is currently a subject of controversy. In fact, justifying why some soils accumulate more organic matter than others is not trivial. Some abiotic factors such as organo-mineral associations have classically been invoked as the main drivers for soil C stabilization. However, in this research indirect evidences based on correlations between soil C storage and compositional descriptors of the soil organic matter are presented. It is assumed that the intrinsic structure of soil organic matter should have a bearing in the soil carbon storage. This is examined here by focusing on the methoxyphenols released by direct pyrolysis from a wide variety of topsoil samples from continental Mediterranean ecosystems from Spain with different properties and carbon content. Methoxyphenols are typical signature compounds presumptively informing on the occurrence and degree of alteration of lignin in soils. The methoxyphenol assemblages (12 major guaiacyl- and syringyl-type compounds) were analyzed by pyrolysis-gas chromatography-mass spectrometry. The Shannon-Wiener diversity index was chosen to describe the complexity of this phenolic signature. A series of exploratory statistical analyses (simple regression, partial least squares regression, multidimensional scaling) were applied to analyze the relationships existing between chemical and spectroscopic characteristics and the carbon content in the soils. These treatments coincided in pointing out that significant correlations exist between the progressive molecular diversity of the methoxyphenol assemblages and the concentration of organic carbon stored in the corresponding soils. This potential of the diversity in the phenolic signature as a surrogate index of the carbon storage in soils is tentatively interpreted as the accumulation of plant macromolecules altered into microbially reworked structures not readily recognized by soil enzymes. From a quantitative viewpoint, the partial least squares regression models exclusively based on total abundances of the 12 major methoxyphenols were especially successful in forecasting soil carbon storage. Copyright © 2017 Elsevier B.V. All rights reserved.

Soil organic components distribution in a podzol and the possible relations with the biological soil activities

NASA Astrophysics Data System (ADS)

Alvarez-Romero, Marta; Papa, Stefania; Verstraeten, Arne; Curcio, Elena; Cools, Nathalie; Lozano-Garcia, Beatriz; Parras-Alcántara, Luis; Coppola, Elio

2016-04-01

This research reports the preliminary results of a study based on the SOC (Soil Organic Carbon) fractionation in a pine forest soil (Pinus nigra). Hyperskeletic Albic Podzol soil (P113005, World Reference Base, 2014), described by the following sequence O-Ah-E-Bh-Bs-Cg, was investigated at Zoniën, Belgium. Total (TOC) and extractable (TEC) soil contents were determined by Italian official method of soil analysis. Different soil C fractions were also determined: Humic Acid Carbon (HAC) and Fulvic Acid Carbon (FAC). Not Humic Carbon (NHC) and Humin Carbon (Huc) fractions were obtained by difference. Along the mineral soil profile, therefore, were also tested some enzymatic activities, such as cellulase, xylanase, laccase and peroxidase, involved in the degradation of the main organic substance components, and dehydrogenase activity, like soil microbial biomass index. The results shows a differential TEC fractions distribution in the soil profile along three fronts of progress: (i) An E leaching horizon of TEC; Bh horizon (humic) of humic acids preferential accumulation, morphologically and analytically recognizable, in which humic are more insoluble that fulvic acids, and predominate over the latter; (ii) horizon Bs (spodic) in which fulvic acids are more soluble that humic acid, and predominate in their turn. All enzyme activities appear to be highest in the most superficial part of the mineral profile and decrease towards the deeper layers with different patterns. It is known that the enzymes production in a soil profile reflects the organic substrates availability, which in turn influences the density and the composition of the microbial population. The deeper soil horizons contain microbial communities adapted and specialized to their environment and, therefore, different from those present on the surface The results suggest that the fractionation technique of TEC is appropriate to interpret the podsolisation phenomenon that is the preferential distribution of the different fractions of the SOC. It can form the base study for evaluation of changes in some biological activity along soil profile.

Do agricultural terraces and forest fires recurrence in Mediterranean afforested micro-catchments alter soil quality and soil nutrient content?

NASA Astrophysics Data System (ADS)

E Lucas-Borja, Manuel; Calsamiglia, Aleix; Fortesa, Josep; García-Comendador, Julián; Gago, Jorge; Estrany, Joan

2017-04-01

Bioclimatic characteristics and intense human pressure promote Mediterranean ecosystems to be fire-prone. Afforestation processes resulting from the progressive land abandonment during the last decades led to greater biomass availability increasing the risk of large forest fires. Likewise, the abandonment and lack of maintenance in the terraced lands constitute a risk of land degradation in terms of soil quantity and quality. Despite the effects of fire and the abandonment of terraced lands on soil loss and physico-chemical properties are identified, it is not clearly understood how wildfires and abandonment of terraces affect soil quality and nutrients content. Microbiological soil parameters and soil enzymes activities are biomarkers of the soil microbial communitýs functional ability, which potentially enables them as indicators of change, disturbance or stress within the soil community. The objective of this study was to investigate the effects of terracing (abandoned and non-abandoned) on the soil enzyme activities, microbiological soil parameters and soil nutrients dynamics in three Mediterranean afforested micro-catchments (i.e., < 2 ha) under different forest fire recurrence in the last 20 years; i.e., unburned areas, burned once and burned twice. The combination of the presence of terraces and the recurrence of forest fire, thirty-six plots of 25 m2 were sampled along the these three micro-catchments collecting four replicas at the corners of each plot. The results elucidated how non-terraced and unburned plots presented the highest values of soil respiration rate and extracellular soil enzymes. Differences between experimental plots with different forest fire recurrence or comparing terraced and unburned plots with burned plots were weaker in relation to biochemical and microbiological parameters. Soil nutrient content showed an opposite trend with higher values in terraced plots, although differences were weaker. We conclude that terraced landscapes present poorer soil quality parameters due to land abandonment and the lack of terraced management. In addition, forest fire recurrence exacerbates soil degradation processes due to the direct effects on vegetation and soil properties.

Timing and magnitude of C partitioning through a young loblolly pine ( Pinus taeda L.) stand using 13C labeling and shade treatments

DOE PAGES

Warren, Jeffrey M.; Iversen, Colleen M.; Garten, Jr., Charles T.; ...

2011-12-30

The dynamics of rapid changes in carbon (C) partitioning within forest ecosystems are not well understood, which limits improvement of mechanistic models of C cycling. Our objective was to inform model processes by describing relationships between C partitioning and accessible environmental or physiological measurements, with a special emphasis on short-term C flux through a forest ecosystem. We exposed eight 7-year-old loblolly pine ( Pinus taeda L.) trees to air enriched with 13CO 2 and then implemented adjacent light shade (LS) and heavy shade (HS) treatments in order to manipulate C uptake and flux. The impacts of shading on photosynthesis, plantmore » water potential, sap flow, basal area growth, root growth, and soil CO 2 efflux rate (CER) were assessed for each tree over a three-week period. The progression of the 13C label was concurrently tracked from the atmosphere through foliage, phloem, roots, and surface soil CO 2 efflux. The HS treatment significantly reduced C uptake, sap flow, stem growth and fine root standing crop, and resulted in greater residual soil water content to 1 m depth. Sap flow was strongly correlated with CER on the previous day, but not the current day, with no apparent treatment effect on the relationship. Although there were apparent reductions in new C flux belowground, the heavy shade treatment did not noticeably reduce the magnitude of belowground autotrophic and heterotrophic respiration based on surface soil CO 2 efflux rate (CER), which was overwhelmingly driven by soil temperature and moisture. The 13C label was immediately detected in foliage on label day (half-life = 0.5 d), progressed through phloem by day 2 (half-life = 4.7 d), roots by day 2-4, and subsequently was evident as respiratory release from soil which peaked between days 3-6. The δ 13C of soil CO 2 efflux was strongly correlated with phloem 13C on the previous day, or two days earlier. While the 13C label was readily tracked through the ecosystem, the fate of root C through respiratory, mycorrhizal or exudative release pathways were not assessed. Lastly, these data detail the timing and relative magnitude of C flux through various components of a young pine stand in relation to environmental conditions.« less

Science to Support DOE Site Cleanup: The Pacific Northwest National Laboratory Environmental Management Science Program Awards-Fiscal Year 1999 Mid-Year Progress Report

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

Peurrung, L.M.

1999-06-30

Pacific Northwest National Laboratory was awarded ten Environmental Management Science Program (EMSP) research grants in fiscal year 1996, six in fiscal year 1997, and eight in fiscal year 1998. This section summarizes how each grant addresses significant U.S. Department of Energy (DOE) cleanup issues, including those at the Hanford Site. The technical progress made to date in each of these research projects is addressed in more detail in the individual progress reports contained in this document. This research is focused primarily in five areas: Tank Waste Remediation, Decontamination and Decommissioning, Spent Nuclear Fuel and Nuclear Materials, Soil and Groundwater Cleanmore » Up, and Health Effects.« less

Extremely Low Frequency (ELF) Communications System Ecological Monitoring Program Summary of 1990 Progress

DTIC Science & Technology

1991-12-01

evenness, and richness were used to characterize colonization patterns. Processing rates were determined for both fresh and autumn- abscised leaves... acid precipitation on nutrient levels in a forest soil 3 and foliage of red pine seedlings. Houghton, MI: School of Forestry and Wood Products

DIFFUSIVE TRANSPORT OF 2,4,6-TNT FROM A CONTAMINATED SOIL TO OVERLYING WATER. (R825513C013)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

AN OVERVIEW OF RESEARCH ON THE BENEFICIAL EFFECTS OF VEGETATION IN CONTAMINATED SOIL. (R825549C062)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

MODELING OF HEAVY METAL MOVEMENT IN VEGETATED, UNSATURATED SOILS WITH EMPHASIS ON GEOCHEMISTRY. (R825549C046)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

EFFECTS OF AGRICULTURAL SOIL LOSS ON FOREST SUCCESSION RATES AND TREE DIVERSITY IN EAST TENNESSEE. (R825157)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

OPTIMIZATION OF TWO STEP PROCESS FOR REMEDIATION OF SUCARNOOCHEE SOIL WITH PETROLEUM COKE. (R822721C655)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

GENERAL MODEL FOR N2O AND N-2 GAS EMISSIONS FROM SOILS DUE TO DENITRIFICATION. (R824993)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

REGIONAL VARIATION IN FOLIAR CHEMISTRY AND SOIL NITROGEN STATUS AMONG FORESTS OF DIVERSE HISTORY AND COMPOSITION. (R825865)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

TRANSFORMATION AND SURVIVAL OF DONOR, RECIPIENT, AND TRANSFORMANTS OF BACILLUS SUBTILIS IN VITRO AND IN SOIL. (R826107)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Soil type influences the sensitivity of nutrient dynamics to changes in atmospheric CO2

USDA-ARS?s Scientific Manuscript database

Numerous studies have indicated that increases in atmospheric CO2 have the potential to decrease nitrogen availability through the process of progressive nitrogen limitation (PNL). The timing and magnitude of PNL in field experiments is varied due to numerous ecosystem processes. Here we examined ...

Soil type influences the sensitivity of nutrient dynamics to changes in atmospheric CO2

USDA-ARS?s Scientific Manuscript database

Numerous studies have indicated that increases in atmospheric CO2 have the potential to decrease nitrogen availability through the process of progressive nitrogen limitation (PNL). The timing and magnitude of PNL in field experiments is varied due to numerous ecosystem processes. Here we examined th...

CARD Annual Report, Year Ending June 30, 1986.

ERIC Educational Resources Information Center

Iowa State Univ. of Science and Technology, Ames. Center for Agricultural and Rural Development.

This report outlines the activities of the Center for Agricultural and Rural Development (CARD), Iowa State University, for the year ending June 30, 1986. Progress was made in expanding and enhancing the policy research program, which comprises four divisions. The natural resources and conservation program participated with the Soil Conservation…

[14C]PYRENE BOUND RESIDUE EVALUATION USING MIBK FRACTIONATION METHOD FOR CREOSOTE-CONTAMINATED SOIL. (R825549C058)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

[14C] PYRENE BOUND RESIDUE EVALUATION USING MIBK FRACTIONATION METHOD FOR CREOSOTE-CONTAMINATED SOIL. (R825549C051)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

POLYCYCLIC AROMATIC HYDROCARBON BIODEGRADATION AS A FUNCTION OF OXYGEN TENSION IN CONTAMINATED SOIL. (R825549C051)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

EFFECTS OF MYCORRHIZAE AND OTHER SOIL MICROBES ON REVEGETATION OF HEAVY METAL CONTAMINATED MINE SPOIL. (R825549C033)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

THE EFFECT OF PLANTS ON THE DEGRADATION AND TOXICITY OF PETROLEUM CONTAMINANTS IN SOIL: A FIELD ASSESSMENT. (R825413)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

MINERAL SOIL AND SOLUTION RESPONSES TO EXPERIMENTAL N AND S ENRICHMENT AT THE BEAR BROOK WATERSHED IN MAINE. (R825762)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

SOIL ALUMINUM DISTRIBUTION IN THE NEAR-STREAM ZONE AT THE BEAR BROOK WATERSHED IN MAINE. (R825762)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

SOIL TYPE AND FOREST VEGETATION INFLUENCES ON FOREST FLOOR NITROGEN DYNAMICS AT THE BEAR BROOK WATERSHED IN MAINE. (R825762)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

SPATIAL METHODS FOR ASSESSING THE DISTRIBUTION AND IMPACT OF SOIL PHOSPHORUS IN A SUB-TROPICAL FRESHWATER WETLAND. (R827641)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

INDIGENOUS MIXED SOIL BACTERIA IN PRESENCE OF COMPATIBLE PLANTS ARE MORE EFFICIENT IN PCB DEGRADATION. (R828770C008)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

SELECTION AND TEST OF EFFECTIVE CHELATORS FOR REMOVAL OF HEAVY METALS FROM CONTAMINATED SOILS. (R825549C052)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

IMPACTS OF AGING ON IN VIVO AND IN VITRO MEASUREMENTS OF SOIL-BOUND POLYCYCLIC AROMATIC HYDROCARBON AVAILABILITY. (R825408)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

DETERMINING SOIL CONTAMINATION PROFILES FROM INTENSITIES OF CAPTURE-GAMMA RAYS USING ABOVE-SURFACE NEUTRON SOURCES. (R825549C054)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

EFFECTS OF CLIMATE, LANDUSE, AND SOILS ON NDVI DYNAMICS IN THE U.S. GREAT PLAINS. (R824993)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

INSECTICIDAL ACTIVITY AND BIODEGRADATION OF THE TOXIN FROM BACILLUS THURINGIENSIS SUBSP. KURSTAKI BOUND TO HUMIC ACIDS FROM SOIL. (R826107)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

GREENHOUSE STUDY ON ARSENIC SPECIATION AND BIOAVAILABILITY IN TWO PESTICIDE-CONTAMINATED SOILS OF FLORIDA: PRELIMINARY RESULTS. (R830842)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

FATE AND BIOAVAILABILITY OF ARSENIC IN ORGANO-ARSENICAL PESTICIDE APPLIED SOILS. PART-I. INCUBATION STUDY. (R830842)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Research in remote sensing of agriculture, earth resources, and man's environment

NASA Technical Reports Server (NTRS)

Landgrebe, D. A.

1975-01-01

Progress is reported for several projects involving the utilization of LANDSAT remote sensing capabilities. Areas under study include crop inventory, crop identification, crop yield prediction, forest resources evaluation, land resources evaluation and soil classification. Numerical methods for image processing are discussed, particularly those for image enhancement and analysis.

Plant water use responses along secondary forest succession during the 2015-2016 El Niño drought in Panama.

PubMed

Bretfeld, Mario; Ewers, Brent E; Hall, Jefferson S

2018-03-05

Tropical forests are increasingly being subjected to hotter, drier conditions as a result of global climate change. The effects of drought on forests along successional gradients remain poorly understood. We took advantage of the 2015-2016 El Niño event to test for differences in drought response along a successional gradient by measuring the sap flow in 76 trees, representing 42 different species, in 8-, 25- and 80-yr-old secondary forests in the 15-km 2 'Agua Salud Project' study area, located in central Panama. Average sap velocities and sapwood-specific hydraulic conductivities were highest in the youngest forest. During the dry season drought, sap velocities increased significantly in the 80-yr-old forest as a result of higher evaporative demand, but not in younger forests. The main drivers of transpiration shifted from radiation to vapor pressure deficit with progressing forest succession. Soil volumetric water content was a limiting factor only in the youngest forest during the dry season, probably as a result of less root exploration in the soil. Trees in early-successional forests displayed stronger signs of regulatory responses to the 2015-2016 El Niño drought, and the limiting physiological processes for transpiration shifted from operating at the plant-soil interface to the plant-atmosphere interface with progressing forest succession. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Processes regulating progressive nitrogen limitation under elevated carbon dioxide: a meta-analysis

NASA Astrophysics Data System (ADS)

Liang, J.; Qi, X.; Souza, L.; Luo, Y.

2015-10-01

Nitrogen (N) cycle has the potential to regulate climate change through its influence on carbon (C) sequestration. Although extensive researches have been done to explore whether or not progressive N limitation (PNL) occurs under CO2 enrichment, a comprehensive assessment of the processes that regulate PNL is still lacking. Here, we quantitatively synthesized the responses of all major processes and pools in terrestrial N cycle with meta-analysis of CO2 experimental data available in the literature. The results showed that CO2 enrichment significantly increased N sequestration in plant and litter pools but not in soil pool. Thus, the basis of PNL occurrence partially exists. However, CO2 enrichment also significantly increased the N influx via biological N fixation, but decreased the N efflux via leaching. In addition, no general diminished CO2 fertilization effect on plant growth over time was observed. Overall, our analyses suggest that the extra N supply by the increased biological N fixation and decreased leaching may potentially alleviate PNL under elevated CO2 conditions. Moreover, our synthesis showed that CO2 enrichment increased soil ammonium (NH4+) but decreased nitrate (NO3-). The different responses of NH4+ and NO3-, and the consequent biological processes, may result in changes in soil microenvironment, community structures and above-belowground interactions, which could potentially affect the terrestrial biogeochemical cycles and the feedback to climate change.

NASA SMAPVEX 15 Field Campaign Measures Soil Moisture Over Arizona

NASA Image and Video Library

2015-09-09

NASA's SMAP (Soil Moisture Active Passive) satellite observatory conducted a field experiment as part of its soil moisture data product validation program in southern Arizona on Aug. 2-18, 2015. The images here represent the distribution of soil moisture over the SMAPVEX15 (SMAP Validation Experiment 2015) experiment domain, as measured by the Passive Active L-band System (PALS) developed by NASA's Jet Propulsion Laboratory, Pasadena, California, which was installed onboard a DC-3 aircraft operated by Airborne Imaging, Inc. Blue and green colors denote wet conditions and dry conditions are marked by red and orange. The black lines show the nominal flight path of PALS. The measurements show that on the first day, the domain surface was wet overall, but had mostly dried down by the second measurement day. On the third day, there was a mix of soil wetness. The heterogeneous soil moisture distribution over the domain is typical for the area during the North American Monsoon season and provides excellent conditions for SMAP soil moisture product validation and algorithm enhancement. The images are based on brightness temperature measured by the PALS instrument gridded on a grid with 0.6-mile (1-kilometer) pixel size. They do not yet compensate for surface characteristics, such as vegetation and topography. That work is currently in progress. http://photojournal.jpl.nasa.gov/catalog/PIA19879

Influence of climate and eolian dust on the major-element chemistry and clay mineralogy of soils in the northern Bighorn basin, U.S.A.

USGS Publications Warehouse

Reheis, M.C.

1990-01-01

Soil chronosequences in the northern Bighorn basin permit the study of chronologic changes in the major-element chemistry and clay mineralogy of soils formed in different climates. Two chronosequences along Rock Creek in south-central Montana formed on granitic alluvium in humid and semiarid climates over the past two million years. A chronosequence at the Kane fans in north-central Wyoming formed on calcareous alluvium in an arid climate over the past 600,000 years. Detailed analyses of elemental chemistry indicate that the soils in all three areas gradually incorporated eolian dust that contained less zirconium, considered to be chemically immobile during weathering, than did the alluvium. B and C horizons of soils in the wettest of the chronosequences developed mainly at logarithmic rates, suggesting that leaching, initially rapid but decelerating, dominated the dust additions. In contrast, soils in the most arid of the chronosequences developed at linear rates that reflect progressive dust additions that were little affected by leaching. Both weathering and erosion may cause changes with time to appear logarithmic in A horizons of soils under the moist and semiarid climatic regimes. Clay minerals form with time in the basal B and C horizons and reflect climatic differences in the three areas. Vermiculite, mixed-layer illite-smectite, and smectite form in the soils of the moist-climate chronosequence; smectite forms in the semiarid-climate chronosequence; and smectite and palygorskite form in the arid-climate chronosequence. ?? 1990.

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

Chana, L.W.; Smith, K.

