2006 Annual Report 1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter? This project is aligned with NP202 - Soil Resource Management. Soil organic matter is very important because it acts as a glue to help stabilize soil structure and is a major reservoir of both plant nutrients and plant available water. Soil organic matter is the largest terrestrial reservoir of organic carbon, and therefore the cycling of soil organic matter has a big influence on atmospheric levels of greenhouse gasses such as carbon dioxide and methane. In the near future, large-scale harvesting of biomass for production of bioenergy may cause levels of soil organic matter to decline adversely impacting soil quality and increasing the need for energy intensive tillage and fertilizer to sustain productivity. Therefore, new management systems that build organic matter in agricultural soils under sustained biomass harvesting are critically needed. We are studying the fundamental processes and factors that control the cycling of organic carbon and nitrogen in soils and how these processes and factors influence soil structure, carbon sequestration, and the ability of soils to retain plant nutrients and plant available water. We are also developing tools to rapidly quantify soil structure and the spatial variation in levels of soil organic carbon and other soil properties at a field scale. And, we are evaluating charcoal amendments as a means of enhancing soil quality and the sustainability of biomass harvesting. 2.List by year the currently approved milestones (indicators of research progress) Objective 1: Develop a mechanistic understanding of processes controlling the formation and stabilization of organic matter in soils that enhance stabilization of soil structure. 12 Months 1. Install laboratory analyses for (1) amino acids and amino sugars, (2) carbohydrates, and (3) non-lignin derived phenolic compounds. 2. Complete work on characterization soil clay-humic complexes. 3. Complete investigations of the influence of saturating cation and clay swelling on sorption of DNOC by smectites. 4. Conduct a small field study of 15N-amended microplots that are imbedded in rice fields in Arkansas in which crop residues are decomposed under varying degrees of aerobic conditions. 5. Summarize knowledge gained from different fractionation procedures. 24 Months 6. Collect soil samples from rice-based soils in Eastern Arkansas that differ by crop rotation, tillage, and manure management. Collect samples from a long-term tillage trial for continuous corn outside Ames, IA. Separate the sampled soils into aggregate classes, and begin their analyses and also that of previously collected samples from a continuous corn rotation in Nebraska. 7. Design and establish field plot experiments to evaluate the impact of charcoal additions on soil productivity. 8. Design experiments to test the interaction between cation exchange reactions and pesticide adsorption 9: Analyze plant and soil samples from the first year. 10. Develop a procedure that integrates densitometric extraction with chemical extraction: most likely it will consist of (1) a light fraction, and (2) a heavy fraction that is further divided by particle size. Each of these will then be chemically extracted into the mobile humic acid fraction and calcium humate fraction. 36 Months 11. Continue biochemical analyses of these samples. 12. Design and initiate soil column studies to quantify the impact of charcoal additions on nutrient cycling and the ability of soils to filter environmental contaminants 13. Conduct experiments testing the interaction between cation exchange reactions and pesticide adsorption 14. Conduct a second year of 15N-amended microplots. 15. Collect soil samples from various field trials that compare no-tillage with conventional tillage. Begin integrated fractionation and subsequent biochemical analyses of extracted fractions. 48 Months 16. Complete biochemical analyses and summarize data. 17. Complete investigation of the interactions between cation exchange reactions and pesticide adsorption 18. Analyze plant and soil samples from the second year. 19. Continue integrated fractionation followed by biochemical analyses. 60 Months 20. Complete study on the efficacy of biochemical compounds in promoting soil aggregation and under which conditions. 21. Complete soil column experiments 22. Prepare manuscripts that evaluate the benefit of aerobic decomposition of crop residues to availability of soil nitrogen (N). 23. Complete study evaluating the relative significance of biochemical classes to aggregation under various field rotations and tillage. Objective 2: Develop tools for in situ assessment of soil organic carbon and soil structure. 12 Months 24. Analyze preliminary data on twelve-wire monofunction probe. Design and conduct laboratory experiments for the undisturbed soil cores collected from a cropping rotation study using the twelve-wire monofunction probe and other soil structure analyses. 25. Design and conduct experiments to test a regional calibration model for the third generation prototype of the on-the-go near infrared diffuse reflectance spectroscopy (NIRS) system for mapping soil properties. 24 Months 26. Build monofunction thermal probe and monofunction electrical conductivity probe, and design and conduct preliminary experiments. 27. Complete design and construction of a prototype of stop-and-probe NIRS soil profile probe. 36 Months 28. Design experiments to test the stop-and-probe NIRS soil profile probe. 48 Months 29. Build multi-function probe, and design and conduct preliminary experiments. 30. Complete initial testing of the stop-and-probe NIRS soil profile probe. 