2007 Annual Report
Herbicide Behavior in Agricultural Soils. Problem: Isoxaflutole, a relatively new pre-emergence herbicide used in corn production, and its breakdown product, DKN, have been detected in groundwater and surface water in the United States. To develop management practices that reduce the threat of water contamination by isoxaflutole and DKN, information is required about the rate at which these herbicides disappear from soil after they are applied. Accomplishment: This study was conducted to measure how quickly these herbicides were degraded in soil, and to what extent they were transported through soil under typical field conditions in a moist, cool environment. Herbicide measurements and simulation modeling showed that little of the herbicide moved deeper than the plant root zone, and that herbicide uptake by plants may be an important route of herbicide dissipation. Impact: The results of these studies will help guide additional research to quantify the processes affecting pesticide dissipation under field conditions, and will be useful to federal and state regulatory agencies and pesticide manufacturers when evaluating pesticide labeling requirements and application restrictions. This research addresses the Problem Area "Managing Pesticides in Soils" of the Soil Resource Management National Program (NP202) Action Plan.
Earthworm and Invasive Species Effects on Soil Ecosystems. Problem: Exotic species of earthworms are becoming more prevalent in agroecosystems, but their effects on organic matter, microbial activity, and mineralization of carbon and nitrogen have previously been ignored. Management factors and natural habitat characteristics affect earthworm communities, both of which influence the growing problem of invasive species. Accomplishment: Research evaluated the influence of disturbance, competitive pressures, and habitat characteristics on the ability of exotics to invade native ecosystems. Results suggest that exotic earthworms are capable of exploiting resources not fully utilized by native species. Impact: Scientists and policy makers used this research to predict the effects of exotic earthworm invasions on the stability of natural ecosystems; these efforts led to the development of a conceptual framework for determining the risk and establishing policy for exotic imports. This research addresses the Problem Area "Understanding and Managing Soil Biology and Rhizosphere Ecology" of the Soil Resource Management National Program (NP202) Action Plan.
Retention and Predicted Mobility of Herbicides in Soils. Problem: Determinations of pesticide behavior under local conditions are required for accurate prediction of pesticide contamination of sediments, surface water, groundwater, and air. Recent surveys have detected pesticides in surface water and groundwater of the Baltic region, but there is little information in the peer-reviewed literature regarding the fate of pesticides in Baltic soils. Accomplishment: This study was conducted to evaluate the extent to which eight herbicides were retained by seven agricultural soils of Lithuania, and to estimate the potential for these herbicides to move from the site of application to surface water and groundwater. Only one of the herbicides was predicted to be mobile in all seven soils. Impact: Herbicide management is important to the continued increase in agricultural production and profitability in the Baltic region, and these results will be useful in identifying critical areas requiring improved management practices to reduce water contamination by pesticides. These results also provide information regarding the impact of soil properties on pesticide retention by soils, which is important for the safe management of pesticides worldwide. This research addresses the Problem Area "Managing Pesticides in Soils" of the Soil Resource Management National Program (NP202) Action Plan.
Papiernik, S.K., Lindstrom, M.J., Schumacher, T.E., Schumacher, J.A., Malo, D.D., Lobb, D.A. 2007. Characterization of Soil Profiles in a Landscape Affected by Long-term Tillage. Soil & Tillage Research. 93:335-345.
Papiernik, S.K., Koskinen, W.C., Cox, L., Rice, P.J., Clay, S.A., Werdin-Pfisterer, N.R., Norberg, K. 2006. Sorption-desorption of imidacloprid and its metabolites in soil and vadose zone materials. Journal of Agricultural and Food Chemistry. 54:8163-8170.
Callaham, Jr., M.A., Gonzalez, G., Hale, C.M., Heneghan, L., Lachnicht Weyers, S.L., Zou, X. 2006. Policy and management responses to earthworm invasions in North America. Biological Invasions. 8:1317-1329.
Hendrix, P., Baker, G., Callaham, Jr., M., Damoff, G., Fragoso, C., Gonzalzez, G., James, S., Lachnicht Weyers, S.L., Winsome, T., Zou, X.M. 2006. Invasion of exotic earthworms into ecosystems inhabited by native earthworms. Biological Invasions. 8:1287-1300.
Li, Y., Zhang, Q.W., Reicosky, D.C., Lindstrom, M.J., Bai, L.Y., Li, L. 2007. Changes in soil organic carbon induced by tillage and water erosion on a steep cultivated hillslope in the Chinese Loess Plateau from 1898-1954 and 1954-1998. Journal of Geophysical Research-Biogeosciences. 112:G01021.
Zheng, W., Yates, S.R., Papiernik, S.K. 2006. Conversion of metam sodium and emission of fumigant from soil columns. Atmospheric Environment. 40:7046-7056.
Lobb, D., Huffman, E., Reicosky, D.C. 2007. Importance of Information on Tillage Practices in the Modelling of Environmental Processes and in the Use of Environmental Indicators. Journal of Environmental Management. 82:377-387.
Li, S., Lobb, D., Lindstrom, M.J. 2007. Tillage translocation and tillage erosion in cereal-based production in Manitoba, Canada. Soil & Tillage Research. 94:164-182.
Venterea, R.T., Baker, J.M., Dolan, M.S., Spokas, K.A. 2006. Carbon and nitrogen storage are greater under biennial tillage in a Minnesota corn-soybean rotation. Soil Science Society of America Journal. 70:1752-1762.
Johnson, J.M., Coleman, M.D., Gesch, R.W., Jaradat, A.A., Mitchell, R., Reicosky, D.C., Wilhelm, W.W. 2007. Biomass-bioenergy crops in the United States: A changing paradigm. The Americas Journal of Plant Science and Biotechnology. 1(1):1-28.
Lal, R., Reicosky, D.C., Hanson, J.D. 2007. Evolution of the Plow over 10,000 Years and the Rationale for No-till Farming. Soil & Tillage Research. 93:1-12.
Li, S., Lobb, D.A., Lindstrom, M.J., Farenhorst, A. 2007. Tillage and water erosion on different landscapes in the northern North American Great Plains evaluated using 137Cs technique and soil erosion models. Catena. 70:493-505.