Soil from a site contaminated with heavy metals (predominantly lead) was treated using the TERRAMET{reg_sign} lead extraction process. Earthworm acute toxicity and plant seed germination/root elongation (SG/RE) bioassays were used to evaluate the toxicity of the soil before treatment (BT), after treatment (AT) and after treatment, followed by rinsing with water, intended to simulate exposure to rainfall (RT). The results showed BT and RT were not toxic to earthworms in a 14-day exposure while AT showed significant toxicity. The LC{sub 50} values for Eisenia and Lumbricus were 44.04 and 28.83 (as % AT soil/test soil mixture), respectively. The phytotoxicity datamore » indicated that all 3 test soils significantly inhibited lettuce SG/RE in a dose-related manner, with AT being the most phytotoxic. In oats, RT had no effect on SG/RE and AT was more toxic than BT. For the two local-site grass seeds tested (blue grama and sideoat grama), the AT soil was the most phytotoxic followed by BT and RT. The results suggest that the soil after this remediation process exerts significant toxicity on both plant and earthworm, but after a rain-simulating rinse, the toxicity is the same as, or less than, the toxicity before treatment. Further studies are in progress to confirm the assumption that the high salt concentrations generated by acidification during the leaching process, followed by neutralization are responsible for the increased toxicity of unrinsed soil in both plant and earthworm.« less

Managing soils for long-term productivity

PubMed Central

Syers, J. K.

1997-01-01

Meeting the goal of long-term agricultural productivity requires that soil degradation be halted and reversed. Soil fertility decline is a key factor in soil degradation and is probably the major cause of declining crop yields. There is evidence that the contribution of declining soil fertility to soil degradation has been underestimated.
Sensitivity to soil degradation is implicit in the assessment of the sustainability of land management practices, with wide recognition of the fact that soils vary in their ability to resist change and recover subsequent to stress. The concept of resilience in relation to sustainability requires further elaboration and evaluation.
In the context of soil degradation, a decline in soil fertility is primarily interpreted as the depletion of organic matter and plant nutrients. Despite a higher turnover rate of organic matter in the tropics there is no intrinsic difference between the organic matter content of soils from tropical and temperate regions. The level of organic matter in a soil is closely related to the above and below ground inputs. In the absence of adequate organic material inputs and where cultivation is continuous, soil organic matter declines progressively. Maintaining the quantity and quality of soil organic matter should be a guiding principle in developing management practices.
Soil microbial biomass serves as an important reservoir of nitrogen (N), phosphorus (P) and sulphur (S), and regulates the cycling of organic matter and nutrients. Because of its high turnover rate, microbial biomass reacts quickly to changes in management and is a sensitive indicator for monitoring and predicting changes in soil organic matter. Modelling techniques have been reasonably successful in predicting changes in soil organic matter with different organic material inputs, but there is little information from the tropics.
Nutrient depletion through harvested crop components and residue removal, and by leaching and soil erosion accentuates the often very low inherent fertility of many soils in the tropics. An integrated approach involving inorganic and organic inputs is required where animal and plant residues are returned, as far as practicable. Chemical fertilizers alone cannot achieve long-term productivity on many soils and organic material inputs are required to maintain soil organic matter levels and crop productivity. A major research effort is required to develop improved strategies for halting and reversing soil degradation if long-term productivity is to be secured.

Case studies: Soil mapping using multiple methods

NASA Astrophysics Data System (ADS)

Petersen, Hauke; Wunderlich, Tina; Hagrey, Said A. Al; Rabbel, Wolfgang; Stümpel, Harald

2010-05-01

Soil is a non-renewable resource with fundamental functions like filtering (e.g. water), storing (e.g. carbon), transforming (e.g. nutrients) and buffering (e.g. contamination). Degradation of soils is meanwhile not only to scientists a well known fact, also decision makers in politics have accepted this as a serious problem for several environmental aspects. National and international authorities have already worked out preservation and restoration strategies for soil degradation, though it is still work of active research how to put these strategies into real practice. But common to all strategies the description of soil state and dynamics is required as a base step. This includes collecting information from soils with methods ranging from direct soil sampling to remote applications. In an intermediate scale mobile geophysical methods are applied with the advantage of fast working progress but disadvantage of site specific calibration and interpretation issues. In the framework of the iSOIL project we present here some case studies for soil mapping performed using multiple geophysical methods. We will present examples of combined field measurements with EMI-, GPR-, magnetic and gammaspectrometric techniques carried out with the mobile multi-sensor-system of Kiel University (GER). Depending on soil type and actual environmental conditions, different methods show a different quality of information. With application of diverse methods we want to figure out, which methods or combination of methods will give the most reliable information concerning soil state and properties. To investigate the influence of varying material we performed mapping campaigns on field sites with sandy, loamy and loessy soils. Classification of measured or derived attributes show not only the lateral variability but also gives hints to a variation in the vertical distribution of soil material. For all soils of course soil water content can be a critical factor concerning a succesful application of geophysical methods, e.g. GPR on wet loessy soils will result in a high attenuation of signals. Furthermore, with this knowledge we support the development of geophysical pedo-transfer-functions, i.e. the link between geophysical to soil parameters, which is active researched in another work package of the iSOIL project. Acknowledgement: iSOIL-Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping is a Collaborative Project (Grant Agreement number 211386) co-funded by the Research DG of the European Commission within the RTD activities of the FP7 Thematic Priority Environment.

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

Abraham, TJ

A testing facility (Cold Test Loop) was constructed and operated to demonstrate the efficacy of the Accelerated Waste Retrieval (AWR) Project's planned sluicing approach to the remediation of Silos 1 and 2 at the Fernald Environmental Management Project near Cincinnati, Ohio. The two silos contain almost 10,000 tons of radium-bearing low-level waste, which consists primarily of solids of raffinates from processing performed on ores from the Democratic Republic of Congo (commonly referred to as ''Belgium Congo ores'') for the recovery of uranium. These silos are 80 ft in diameter, 36 ft high to the center of the dome, and 26.75more » ft to the top of the vertical side walls. The test facility contained two test systems, each designed for a specific purpose. The first system, the Integrated Test Loop (ITL), a near-full-scale plant including the actual equipment to be installed at the Fernald Site, was designed to demonstrate the sluicing operation and confirm the selection of a slurry pump, the optimal sluicing nozzle operation, and the preliminary design material balance. The second system, the Component Test Loop (CTL), was designed to evaluate many of the key individual components of the waste retrieval system over an extended run. The major results of the initial testing performed during July and August 2002 confirmed that the AWR approach to sluicing was feasible. The ITL testing confirmed the following: (1) The selected slurry pump (Hazleton 3-20 type SHW) performed well and is suitable for AWR application. However, the pump's motor should be upgraded to a 200-hp model and be driven by a 150-hp variable-frequency drive (VFD). A 200-hp VFD is not much more expensive and would allow the pump to operate at full speed. (2) The best nozzle performance was achieved by using 15/16-in. nozzles operated alternately. This configuration appeared to most effectively mine the surrogate. (3) The Solartron densitometer, which was tested as an alternative mass flow measurement device, did not operate effectively. Consequently, it is not suitable for application to the AWR process. (4) Initially, the spray ring (operated at approximately 2300 psi) and the nozzles provided by the pump vendor did not perform acceptably. The nozzles were replaced with a more robust model, and the performance was then acceptable. (5) The average solids concentration achieved in the slurry before Bentogrout addition was approximately 16% by weight. The solids concentration of the slurry after Bentogrout addition ranged from 26% to approximately 40%. The slurry pump and ITL system performed well at every concentration. No line plugging or other problems were noted. The results of the CTL runs and later ITL testing are summarized in an appendix to this report.« less

The consecutive dry days to trigger rainfall over West Africa

NASA Astrophysics Data System (ADS)

Lee, J. H.

2018-01-01

In order to resolve contradictions in addressing a soil moisture-precipitation feedback mechanism over West Africa and to clarify the impact of antecedent soil moisture on subsequent rainfall evolution, we first validated various data sets (SMOS satellite soil moisture observations, NOAH land surface model, TRMM rainfall, CMORPH rainfall and HadGEM climate models) with the Analyses Multidisciplinaires de la Mousson Africaine (AMMA) field campaign data. Based on this analysis, it was suggested that biases of data sets might cause contradictions in studying mechanisms. Thus, by taking into account uncertainties in data, it was found that the approach of consecutive dry days (i.e. a relative comparison of time-series) showed consistency across various data sets, while the direct comparison approach for soil moisture state and rainfall did not. Thus, it was discussed that it may be difficult to directly relate rain with soil moisture as the absolute value, however, it may be reasonable to compare a temporal progress of the variables. Based upon the results consistently showing a positive relationship between the consecutive dry days and rainfall, this study supports a negative feedback often neglected by climate model structure. This approach is less sensitive to interpretation errors arising from systematic errors in data sets, as this measures a temporal gradient of soil moisture state.

Mitigation potential of soil carbon management overestimated by neglecting N2O emissions

NASA Astrophysics Data System (ADS)

Lugato, Emanuele; Leip, Adrian; Jones, Arwyn

2018-03-01

International initiatives such as the `4 per 1000' are promoting enhanced carbon (C) sequestration in agricultural soils as a way to mitigate greenhouse gas emissions1. However, changes in soil organic C turnover feed back into the nitrogen (N) cycle2, meaning that variation in soil nitrous oxide (N2O) emissions may offset or enhance C sequestration actions3. Here we use a biogeochemistry model on approximately 8,000 soil sampling locations in the European Union4 to quantify the net CO2 equivalent (CO2e) fluxes associated with representative C-mitigating agricultural practices. Practices based on integrated crop residue retention and lower soil disturbance are found to not increase N2O emissions as long as C accumulation continues (until around 2040), thereafter leading to a moderate C sequestration offset mostly below 47% by 2100. The introduction of N-fixing cover crops allowed higher C accumulation over the initial 20 years, but this gain was progressively offset by higher N2O emissions over time. By 2060, around half of the sites became a net source of greenhouse gases. We conclude that significant CO2 mitigation can be achieved in the initial 20-30 years of any C management scheme, but after that N inputs should be controlled through appropriate management.

Early Response of Soil Properties and Function to Riparian Rainforest Restoration

PubMed Central

Gageler, Rose; Bonner, Mark; Kirchhof, Gunnar; Amos, Mark; Robinson, Nicole; Schmidt, Susanne; Shoo, Luke P.

2014-01-01

Reforestation of riparian zones is increasingly practiced in many regions for purposes of biodiversity conservation, bank stabilisation, and improvement in water quality. This is in spite of the actual benefits of reforestation for recovering underlying soil properties and function remaining poorly understood. Here we compare remnant riparian rainforest, pasture and reforestation plantings aged 2–20 years in an Australian subtropical catchment on ferrosols to determine the extent to which reforestation restores key soil properties. Of the nine soil attributes measured (total nitrogen, nitrate and ammonium concentrations, net nitrification and ammonification rates, organic carbon, bulk density, fine root biomass and water infiltration rates), only infiltration rates were significantly lower in pasture than remnant riparian rainforest. Within reforestation plantings, bulk density decreased up to 1.4-fold and infiltration rates increased up to 60-fold with time post-reforestation. Our results suggest that the main outcome of belowground processes of early reforestation is the recovery of the soils' physical structure, with potential beneficial ecosystem services including reduced runoff, erosion and associated sediment and nutrient loads in waterways. We also demonstrate differential impacts of two commonly planted tree species on a subset of soil properties suggesting that preferential planting of select species could accelerate progress on specific restoration objectives. PMID:25117589

Early response of soil properties and function to riparian rainforest restoration.

PubMed

Gageler, Rose; Bonner, Mark; Kirchhof, Gunnar; Amos, Mark; Robinson, Nicole; Schmidt, Susanne; Shoo, Luke P

2014-01-01

Reforestation of riparian zones is increasingly practiced in many regions for purposes of biodiversity conservation, bank stabilisation, and improvement in water quality. This is in spite of the actual benefits of reforestation for recovering underlying soil properties and function remaining poorly understood. Here we compare remnant riparian rainforest, pasture and reforestation plantings aged 2-20 years in an Australian subtropical catchment on ferrosols to determine the extent to which reforestation restores key soil properties. Of the nine soil attributes measured (total nitrogen, nitrate and ammonium concentrations, net nitrification and ammonification rates, organic carbon, bulk density, fine root biomass and water infiltration rates), only infiltration rates were significantly lower in pasture than remnant riparian rainforest. Within reforestation plantings, bulk density decreased up to 1.4-fold and infiltration rates increased up to 60-fold with time post-reforestation. Our results suggest that the main outcome of belowground processes of early reforestation is the recovery of the soils' physical structure, with potential beneficial ecosystem services including reduced runoff, erosion and associated sediment and nutrient loads in waterways. We also demonstrate differential impacts of two commonly planted tree species on a subset of soil properties suggesting that preferential planting of select species could accelerate progress on specific restoration objectives.

[Key microbial processes in nitrous oxide emissions of agricultural soil and mitigation strategies].

PubMed

Zhu, Yong-Guan; Wang, Xiao-Hui; Yang, Xiao-Ru; Xu, Hui-Juan; Jia, Yan

2014-02-01

Nitrous oxide (N2O) is a powerful atmospheric greenhouse gas, which does not only have a strong influence on the global climate change but also depletes the ozone layer and induces the enhancement of ultraviolet radiation to ground surface, so numerous researches have been focused on global climate change and ecological environmental change. Soil is the foremost source of N2O emissions to the atmosphere, and approximately two-thirds of these emissions are generally attributed to microbiological processes including bacterial and fungal denitrification and nitrification processes, largely as a result of the application of nitrogenous fertilizers. Here the available knowledge concerning the research progress in N2O production in agricultural soils was reviewed, including denitrification, nitrification, nitrifier denitrification and dissimilatory nitrate reduction to ammonium, and the abiotic (including soil pH, organic and inorganic nitrogen, organic matter, soil humidity and temperature) and biotic factors that have direct and indirect effects on N2O fluxes from agricultural soils were also summarized. In addition, the strategies for mitigating N2O emissions and the future research direction were proposed. Therefore, these studies are expected to provide valuable and scientific evidence for the study on mitigation strategies for the emission of greenhouse gases, adjustment of nitrogen transformation processes and enhancement of nitrogen use efficiency.

Carcass mass has little influence on the structure of gravesoil microbial communities.

PubMed

Weiss, Sophie; Carter, David O; Metcalf, Jessica L; Knight, Rob

2016-01-01

Little is known about how variables, such as carcass mass, affect the succession pattern of microbes in soils during decomposition. To investigate the effects of carcass mass on the soil microbial community, soils associated with swine (Sus scrofa domesticus) carcasses of four different masses were sampled until the 15th day of decomposition during the month of June in a pasture near Lincoln, Nebraska. Soils underneath swine of 1, 20, 40, and 50 kg masses were investigated in triplicate, as well as control sites not associated with a carcass. Soil microbial communities were characterized by sequencing the archaeal, bacterial (16S), and eukaryotic (18S) rRNA genes in soil samples. We conclude that time of decomposition was a significant influence on the microbial community, but carcass mass was not. The gravesoil associated with 1 kg mass carcasses differs most compared to the gravesoil associated with other carcass masses. We also identify the 15 most abundant bacterial and eukaryotic taxa, and discuss changes in their abundance as carcass decomposition progressed. Finally, we show significant decreases in alpha diversity for carcasses of differing mass in pre-carcass rupture (days 0, 1, 2, 4, 5, and 6 postmortem) versus post-carcass rupture (days 9 and 15 postmortem) microbial communities.

Streambeds Merit Recognition as a Scientific Discipline

NASA Astrophysics Data System (ADS)

Constantz, J. E.

2016-12-01

Streambeds are generally viewed as simply sediments beneath streams, sediments topping alluvial aquifers, or sediments housing aquatic life, rather than as distinct geographic features comparable to soils and surficial geologic formations within watersheds. Streambeds should be viewed as distinct elements within watersheds, e.g., as akin to soils. In this presentation, streambeds are described as central features in watersheds, cycling water between the surface and underlying portions of the watershed. Regarding their kinship to soils, soils are often described as surficial sediments largely created by atmospheric weathering of underlying geologic parent material, and similarly, streambeds should be described as submerged sediments largely created by streamflow modification of underlying geologic parent material. Thus, streambeds are clearly overdue for recognition as their own scientific discipline along side other well-recognized disciplines within watersheds; however, slowing progress in this direction, the point is often made that hyporheic zones should be considered comparable to streambeds, but this is as misguided as equating unsaturated zones to soils. Streambeds and soils are physical geographic features of relatively constant volume, while hyporheic and unsaturated zones are hydrologic features of varying volume. Expanded upon in this presentation, 'Streambed Science' is proposed for this discipline, which will require both a well-designed protocol to physically characterize streambeds as well as development of streambed taxonomy, for suitable recognition as an independent discipline within watersheds.

An ecological engineering approach for keeping water from reaching interred wastes in arid or semiarid regions

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

Anderson, J.E.

1997-12-31

This paper describes application of a soil-plant cover system (SPCS) to preclude water from reaching interred wastes in arid and semiarid regions. Where potential evapotranspiration far exceeds precipitation, water can be kept from reaching buried wastes by (1) providing a sufficiently deep cap of soil to store precipitation that falls while plants are dormant and (2) maintaining plant cover to deplete soil moisture during the growing season, thereby emptying the storage reservoir. Research at the Idaho National Engineering Laboratory (INEL) has shown that 2 m of soil is adequate to store moisture from snowmelt and spring rains. Healthy stands ofmore » perennial grasses and shrubs adapted to the INEL climate use all available soil moisture, even during a very wet growing season. However, burrowing by small mammals or ants may affect the performance of a SPCS by increasing infiltration of water. Intrusion barriers of gravel and cobble can be used to restrict burrowing, but emplacement of such barriers affects soil moisture storage and plant rooting depths. A replicated field experiment to investigate the implications of those effects is in progress. Incorporation of an SPCS should be considered in the design of isolation barriers for shallow land burial of hazardous wastes in and regions.« less

Raw or incubated olive-mill wastes and its biotransformed products as agricultural soil amendments-effect on sorption-desorption of triazine herbicides.

PubMed

Delgado-Moreno, Laura; Almendros, Gonzalo; Peña, Aránzazu

2007-02-07

Raw olive-mill waste and soil amendments obtained from their traditional composting or vermicomposting were added, at rates equivalent to 200 Mg ha-1, to a calcareous silty clay loam soil in a laboratory test, in order to improve its fertility and physicochemical characteristics. In particular, the effects on the sorption-desorption processes of four triazine herbicides have been examined. We found that comparatively hydrophobic herbicides terbuthylazine and prometryn increased their retention on amended soil whereas the more polar herbicides simazine and cyanazine were less affected. Soil application of olive cake, without transformation, resulted in the highest herbicide retention. Its relatively high content in aliphatic fractions and lipids could explain the increased herbicide retention through hydrophobic bonding and herbicide diffusion favored by poorly condensed macromolecular structures. On the other hand, the condensed aromatic structure of the compost and vermicompost from olive cake could hinder diffusion processes, resulting in lower herbicide sorption. In fact, the progressive humification in soil of olive-mill solid waste led to a decrease of sorption capacity, which suggested important changes in organic matter quality and interactions during the mineralization process. When soil amended with vermicompost was incubated for different periods of time, the enhanced herbicide sorption capacity persisted for 2 months. Pesticide desorption was reduced by the addition of fresh amendments but was enhanced during the transformation process of amendments in soil. Our results indicate the potential of soil amendments based on olive-mill wastes in the controlled, selective release of triazine herbicides, which varies depending on the maturity achieved by their biological transformation.

Diversity and Ecology of Viruses in Hyperarid Desert Soils

PubMed Central

Zablocki, Olivier; Adriaenssens, Evelien M.

2015-01-01

In recent years, remarkable progress has been made in the field of virus environmental ecology. In marine ecosystems, for example, viruses are now thought to play pivotal roles in the biogeochemical cycling of nutrients and to be mediators of microbial evolution through horizontal gene transfer. The diversity and ecology of viruses in soils are poorly understood, but evidence supports the view that the diversity and ecology of viruses in soils differ substantially from those in aquatic systems. Desert biomes cover ∼33% of global land masses, and yet the diversity and roles of viruses in these dominant ecosystems remain poorly understood. There is evidence that hot hyperarid desert soils are characterized by high levels of bacterial lysogens and low extracellular virus counts. In contrast, cold desert soils contain high extracellular virus titers. We suggest that the prevalence of microbial biofilms in hyperarid soils, combined with extreme thermal regimens, exerts strong selection pressures on both temperate and virulent viruses. Many desert soil virus sequences show low values of identity to virus genomes in public databases, suggesting the existence of distinct and as-yet-uncharacterized soil phylogenetic lineages (e.g., cyanophages). We strongly advocate for amplification-free metavirome analyses while encouraging the classical isolation of phages from dominant and culturable microbial isolates in order to populate sequence databases. This review provides an overview of recent advances in the study of viruses in hyperarid soils and of the factors that contribute to viral abundance and diversity in hot and cold deserts and offers technical recommendations for future studies. PMID:26590289

Using SMAP to identify structural errors in hydrologic models

NASA Astrophysics Data System (ADS)

Crow, W. T.; Reichle, R. H.; Chen, F.; Xia, Y.; Liu, Q.