60 Months 31. Collect undisturbed soil cores from soil management areas, and design and conduct experiments with multifunction probe. 32. Develop protocols for building regional calibration models of the on-the-go NIRS system for mapping soil properties. 4a.List the single most significant research accomplishment during FY 2006. Title: Sorption of dinitro-o-cresol on clay. Subordinate project title: Mechanisms and forces controlling pesticide retention by soil clay minerals. Cooperating Institutions: USDA-ARS-National Soil Tilth Laboratory, Michigan State University, and Purdue University. National Programs: NP202 Problem Area 7: Managing Pesticides in Soils. An understanding of adsorption mechanisms helps scientists and engineers predict which pesticides and other organic compounds are likely to stick to soil particles and which are likely to move and end up as contaminants in the ground water. Recent work has demonstrated that an organic acid known as dinitro-o-cresol (DNOC) is very strongly adsorbed by potassium-saturated clays at low pH. We discovered that DNOC is also very strongly adsorbed by potassium-clays at high pH and that potassium ions are co-adsorbed with the DNOC. We also discovered that DNOC is strongly adsorbed on some calcium-clays at low pH but not at high pH. Based on these observations, we proposed that DNOC is adsorbed as a complex with potassium. This information will help scientist and engineers to better predict the fate of DNOC in soil environments, and is a significant advance in scientific understanding because we describe a new mechanism by which organic molecules can adsorb on clays. NP202 Problem Area 7: Managing Pesticides in Soils. Title: Sorption of tetracycline by soil materials. Large quantities of antibiotics are used in animal production both to fight disease and to promote growth. Most of these antibiotics pass right through animals without being chemically altered, and hence manure often contains detectable levels of antibiotics. There is concern that antibiotics present in manured soils will encourage the development of antibiotic resistant bacteria, which may pose a threat to human health. We discovered that >96% of tetracycline and chlorotetracycline (two commonly used antibiotics) was adsorbed almost irreversibly by soil. Soil clay minerals were found to adsorb more of the antibiotics than the soil organic matter and we also discovered that soil organic matter competes with the antibiotics for places to adsorb on the surfaces of clay minerals. This information will help scientists to better understand the fate of antibiotics in soils and thereby to better assess the risk posed by the use of antibiotics in animal production. 4b.List other significant research accomplishment(s), if any. NP202 Problem Area 7: Managing Pesticides in Soils. Title: Sorption of tetracycline by soil materials. Large quantities of antibiotics are used in animal production both to fight disease and to promote growth. Most of these antibiotics pass right through animals without being chemically altered, and hence manure often contains detectable levels of antibiotics. There is concern that antibiotics present in manured soils will encourage the development of antibiotic resistant bacteria, which may pose a threat to human health. We discovered that >96% of tetracycline and chlorotetracycline (two commonly used antibiotics) was adsorbed almost irreversibly by soil. Soil clay minerals were found to adsorb more of the antibiotics than the soil organic matter and we also discovered that soil organic matter competes with the antibiotics for places to adsorb on the surfaces of clay minerals. This information will help scientists to better understand the fate of antibiotics in soils and thereby to better assess the risk posed by the use of antibiotics in animal production. Title: Potassium concentrations influence pesticide sorption by clays. Subordinate project title: Mechanisms and forces controlling pesticide retention by soil clay minerals. Cooperating Institutions: USDA-ARS-National Soil Tilth Laboratory, Michigan State University, and Purdue University. National Program: NP202 Problem Area 7: Managing Pesticides in Soils. One of the most important factors affecting the fate of organic chemicals in soils is the ability of the organic chemical to adsorb to soil particles. For many years, organic chemicals were believed to primarily adsorb to soil organic matter, but recent research has demonstrated that soil clay minerals are also very important for adsorption of some classes of organic chemicals. We discovered that sorption of four herbicides on clays increases substantially with the concentration of potassium chloride in the soil solution, but the concentration of calcium chloride in the soil solution has little effect on sorption of the pesticides. Swelling of clays decreases with increasing concentration of potassium chloride and this makes the clays better able to adsorb the pesticides, whereas clay swelling is not effected by calcium chloride concentration. This research will help scientists better understand how organic molecules interact with soil clays and hence better predict the fate of pesticides and other organic chemical contaminants in soil environments, and may also interest the chemical industry as they seek to produce better pesticide formulations. 