2017-12-01

Despite decades of effort, and the development of progressively more complex models, there continues to be underlying uncertainty regarding the representation of basic water and energy balance processes in land surface models. Soil moisture occupies a central conceptual position between atmosphere forcing of the land surface and resulting surface water fluxes. As such, direct observations of soil moisture are potentially of great value for identifying and correcting fundamental structural problems affecting these models. However, to date, this potential has not yet been realized using satellite-based retrieval products. Using soil moisture data sets produced by the NASA Soil Moisture Active/Passive mission, this presentation will explore the use of the remotely-sensed soil moisture data products as a constraint to reject certain types of surface runoff parameterizations within a land surface model. Results will demonstrate that the precision of the SMAP Level 4 Surface and Root-Zone soil moisture product allows for the robust sampling of correlation statistics describing the true strength of the relationship between pre-storm soil moisture and subsequent storm-scale runoff efficiency (i.e., total storm flow divided by total rainfall both in units of depth). For a set of 16 basins located in the South-Central United States, we will use these sampled correlations to demonstrate that so-called "infiltration-excess" runoff parameterizations under predict the importance of pre-storm soil moisture for determining storm-scale runoff efficiency. To conclude, we will discuss prospects for leveraging this insight to improve short-term hydrologic forecasting and additional avenues for SMAP soil moisture products to provide process-level insight for hydrologic modelers.

Growth form and seasonal variation in leaf gas exchange of Colophospermum mopane savanna trees in northwest Botswana.

PubMed

Veenendaal, Elmar M; Mantlana, Khanyisa B; Pammenter, Norman W; Weber, Piet; Huntsman-Mapila, Phillipa; Lloyd, Jon

2008-03-01

We investigated differences in physiological and morphological traits between the tall and short forms of mopane (Colophospermum mopane (Kirk ex Benth.) Kirk ex J. Léonard) trees growing near Maun, Botswana on a Kalahari sandveld overlying an impermeable calcrete duricrust. We sought to determine if differences between the two physiognomic types are attributable to the way they exploit available soil water. The tall form, which was located on deeper soil than the short form (5.5 versus 1.6 m), had a lower leaf:fine root biomass ratio (1:20 versus 1:6), but a similar leaf area index (0.9-1.0). Leaf nitrogen concentrations varied between 18 and 27 mg g(-1) and were about 20% higher in the tall form than in the short form. Maximum net assimilation rates (A sat) occurred during the rainy seasons (March-April 2000 and January-February 2001) and were similar in the tall and short forms (15-22 micromol m(-2) s(-1)) before declining to less than 10 micromol m(-2) s(-1) at the end of the rainy season in late April. As the dry season progressed, A sat, soil water content, predawn leaf water potential (Psi pd) and leaf nitrogen concentration declined rapidly. Before leaf abscission, Psi pd was more negative in the short form (-3.4 MPa) than in the tall form (-2.7 MPa) despite the greater availability of soil water beneath the short form trees. This difference appeared attributable to differences in root depth and density between the physiognomic types. Stomatal regulation of water use and carbon assimilation differed between years, with the tall form having a consistently more conservative water-use strategy as the dry season progressed than the short form.

[Impact of rural land market on farm household's behavior of soil & water conservation and its regional difference: A case study of Xingguo, Shangrao, and Yujiang County in Jiangxi province ecologically vulnerable districts].

PubMed

Zhong, Tai-Yang; Huang, Xian-jin

2006-02-01

The paper analyzed the farm households' decision-making progress of soil & water conservation and its two-stage conceptual model. It also discussed the impacts of rural land market on the farm households' behavior of soil & water conservation. Given that, the article established models for the relations between the land market and soil & water conservation, and the models' parameters were estimated with Heckman's two-stage approach by using the farm household questionnaires in Xingguo, Shangrao and Yujiang counties of Jiangxi province. The paper analyzed the impact o f rural land market on farm household's behavior of soil & water conservation and its regional difference with the result of model estimation. The results show that the perception of soil & water loss and the tax & fee on the farm land have significant influence upon the soil and water conservation from the view of the population; however, because of different social and economic condition, and soil & water loss, there are differences of the influence among the three sample counties. These differences go as follows in detail: In Xingguo County, the rent-in land area and its cost have remarkable effect on the farm households' soil & water conservation behavior; In Yujiang County, the rent-in land area, rent-in cost and rent-out land area remarkably influence the farm households' behavior of soil and water conservation, with the influence of the rent-in land area being greater than Xingguo County; In Shangrao County, only rent-out land area has significant influence on the behaviors of soil & water conservation; In all samples, Xingguo County and Yujiang County samples, the rent-out income has no significant influence on the farm household's decision-making behavior soil and water conservation. Finally, the paper put forward some suggestions on how to bring the soil & water loss under control and use land resource in sustainable ways.

Effects of plant diversity, N fertilization, and elevated carbon dioxide on grassland soil N cycling in a long-term experiment.

PubMed

Mueller, Kevin E; Hobbie, Sarah E; Tilman, David; Reich, Peter B

2013-04-01

The effects of global environmental changes on soil nitrogen (N) pools and fluxes have consequences for ecosystem functions such as plant productivity and N retention. In a 13-year grassland experiment, we evaluated how elevated atmospheric carbon dioxide (CO2 ), N fertilization, and plant species richness alter soil N cycling. We focused on soil inorganic N pools, including ammonium and nitrate, and two N fluxes, net N mineralization and net nitrification. In contrast with existing hypotheses, such as progressive N limitation, and with observations from other, often shorter, studies, elevated CO2 had relatively static and small, or insignificant, effects on soil inorganic N pools and fluxes. Nitrogen fertilization had inconsistent effects on soil N transformations, but increased soil nitrate and ammonium concentrations. Plant species richness had increasingly positive effects on soil N transformations over time, likely because in diverse subplots the concentrations of N in roots increased over time. Species richness also had increasingly positive effects on concentrations of ammonium in soil, perhaps because more carbon accumulated in soils of diverse subplots, providing exchange sites for ammonium. By contrast, subplots planted with 16 species had lower soil nitrate concentrations than less diverse subplots, especially when fertilized, probably due to greater N uptake capacity of subplots with 16 species. Monocultures of different plant functional types had distinct effects on N transformations and nitrate concentrations, such that not all monocultures differed from diverse subplots in the same manner. The first few years of data would not have adequately forecast the effects of N fertilization and diversity on soil N cycling in later years; therefore, the dearth of long-term manipulations of plant species richness and N inputs is a hindrance to forecasting the state of the soil N cycle and ecosystem functions in extant plant communities. © 2012 Blackwell Publishing Ltd.

Soil development over millennial timescales - a comparison of soil chronosequences of different climates and lithologies

NASA Astrophysics Data System (ADS)

Sauer, D.; Schülli-Maurer, I.; Wagner, S.; Scarciglia, F.; Sperstad, R.; Svendgård-Stokke, S.; Sørensen, R.; Schellmann, G.

2015-07-01

This paper reports soil development over time in different climates, on time-scales ranging from a few thousand to several hundred thousand years. Changes in soil properties over time, underlying soil-forming processes and their rates are presented. The paper is based on six soil chronosequences, i.e. sequences of soils of different age that are supposed to have developed under the similar conditions with regard to climate, vegetation and other living organisms, relief and parent material. The six soil chronosequences are from humid-temperate, Mediterranean and semi-arid climates. They are compared with regard to soil thickness increase, changes in soil pH, formation of pedogenic iron oxides (expressed as Fed/Fet ratios), clay formation, dust influx (both reflected in clay/silt ratios), and silicate weathering and leaching of base cations(expressed as (Ca+Mg+K+Na)/Al molar ratios) over time. This comparison reveals that the increase of solum thickness with time can be best described by logarithmic equations in all three types of climates. Fed/Fet ratios (proportion of pedogeniciron Fed compared to total iron Fet) reflects the transformation of iron in primary minerals into pedogeniciron. This ratio usually increases with time, except for regions, where the influx of dust (having low Fed/Fet ratios) prevails over the process of pedogeniciron oxide formation, which is the case in the Patagonian chronosequences. Dust influx has also a substantial influence on the time courses of clay/silt ratios and on element indices of silicate weathering. Using the example of a 730 kasoil chronosequence from southern Italy, the fact that soils of long chronosequences inevitably experienced major environmental changes is demonstrated, and, consequentially a modified definition of requirements for soil chronosequences is suggested. Moreover, pedogenic thresholds, feedback systems and progressive versus regressive processes identified in the soil chronosequences are discussed.

Vegetation-induced turbulence influencing evapotranspiration-soil moisture coupling: Implications for semiarid regions

NASA Astrophysics Data System (ADS)

Haghighi, E.; Kirchner, J. W.; Entekhabi, D.

2016-12-01

The relationship between soil moisture and evapotranspiration (ET) fluxes is an important component of land-atmosphere interactions controlling hydrology-climate feedback processes. Important as this relationship is, it remains empirical and physical mechanisms governing its dynamics are insufficiently studied. This is particularly of importance for semiarid regions (currently comprising about half of the Earth's land surface) where the shallow surface soil layer is the primary source of ET and direct evaporation from bare soil is likely a large component of the total flux. Hence, ET-soil moisture coupling in these regions is hypothesized to be strongly influenced by soil evaporation and associated mechanisms. Motivated by recent progress in mechanistic modeling of localized heat and mass exchange rates from bare soil surfaces covered by cylindrical bluff-body elements, we developed a physically based ET model explicitly incorporating coupled impacts of soil moisture and vegetation-induced turbulence in the near-surface region. Model predictions of ET and its partitioning were in good agreement with measured data and suggest that the strength and nature of ET-soil moisture interactions in sparsely vegetated areas are strongly influenced by aerodynamic (rather than radiative) forcing namely wind speed and near-surface turbulence generation as a function of vegetation type and cover fraction. The results demonstrated that the relationship between ET and soil moisture varies from a nonlinear function (the dual regime behavior) to a single moisture-limited regime (linear relationship) by increasing wind velocity and enhancing turbulence generation in the near-surface region (small-scale woody vegetation species of low cover fraction). Potential benefits of this study for improving accuracy and predictive capabilities of remote sensing techniques when applied to semiarid environments will also be discussed.

Soil nitrogen accretion along a floodplain terrace chronosequence in northwest Alaska: Influence of the nitrogen-fixing shrub Shepherdia canadensis

USGS Publications Warehouse

Rhoades, Charles; Binkley, Dan; Oskarsson, Hlynur; Stottlemyer, Robert

2008-01-01

Nitrogen enters terrestrial ecosystems through multiple pathways during primary succession. We measured accumulation of total soil nitrogen and changes in inorganic nitrogen (N) pools across a 300-y sequence of river terraces in northwest Alaska and assessed the contribution of the nitrogen-fixing shrub Shepherdia canadensis. Our work compared 5 stages of floodplain succession, progressing from a sparsely vegetated silt cap to dense shrubby vegetation, balsam poplar-dominated (Populus balsamifera) and white spruce-dominated (Picea glauca) mixed forests, and old-growth white spruce forest. Total soil N (0–30 cm depth) increased throughout the age sequence, initially by 2.4 g N·m−2·y−1 during the first 120 y of terrace development, then by 1.6 g N·m−2·y−1 during the subsequent 2 centuries. Labile soil N, measured by anaerobic incubation, increased most rapidly during the first 85 y of terrace formation, then remained relatively constant during further terrace development. On recently formed terraces, Shepherdia shrubs enriched soil N pools several-fold compared to soil beneath Salix spp. shrubs or intercanopy sites. Total and labile soil N accretion was proportional to Shepherdia cover during the first century of terrace development, and mineral soil δ15N content indicated that newly formed river terraces receive substantial N through N-fixation. About half the 600 g total N·m−2 accumulated across the river terrace chronosequence occurred during the 120 y when S. canadensis was dominant. Sediment deposited by periodic flooding continued to add N to terrace soils after the decline in Shepherdia abundance and may have contributed 25% of the total N found in the floodplain terrace soils.

Methane Emissions from Natural Gas Vehicles in Beijing, Baoding, and Shijiazhuang, China during CAREBEIJING Field Campaign

NASA Astrophysics Data System (ADS)

Pérez García-Pando, C.; Miller, R. L.; Perlwitz, J. P.; Kok, J. F.; Scanza, R.; Mahowald, N. M.

2014-12-01

Mineral dust created by wind erosion of soil particles is the dominant aerosol by mass in the atmosphere. It exerts significant effects on radiative fluxes, clouds, ocean biogeochemistry, and human health. Models that predict the lifecycle of mineral dust aerosols generally assume a globally uniform mineral composition. However, this simplification limits our understanding of the role of dust in the Earth system, since the effects of dust strongly depend on the particles' physical and chemical properties, which vary with their mineral composition. Hence, not only a detailed understanding of the processes determining the dust emission flux is needed, but also information about its size dependent mineral composition. Determining the mineral composition of dust aerosols is complicated. The largest uncertainty derives from the current atlases of soil mineral composition. These atlases provide global estimates of soil mineral fractions, but they are based upon massive extrapolation of a limited number of soil samples assuming that mineral composition is related to soil type. This disregards the potentially large variability of soil properties within each defined soil type. In addition, the analysis of these soil samples is based on wet sieving, a technique that breaks the aggregates found in the undisturbed parent soil. During wind erosion, these aggregates are subject to partial fragmentation, which generates differences on the size distribution and composition between the undisturbed parent soil and the emitted dust aerosols. We review recent progress on the representation of the mineral and chemical composition of dust in climate models. We discuss extensions of brittle fragmentation theory to prescribe the emitted size-resolved dust composition, and we identify key processes and uncertainties based upon model simulations and an unprecedented compilation of observations.

Dust Composition in Climate Models: Current Status and Prospects

NASA Astrophysics Data System (ADS)

Pérez García-Pando, C.; Miller, R. L.; Perlwitz, J. P.; Kok, J. F.; Scanza, R.; Mahowald, N. M.

2015-12-01

Mineral dust created by wind erosion of soil particles is the dominant aerosol by mass in the atmosphere. It exerts significant effects on radiative fluxes, clouds, ocean biogeochemistry, and human health. Models that predict the lifecycle of mineral dust aerosols generally assume a globally uniform mineral composition. However, this simplification limits our understanding of the role of dust in the Earth system, since the effects of dust strongly depend on the particles' physical and chemical properties, which vary with their mineral composition. Hence, not only a detailed understanding of the processes determining the dust emission flux is needed, but also information about its size dependent mineral composition. Determining the mineral composition of dust aerosols is complicated. The largest uncertainty derives from the current atlases of soil mineral composition. These atlases provide global estimates of soil mineral fractions, but they are based upon massive extrapolation of a limited number of soil samples assuming that mineral composition is related to soil type. This disregards the potentially large variability of soil properties within each defined soil type. In addition, the analysis of these soil samples is based on wet sieving, a technique that breaks the aggregates found in the undisturbed parent soil. During wind erosion, these aggregates are subject to partial fragmentation, which generates differences on the size distribution and composition between the undisturbed parent soil and the emitted dust aerosols. We review recent progress on the representation of the mineral and chemical composition of dust in climate models. We discuss extensions of brittle fragmentation theory to prescribe the emitted size-resolved dust composition, and we identify key processes and uncertainties based upon model simulations and an unprecedented compilation of observations.

Influence of selected physicochemical parameters on microbiological activity of mucks.

NASA Astrophysics Data System (ADS)

Całka, A.; Sokołowska, Z.; Warchulska, P.; Dąbek-Szreniawska, M.

2009-04-01

One of the basic factor decided about soil fertility are microorganisms that together with flora, determine trend and character of biochemical processes as well totality of fundamental transformations connected with biogeochemistry and physicochemical properties of soil. Determination of general bacteria number, quantity of selected groups of microorganisms and investigation of respiration intensity let estimate microbiological activity of soil. Intensity of microbiological processes is directly connected with physicochemical soil parameters. In that case, such structural parameters as bulk density, porosity, surface or carbon content play significant role. Microbiological activity also changes within the bounds of mucks with different stage of humification and secondary transformation. Knowledge of relations between structural properties, microorganism activity and degree of transformation and humification can lead to better understanding microbiological processes as well enable to estimate microbiological activity at given physicochemical conditions and at progressing process of soil transformation. The study was carried out on two peaty-moorsh (muck) soils at different state of secondary transformation and humification degree. Soil samples were collected from Polesie Lubelskie (layer depth: 5 - 25 cm). Investigated mucks originated from soils formed from low peatbogs. Soil sample marked as I belonged to muck group weakly secondary transformed. Second sample (II) represented soil group with middle stage of secondary transformation. The main purpose of the research was to examine the relations between some physicochemical and surface properties and their biological activity. Total number and respiration activity of microorganisms were determined. The effectiveness of utilizing the carbon substances from the soil by the bacteria increased simultaneously with the transformation state of the peat-muck soils. Quantity of organic carbon decreased distinctly in the soil at the higher stage of secondary transformation and it influenced quantity and activity of soil microorganisms. Bulk density and surface increased with increasing secondary transformation degree. On the other hand, porosity decreased with increasing secondary transformation index. Process of secondary transformation influenced the soil environment for the microbes by changing the physicochemical properties. This way it influenced the number of microorganisms and caused changes of biological activity in the soils.

Chemical weathering and loess inputs to soils in New Zealand's Wairarapa region

NASA Astrophysics Data System (ADS)

Lukens, C. E.; Norton, K. P.

2017-12-01

Geochemical mass-balance approaches are commonly used in soils to evaluate patterns in chemical weathering. In conjuction with cosmogenic nuclide measurements of total denudation or soil production, mass-balance approaches have been used to constrain rates of chemical weathering across a variety of landscapes. Here we present geochemical data from a series of soil pits in the Wairarapa region of New Zealand's North Island, where rates of soil production equal rates of total denudation measured using 10Be at sites nearby (i.e., the landscape is in steady state). Soil density increases with depth, consistent with steady weathering over the average soil residence time. However, soil geochemistry indicates very little chemical weathering has occurred, and immobile elements (Zr, Ti, and V) are depleted in soils relative to bedrock. This is contrary to the expected observation, wherein immobile elements should be enriched in soils relative to parent bedrock as weathered mobile solutes are progressively removed from soil. Our geochemical measurements suggest contributions from an exernal source, which has a different chemical composition than the underlying bedrock. We hypothesize that loess constitutes a substantial influx of additional material, and use a mixing model to predict geochemical patterns within soil columns. We evaluate the relative contributions of several likely loess sources, including tephra from the nearby Taupo Volcanic Center, local loess deposits formed during glacial-interglacial transitions, and far-travelling Australian dust. Using an established mass-balance approach with multiple immobile elements, we calculate the fraction of mass in soils contributed by loess to be as much as 25%. Combined with 10Be-derived estimates of soil production, we calculate average loess fluxes up to 320 t/km2/yr, which are consistent with previous estimates of loess acculumation over the late Holocene. Accounting for loess input, we find that chemical weathering fluxes are remarkably low in these soils, which sit atop fractured graywacke that likely contributes very few weatherable primary minerals. The significant loess flux in this region may have important implications for estimates of total denudation and soil production, and must be accounted for to determine patterns in chemical weathering.

Assessment of Food Chain Pathway Parameters in Biosphere Models: Annual Progress Report for Fiscal Year 2004

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

Napier, Bruce A.; Krupka, Kenneth M.; Fellows, Robert J.

2004-12-02

This Annual Progress Report describes the work performed and summarizes some of the key observations to date on the U.S. Nuclear Regulatory Commission’s project Assessment of Food Chain Pathway Parameters in Biosphere Models, which was established to assess and evaluate a number of key parameters used in the food-chain models used in performance assessments of radioactive waste disposal facilities. Section 2 of this report describes activities undertaken to collect samples of soils from three regions of the United States, the Southeast, Northwest, and Southwest, and perform analyses to characterize their physical and chemical properties. Section 3 summarizes information gathered regardingmore » agricultural practices and common and unusual crops grown in each of these three areas. Section 4 describes progress in studying radionuclide uptake in several representative crops from the three soil types in controlled laboratory conditions. Section 5 describes a range of international coordination activities undertaken by Project staff in order to support the underlying data needs of the Project. Section 6 provides a very brief summary of the status of the GENII Version 2 computer program, which is a “client” of the types of data being generated by the Project, and for which the Project will be providing training to the US NRC staff in the coming Fiscal Year. Several appendices provide additional supporting information.« less

Spectral effects of dehydration on phyllosilicates

NASA Technical Reports Server (NTRS)

Bruckenthal, E. A.; Singer, R. B.

1987-01-01

Six phyllosilicates were progressively dehydrated under controlled conditions in an effort to study the spectral effects of their dehydration. The spectra obtained at each level of hydration provide information that may be used in future spectroscopic observations of the planets, as well as a data set which compliments the existing body of terrestrial soil knowledge.

Progress in developing disease control strategies for hybrid poplars

Treesearch

Michael E. Ostry

2000-01-01

Hybrid poplars are being grown throughout many regions of the world for purposes including the production of fiber and energy, ornamental landscape plantings, and soil stabilization. Disease has often been responsible for planting failures resulting in poplars being labeled the universal host to many damaging pathogens. However, many of the poplar species and their...

COMPARISON OF N2O EMISSIONS FROM SOILS AT THREE TEMPERATE AGRICULTURAL SITES: SIMULATIONS OF YEAR-ROUND MEASUREMENTS BY FOUR MODELS. (R824993)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

DEHALOGENATION OF DICHLOROETHENE IN A CONTAMINATED SOIL: FATTY ACIDS AND ALCOHOLS AS ELECTRON DONORS AND AN APPARENT REQUIREMENT FOR TETRACHLOROETHENE. (R825511C037)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

The role of subsurface flow in hillslope and streambank erosion: A review of status and research needs

USDA-ARS?s Scientific Manuscript database

Sediment is the most common cause of stream impairment. Great progress has been made in understanding processes of soil erosion due to surface runoff and incorporating these in prediction technologies. However, in many landscapes the dominant source of sediment is derived from mass wasting of hillsl...

COUPLING SUPERCRITICAL CO2 AND SUBCRITICAL (HOT) WATER FOR THE DETERMINATION OF DACTHAL AND ITS ACID METABOLITES IN SOIL (R821195)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

EFFECTS OF CO-CONTAMINANTS ON THE DISPOSITION OF POLYCHLORINATED DIBENZO-P-DIOXINS AND POLYCHLORINATED DIBENZOFURANS IN SATURATED SOILS. (R825549C032)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Progress and Opportunities for Women in Agricultural Sciences.

ERIC Educational Resources Information Center

Kuehl, R. J.; And Others

1987-01-01

Reviews the numerical gains that women have made in employment in the agricultural sciences in the last five years, and the career opportunities that currently exist. Discusses trends in recruiting women into the agricultural sciences, the increase in doctoral degrees conferred upon women, and the need for more women in agronomy and soil science.…

FIELD AND LABORATORY EVALUATION OF THE IMPACT OF TALL FESCUE ON PAH DEGRADATION IN AN AGED CREOSOTE-CONTAMINATED SURFACE SOIL. (R828770)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

FIELD AND LABORATORY EVALUATION OF THE IMPACT OF TALL FESCUE ON PAH DEGRADATION IN AN AGED CREOSOTE-CONTAMINATED SURFACE SOIL. (R828770C004)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

FIELD AND LABORATORY EVALUATION OF THE IMPACT OF TALL FESCUE ON PAH DEGRADATAION IN AN AGED CREOSOTE-CONTAMINATED SURFACE SOIL. (R828770)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

CHEMICAL CHARACTERIZATION OF A CHELATOR-TREATED SOIL HUMATE BY SOLUTION-STATE MULTINUCLEAR TWO-DIMENSIONAL NMR WITH FTIR AND PYROLYSIS-GCMS. (R825433C007)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Interactive initialization of heat flux parameters for numerical models using satellite temperature measurements

NASA Technical Reports Server (NTRS)

Carlson, T. N. (Principal Investigator)

1982-01-01

Progress made in HCMM research, including testing the interactive minicomputer system and preparation of a paper on the analysis of regional scale soil moisture patterns, is summarized. An exhibit on remote sensing including a videotape display of HCMM images, most of them of the State College area, was prepared.

PERSISTENCE AND BIOLOGICAL ACTIVITY IN SOIL OF INSECTICIDAL PROTEINS FROM BACILLUS THURINGIENSIS AND OF BACTERIAL DNA BOUND ON CLAYS AND HUMIC ACIDS. (R826107)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Soil compaction related to grazing and its effects on herbaceous roots frequency and soil organic matter content in rangelands of SW Spain

NASA Astrophysics Data System (ADS)

Pulido, Manuel; Schnabel, Susanne; Francisco Lavado Contador, Joaquín; Miralles Mellado, Isabel

2016-04-01

Rangelands in SW Spain occupy a total surface area of approximately 6 million ha and constitute the most representative extensive ranching system of the Iberian Peninsula gathering more than 13 million livestock heads. They are characterised by an herbaceous layer, mostly composed of therophytic species, with a disperse tree cover, mainly holm oak and cork oak (Quercus ilex rotundifolia and Q. suber), interspersed with shrubs in many places. This type of land system is of ancient origin and experienced frequent changes in land use in the past, since agricultural, livestock and forestry activities have coexisted within the same farms. In recent decades, livestock farming has become dominant due, in part, to the subsidies of the Common Agriculture Policy. Since Spain joined the European Union in 1986 until the year 2000, the number of domestic animals doubled, particularly cattle, and consequently animal stocking rates have increased on average from 0.40 AU ha-1 up to 0.70 AU ha-1. This increase in animal stocking rates, along with a progressive substitution of cattle instead of sheep in many farms, has led to the occurrence of land degradation processes such as the reduction of grass cover or soil compaction in heavily grazed areas. Previous research has evidenced higher values of soil bulk density and resistance to penetration as well as larger bare surface areas in spring in fenced areas with animal stocking rates above 1 AU ha-1. However, a better understanding of how increasing bulk density or resistance to penetration influence the frequency of herbaceous roots and how a reduction in the frequency of roots affects soil organic matter content in rangelands is still unknown. Therefore, the main goal of this study was to determine possible relationships between the frequencies of herbaceous roots and soil organic matter content in order to understand the effect of excessive animal numbers on the depletion of soil fertility by reducing progressively the quantity of roots. The study was carried out in 22 fenced areas belonging to 10 privately-owned farms grazed under different intensities (range: 0.19 - 15.76 AU ha-1 year-1). A total number of 597 undisturbed core samples and 311 bulk samples were collected in order to determine bulk density and soil organic matter content, among other many properties. Resistance to soil penetration was quantified using Eijkelkamp Penetrologger in 890 random points at different depth (0-80 cm) and soil moisture content (dry and wet). The frequency of herbaceous roots was estimated for each soil horizon in 47 soil profiles, described according to FAO and categorized in 4 classes: none-few, common, abundant and many. All variables were pair-wise correlated and their mean values were compared between the different classes of root frequency. Results showed an inverse relationship between soil resistance to penetration and the frequency of herbaceous roots, i.e. the amount of roots lower in soils with high resistance to penetration. Soil horizons with none or few, common, abundant and many roots averaged 0.74%, 1.27%, 2.23% and 2.70% of SOM, respectively, showing significant differences between groups. Furthermore, SOM showed negative coefficients of correlation with resistance to penetration under dry (r=-0.34, p<0.05) and under wet conditions (r=-0.11, p<0.05) and bulk density (r=-0.31, p<0.05). The values herein observed confirm that soil compaction provoked by an excessive number of animals can decrease the content of soil organic matter by reducing the quantity of herbaceous roots although further research is still needed.

Mars aqueous chemistry experiment

NASA Technical Reports Server (NTRS)

Clark, Benton C.; Mason, Larry W.

1994-01-01

Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. The second year of the MACE project has shown significant progress in two major areas. MACE Instrument concept definition is a baseline design that has been generated for the complete MACE instrument, including definition of analysis modes, mass estimates and thermal model. The design includes multiple reagent reservoirs, 10 discrete analysis cells, sample manipulation capability, and thermal control. The MACE Measurement subsystems development progress is reported regarding measurement capabilities for aqueous ion sensing, evolved gas sensing, solution conductivity measurement, reagent addition (titration) capabilities, and optical sensing of suspended particles.

[Research progress on the dual-mulching of ridge and furrow technology in dry farming regions of northern China: A review.

PubMed

Li, Rong; Hou, Xian Qing; Wang, Xiao Min; Jia, Zhi Kuan; Han, Qing Fang

2016-04-22

The precipitation exiguity and water deficiency are the major factors limiting crop growth in dry farming regions of northern China. Dual-mulching of ridges and furrows, which have been widely concerned both domestically and internationally, could increase the utilization efficiency of precipitation and crop yield. In this paper, we reviewed the concept and model of dual-mulching of ridges and furrows, its supporting farm machinery and implements as well as its ecological effects on soil and crops. Based on the current research progress of cultivation techniques using harvested rainfall in ridge and furrow, priority of future research aspects of the dual-mulching of ridges and furrows were suggested as follows: 1) to establish the suitable ridge-furrow ratios for different crops in different types of dry farming regions of northern China; 2) to pay more attention to the study of coupling effects of soil moisture with temperature, fertility and other factors; 3) to explore better environment-friendly mulching materials; 4) to enhance the research on technical evaluation and popularization, and the design of supporting farm machinery and implements.

Mars aqueous chemistry experiment

NASA Astrophysics Data System (ADS)

Clark, Benton C.; Mason, Larry W.

1994-06-01

Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. The second year of the MACE project has shown significant progress in two major areas. MACE Instrument concept definition is a baseline design that has been generated for the complete MACE instrument, including definition of analysis modes, mass estimates and thermal model. The design includes multiple reagent reservoirs, 10 discrete analysis cells, sample manipulation capability, and thermal control. The MACE Measurement subsystems development progress is reported regarding measurement capabilities for aqueous ion sensing, evolved gas sensing, solution conductivity measurement, reagent addition (titration) capabilities, and optical sensing of suspended particles.

Mass-movement and flood-induced deposits in Lake Ledro, southern Alps, Italy: implications for Holocene palaeohydrology and natural hazards

NASA Astrophysics Data System (ADS)

Simonneau, A.; Chapron, E.; Vannière, B.; Wirth, S. B.; Gilli, A.; Di Giovanni, C.; Anselmetti, F. S.; Desmet, M.; Magny, M.

2013-03-01

High-resolution seismic profiles and sediment cores from Lake Ledro combined with soil and riverbed samples from the lake's catchment area are used to assess the recurrence of natural hazards (earthquakes and flood events) in the southern Italian Alps during the Holocene. Two well-developed deltas and a flat central basin are identified on seismic profiles in Lake Ledro. Lake sediments have been finely laminated in the basin since 9000 cal. yr BP and frequently interrupted by two types of sedimentary events (SEs): light-coloured massive layers and dark-coloured graded beds. Optical analysis (quantitative organic petrography) of the organic matter present in soil, riverbed and lacustrine samples together with lake sediment bulk density and grain-size analysis illustrate that light-coloured layers consist of a mixture of lacustrine sediments and mainly contain algal particles similar to the ones observed in background sediments. Light-coloured layers thicker than 1.5 cm in the main basin of Lake Ledro are synchronous to numerous coeval mass-wasting deposits remoulding the slopes of the basin. They are interpreted as subaquatic mass-movements triggered by historical and pre-historical regional earthquakes dated to AD 2005, AD 1891, AD 1045 and 1260, 2545, 2595, 3350, 3815, 4740, 7190, 9185 and 11 495 cal. yr BP. Dark-coloured SEs develop high-amplitude reflections in front of the deltas and in the deep central basin. These beds are mainly made of terrestrial organic matter (soils and lignocellulosic debris) and are interpreted as resulting from intense hyperpycnal flood event. Mapping and quantifying the amount of soil material accumulated in the Holocene hyperpycnal flood deposits of the sequence allow estimating that the equivalent soil thickness eroded over the catchment area reached up to 5 mm during the largest Holocene flood events. Such significant soil erosion is interpreted as resulting from the combination of heavy rainfall and snowmelt. The recurrence of flash flood events during the Holocene was, however, not high enough to affect pedogenesis processes and highlight several wet regional periods during the Holocene. The Holocene period is divided into four phases of environmental evolution. Over the first half of the Holocene, a progressive stabilization of the soils present through the catchment of Lake Ledro was associated with a progressive reforestation of the area and only interrupted during the wet 8.2 event when the soil destabilization was particularly important. Lower soil erosion was recorded during the mid-Holocene climatic optimum (8000-4200 cal. yr BP) and associated with higher algal production. Between 4200 and 3100 cal. yr BP, both wetter climate and human activities within the drainage basin drastically increased soil erosion rates. Finally, from 3100 cal. yr BP to the present-day, data suggest increasing and changing human land use.

Multidisciplinary distinction of mass-movement and flood-induced deposits in lacustrine environments: implications for Holocene palaeohydrology and natural hazards (Lake Ledro, Southern Alps, Italy)

NASA Astrophysics Data System (ADS)

Simonneau, A.; Chapron, E.; Vannière, B.; Wirth, S. B.; Gilli, A.; Di Giovanni, C.; Anselmetti, F. S.; Desmet, M.; Magny, M.

2012-08-01

High-resolution seismic profiles and sediment cores from Lake Ledro combined with soil and river-bed samples from the lake's catchment area are used to assess the recurrence of natural hazards (earthquakes and flood events) in the southern Italian Alps during the Holocene. Two well-developed deltas and a flat central basin are identified on seismic profiles in Lake Ledro. Lake sediments are finely laminated in the basin since 9000 cal. yr BP and frequently interrupted by two types of sedimentary events: light-coloured massive layers and dark-coloured graded beds. Optical analysis (quantitative organic petrography) of the organic matter occurring in soils, river beds and lacustrine samples together with lake-sediment bulk density and grain-size analysis illustrate that light-coloured layers consist of a mixture of lacustrine sediments and mainly contain algal particles similar to the ones observed in background sediments. Light-coloured layers thicker than 1.5 cm in the main basin of Lake Ledro are dense and synchronous to numerous coeval mass-wasting deposits remoulding the slopes of the basin. They are interpreted as subaquatic mass movements triggered by historical and pre-historical regional earthquakes dated to 2005 AD, 1891 AD, 1045 AD and 1260, 2545, 2595, 3350, 3815, 4740, 7190, 9185 and 11495 cal. yr BP. Dark-coloured sedimentary event are dense and develop high-amplitude reflections in front of the deltas and in the deep central basin. These beds are mainly made of terrestrial organic matter (soils and ligno-cellulosic debris) and are interpreted as resulting from intense hyperpycnal flood events. Mapping and quantifying the amount of soil material accumulated in the Holocene hyperpycnal flood deposits of the sequence and applying the De Ploey erosion model allow estimating that the equivalent soil thickness eroded over the catchment area reached up to 4 mm during the largest Holocene flood events. Such significant soil erosion is interpreted as resulting from the combination of heavy rainfall and snowmelt. The recurrence of flash-flood events during the Holocene was however not high enough to affect pedogenesis processes and highlight several wet regional periods during the Holocene. The Holocene period is divided into four phases of environmental evolution. Over the first half of the Holocene, a progressive stabilization of the soils present through the catchment of Lake Ledro was associated with a progressive reforestation of the area and only interrupted during the wetter 8.2 event when the soil destabilization was particularly important. Lower soil erosion was recorded during the Mid-Holocene climatic optimum (8000-4200 cal. yr BP) and associated with higher algal production. Between 4200 and 3100 cal. yr BP, both wetter climate and human activities within the drainage basin drastically increased soil erosion rates. Finally, from 3100 cal. yr BP to the present-day, results suggest increasing and changing human land-use.

Modeling soil heating and moisture transport under extreme conditions: Forest fires and slash pile burns

NASA Astrophysics Data System (ADS)

Massman, W. J.

2012-10-01

Heating any soil during a sufficiently intense wildfire or prescribed burn can alter it irreversibly, causing many significant, long-term biological, chemical, and hydrological effects. Given the climate-change-driven increasing probability of wildfires and the increasing use of prescribed burns by land managers, it is important to better understand the dynamics of the coupled heat and moisture transport in soil during these extreme heating events. Furthermore, improved understanding and modeling of heat and mass transport during extreme conditions should provide insights into the associated transport mechanisms under more normal conditions. The present study describes a numerical model developed to simulate soil heat and moisture transport during fires where the surface heating often ranges between 10,000 and 100,000 W m-2 for several minutes to several hours. Basically, the model extends methods commonly used to model coupled heat flow and moisture evaporation at ambient conditions into regions of extreme dryness and heat. But it also incorporates some infrequently used formulations for temperature dependencies of the soil specific heat, thermal conductivity, and the water retention curve, as well as advective effects due to the large changes in volume that occur when liquid water is rapidly volatilized. Model performance is tested against laboratory measurements of soil temperature and moisture changes at several depths during controlled heating events. Qualitatively, the model agrees with the laboratory observations, namely, it simulates an increase in soil moisture ahead of the drying front (due to the condensation of evaporated soil water at the front) and a hiatus in the soil temperature rise during the strongly evaporative stage of the soil drying. Nevertheless, it is shown that the model is incapable of producing a physically realistic solution because it does not (and, in fact, cannot) represent the relationship between soil water potential and soil moisture at extremely low soil moisture contents (i.e., residual or bound water: θ < 0.01 m3 m-3, for example). Diagnosing the model's performance yields important insights into how to make progress on modeling soil evaporation and heating under conditions of high temperatures and very low soil moisture content.

Moessbauer Spectroscopy for Lunar Resource Assessment: Measurement of Mineralogy and Soil Maturity

NASA Technical Reports Server (NTRS)

Morris, R. V.; Agresti, D. G.; Shelfer, T. D.; Pimperl, M. M.; Shen, M.-H.; Gibson, M. A.; Wills, E. L.

1992-01-01

First-order assessment of lunar soil as a resource includes measurement of its mineralogy and maturity. Soils in which the mineral ilmenite is present in high concentrations are desirable feedstock for the production of oxygen at a lunar base. The maturity of lunar soils is a measure of their relative residence time in the upper 1 mm of the lunar surface. Increasing maturity implies increasing load of solar wind species (e.g., N, H, and He-3), decreasing mean grain size, and increasing glass content. All these physicochemical properties that vary in a regular way with maturity are important parameters for assessing lunar soil as a resource. For example, He-3 can be extracted and potentially used for nuclear fusion. A commonly used index for lunar soil maturity is I(sub s)/FeO, which is the concentration of fine-grained metal determined by ferromagnetic resonance (I(sub s)) normalized to the total iron content (as FeO). I(sub s)/FeO has been measured for virtually every soil returned by the Apollo and Luna missions to the Moon. Because the technique is sensitive to both oxidation state and mineralogy, iron Moessbauer spectroscopy (FeMS) is a viable technique for in situ lunar resource assessment. Its utility for mineralogy is apparent from examination of published FeMS data for lunar samples. From the data published, it can be inferred that FeMS data can also be used to determine soil maturity. The use of FeMS to determine mineralogy and maturity and progress on development of a FeMS instrument for lunar surface use are discussed.

Sulfur Cycle

NASA Technical Reports Server (NTRS)

Hariss, R.; Niki, H.

1985-01-01

Among the general categories of tropospheric sulfur sources, anthropogenic sources have been quantified the most accurately. Research on fluxes of sulfur compounds from volcanic sources is now in progress. Natural sources of reduced sulfur compounds are highly variable in both space and time. Variables, such as soil temperature, hydrology (tidal and water table), and organic flux into the soil, all interact to determine microbial production and subsequent emissions of reduced sulfur compounds from anaerobic soils and sediments. Available information on sources of COS, CS2, DMS, and H2S to the troposphere in the following paragraphs are summarized; these are the major biogenic sulfur species with a clearly identified role in tropospheric chemistry. The oxidation of SO2 to H2SO4 can often have a significant impact on the acidity of precipitation. A schematic representation of some important transformations and sinks for selected sulfur species is illustrated.

Enhancement of the microbial community biomass and diversity during air sparging bioremediation of a soil highly contaminated with kerosene and BTEX.

PubMed

Kabelitz, Nadja; Machackova, Jirina; Imfeld, Gwenaël; Brennerova, Maria; Pieper, Dietmar H; Heipieper, Hermann J; Junca, Howard

2009-03-01

In order to obtain insights in complexity shifts taking place in natural microbial communities under strong selective pressure, soils from a former air force base in the Czech Republic, highly contaminated with jet fuel and at different stages of a bioremediation air sparging treatment, were analyzed. By tracking phospholipid fatty acids and 16S rRNA genes, a detailed monitoring of the changes in quantities and composition of the microbial communities developed at different stages of the bioventing treatment progress was performed. Depending on the length of the air sparging treatment that led to a significant reduction in the contamination level, we observed a clear shift in the soil microbial community being dominated by Pseudomonads under the harsh conditions of high aromatic contamination to a status of low aromatic concentrations, increased biomass content, and a complex composition with diverse bacterial taxonomical branches.

Solute profiles in soils, weathering gradients and exchange equilibrium/disequilibrium

USGS Publications Warehouse

White, A.F.; Schulz, M.S.; Stonestrom, David A.; Vivit, D.V.; Fitzpatrick, J.; Bullen, T.