4c.List significant activities that support special target populations. None. 4d.Progress report. This is an in-house "D" project and progress is adequately covered under 3A above, hence no additional progress report is included here. 5.Describe the major accomplishments to date and their predicted or actual impact. Title: Sorption of dinitro-o-cresol on clay. Subordinate project title: Mechanisms and forces controlling pesticide retention by soil clay minerals. Cooperating Institutions: USDA-ARS-National Soil Tilth Laboratory, Michigan State University, and Purdue University. National Programs: NP202 Problem Area 7: Managing Pesticides in Soils. An understanding of adsorption mechanisms helps scientists and engineers predict which pesticides and other organic compounds are likely to stick to soil particles and which are likely to move and end up as contaminants in the ground water. Recent work has demonstrated that an organic acid known as dinitro-o-cresol (DNOC) is very strongly adsorbed by potassium-saturated clays at low pH. We discovered that DNOC is also very strongly adsorbed by potassium-clays at high pH and that potassium ions are co-adsorbed with the DNOC. We also discovered that DNOC is strongly adsorbed on some calcium-clays at low pH but not at high pH. Based on these observations, we proposed that DNOC is adsorbed as a complex with potassium. This information will help scientist and engineers to better predict the fate of DNOC in soil environments, and is a significant advance in scientific understanding because we describe a new mechanism by which organic molecules can adsorb on clays. NP202 Problem Area 7: Managing Pesticides in Soils. Title: Sorption of tetracycline by soil materials. Large quantities of antibiotics are used in animal production both to fight disease and to promote growth. Most of these antibiotics pass right through animals without being chemically altered, and hence manure often contains detectable levels of antibiotics. There is concern that antibiotics present in manured soils will encourage the development of antibiotic resistant bacteria, which may pose a threat to human health. We discovered that >96% of tetracycline and chlorotetracycline (two commonly used antibiotics) was adsorbed almost irreversibly by soil. Soil clay minerals were found to adsorb more of the antibiotics than the soil organic matter and we also discovered that soil organic matter competes with the antibiotics for places to adsorb on the surfaces of clay minerals. This information will help scientists to better understand the fate of antibiotics in soils and thereby to better assess the risk posed by the use of antibiotics in animal production. Title: Potassium concentrations influence pesticide sorption by clays. Subordinate project title: Mechanisms and forces controlling pesticide retention by soil clay minerals. Cooperating Institutions: USDA-ARS-National Soil Tilth Laboratory, Michigan State University, and Purdue University. National Program: NP202 Problem Area 7: Managing Pesticides in Soils. One of the most important factors affecting the fate of organic chemicals in soils is the ability of the organic chemical to adsorb to soil particles. For many years, organic chemicals were believed to primarily adsorb to soil organic matter, but recent research has demonstrated that soil clay minerals are also very important for adsorption of some classes of organic chemicals. We discovered that sorption of four herbicides on clays increases substantially with the concentration of potassium chloride in the soil solution, but the concentration of calcium chloride in the soil solution has little effect on sorption of the pesticides. Swelling of clays decreases with increasing concentration of potassium chloride and this makes the clays better able to adsorb the pesticides, whereas clay swelling is not effected by calcium chloride concentration. This research will help scientists better understand how organic molecules interact with soil clays and hence better predict the fate of pesticides and other organic chemical contaminants in soil environments, and may also interest the chemical industry as they seek to produce better pesticide formulations. 6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products? Information on the ability of a prototype field mobile NIRS to quantify the spatial distribution of soil organic carbon was transferred to a small private company under terms of a Cooperative Research and Development Agreement (CRADA). The company has developed a field mobile NIRS system that is being marketed as a commercial product this year. Scientists are anticipated to be the primary users of the system for several years. As algorithms and calibration databases become available, the system will likely be used by crop consultants, extension agents, and both federal and state action agencies to enhance soil inventory and site-specific land use management. 7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below). Olk, D.C., Gregorich, E.G., Farenhorst, A, Hayes, M.H.B., Paul, E.A. and Simpson, M.J. 2006. Biological, chemical, and physical fractionations for soil organic matter. 13th Meeting of the International Humic Substances Society, July 30 – August 4, 2006, Karlsruhe, Germany: (in press). Expected audience (300 scientists, students, and private sector employees). Pereira, T.R., D.A. Laird, C.T. Johnston, B.J. Teppen, H. Li, and S.A. Boyd. 2006. Sorption of dinitrophenol herbicide on K and Ca saturated smectites in aqueous suspensions. P. 216. Bridging Clays, Program and Abstracts, Joint meeting of the Clay Mineral Society and the French Clay Group, June 3-7, 2006, Ile d'Oleron, France. Teppen, B.J., H. Li, D.A. Laird, C.T. Johnston, and S.A. Boyd. 2006. Hydrophobic contributions to the sorption of organics from water to smectites. P. 255. Bridging Clays, Program and Abstracts, Joint meeting of the Clay Mineral Society and the French Clay Group, June 3-7, 2006, Ile d'Oleron, France.