2008-01-01

The spatial and temporal changes in hydrology and pore water elemental and 87/86Sr compositions were used to determine contemporary weathering rates in a 65 to 226 ky old soil chronosequence formed from granitic sediments deposited on marine terraces along coastal California. Cl-corrected Na, K and Si increased with depth denoting inputs from the weathering of plagioclase and K-feldspar. Solute 87/86Sr exhibited progressive mixing of sea water-dominated precipitation with inputs from less radiogenic plagioclase. Linear approximations to these weathering gradients were used to determine plagioclase weathering rates of between 0.38 and 8.9×10−15 moles m−2 s−1. The lack of corresponding weathering gradients for Ca and Sr indicated short-term equilibrium with the clay ion exchange pool which requires periodic resetting by natural perturbations to maintain continuity, in spite of soil composition changes reflecting the effects of long-term weathering.

Wind farm and solar park effects on plant–soil carbon cycling: uncertain impacts of changes in ground-level microclimate

PubMed Central

Armstrong, Alona; Waldron, Susan; Whitaker, Jeanette; Ostle, Nicholas J

2014-01-01

Global energy demand is increasing as greenhouse gas driven climate change progresses, making renewable energy sources critical to future sustainable power provision. Land-based wind and solar electricity generation technologies are rapidly expanding, yet our understanding of their operational effects on biological carbon cycling in hosting ecosystems is limited. Wind turbines and photovoltaic panels can significantly change local ground-level climate by a magnitude that could affect the fundamental plant–soil processes that govern carbon dynamics. We believe that understanding the possible effects of changes in ground-level microclimates on these phenomena is crucial to reducing uncertainty of the true renewable energy carbon cost and to maximize beneficial effects. In this Opinions article, we examine the potential for the microclimatic effects of these land-based renewable energy sources to alter plant–soil carbon cycling, hypothesize likely effects and identify critical knowledge gaps for future carbon research. PMID:24132939

Prediction of soil properties using imaging spectroscopy: Considering fractional vegetation cover to improve accuracy

NASA Astrophysics Data System (ADS)

Franceschini, M. H. D.; Demattê, J. A. M.; da Silva Terra, F.; Vicente, L. E.; Bartholomeus, H.; de Souza Filho, C. R.

2015-06-01

Spectroscopic techniques have become attractive to assess soil properties because they are fast, require little labor and may reduce the amount of laboratory waste produced when compared to conventional methods. Imaging spectroscopy (IS) can have further advantages compared to laboratory or field proximal spectroscopic approaches such as providing spatially continuous information with a high density. However, the accuracy of IS derived predictions decreases when the spectral mixture of soil with other targets occurs. This paper evaluates the use of spectral data obtained by an airborne hyperspectral sensor (ProSpecTIR-VS - Aisa dual sensor) for prediction of physical and chemical properties of Brazilian highly weathered soils (i.e., Oxisols). A methodology to assess the soil spectral mixture is adapted and a progressive spectral dataset selection procedure, based on bare soil fractional cover, is proposed and tested. Satisfactory performances are obtained specially for the quantification of clay, sand and CEC using airborne sensor data (R2 of 0.77, 0.79 and 0.54; RPD of 2.14, 2.22 and 1.50, respectively), after spectral data selection is performed; although results obtained for laboratory data are more accurate (R2 of 0.92, 0.85 and 0.75; RPD of 3.52, 2.62 and 2.04, for clay, sand and CEC, respectively). Most importantly, predictions based on airborne-derived spectra for which the bare soil fractional cover is not taken into account show considerable lower accuracy, for example for clay, sand and CEC (RPD of 1.52, 1.64 and 1.16, respectively). Therefore, hyperspectral remotely sensed data can be used to predict topsoil properties of highly weathered soils, although spectral mixture of bare soil with vegetation must be considered in order to achieve an improved prediction accuracy.

Seasonal and diurnal patterns of soil water potential in the rhizosphere of blue oaks: evidence for hydraulic lift.

PubMed

Ishikawa, C Millikin; Bledsoe, C S

2000-12-01

In a 3-year study, seasonal and daily soil water fluctuations in a California blue oak woodland were investigated by measuring soil water potential (Ψ s ) at hourly intervals. Soil water potential remained relatively high well into the annual summer drought, with values above -0.5 MPa until June even in a dry year. As drought progressed, Ψ s (at 25, 50, 75, and 100 cm depth) decreased to less than -3 MPa, providing evidence for continued blue oak root activity throughout the summer. We observed diurnal Ψ s fluctuations (gradual increase at night and rapid decrease during daytime) characteristic of hydraulic lift, a process by which plant roots redistribute water from wet to dry soil layers. These diurnal fluctuations were observed at all four soil depths and began to appear when Ψ s reached approximately -0.3 MPa. When Ψ s reached approximately -3 MPa, fluctuations became "offset" from those typical of hydraulic lift. These offset fluctuations (apparent at low water potentials when temperature fluctuations were large) closely followed diurnal fluctuations in soil temperature. We propose that these offset patterns resulted from a combination of hydraulic lift cessation and an over-correction for temperature in the model used to calculate Ψ s from raw sensor data. The appearance and disappearance of hydraulic lift fluctuations seemed to depend on Ψ s . While soil temperatures and dates at which hydraulic lift appeared (and disappeared) were significantly different between wet and dry years, Ψ s values associated with hydraulic lift appearance were not significantly different. Hydraulic lift occurred too late in summer to benefit annual forage grasses. However, water released by blue oak trees at night could slow the rate of soil water depletion and extend blue oaks' growing season.

Reduced dry season transpiration is coupled with shallow soil water use in tropical montane forest trees.

PubMed

Muñoz-Villers, Lyssette E; Holwerda, Friso; Alvarado-Barrientos, M Susana; Geissert, Daniel R; Dawson, Todd E

2018-06-25

Tropical montane cloud forests (TMCF) are ecosystems particularly sensitive to climate change; however, the effects of warmer and drier conditions on TMCF ecohydrology remain poorly understood. To investigate functional responses of TMCF trees to reduced water availability, we conducted a study during the 2014 dry season in the lower altitudinal limit of TMCF in central Veracruz, Mexico. Temporal variations of transpiration, depth of water uptake and tree water sources were examined for three dominant, brevi-deciduous species using micrometeorological, sap flow and soil moisture measurements, in combination with oxygen and hydrogen stable isotope composition of rainfall, tree xylem, soil and stream water. Over the course of the dry season, reductions in crown conductance and transpiration were observed in canopy species (43 and 34%, respectively) and mid-story trees (23 and 8%), as atmospheric demand increased and soil moisture decreased. Canopy species consistently showed more depleted isotope values compared to mid-story trees. However, MixSIAR Bayesian model results showed that the evaporated (enriched) soil water pool was the main source for trees despite reduced soil moisture. Additionally, while increases in tree water uptake from deeper to shallower soil water sources occurred, concomitant decreases in transpiration were observed as the dry season progressed. A larger reduction in deep soil water use was observed for canopy species (from 79 ± 19 to 24 ± 20%) compared to mid-story trees (from 12 ± 17 to 10 ± 12%). The increase in shallower soil water sources may reflect a trade-off between water and nutrient requirements in this forest.

Influence of redox fluctuations and rainfall on pedogenic iron alteration and soil magnetic properties (Invited)

NASA Astrophysics Data System (ADS)

Thompson, A.; Rancourt, D.; Chadwick, O.; Chorover, J. D.

2009-12-01

Soil iron mineral composition emerges from a dynamic interplay between processes causing selective mineral addition/removal (both physically and chemically-driven) and processes affecting in situ mineral transformation. Discerning the influence of these pedogenic processes in a temporally integrated manner is fundamentally relevant to many biogeochemical questions. Among them is to what extent the Fe-mineral system can be used to constrain paleo-interpretations of oceanic sediments and geological deposits. Here we describe results from field and laboratory experiments designed to explore the effects of variable redox conditions on soil iron mineral transformation. Our experimental systems include: (1) a climate gradient of basaltic soils from the island of Maui, HI (MCG) with a documented decrease in Eh. and (2) laboratory incubations where we subjected soil slurries to a series of bacterially-driven reduction-oxidation cycles. Our prior work in these systems examining the iron isotopic and mineral composition will be combined with in-progress analysis of magnetic susceptibility. Current results indicate that across the field gradient (MCG) we find average increases of 0.56‰±0.09‰ δ56Fe for the surface and subsurface soils that correlate very well (R2=0.88) with 57Fe Mössbauer-determined Fe-oxyhydroxide fraction. Such a correlation is difficult to explain on the basis of strict parameter co-variation with rainfall, and suggests isotopic and mineral composition may be coupled through in situ mineral transformation processes in these soils. In our soil slurry incubation experiments we reported previously that repeated redox oscillations generate a cumulative increase in Fe mineral crystallinity. Integration of these results with magnetic susceptibility measurements will provide the context for discussing how dynamic redox processes alter soil magnetic properties most often drawn on for paleoclimate interpretations.

Remediation of PCB contaminated soils in the Canadian Arctic: excavation and surface PRB technology.

PubMed

Kalinovich, Indra; Rutter, Allison; Poland, John S; Cairns, Graham; Rowe, R Kerry

2008-12-15

The site BAF-5 is located on the summit of Resolution Island, Nunavut, just southeast of Baffin Island at 61 degrees 35'N and 60 degrees 40'W. The site was part of a North American military defense system established in the 1950s that became heavily contaminated with PCBs during and subsequent, its operational years. Remediation through excavation of the PCB contaminated soil at Resolution Island began in 1999 and at its completion in 2006 approximately 5 tonnes of pure PCBs in approximately 20,000 m3 of soil were remediated. Remediation strategies were based on both quantity of soil and level of contamination in the soil. Excavation removed 96% of the PCB contaminated soil on site. In 2003, a surface funnel-and-gate permeable reactive barrier was design and constructed to treat the remaining contamination left in rock crevices and inaccessible areas of the site. Excavation had destabilized contaminated soil in the area, enabling contaminant migration through erosion and runoff pathways. The barrier was designed to maximize sedimentation through settling ponds. This bulk removal enabled the treatment of highly contaminated fines and water through a permeable gate. The increased sediment loading during excavation required both modifications to the funnel and a shift to a more permeable, granular system. Granulated activated charcoal was chosen for its ability to both act as a particle retention filter and adsorptive filter. The reduction in mass of PCB and volume of soils trapped by the funnel of the barrier indicate that soils are re-stabilizing. In 2007, nonwoven geotextiles were re-introduced back into the filtration system as fine filtering could be achieved without clogging. Monitoring sites downstream indicate that the barrier system is effective. This paper describes the field progress of PCB remediation at Resolution Island.

Total organic carbon and humus fractions in restored soils from limestone quarries in semiarid climate, SE Spain

NASA Astrophysics Data System (ADS)

Luna Ramos, Lourdes; Miralles Mellado, Isabel; Ángel Domene Ruiz, Miguel; Solé Benet, Albert

2016-04-01

Mining activities generate erosion and loss of plant cover and soil organic matter (SOM), especially in arid and semiarid Mediterranean regions. A precondition for ecosystem restoration in such highly disturbed areas is the development of functional soils with sufficient organic matter. But the SOM quality is also important to long-term C stabilization. The resistance to biodegradation of recalcitrant organic matter fractions has been reported to depend on some intrinsic structural factors of humic acid substances and formation of amorphous organo-mineral recalcitrant complexes. In an experimental soil restoration in limestone quarries in the Sierra de Gádor (Almería), SE Spain, several combinations of organic amendments (sewage sludge and compost from domestic organic waste) and mulches (gravel and woodchip) were added in experimental plots using a factorial design. In each plot, 75 native plants (Anthyllis cytisoides, A. terniflora and Macrochloa tenacissima) were planted and five years after the start of the experiment total organic carbon (TOC), physico-chemical soil properties and organic C fractions (particulate organic matter, H3PO4-fulvic fraction, fulvic acids (FA), humic acids (HA) and humin) were analyzed. We observed significant differences between treatments related to the TOC content and the HA/FA ratio. Compost amendments increased the TOC, HA content and HA/FA ratio, even higher than in natural undisturbed soils, indicating an effective clay humus-complex pointing to progressively increasing organic matter quality. Soils with sewage sludge showed the lowest TOC and HA/FA ratio and accumulated a lower HA proportion indicating poorer organic matter quality and comparatively lower resilience than in natural soils and soils amended with compost.

History and progress of the North American Soil Geochemical Landscapes Project, 2001-2010

USGS Publications Warehouse

Smith, David B.; Cannon, William F.; Woodruff, Laurel G.; Rivera, Francisco Moreira; Rencz, Andrew N.; Garrett, Robert G.

2012-01-01

In 2007, the U.S. Geological Survey, the Geological Survey of Canada, and the Mexican Geological Survey initiated a low-density (1 site per 1600 km2, 13323 sites) geochemical and mineralogical survey of North American soils (North American Soil Geochemical Landscapes Project). Sampling and analytical protocols were developed at a series of workshops in 20032004 and pilot studies were conducted from 20042007. The ideal sampling protocol at each site includes a sample from 05 cm depth, a composite of the soil A horizon, and a sample from the soil C horizon. The 3, HClO4, and HF. Separate methods are used for As, Hg, Se, and total C on this same size fraction. The major mineralogical components are determined by a quantitative X-ray diffraction method. Sampling in the conterminous U.S. was completed in 2010 (c. 4800 sites) with chemical and mineralogical analysis currently underway. In Mexico, approximately 66% of the sampling (871 sites) had been done by the end of 2010 with completion expected in 2012. After completing sampling in the Maritime provinces and portions of other provinces (472 sites, 7.6% of the total), Canada withdrew from the project in 2010. Preliminary results for a swath from the central U.S. to Florida clearly show the effects of soil parent material and climate on the chemical and mineralogical composition of soils. A sample archive will be established and made available for future investigations.

Changes in soil respiration components and their specific respiration along three successional forests in the subtropics

DOE PAGES

Han, Tianfeng; Liu, Juxiu; Wang, Gangsheng; ...

2016-01-16

1.Understanding how soil respiration components change with forest succession is critical for modelling and predicting soil carbon (C) processes and its sequestration below-ground. The specific respiration (a ratio of respiration to biomass) is increasingly being used as an indicator of forest succession conceptually based on Odum's theory of ecosystem development. However, the hypothesis that specific soil respiration declines with forest succession remains largely untested. 2.We used a trenching method to partition soil respiration into heterotrophic respiration and autotrophic respiration (R H and R A) and then evaluated the specific R H and specific R A in three successional forests inmore » subtropical China. 3.Our results showed a clear seasonality in the influence of forest succession on R H, with no significant differences among the three forests in the dry season but a higher value in the old-growth forest than the other two forests in the wet season. R A in the old-growth forest tended to be the highest among the three forests. Both the specific R H and specific R A decreased with the progressive maturity of three forests. 4.Lastly, our results highlight the importance of forest succession in determining the variation of R H in different seasons. With forest succession, soil microbes and plant roots become more efficient to conserve C resources, which would result in a greater proportion of C retained in soils.« less

Carbon isotopic composition of forest soil respiration in the decade following bark beetle and stem girdling disturbances in the Rocky Mountains: Carbon isotopes of soil respiration following disturbance

DOE PAGES

Maurer, Gregory E.; Chan, Allison M.; Trahan, Nicole A.; ...

2016-04-26

Bark beetle outbreaks are widespread in western North American forests, reducing primary productivity and transpiration, leading to forest mortality across large areas and altering ecosystem carbon cycling. Here the carbon isotope composition (δ13C) of soil respiration (δJ) was monitored in the decade after disturbance for forests affected naturally by mountain pine beetle infestation and artificially by stem girdling. The seasonal mean δJ changed along both chronosequences. We found (a) enrichment of δJ relative to controls (<1 ‰) in near-surface soils in the first 2 years after disturbance; (b) depletion (1‰ or no change) during years 3–7; and (c) a secondmore » period of enrichment (1–2‰) in years 8–10. Results were consistent with isotopic patterns associated with the gradual death and decomposition of rhizosphere organisms, fine roots, conifer needles and woody roots and debris over the course of a decade after mortality. Finally, δJ was progressively more 13C-depleted deeper in the soil than near the surface, while the bulk soil followed the well-established pattern of 13C-enrichment at depth. Overall, differences in δJ between mortality classes (<1‰) and soil depths (<3‰) were smaller than variability within a class or depth over a season (up to 6‰).« less

Variation of Desert Soil Hydraulic Properties with Pedogenic Maturity

NASA Astrophysics Data System (ADS)

Nimmo, J. R.; Perkins, K. S.; Mirus, B. B.; Schmidt, K. M.; Miller, D. M.; Stock, J. D.; Singha, K.

2006-12-01

Older alluvial desert soils exhibit greater pedogenic maturity, having more distinct desert pavements, vesicular (Av) horizons, and more pronounced stratification from processes such as illuviation and salt accumulation. These and related effects strongly influence the soil hydraulic properties. Older soils have been observed to have lower saturated hydraulic conductivity, and possibly greater capacity to retain water, but the quantitative effect of specific pedogenic features on the soil water retention or unsaturated hydraulic conductivity (K) curves is poorly known. With field infiltration/redistribution experiments on three different-aged soils developed within alluvial wash deposits in the Mojave National Preserve, we evaluated effective hydraulic properties over a scale of several m horizontally and to 1.5 m depth. We then correlated these properties with pedogenic features. The selected soils are (1) recently deposited sediments, (2) a soil of early Holocene age, and (3) a highly developed soil of late Pleistocene age. In each experiment we ponded water in a 1-m-diameter infiltration ring for 2.3 hr. For several weeks we monitored subsurface water content and matric pressure using surface electrical resistance imaging, dielectric-constant probes, heat-dissipation probes, and tensiometers. Analysis of these data using an inverse modeling technique gives the water retention and K properties needed for predictive modeling. Some properties show a consistent trend with soil age. Progressively more developed surface and near-surface features such as desert pavement and Av horizons are the likely cause of an observed consistent decline of infiltration capacity with soil age. Other properties, such as vertical flow retardation by layer contrasts, appear to have a more complicated soil-age dependence. The wash deposits display distinct depositional layering that has a retarding effect on vertical flow, an effect that may be less pronounced in the older Holocene soil, where the original depositional structure has a relatively modest influence. Anisotropy at the scale of centimeters is of major importance in the Pleistocene soil, with developed horizons that tend to hold water within about 0.5 m of the surface for a longer duration than in the two younger soils. Correlation of these and related pedogenic features with soil hydraulic properties is a first step toward the estimation of effective hydraulic properties of widely varying Mojave Desert soils, as needed for large-scale evaluation of soil moisture dynamics in relation to ecological habitat quality.

Environmental Controls on Multi-Scale Soil Nutrient Variability in the Tropics: the Importance of Land-Cover Change

NASA Astrophysics Data System (ADS)

Holmes, K. W.; Kyriakidis, P. C.; Chadwick, O. A.; Matricardi, E.; Soares, J. V.; Roberts, D. A.

2003-12-01

The natural controls on soil variability and the spatial scales at which correlation exists among soil and environmental variables are critical information for evaluating the effects of deforestation. We detect different spatial scales of variability in soil nutrient levels over a large region (hundreds of thousands of km2) in the Amazon, analyze correlations among soil properties at these different scales, and evaluate scale-specific relationships among soil properties and the factors potentially driving soil development. Statistical relationships among physical drivers of soil formation, namely geology, precipitation, terrain attributes, classified soil types, and land cover derived from remote sensing, were included to determine which factors are related to soil biogeochemistry at each spatial scale. Surface and subsurface soil profile data from a 3000 sample database collected in Rond“nia, Brazil, were used to investigate patterns in pH, phosphorus, nitrogen, organic carbon, effective cation exchange capacity, calcium, magnesium, potassium, aluminum, sand, and clay in this environment grading from closed canopy tropical forest to savanna. We focus on pH in this presentation for simplicity, because pH is the single most important soil characteristic for determining the chemical environment of higher plants and soil microbial activity. We determined four spatial scales which characterize integrated patterns of soil chemistry: less than 3 km; 3 to 10 km; 10 to 68 km; and from 68 to 550 km (extent of study area). Although the finest observable scale was fixed by the field sampling density, the coarser scales were determined from relationships in the data through coregionalization modeling, rather than being imposed by the researcher. Processes which affect soils over short distances, such as land cover and terrain attributes, were good predictors of fine scale spatial components of nutrients; processes which affect soils over very large distances, such as precipitation and geology, were better predictors at coarse spatial scales. However, this result may be affected by the resolution of the available predictor maps. Land-cover change exerted a strong influence on soil chemistry at fine spatial scales, and had progressively less of an effect at coarser scales. It is important to note that land cover, and interactions among land cover and the other predictors, continued to be a significant predictor of soil chemistry at every spatial scale up to hundreds of thousands of kilometers.

Microbial community composition explains soil respiration responses to changing carbon inputs along an Andes-to-Amazon elevation gradient

PubMed Central

Whitaker, Jeanette; Ostle, Nicholas; Nottingham, Andrew T; Ccahuana, Adan; Salinas, Norma; Bardgett, Richard D; Meir, Patrick; McNamara, Niall P; Austin, Amy

2014-01-01

1. The Andes are predicted to warm by 3–5 °C this century with the potential to alter the processes regulating carbon (C) cycling in these tropical forest soils. This rapid warming is expected to stimulate soil microbial respiration and change plant species distributions, thereby affecting the quantity and quality of C inputs to the soil and influencing the quantity of soil-derived CO2 released to the atmosphere. 2. We studied tropical lowland, premontane and montane forest soils taken from along a 3200-m elevation gradient located in south-east Andean Peru. We determined how soil microbial communities and abiotic soil properties differed with elevation. We then examined how these differences in microbial composition and soil abiotic properties affected soil C-cycling processes, by amending soils with C substrates varying in complexity and measuring soil heterotrophic respiration (RH). 3. Our results show that there were consistent patterns of change in soil biotic and abiotic properties with elevation. Microbial biomass and the abundance of fungi relative to bacteria increased significantly with elevation, and these differences in microbial community composition were strongly correlated with greater soil C content and C:N (nitrogen) ratios. We also found that RH increased with added C substrate quality and quantity and was positively related to microbial biomass and fungal abundance. 4. Statistical modelling revealed that RH responses to changing C inputs were best predicted by soil pH and microbial community composition, with the abundance of fungi relative to bacteria, and abundance of gram-positive relative to gram-negative bacteria explaining much of the model variance. 5. Synthesis. Our results show that the relative abundance of microbial functional groups is an important determinant of RH responses to changing C inputs along an extensive tropical elevation gradient in Andean Peru. Although we do not make an experimental test of the effects of climate change on soil, these results challenge the assumption that different soil microbial communities will be ‘functionally equivalent’ as climate change progresses, and they emphasize the need for better ecological metrics of soil microbial communities to help predict C cycle responses to climate change in tropical biomes. PMID:25520527

Peculiarities of changes in the soil cover of landscapes adjacent to a megalopolis

NASA Astrophysics Data System (ADS)

Lazareva, Margarita; Aparin, Boris; Sukhacheva, Elena

2017-04-01

The progressive growth of cities has a significant impact on the soil cover of territories adjacent to the same. Megalopolises are centers of anthropogenic impact on the soils. Generally, forms and intensity of the urban impact on the soil cover weaken with increasing distance from the city's boundaries. In this respect, ample opportunities for the analysis of urban impact on the adjacent territories are provided by the study of the soil cover in the Leningrad Region (the LR). Saint Petersburg is a major European megalopolis, which is the administrative center of the LR. The time period of Saint Petersburg's impact on the environment does not exceed 300 years, which allows us to identify very clearly the character and areas of its impact on the soil cover. Over the past decades, there have been significant changes in the soils and the soil cover of the LR. In a large territory, there appeared new anthropogenic soils and soil cover organization forms, having no natural analogues, with a dramatic increase in the surface area of degraded soils. To access the current state of soil cover, to identify the role of anthropogenic factors of changes in this state; to carry out land reclamation, remediation and rehabilitation measures; to perform land cadastral valuation etc., we need an information resource containing data on the current state of soils and soil cover in the LR, the key element of which should be a map. We carried out mapping and created a 1:200 000 digital soil map (DSM) for the LR's territories. Diagnostics of soil contours were performed using traditionally drawn-up (paper) maps of soils and soil-formation factors; satellite images (Google, Yandex); data of remote sensing (Spot 5, Landsat 7,8); digital maps of main soil-formation factors (topographical ones, etc.). The digital soil map of the LR has been created in the geographic information system - QGIS. The map clarifies the contours of natural soils and soil combinations, and shows, for the first time, the contours of: - non-soil formations; - soils of the initial soil formation; - soils of agricultural lands within their existing boundaries; - soils and soil combinations that are specific for human settlements and horticultural land plots; - fallow lands; - anthropogenically disturbed soils. During the analysis of the created digital medium-scale soil map, we identified some changes in the soil cover of the territories adjacent to Saint Petersburg. Virtually in all the landscapes, we found a large number of soil cover structures, the components of which, along with natural soils, are anthropogenically disturbed soils, anthropogenic soils and non-soil formations. We revealed that the human impact on the soil cover is manifested within the range that varies from insignificant changes in soil parameters to radical transformations of the soil profile, complete destruction of soil and "creation" of new soil forms and soil cover organization forms. We have developed a typology of anthropogenically changed and anthropogenically created soil cover structures, taking into consideration the types of the economic impact on and the quality of environmental functions performed by the soils.

A historical review of the methods of determination of soil properties for soil quality and land degradation assessment

NASA Astrophysics Data System (ADS)

Pulido, Manuel; Schnabel, Susanne; Francisco Lavado Contador, Joaquín; Gómez-Gutiérrez, Álvaro; Miralles, Isabel; Lozano-Parra, Javier; Antoneli, Valdemir; Brevik, Eric C.; Cerdà, Artemi

2017-04-01

Properly assessing soil quality and land degradation is one of the main concerns of soil scientists in recent decades. Nowadays there are several available assessment systems based mainly on indicators, i.e. on soil-related parameters, that allow one to determine the current state of natural soils at different scales. These systems vary depending on ecosystem type and soil function studied as well as the accuracy of the methods (techniques and tools) historically used in the determination of several soil parameters. In this study, we show a historical review of many methods of determining soil properties used regularly as soil quality and land degradation indicators. We have considered 5 worldwide historical periods: [1] The pioneers: before 1889, [2] USDA impulse: 1889 - 1945, [3] Productivity paradigm: 1946 - 1972, [4] Conservationist paradigm: 1973 - 2001, and [5] Current methodologies: 2002 - present. The limits of each period have been determined according to some key milestones, for humanity in general and soil science in particular, such as the creation of the United States Department of Agriculture (USDA) in 1889, the end of World War II in 1945 or the publication of relevant works such as The limits to growth in 1972. The development of the Soil Management Assessment Framework (SMAF) indexing tool by American soil scientists in 2001 marks a turning point from which new methodologies and paradigms began to be dominant among methods of determination. Finally, the methods historically used to determine more than 100 soil properties have been reviewed by consulting around 1,500 references published between 1305 and 2017. Approximately 10% of the references were key works to contextualize the first two historical periods, i.e. before 1945, and almost half of all references were published in the second half of the twentieth century (1946 - 2001). A logical tendency in gaining progressively accuracy in methods has been observed as well as a major boom in the study of biochemical properties such as enzyme activity in the last period.

Looking for Changes in Soil over Time

NASA Technical Reports Server (NTRS)

2006-01-01

The grinding teeth have worn away on the rock abrasion tool of NASA's Mars Exploration Rover Spirit (after exposing interiors of five time more rock targets than its design goal of three rocks) but the tool still has useful wire bristles for brushing targets. In this image, a figure-eight-like imprint in the Martian soil marks the spot where Spirit has begun examining subsurface deposits layer by layer. The circular indentations resulted from brushing by the rock abrasion tool, one of several instruments on the rover's robotic arm. As an effective brushing tool it is now fulfilling a soil profiling experiment on a target called 'Progress.'

The experiment is a multi-step process of carefully brushing away fine layers of soil and then using the Moessbauer and alpha particle X-ray spectrometers, microscopic imager, and panoramic camera to examine the exposed surfaces during the long Martian winter.

This view is a mosaic of exposures taken by Spirit's microscopic imager during the rover's 830th Martian day (May 4, 2006). The total area shown is about 6 centimeters (2.4 inches) square.

Compositional Stability of the Bacterial Community in a Climate-Sensitive Sub-Arctic Peatland.

PubMed

Weedon, James T; Kowalchuk, George A; Aerts, Rien; Freriks, Stef; Röling, Wilfred F M; van Bodegom, Peter M

2017-01-01

The climate sensitivity of microbe-mediated soil processes such as carbon and nitrogen cycling offers an interesting case for evaluating the corresponding sensitivity of microbial community composition to environmental change. Better understanding of the degree of linkage between functional and compositional stability would contribute to ongoing efforts to build mechanistic models aiming at predicting rates of microbe-mediated processes. We used an amplicon sequencing approach to test if previously observed large effects of experimental soil warming on C and N cycle fluxes (50-100% increases) in a sub-arctic Sphagnum peatland were reflected in changes in the composition of the soil bacterial community. We found that treatments that previously induced changes to fluxes did not associate with changes in the phylogenetic composition of the soil bacterial community. For both DNA- and RNA-based analyses, variation in bacterial communities could be explained by the hierarchy: spatial variation (12-15% of variance explained) > temporal variation (7-11%) > climate treatment (4-9%). We conclude that the bacterial community in this environment is stable under changing conditions, despite the previously observed sensitivity of process rates-evidence that microbe-mediated soil processes can alter without concomitant changes in bacterial communities. We propose that progress in linking soil microbial communities to ecosystem processes can be advanced by further investigating the relative importance of community composition effects versus physico-chemical factors in controlling biogeochemical process rates in different contexts.

Formation of nonextractable soil residues: A stable isotope approach

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

Richnow, H.H.; Eschenback, A.; Mahro, B.

1999-11-01

Stable carbon isotopic measurements were employed to characterize the transformation of a {sup 13}C-labeled polycyclic aromatic hydrocarbon (PAH), anthracene, in a closed soil bioreactor system. The {sup 13}C-label was used to calculate a carbon mass balance including mineralization and the formation of nonextractable soil-bound residues. Similar results were obtained from {sup 13}C-labeled carbon and {sup 14}C-labeled carbon mass balance calculations for separate batch experiments with labeled anthracene. In concentration ranges typical for real PAH-contaminated sites, the sensitivity of the {sup 13}C tracer method meets the requirements of classical radiotracer experiments. Therefore, the authors balancing method based on stable isotope-labeled chemicalsmore » may supplement or substitute radiotracer experiments under many circumstances. One major advantage of using stable isotope-labeled tracers is the possible application in transformation studies where the use of radioactive substances is of environmental concern. The transformation of {sup 13}C-labeled PAH into nonextractable residues clearly depends on the metabolic activity of the soil microflora and occurs during an early phase of biodegradation. Successive contamination of the soil by anthracene leads to a progressive adaptation of the microflora to a complete mineralization of anthracene in the soil. The extent of residue formation is controlled by the capability of the microflora to degrade the contaminant. Results of long-term experiments indicate that nonextractable residues are relatively stable over time.« less

Enzymology under global change: organic nitrogen turnover in alpine and sub-Arctic soils.

PubMed

Weedon, James T; Aerts, Rien; Kowalchuk, George A; van Bodegom, Peter M

2011-01-01

Understanding global change impacts on the globally important carbon storage in alpine, Arctic and sub-Arctic soils requires knowledge of the mechanisms underlying the balance between plant primary productivity and decomposition. Given that nitrogen availability limits both processes, understanding the response of the soil nitrogen cycle to shifts in temperature and other global change factors is crucial for predicting the fate of cold biome carbon stores. Measurements of soil enzyme activities at different positions of the nitrogen cycling network are an important tool for this purpose. We review a selection of studies that provide data on potential enzyme activities across natural, seasonal and experimental gradients in cold biomes. Responses of enzyme activities to increased nitrogen availability and temperature are diverse and seasonal dynamics are often larger than differences due to experimental treatments, suggesting that enzyme expression is regulated by a combination of interacting factors reflecting both nutrient supply and demand. The extrapolation from potential enzyme activities to prediction of elemental nitrogen fluxes under field conditions remains challenging. Progress in molecular '-omics' approaches may eventually facilitate deeper understanding of the links between soil microbial community structure and biogeochemical fluxes. In the meantime, accounting for effects of the soil spatial structure and in situ variations in pH and temperature, better mapping of the network of enzymatic processes and the identification of rate-limiting steps under different conditions should advance our ability to predict nitrogen fluxes.

Segregation and Alteration of Phenolic and Aliphatic Components of Root and Leaf Litter by Detritivores and Microbes

NASA Astrophysics Data System (ADS)

Filley, T. R.; Altmann, J.; Szlavecz, K. A.; Kalbitz, K.; Gamblin, D.; Nierop, K.

2012-12-01

The physical and microbial transformation of plant detritus in the litter layer and soil is accompanied by chemical separation of progressively soluble fractions and their movement into the rhizosphere driving subsequent soil processes. We investigated the combined action of specific detritivores, microbial decay, and leaching on the chemical separation of plant aromatic and aliphatic components from root, wood, and leaf tissue using 13C-TMAH thermochemolysis. This method enabled the simultaneous analysis of hydrolyzable tannin and lignin fragments, substituted fatty acids, and condensed tannin composition and revealed process-specific chemical transformations to plant secondary compounds. Long-term incubation and field sampling demonstrated how plant residues are progressively leached of the water soluble, oxidized fragments generated through decay. The residues appeared only slightly altered, in the case of brown rot wood, or enriched in aliphatic fragments, in the case of leaf and root tissue. Water extractable fractions were always selectively dominated by polyphenolics, either as demethylated lignin or tannins, and nearly devoid of aliphatic materials, despite high concentrations in the starting materials. Additionally, for plant materials with high tannin contents, such as pine needles, consumption and passage through some arthropod guts revealed what appeared to be microbially-mediated methylation of phenols, and a loss of tannins in leachates. These findings are indications for an in-situ phenol detoxification mechanism. This research provides important information regarding the links between biochemical decay and the chemical nature of organic matter removed and remaining in the soil profile.

Quantifying the main sediment sources in agricultural landscapes of Southern Brazil cultivated with conventional and conservation practices

NASA Astrophysics Data System (ADS)

Evrard, Olivier; Le Gall, Marion; Tiecher, Tales; Gomes Minella, Jean Paolo; Laceby, J. Patrick; Ayrault, Sophie

2017-04-01

Agricultural expansion that occurred in the 1960s in Southern Brazil significantly increased soil erosion and sediment supply to the river networks. To limit the deleterious impacts of soil erosion, conservation practices were progressively implemented in the 1990s, including the direct sowing of crops on a soil densely covered with plant residues, contour farming, the installation of ponds to trap sediment in the landscape and the use of crop rotations. However, there remains a lack of observational data to investigate the impact of these conservation practices on soil erosion and sediment supply. This data is crucial to protect soil resources and maintain the sustainability of food production systems in this region of the world characterized by a rapidly increasing population. Accordingly, sediment sources were investigated in the Guaporé catchment (2,032 km2) representative of the cultivated environments found in this part of the world. In the upper catchment, the landscape is characterized by gentle slopes and deep soils (Ferralsols, Nitisols) corresponding to the edge of the basaltic plateau. Soybean, corn and wheat under direct sowing are the main crops in this area. In contrast, steep and shallow soils (Luvisols, Acrisols, Leptosols) highly connected to the rivers are found in the lower catchment, where tobacco and corn fields are cultivated with conventional ploughing. These soil types were characterized by elemental geochemistry and 87Sr/86Sr ratios. Sediment sources were then modelled using the optimal suite of properties (87Sr/86Sr ratios, K, Ti, Co, As, Ba, and Pb). The results demonstrate that sediment collected at the catchment outlet during two hydrological years (2012-2014) mainly originated from downstream soils (Luvisols, Acrisols, Leptosols; 92±3%), with this proportion remaining stable throughout the monitoring period. This research indicates that conservation practices implemented in the upper catchment are effective and that similar methods should be applied to downstream soils in order to conserve soil resources and limit the degradation of freshwater environments.

Soil magnetic susceptibility mapping as a pollution and provenance tool: an example from southern New Zealand

NASA Astrophysics Data System (ADS)

Martin, A. P.; Ohneiser, C.; Turnbull, R. E.; Strong, D. T.; Demler, S.

2018-02-01

The presence or absence, degree and variation of heavy metal contamination in New Zealand soils is a matter of ongoing debate as it affects soil quality, agriculture and human health. In many instances, however, the soil heavy metal concentration data do not exist to answer these questions and the debate is ongoing. To address this, magnetic susceptibility (a common proxy for heavy metal contamination) values were measured in topsoil (0-30 cm) and subsoil (50-70 cm) at grid sites spaced at 8 km intervals across ca. 20 000 km2 of southern New Zealand. Samples were measured for both mass- and volume-specific magnetic susceptibility, with results being strongly, positively correlated. Three different methods of determining anomalies were applied to the data including the topsoil-subsoil difference method, Tukey boxplot method and geoaccumulation index method, with each method filtering out progressively more anomalies. Additional soil magnetic (hysteresis, isothermal remanence and thermomagnetic) measurements were made on a select subset of samples from anomalous sites. Magnetite is the dominant remanence carrying mineral, and magnetic susceptibility is governed by that minerals concentration in soils, rather than mineral type. All except two anomalous sites have a dominant geogenic source (cf. anthropogenic). By proxy, heavy metal contamination in southern New Zealand soils is minimal, making them relatively pristine. The provenance of the magnetic minerals in the anomalous sites can be traced back to likely sources in outcrops of igneous rocks within the same catchment, terrane or rock type: a distance of <100 km but frequently <1 km. Soil provenance is a key step when mapping element or isotopic distribution, vectoring to mineralization or studying soil for agricultural suitability, water quality or environmental regulation. Measuring soil magnetic susceptibility is a useful, quick and inexpensive tool that usefully supplements soil geochemical data.

Effect on a long-term afforestation of pine in a beech domain in NE-Spain as reflected in soil C and N isotopic signature

NASA Astrophysics Data System (ADS)

Girona García, Antonio; Badía-Villas, David; González-Pérez, José Antonio; Tomás Jiménez-Morillo, Nicasio; Martí-Dalmau, Clara

2015-04-01

The replacement of native beech forests (Fagus sylvatica) by Scots pine (Pinus sylvestris) afforestation may exert changes in soil properties, particularly in soil organic matter (SOM) (Carceller and Vallejo, 1996). Stable isotopic signatures of light elements (d13C, d15N) in soils and plants are valuable proxies for the identification of biogeochemical processes and their rates in the pedosphere (Andreeva et al., 2013 and refs therein). In this work the C and N stable isotopic analysis is used as a proxy to detect changes in SOM surrogated to the effect of centennial replacement of beech by the Scots pinewood. Two acid soil profiles, developed on quartzites under a humid climate at an altitude of 1400-1500 masl, have been sampled in Moncayo (Iberian range, NE-Spain). For each soil profile three O-layers (litter: OL, fragmented litter OF and humified litter OH) and mineral soil horizons (Ah, E, Bhs and C) were sampled. Content and bulk isotopic signature of light elements (C and N) were analysed in a Flash 2000 elemental micro-analyser coupled via a ConFlo IV interface to a Delta V Advantage isotope ratio mass spectrometer (IRMS) (Thermo Scientific, Bremen, Germany). Isotopic ratios are reported as parts per thousand deviations from appropriate standards. The standard deviations of d13C and d15N were typically less than ± 0.05 per thousand, ± 0.2 per thousand, respectively. After 100 years since the pine afforestation, no differences on C content were observed in the O-layers, ranging from 30-47% in pine soils and 37-47 % in beech soils. Similarly, no differences on N content were observed in the O-layers, ranging from 1.24-1.86 % in pine soils and 1.70-1.71 % in beech soils. C and N contents decrease progressively in depth with the exception of E-horizons where the lowest C and N content values were found. C/N ratio is higher in pine soil (20.7-38.1) than in beech O soil horizons (21.8-27.5), showing similar behavior with soil depth. Pine biomass was slightly enriched in 13C as compared to that from beech (OL enrichment factor= 1.24 ± 0.13 per thousand). Along the soil profile the C isotopic signature (d13C) reflects the main vegetation signature being higher in pine than beech in the organic soil horizons (OL, OF and OH) down to the first mineral Ah horizon. At deeper horizons d13C value tends to equal that of the original beech soil indicating a limited influence of the afforested specie with depth even 100 years after afforestation. A consistent enrichment in d15N with depth was observed in the two profiles. This N enrichments have been related with progressive N losses being particularly pronounced in forest soils (Szpak, 2014 and refs therein). This phenomenon can be also related to migrations of N forms in a more evolved organic matter. In this view N losses in organic layers under beech seem to be less pronounced that under the alien pine. REFERENCES: Andreeva BD, Zech M, Glaser B, Erbajeva MA, Chimitdorgieva, Ermakova OD, Zech, W. (2013). Stable isotope (δ13C, δ15N, δ18O) record of soils in Buryatia, southern Siberia: Implications for biogeochemical and paleoclimatic interpretations. Quaternary International 290-291 (2013) 82-94 pp. Carceller F, Vallejo VR (1996). Influencia de la vegetación en los procesos de podsolización en los suelos de la Sierra del Moncayo (Zaragoza). Geogaceta 1127-1130. Szpak P (2014). Complexities of nitrogen isotope biogeochemistry in plant-soil systems: implications for the study of ancient agricultural and animal management practices. Front. Plant Sci. 5: 288 1-19 pp. Acknowledgements: This study is part of the results of the FUEGOSOL (CGL2013-43440-R) and GEOFIRE Projects (CGL2012-38655-C04-01) funded by the Spanish Ministry for Economy and Competitiveness. N.T Jiménez-Morillo is funded by a FPI research grant (BES-2013-062573).

Topographic Controls on Spatial Patterns of Soil Texture and Moisture in a Semi-arid Montane Catchment with Aspect-Dependent Vegetation

NASA Astrophysics Data System (ADS)

Lehman, B. M.; Niemann, J. D.

2008-12-01

Soil moisture exerts significant control over the partitioning of latent and sensible energy fluxes, the magnitude of both vertical and lateral water fluxes, the physiological and water-use characteristics of vegetation, and nutrient cycling. Considerable progress has been made in determining how soil characteristics, topography, and vegetation influence spatial patterns of soil moisture in humid environments at the catchment, hillslope, and plant scales. However, understanding of the controls on soil moisture patterns beyond the plant scale in semi-arid environments remains more limited. This study examines the relationships between the spatial patterns of near surface soil moisture (upper 5 cm), terrain indices, and soil properties in a small, semi-arid, montane catchment. The 8 ha catchment, located in the Cache La Poudre River Canyon in north-central Colorado, has a total relief of 115 m and an average elevation of 2193 m. It is characterized by steep slopes and shallow, gravelly/sandy soils with scattered granite outcroppings. Depth to bedrock ranges from 0 m to greater than 1 m. Vegetation in the catchment is highly correlated with topographic aspect. In particular, north-facing hillslopes are predominately vegetated by ponderosa pines, while south-facing slopes are mostly vegetated by several shrub species. Soil samples were collected at a 30 m resolution to characterize soil texture and bulk density, and several datasets consisting of more than 300 point measurements of soil moisture were collected using time domain reflectometry (TDR) between Fall 2007 and Summer 2008 at a 15 m resolution. Results from soil textural analysis performed with sieving and the ASTM standard hydrometer method show that soil texture is finer on the north-facing hillslope than on the south-facing hillslope. Cos(aspect) is the best univariate predictor of silts, while slope is the best predictor of coarser fractions up to fine gravel. Bulk density increases with depth but shows no significant relationship with topographic indices. When the catchment average soil moisture is low, the variance of soil moisture increases with the average. When the average is high, the variance remains relatively constant. Little of the variation in soil moisture is explained by topographic indices when the catchment is either very wet or dry; however, when the average soil moisture takes on intermediate values, cos(aspect) is consistently the best predictor among the terrain indices considered.

Physiological variation among native and exotic winter annuals associated with microphytic soil crusts in the Mojave Desert

USGS Publications Warehouse

DeFalco, Lesley; Detling, James K.; Tracy, C. Richard; Warren, Steven D.

2001-01-01

Microbiotic crusts are important components of many aridland soils. Research on crusts typically focuses on the increase in soil fertility due to N-fixing micro-organisms, the stabilization of soils against water and wind erosion and the impact of disturbance on N-cycling. The effect of microbiotic crusts on the associated plant community has received little attention. We quantified the influence of crusts on the production, species diversity, nutrient content and water relations of winter annual plant species associated with microbiotic soil crusts in the northeast Mojave Desert. Shoot biomass of winter annuals was 37% greater and plant density was 77% greater on crusts than were biomass and density on soils lacking crust cover (=bare soils). This greater production of annuals on crusts was likely due to enhanced soil conditions including an almost two-fold increase in soil organic matter and inorganic N compared to bare soils. Crusted soils also had 53% greater volumetric water content than bare soils during November and December, the time when winter annuals become established. As plant development progressed into spring, however, soil water availability decreased: More negative plant xylem water potentials were associated with greater plant biomass on crusted soils. Plants associated with microbiotic soil crusts had lower concentrations of N in shoots (mg N g−1 dry mass). However, total shoot N (mg N m−2) was the same in plants growing on the different soil types when biomass production peaked in April. Shoots had similar patterns in their concentration and content of P. Species diversity of annuals was not statistically different between the two soil types. Yet, while native annuals comprised the greatest proportion of shoot biomass on bare soils, exotic forbs and grasses produced more biomass on crusts. Total shoot nutrient content (biomass×concentration) of the two exotic annual species examined was dramatically greater on crusts than bare soils; only one native species had greater shoot content of N and P when growing on crusts than bare soils. Microbiotic crusts appear to increase site fertility in the northeast Mojave Desert, but nutrients and water distributed within a greater biomass of annual plants growing on microbiotic crusts likely resulted in lower concentrations of nutrients in plant tissue and lower xylem pressure potentials than plants growing on bare soils. Exotic annuals growing on crusts appear to respond to the higher N availability by growing faster, potentially outcompeting native annual species.

CHELATING EXTRACTION OF LEAD AND COPPER FROM AN AUTHENTIC CONTAMINATED SOIL USING N-(2-ACETAMIDO)IMINODIACETIC ACID AND S CARBOXYMETHYL-L-CYSTEINE. (R825549C052)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

BACILLUS THURINGIENSIS (BT) TOXIN RELEASED FROM ROOT EXUDATES AND BIOMASS OF BT CORN HAS NO APPARENT EFFECT ON EARTHWORMS, NEMATODES, PROTOZOA, BACTERIA, AND FUNGI IN SOIL. (R826107)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Hardwood Fertilization: Research Progress in the Midsouth

Treesearch

B. G. Blackmon

1974-01-01

To meet the increasing demand for wood and wood products, the Southern Hardwoods Laboratory is investigating silvicultural techniques such as fertilization. Sweetgum, water oak, and willow oak have responded to N and NPK on clay soils of the Mississippi River floodplain. Yellow-poplar growth has been improved by NPK fertilizers on eroded sites in the Silty Uplands, and...

Soil quality and productivity responses to watershed restoration in the Ouachita mountains of Arkansas, USA

Treesearch

John A. Stanturf; Daniel A. Marion; Martin Spetich; Kenneth Luckow; James M. Guldin; Hal O. Liechty; Calvin E. Meier

2000-01-01

The Ouachita Mountains Ecosystem Management Research Project (OEMP) is a large interdisciplinary research project designed to provide the scientific foundation for landscape management at the scale of watersheds. The OEMP has progressed through three phases: developing natural regeneration alternatives to clearcutting and planting; testing of these alternatives at the...

The properties and evolution of artificial soil-like bodies in the urban environment

NASA Astrophysics Data System (ADS)

Ivannikov, Fedor; Prokofieva, Tatiana

2010-05-01

Technogenic sediments as well as urban brownfields make to 90 % from the area of territory of Moscow. Today, in Moscow soil remediation and reclamation occurs by designing and constructing of lawns. Both naked sediments and mature city soils - urbanozems (according prof. M.Stroganova, Urbic Thechnosol - according WRB), are exposing by this reclamation. The reclaiming soil-like bodies named tehnozems (Technosols?). After their creation, tehnozems begin to operate under natural soil processes. This, in our opinion, can be considered the zero-moment for city soil formation The purpose of our research was to reveal the basic trend in technozems transformations, and also to understand the effectiveness of reclamation through construction on various tehnozem bases. In our research we examine sites within the city boundaries on various elements of a relief with various ages and different histories of nature management. The most typical objects of research - different varieties of city soils and soil-like bodies - have been allocated on these sites. With these objects we perform a set of physical, chemical and biological analyses. The following characteristics were identified: pH(H2O), organic carbon, soluble potassium, available phosphorus, total content of heavy metals (Zn, Cu, Cd, Pb), Red-Ox potential, penetration resistance, bulk density, cellulosolytic activity, species composition of soil animals and microbiological inoculation on anitrogenous medium Then, having learned the properties of city soils and soil-like bodies, we have tried to construct a trend of anthropogenous transformation of soil-like bodies. I. Natural soils collapse under action on settlements and covered by a technogenic ground. Then it is imposed a peat compost mix on them, for reclamation this territories. II. However, recultivation is unable to occur, and weed vegetation begins growing along with the formation of underdeveloped soils (Regosols and Arenosols). Furthermore, in a soil-like body, as well as in underdeveloped soil, soil processes are progressed, for example: humification, calcalization, zooturbation, etc. Technozems are also becoming Regopsols, but humic horizon is forming in both cases in different time (from 5-6 to as many as 30 years) III. Carbonate dust, trace materials, and other products of urban activity are added to soil surface. Then all this products are included in process of soilformation. This urban depositions change soil properties. Accumulation of carbonates, heavy metals, and artifacts is taking place. As a result the special urban soil - urbanozem is forming. It grows till the certain moment while it again not reclamation with formation the technozem on urbanozem basis. .

Physiological variation among native and exotic winter annual plants associated with microbiotic crusts in the Mojave Desert

USGS Publications Warehouse

DeFalco, L.A.; Detling, J.K.; Tracy, C.R.; Warren, S.D.

2001-01-01

Microbiotic crusts are important components of many aridland soils. Research on crusts typically focuses on the increase in soil fertility due to N-fixing micro-organisms, the stabilization of soils against water and wind erosion and the impact of disturbance on N-cycling. The effect of microbiotic crusts on the associated plant community has received little attention. We quantified the influence of crusts on the production, species diversity, nutrient content and water relations of winter annual plant species associated with microbiotic soil crusts in the northeast Mojave Desert. Shoot biomass of winter annuals was 37% greater and plant density was 77% greater on crusts than were biomass and density on soils lacking crust cover (=bare soils). This greater production of annuals on crusts was likely due to enhanced soil conditions including an almost two-fold increase in soil organic matter and inorganic N compared to bare soils. Crusted soils also had 53% greater volumetric water content than bare soils during November and December, the time when winter annuals become established. As plant development progressed into spring, however, soil water availability decreased: More negative plant xylem water potentials were associated with greater plant biomass on crusted soils. Plants associated with microbiotic soil crusts had lower concentrations of N in shoots (mg N g-1 dry mass). However, total shoot N (mg N m-2) was the same in plants growing on the different soil types when biomass production peaked in April. Shoots had similar patterns in their concentration and content of P. Species diversity of annuals was not statistically different between the two soil types. Yet, while native annuals comprised the greatest proportion of shoot biomass on bare soils, exotic forbs and grasses produced more biomass on crusts. Total shoot nutrient content (biomass x concentration) of the two exotic annual species examined was dramatically greater on crusts than bare soils; only one native species had greater shoot content of N and P when growing on crusts than bare soils. Microbiotic crusts appear to increase site fertility in the northeast Mojave Desert, but nutrients and water distributed within a greater biomass of annual plants growing on microbiotic crusts likely resulted in lower concentrations of nutrients in plant tissue and lower xylem pressure potentials than plants growing on bare soils. Exotic annuals growing on crusts appear to respond to the higher N availability by growing faster, potentially outcompeting native annual species.

Parametrizing Evaporative Resistance for Heterogeneous Sparse Canopies through Novel Wind Tunnel Experimentation

NASA Astrophysics Data System (ADS)

Sloan, B.; Ebtehaj, A. M.; Guala, M.

2017-12-01

The understanding of heat and water vapor transfer from the land surface to the atmosphere by evapotranspiration (ET) is crucial for predicting the hydrologic water balance and climate forecasts used in water resources decision-making. However, the complex distribution of vegetation, soil and atmospheric conditions makes large-scale prognosis of evaporative fluxes difficult. Current ET models, such as Penman-Monteith and flux-gradient methods, are challenging to apply at the microscale due to ambiguity in determining resistance factors to momentum, heat and vapor transport for realistic landscapes. Recent research has made progress in modifying Monin-Obukhov similarity theory for dense plant canopies as well as providing clearer description of diffusive controls on evaporation at a smooth soil surface, which both aid in calculating more accurate resistance parameters. However, in nature, surfaces typically tend to be aerodynamically rough and vegetation is a mixture of sparse and dense canopies in non-uniform configurations. The goal of our work is to parameterize the resistances to evaporation based on spatial distributions of sparse plant canopies using novel wind tunnel experimentation at the St. Anthony Falls Laboratory (SAFL). The state-of-the-art SAFL wind tunnel was updated with a retractable soil box test section (shown in Figure 1), complete with a high-resolution scale and soil moisture/temperature sensors for recording evaporative fluxes and drying fronts. The existing capabilities of the tunnel were used to create incoming non-neutral stability conditions and measure 2-D velocity fields as well as momentum and heat flux profiles through PIV and hotwire anemometry, respectively. Model trees (h = 5 cm) were placed in structured and random configurations based on a probabilistic spacing that was derived from aerial imagery. The novel wind tunnel dataset provides the surface energy budget, turbulence statistics and spatial soil moisture data under varying atmospheric stability for each sparse canopy configuration. We will share initial data results and progress toward the development of new parametrizations that can account for the evolution of a canopy roughness sublayer on the momentum, heat and vapor resistance terms as a function of a stochastic representation of canopy spacing.

Process based modelling of soil organic carbon redistribution on landscape scale

NASA Astrophysics Data System (ADS)

Schindewolf, Marcus; Seher, Wiebke; Amorim, Amorim S. S.; Maeso, Daniel L.; Jürgen, Schmidt

2014-05-01

Recent studies have pointed out the great importance of erosion processes in global carbon cycling. Continuous erosion leads to a massive loss of top soils including the loss of organic carbon accumulated over long time in the soil humus fraction. Lal (2003) estimates that 20% of the organic carbon eroded with top soils is emitted into atmosphere, due to aggregate breakdown and carbon mineralization during transport by surface runoff. Furthermore soil erosion causes a progressive decrease of natural soil fertility, since cation exchange capacity is associated with organic colloids. As a consequence the ability of soils to accumulate organic carbon is reduced proportionately to the drop in soil productivity. The colluvial organic carbon might be protected from further degradation depending on the depth of the colluvial cover and local decomposing conditions. Some colluvial sites can act as long-term sinks for organic carbon. The erosional transport of organic carbon may have an effect on the global carbon budget, however, it is uncertain, whether erosion is a sink or a source for carbon in the atmosphere. Another part of eroded soils and organic carbon will enter surface water bodies and might be transported over long distances. These sediments might be deposited in the riparian zones of river networks. Erosional losses of organic carbon will not pass over into atmosphere for the most part. But soil erosion limits substantially the potential of soils to sequester atmospheric CO2 by generating humus. The present study refers to lateral carbon flux modelling on landscape scale using the process based EROSION 3D soil loss simulation model, using existing parameter values. The selective nature of soil erosion results in a preferentially transport of fine particles while less carbonic larger particles remain on site. Consequently organic carbon is enriched in the eroded sediment compared to the origin soil. For this reason it is essential that EROSION 3D provides the grain size distribution (clay, silt and sand) of the transported sediment. A test slope is modeled covering certain land use and soil management scenarios referring to different rainfall events. Results allow first insights on carbon loss and depletion on sediment delivery areas as well as carbon gains and enrichments on deposition areas on landscape scale. Lal, R. (2003). Soil erosion and the global carbon budget. Environment International vol. 29: 437-450.

Developing SoilML as a global standard for the collation and transfer of soil data and information.

NASA Astrophysics Data System (ADS)

Montanarella, Luca; Wilson, Peter; Cox, Simon; McBratney, Alex; Ahamed, Sonya; McMillan, Bob; Jacquier, David; Fortner, Jim

2010-05-01

There is an increasing need to collect, collate and share soil data and information within countries, across regions and globally. Timely access to consistent and authoritative data and information is critical to issues related to food production, climate change, water management, energy production and biodiversityl. Soil data and information is managed by numerous agencies and organisations using a plethora of processes, scales and standards. A number of national and international activities and projects are currently dealing with the issues associated with collation of disparate data sets. Standards are being developed for data storage, transfer and collation like, for example, in the GobalSoilMap.net project, e-SOTER and the EU Inspire GS-SOIL. Individually these will not provide a single internationally recognised and adopted standard for soil data and information exchange. A recent GlobalSoilMap.net meeting held in Wageningen, The Netherlands, discussed the needs of a harmonized information model for collation of a global 90 metre grid of key soil attributes (organic carbon, soil texture, pH, depth to bedrock/impeding layer, and predictions of bulk density and available water capacity) at six specified depth increments. The meeting considered a number of existing data base implementations (such as ASRIS, NASIS, WISE, SOTER) as well as emerging abstract information models that are being expressed in UML (such as e-SOTER). It examined related information models, such as GeoSciML and the lessons learnt in developing and implementing such community agreed models, features and vocabularies. There is a need to develop a global soil information standard, to be called SoilML, that would allow access and use of data across a broad range of international initiatives (such as GEOSS and INSPIRE) as well as supporting national, regional and local data interoperability and integration. The meeting agreed to adopt the interoperability approaches of formalising the information model in UML with XML encoding for data transfer as well as re-using existing features and patterns where appropriate such as those found in GeoSciML and Observations and Measurements. It has been proposed to establish a formal Working Group on Soil Information Standards under the International Union of Soil Science to give the SoilML information model both scientific credibility and international standing. A number of meetings and workshops are being planned to progress the draft SoilML information model

Isotopic Evolution of Soil Organic Matter Affects Paleo-vegetation and Paleo-pCO2 Reconstructions

NASA Astrophysics Data System (ADS)

Bowen, G. J.; Beerling, D. J.

2004-12-01

The stable carbon isotope ratio (\\delta13C) of fossil terrestrial organic matter is used to study several aspects of biosphere/atmosphere coupling in the geologic past. These range from vegetation response to climatic and pCO2 shifts to reconstruction of paleo-pCO2 levels. Although screening for diagenesis is typical in these studies, few have taken into account the ubiquitous but poorly understood phenomenon of progressive 13C-enrichment of soil organic matter during its decay, which is observed in modern soils worldwide. We present a simple model that describes this phenomenon and the interaction of soil organic carbon and CO2 concentrations, fluxes and \\delta13C values. At its most basic level, the model suggests that bulk organic matter from sub-surface soil horizons will be variably enriched in 13C relative to the vegetation living on the soil surface. This complicates interpretation of paleo-isotopic records used in C3/C4 vegetation reconstructions, and may account for anomalously heavy fossil organic carbon isotope values measured in some paleosols pre-dating the end-Miocene expansion of C4 floras. The model also demonstrates that the \\delta13C evolution of soil organic carbon during its decay generates 2 types of biases that may affect soil mineral paleo-pCO2 proxies. The first type of bias results from a steady-state inequality between the \\delta13C of organic carbon at a single depth within the soil and that of respired CO2 in the soil. This bias is present when fossil organic matter is used to reconstruct the \\delta13C of soil-respired carbon, and can be minimized with appropriate sampling methods. The second type of bias results from a dynamic, seasonal imbalance in respiration, which may cause the soil \\delta13CO2 flux during times of soil mineral formation to deviate from that of the annually integrated flux. At present, this bias can not be fully described or corrected for due to inadequacies in our knowledge of soil \\delta13C dynamics and the timing of soil mineral formation. Given the strong dependence of paleo-pCO2 reconstructions on data from soil mineral isotopes, further work on these topics is warranted.

Probing soil nitrogen transformations using triple nitrate isotopes

NASA Astrophysics Data System (ADS)

Yu, Z.; Elliott, E. M.

2017-12-01

Models of soil nitrogen (N) transformations are essential for understanding biogeochemical N cycling and its environmental implications. While natural abundance stable N isotopes (δ15N) of the soil N pool are widely used to infer soil N dynamics, its quantitative use is limited by uncertainties in the relevant isotopic fractionations. Oxygen-17 isotope anomalies in nitrate (Δ17O-NO3-), originating from mass-independent fractionation during photochemical NO3- formation, are a conservative tracer of atmospherically deposited NO3- in terrestrial ecosystems. Therefore, measurement of soil Δ17O-NO3- may provide additional tracing power for δ15N-based process models, in that Δ17O-NO3- is not altered by mass-dependent isotopic fractionations. In this study, we conducted both laboratory and field experiments to assess the effectiveness of using triple NO3- isotopes (Δ17O, δ15N, δ18O) for modeling soil N transformations. Surface soil (0-7 cm) was sampled from an urban riparian area and temperate, upland forests in rural and urban settings for batch incubations and amendments with Δ17O-enriched NO3-. After amendment, the soils were extracted on six occasions over a 4-day period to measure concentrations and isotopic composition of NO3- and ammonium. A Δ17O-based numerical model was developed and used to derive gross N fluxes. In situ field soil and lysimeter sampling was also conducted at the rural forest site on five consecutive days immediately following snowmelt input of Δ17O-enriched NO3-. The results show that the temporal dynamics of Δ17O-NO3- can provide quantitative information on soil N turnover. In the laboratory incubations, modeled gross nitrification and denitrification rates were significantly higher for the urban forest and riparian soils, consistent with results from inhibitor-based potential measurements. Non-zero Δ17O-NO3- values, up to 4.3‰, were measured in the rural forest soil following the snowmelt event. A numerical model of the progressive decrease of soil Δ17O-NO3- indicates high NO3- production and consumption rates, revealing active post-snowmelt N cycling in soils. These preliminary results suggest that the triple NO3- isotopes are a powerful tracer for probing soil N transformations and future applications are expected to help disentangle soil N cycling complexity.

Pedogenic replacement of aluminosilicate grains by CaCO3 in Ustollic Haplargids, south-central Montana, U.S.A.

USGS Publications Warehouse

Reheis, M.C.

1988-01-01

A chronosequence of calcic soils formed on granitic glaciofluvial terrace deposits of Rock Creek and the Clarks Fork in south-central Montana shows progressive replacement of aluminosilicate parent-material grains by calcium-magnesium carbonate. The terraces range from late Pliocene to Holocene in age as dated by tephrochronology, correlation, and stream incision rates. Replacement is first seen in soils that are as old as 120,000 yr; the amount and degree of replacement increase in soils older than 120,000 yr along with the development of calcic horizons. Under the petrographic microscope, carbonate replacement of quartz, feldspars, and the groundmass of andesite grains in Rock Creek soils is shown by embayed grains, networks of carbonate along cracks and between parts of polycrystalline grains and optically aligned grain fragments within carbonate masses. Microprobe data suggest that silica is released by replacement because it is absent from carbonate-filled spaces and is depleted in corrosion pits. Little microscopic evidence exists to support displacement of framework grains by carbonate because fragments of a single grain are rarely rotated out of optical alignment. In the calcic soils of Rock Creek, K-fabric (grains floating in a carbonate matrix) may form by both replacement and displacement. ?? 1988.

Lead sequestration and species redistribution during soil organic matter decomposition

USGS Publications Warehouse

Schroth, A.W.; Bostick, B.C.; Kaste, J.M.; Friedland, A.J.

2008-01-01

The turnover of soil organic matter (SOM) maintains a dynamic chemical environment in the forest floor that can impact metal speciation on relatively short timescales. Here we measure the speciation of Pb in controlled and natural organic (O) soil horizons to quantify changes in metal partitioning during SOM decomposition in different forest litters. We provide a link between the sequestration of pollutant Pb in O-horizons, estimated by forest floor Pb inventories, and speciation using synchrotron-based X-ray fluorescence and X-ray absorption spectroscopy. When Pb was introduced to fresh forest Oi samples, it adsorbed primarily to SOM surfaces, but as decomposition progressed over two years in controlled experiments, up to 60% of the Pb was redistributed to pedogenic birnessite and ferrihydrite surfaces. In addition, a significant fraction of pollutant Pb in natural soil profiles was associated with similar mineral phases (???20-35%) and SOM (???65-80%). Conifer forests have at least 2-fold higher Pb burdens in the forest floor relative to deciduous forests due to more efficient atmospheric scavenging and slower organic matter turnover. We demonstrate that pedogenic minerals play an important role in surface soil Pb sequestration, particularly in deciduous forests, and should be considered in any assessment of pollutant Pb mobility. ?? 2008 American Chemical Society.

Spatiotemporal monitoring of soil salinization in irrigated Tadla Plain (Morocco) using satellite spectral indices

NASA Astrophysics Data System (ADS)

El Harti, Abderrazak; Lhissou, Rachid; Chokmani, Karem; Ouzemou, Jamal-eddine; Hassouna, Mohamed; Bachaoui, El Mostafa; El Ghmari, Abderrahmene

2016-08-01

Soil salinization is major environmental issue in irrigated agricultural production. Conventional methods for salinization monitoring are time and money consuming and limited by the high spatiotemporal variability of this phenomenon. This work aims to propose a spatiotemporal monitoring method of soil salinization in the Tadla plain in central Morocco using spectral indices derived from Thematic Mapper (TM) and Operational Land Imager (OLI) data. Six Landsat TM/OLI satellite images acquired during 13 years period (2000-2013) coupled with in-situ electrical conductivity (EC) measurements were used to develop the proposed method. After radiometric and atmospheric correction of TM/OLI images, a new soil salinity index (OLI-SI) is proposed for soil EC estimation. Validation shows that this index allowed a satisfactory EC estimation in the Tadla irrigated perimeter with coefficient of determination R2 varying from 0.55 to 0.77 and a Root Mean Square Error (RMSE) ranging between 1.02 dS/m and 2.35 dS/m. The times-series of salinity maps produced over the Tadla plain using the proposed method show that salinity is decreasing in intensity and progressively increasing in spatial extent, over the 2000-2013 period. This trend resulted in a decrease in agricultural activities in the southwestern part of the perimeter, located in the hydraulic downstream.

Resonant generation of internal waves on the soft sea bed by a surface water wave

NASA Astrophysics Data System (ADS)

Wen, Feng

1995-08-01

The nonlinear response of an initially flat sea bed to a monochromatic surface progressive wave was studied using the multiple scale perturbation method. Two opposite-traveling subliminal internal ``mud'' waves are selectively excited and form a resonant triad with the surface wave. The amplitudes of the internal waves grow on a time scale much longer than the period of the surface wave. It was found that the sea bed response is critically dependent on the density ratio of water and soil, depth of water, and depth and viscosity of the saturated soil. The result of instability analysis is in qualitative agreement with the result of a wave flume experiment.

Ecological stress and sex evolution in soil microfungi.

PubMed Central

Grishkan, Isabella; Korol, Abraham B; Nevo, Eviatar; Wasser, Solomon P

2003-01-01

The elucidation of the origin and maintenance of sex is a major unsolved problem in evolutionary biology. A number of hypotheses have been elaborated, but the scarcity of empirical data limits further progress. During recent years, the general inclination has changed towards pluralistic models of sex evolution, due partly to an increased diversity of studied organisms. Fungi are among the most promising organisms for testing sexual causation, as demonstrated in recent laboratory experiments. However, reconciling theory and evidence necessitates critical field observations. Here, we report new estimates of the distribution of morphologically sexual and asexual soil microfungi in nature, which indicate a remarkable trend towards increased sexuality with increasing climatic stress. PMID:12590766

Generation of 3-D surface maps in waste storage silos using a structured light source

NASA Technical Reports Server (NTRS)

Burks, B. L.; Rowe, J. C.; Dinkins, M. A.; Christensen, B.; Selleck, C.; Jacoboski, D.; Markus, R.

1992-01-01

Surface contours inside the large waste storage tanks typical of the Department of Energy (DOE) complex are, in general, highly irregular. In addition to pipes and other pieces of equipment in the tanks, the surfaces may have features such as mounds, fissures, crystalline structures, and mixed solid and liquid forms. Prior to remediation activities, it will be necessary to characterize the waste to determine the most effective remediation approaches. Surface contour data will be required both prior to and during remediation. The use is described of a structured light source to generate 3-D surface contour maps of the interior of waste storage silos at the Feed Materials Production Center at Fernald, OH. The landscape inside these large waste storage tanks bears a strong resemblance to some of the landscapes that might be encountered during lunar or planetary exploration. Hence, these terrestrial 3-D mapping techniques may be directly applicable to extraterrestrial exploration. In further development, it will be demonstrated that these 3-D data can be used for robotic task planning just as 3-D surface contour data of a satellite could be used to plan maintenance tasks for a space-based servicing robot.

The international research progress of Ammonia(NH3) emissions and emissions reduction technology in farmland ecosystem

NASA Astrophysics Data System (ADS)

Yang, W. Z.; Jiao, Y.

2017-03-01

NH3 is the important factor leading to the grey haze, and one of the main causes of environmental problems of serious ecological imbalance, such as acid rain and air quality deterioration. The fertilizer excessive application of the current farmland results NH3 emissions intensity greatly. In order to clear the farmland NH3 emissions research status and achievements, the literature of farmland NH3 emission related were retrievaled by the SCI journals and Chinese science citation database. Some factors of NH3 emission were analyzed such as soil factors, climate factors and farmland management measures. The research progress was inductived on farmland NH3 emission reduction technology. The results will help to clarify farmland NH3 emissions research progress. The theoretical guidance was provided on the future of farmland NH3 emissions research.

Scientific realism and wishful thinking in soil hydrology

NASA Astrophysics Data System (ADS)

Flühler, H.

2009-04-01

In our field we often learn - or could have learned - more from failures than from successes provided we had postulated testable hypotheses to be accepted or rejected. In soil hydrology, hypotheses are testable if independent information quantifying the pertinent system features is at hand. This view on how to operate is an idealized concept of how we could or should have worked. In reality, the path to success is more tortuous and we usually progress differently obeying to other professional musts. Although we missed some shortcuts over the past few decades, we definitely made significant progress in understanding vadose zone progresses, but we could have advanced our system understanding faster by more rigorously questioning the fundamental assumptions. I will try to illustrate the tortuous path of learning and identify some causes of the slowed-down learning curve. In the pioneering phase of vadose zone research many models have been mapped in our minds and implemented on our computers. Many of them are now well established, powerful and represent the state-of-the-art even when they do not work. Some of them are based on erroneous or misleading concepts. Even when based on adequate concepts they might have been applied in the wrong context or inadequate models may have lead to apparent success. I address this process of collective learning with the intention that we spend more time and efforts to find the right question instead of improving tools, which are questionably suitable for solving the main problems.

Evolution of organic matter fractions after application of co-compost of sewage sludge with pruning waste to four Mediterranean agricultural soils. A soil microcosm experiment.

PubMed

Pérez-Lomas, A L; Delgado, G; Párraga, J; Delgado, R; Almendros, G; Aranda, V

2010-10-01

The effect of co-compost application from sewage sludge and pruning waste, on quality and quantity of soil organic carbon (SOC) in four Mediterranean agricultural soils (South Spain), was studied in soil microcosm conditions. Control soil samples (no co-compost addition) and soils treated with co-composts to a rate equivalent of 140 Mg ha(-1) were incubated for 90 days at two temperatures: 5 and 35 degrees C. The significances of incubation temperature and the addition of co-compost, on the evolution of the different fractions of SOC, were studied using a 2(3) factorial design. The co-compost amendment increased the amounts of humic fractions: humic acids (HA) (1.9 times), fulvic acids (FA) (3.3 times), humin (1.5 times), as well as the free organic matter (1.4 times) and free lipids (21.8 times). Incubation of the soils enhanced its biological activity mainly in the amended soils and at 35 degrees C, leading to progressive SOC mineralization and humification, concomitant to the preferential accumulation of HA. The incubation results show large differences depending on temperature and soil types. This fact allows us to select suitable organic amendment for the soil when a rapid increase in nutrients through mineralization is preferred, or in cases intending the stabilization and preservation of the SOC through a process of humification. In soils with HA of more than 5 E(4)/E(6) ratio, the incubation temperature increased rates of mineralization and humification, whereas lower temperatures limited the extent of both processes. In these soils the addition of co-compost in spring or summer is the most recommendable. In soils with HA of lower E(4)/E(6) ratio (<5), the higher temperature favoured mineralization but not humification, whereas the low temperature maintained the SOC levels and even increased the HA/FA ratio. In these soils the moment of addition of organic amendment should be decided depending on the effect intended. On the other hand, the lower the SOC content in the original soil, the greater are the changes observed in the SOC after amendment with co-compost. The results suggest that proper recommendations for optimum organic matter evolution after soil amendment is possible after considering a small set of characteristics of soil and the corresponding soil organic matter fractions, in particular HA. (c) 2010 Elsevier Ltd. All rights reserved.

Soil base saturation combines with Beech Bark Disease to influence composition and structure of Sugar Maple-Beech forests in an acid rain-impacted region

USGS Publications Warehouse

Lawrence, Gregory B.; McDonnell, Todd C.; Sullivan, Timothy J.; Dovciak, Martin; Bailey, Scott W.; Antidormi, Michael; Zarfos, Michael R.

2018-01-01

Sugar maple, an abundant and highly valued tree species in eastern North America, has experienced decline from soil calcium (Ca) depletion by acidic deposition, while beech, which often coexists with sugar maple, has been afflicted with beech bark disease (BBD) over the same period. To investigate how variations in soil base saturation combine with effects of BBD in influencing stand composition and structure, measurements of soils, canopy, subcanopy, and seedlings were taken in 21 watersheds in the Adirondack region of NY (USA), where sugar maple and beech were the predominant canopy species and base saturation of the upper B horizon ranged from 4.4 to 67%. The base saturation value corresponding to the threshold for Al mobilization (16.8%) helped to define the species composition of canopy trees and seedlings. Canopy vigor and diameter at breast height (DBH) were positively correlated (P < 0.05) with base saturation for sugar maple, but unrelated for beech. However, beech occupied lower canopy positions than sugar maple, and as base saturation increased, the average canopy position of beech decreased relative to sugar maple (P < 0.10). In low-base saturation soils, soil-Ca depletion and BBD may have created opportunities for gap-exploiting species such as red maple and black cherry, whereas in high-base saturation soils, sugar maple dominated the canopy. Where soils were beginning to recover from acidic deposition effects, sugar maple DBH and basal area increased progressively from 2000 to 2015, whereas for beech, average DBH did not change and basal area did not increase after 2010.

Degradation of metalaxyl and folpet by filamentous fungi isolated from Portuguese (Alentejo) vineyard soils.

PubMed

Martins, M Rosário; Pereira, Pablo; Lima, Nelson; Cruz-Morais, Júlio

2013-07-01

Degradation of xenobiotics by microbial populations is a potential method to enhance the effectiveness of ex situ or in situ bioremediation. The purpose of this study was to evaluate the impact of repeated metalaxyl and folpet treatments on soil microbial communities and to select soil fungal strains able to degrade these fungicides. Results showed enhanced degradation of metalaxyl and folpet in vineyards soils submitted to repeated treatments with these fungicides. Indeed, the greatest degradation ability was observed in vineyard soil samples submitted to greater numbers of treatments. Respiration activities, as determined in the presence of selective antibiotics in soil suspensions amended with metalaxyl and folpet, showed that the fungal population was the microbiota community most active in the degradation process. Batch cultures performed with a progressive increase of fungicide concentrations allowed the selection of five tolerant fungal strains: Penicillium sp. 1 and Penicillium sp. 2, mycelia sterila 1 and 3, and Rhizopus stolonifer. Among these strains, mycelium sterila 3 and R. stolonifer presented only in vineyard soils treated with repeated application of these fungicides and showed tolerance >1,000 mg l(-1) against commercial formulations of metalaxyl (10 %) plus folpet (40 %). Using specific methods for inducing sporulation, mycelium sterila 3 was identified as Gongronella sp. Because this fungus is rare, it was compared using csM13-polymerase chain reaction (PCR) with the two known species, Gongronella butleri and G. lacrispora. The high tolerance to metalaxyl and folpet shown by Gongronella sp. and R. stolonifer might be correlated with their degradation ability. Our results point out that selected strains have potential for the bioremediation of metalaxyl and folpet in polluted soil sites.

Magnetic analyses of soils from the Wind River Range, Wyoming, constrain rates and pathways of magnetic enhancement for soils from semiarid climates

NASA Astrophysics Data System (ADS)

Quinton, Emily E.; Dahms, Dennis E.; Geiss, Christoph E.

2011-07-01

In order to constrain the rate of magnetic enhancement in soils, we investigated modern soils from five fluvial terraces in the eastern Wind River Range, Wyoming. Profiles up to 1.2 m deep were sampled in 5-cm intervals from hand-dug pits or natural riverbank exposures. Soils formed in fluvial terraces correlated to the Sacajawea Ridge (730-610 ka BP), Bull Lake (130-100 ka BP) and Pinedale-age (˜20 ka BP) glacial advances. One soil profile formed in Holocene-age sediment. Abundance, mineralogy, and grain size of magnetic minerals were estimated through magnetic measurements. Magnetic enhancement of the A-horizon as well as an increase in fine-grained magnetic minerals occurred mostly in Bull Lake profiles but was absent from the older profile. Such low rates of magnetic enhancement may limit the temporal resolution of paleosol-based paleoclimate reconstructions in semiarid regions even where high sedimentation rates result in multiple paleosols. A loss of ferrimagnetic and an increase in antiferromagnetic minerals occurred with age. Our findings suggest either the conversion of ferrimagnetic minerals to weakly magnetic hematite with progressing soil age, or the presence of ferrimagnetic minerals as an intermediate product of pedogenesis. Absolute and relative hematite abundance increase with age, making both useful proxies for soil age and the dating of regional glacial deposits. All coercivity proxies are consistent with each other, which suggests that observed changes in HIRM and S-ratio are representative of real changes in hematite abundance rather than shifts in coercivity distributions, even though the modified L-ratio varies widely.

The Longterm Effects of Climate Change in European Shrubland Ecosystems

NASA Astrophysics Data System (ADS)

Emmett, B.; Sowerby, A.; Smith, A.; EU Increase-infrastructure Project Team

2011-12-01

Shrublands constitute significant and important parts of European landscapes providing a large number of important ecosystem services. Biogeochemical cycles in these ecosystems have gained little attention relative to forests and grassland systems. As climate change progresses the potential feedback from the biosphere to the atmosphere through changes in above and below-ground structure and functioning will become increasingly important. A series of replicate long term climate change experiments have been running for ca. 10 years in contrasting shrubland types across Europe to quantify; (a) the potential changes in carbon sequestration, GHG emissions and nutrient cycling, (b) the links to above and below-ground biodiversity, and (c) implications for water quality, in response to warming and repeated summer drought. Results indicate a relatively high rate of below-ground carbon allocation compared to forest systems and the importance of modifying factors such as past and current management, atmospheric deposition and soil type in determining resilience to change. Unexpectedly, sustained reduction in soil moisture over winter (between drought periods and despite major winter rainfall) was observed in the repeated summer drought treatment, along with a reduction in the maximum water-holding capacity attained. The persistent reduction in soil moisture throughout the year resulted in a year-round increase in soil respiration flux, a response that accelerated over time to 40% above control levels in the hydric, organic-rich UK system. As above-ground biomass, litter production and diversity was remarkably stable, changes in soil fungal communities and soil physical structure appear to be critical in driving changes in soil carbon fluxes in this organic-rich site. Current ecosystem models may under-estimate potential changes in carbon loss in response to climate change if changes in soil biological and physical properties are not included.

Phytoremediation potential and ecological and phenological changes of native pioneer plants from weathered oil spill-impacted sites at tropical wetlands.

PubMed

Palma-Cruz, Felipe de J; Pérez-Vargas, Josefina; Rivera Casado, Noemí Araceli; Gómez Guzmán, Octavio; Calva-Calva, Graciano

2016-08-01

Pioneer native plant species from weathered oil spill-affected sites were selected to study their potential for phytoremediation on the basis of their ecological and phenological changes during the phytoremediation process. Experiments were conducted in field and in greenhouse. In field, native plants from aged oil spill-impacted sites with up 400 g of weathered petroleum hydrocarbons per kilogram soil were selected. In the impacted sites, the principal dominant plant species with potential for hydrocarbons removal were Cyperus laxus, Cyperus esculentus, and Ludwigia peploides. In greenhouse, the phenology of the selected plant species was drastically affected by the hydrocarbons level above 325 g total petroleum hydrocarbons (TPH) per kilogram soil after 2 years of phytoremediation of soils from the aged oil spill-impacted sites. From the phytoremediation treatments, a mix-culture of C. laxus, C. esculentus, and L. peploides in soil containing 325 g TPH/kg soil, from which 20.3 % were polyaromatic hydrocarbons (PAH) and 34.2 % were asphaltenes (ASF), was able to remove up 93 % of the TPH, while in unvegetated soil the TPH removal was 12.6 %. Furthermore, evaluation of the biodiversity and life forms of plant species in the impacted sites showed that phytoremediation with C. esculentus, alone or in a mix-culture with C. laxus and L. peploides, reduces the TPH to such extent that the native plant community was progressively reestablished by replacing the cultivated species resulting in the ecological recovery of the affected soil. These results demonstrate that native Cyperus species from weathered oil spill-affected sites, specifically C. esculentus and C. laxus, alone or in a mix-culture, have particular potential for phytoremediation of soils from tropical wetlands contaminated with weathered oil hydrocarbons.

Soil morphology of a debris flow chronosequence in a coniferous forest, southern California, USA

USGS Publications Warehouse

Turk, J.K.; Goforth, B.R.; Graham, R.C.; Kendrick, K.J.

2008-01-01

Soils on a series of debris flow deposits, ranging from < 1 to 244??years old, were described and sampled in order to investigate the early stages of soil development. The parent material at the site is debris flow regolith, composed mainly of gneiss, the soil moisture regime is xeric, and the vegetation is mixed coniferous forest. Ages of the deposits were assessed using dendrochronology. Morphologic trends in the organic horizons included a thickening of the humus form over time, along with the development of Fm and Hr horizons. The humus forms underwent a progression from Mormodors (20??years old), to Hemimors (26-101??years old), and finally Lignomors (163??years old) and Resimors (184-244??years old). Changes in physical properties of the uppermost mineral horizons as a function of increasing age included a decrease in the volume of coarse fragments, a linear decrease in bulk density, and a darkening and reddening of the soil color. No significant soil development took place in the subsoil during the time span of this chronosequence. The soils described were classified as Typic Xerofluvents and Typic Xerorthents (Regosols and Leptosols). Buried A horizons were observed in many of the soils. Where the A horizons could be linked to dendrochronology to assess the age of the buried surface, we found that the properties of the buried A horizons do not serve as a good indicator of the age of the surface. This study suggests rapid development of the humus form profile (organic horizons and A horizon) following debris flow deposition and rapid degradation of these horizons when the debris flow surface is buried. ?? 2008 Elsevier B.V.