2007 Annual Report
Cropping system and landscape position affect claypan soil hydraulic properties. Knowledge of the interactions between rainfall and the different soils found across a landscape and managed under contrasting cropping systems (with variables such as different rotations, different tillage practices, and grain crops vs. grass crops) is needed for understanding and modeling water movement in watersheds. We demonstrated that the depth of the claypan horizon in the soil profile was the main controlling factor for practically all sub-soil hydraulic properties. Cropping practices also affected soil hydraulic properties, but mostly in the top 4 inches of the soil and not equally at all landscape positions. Most importantly, this research showed that the greatest improvements in infiltration were achieved on backslope positions managed in permanent grass (such as with the Conservation Reserve Program (CRP)) or hay crops. The findings of this research show that landscape position and management practices interact, and both are important for characterizing hydraulic properties and developing targeted soil-water conservation practices. This understanding will benefit the general public because many watersheds in the U.S. Midwest empty into lakes and rivers used for drinking water and recreation and will benefit producers as new management systems are developed that embrace long-term crop sustainability goals. (NP:202, Component: Soil Water, Problem Area 2: Soil Management to Improve Soil Structure and Hydraulic Properties.)
Electrochemical sensing of soil macronutrients. The conventional practice of soil sample collection and analysis is costly and time consuming when applied at the intensity needed in variable-rate fertilizer management systems, and a more efficient approach would be to sense soil macronutrient status as a machine moves across a field. We identified soil nitrate, phosphate, and potassium ion-selective electrode (ISE) sensors that, when used with the Kelowna multiple-element extracting solution, accurately quantified nutrient levels in laboratory solutions. With proper calibration procedures, the ISE sensors could also accurately measure the nitrate, phosphate, and potassium levels typical in agricultural soils. This combination of sensors and the associated extracting solution could be incorporated into an overall nutrient sensing system that would then be used to target fertilizer to sub-field areas where it would be beneficial, and to reduce fertilizer application in sub-field areas where nutrient levels are already sufficient. Such a system could provide lower food production costs and reduced environmental impacts, benefiting both producers and consumers. (NP:202, Component: Nutrient Management, Problem Area 4: Nutrient Management for Crop Production and Environmental Protection)
Chung, S., Sudduth, K.A. 2006. Soil failure models for vertically operating and horizontally operating strength sensors. Transactions of the ASABE. 49(4):851-863.
Hong, N., Scharf, P.C., Davis, J.G., Kitchen, N.R., Sudduth, K.A. 2007. Economically optimal nitrogen rate reduces soil residual nitrate. Journal of Environmental Quality. 36:354-362
Jang, G., Sudduth, K.A., Hong, S.Y., Kitchen, N.R., Palm, H.L. 2006. Relating hyperspectral image bands and vegetation indices to corn and soybean yield. Korean Journal of Remote Sensing. 22(3):183-197.
Jiang, P., Anderson, S.H., Kitchen, N.R., Sadler, E.J., Sudduth, K.A. 2007. Landscape and conservation management effects on hydraulic properties on a claypan-soil toposequence. Soil Science Society of America Journal. 71:803-811.
Jung, W., Kitchen, N.R., Anderson, S., Sadler, E.J. 2007. Crop management effects on water infiltration for claypan soils. Journal of Soil and Water Conservation. 62(1):55-63.
Jung, W., Kitchen, N.R., Sudduth, K.A., Anderson, S.H. 2006. Spatial characteristics of claypan soil properties in an agricultural field. Soil Science Society of America Journal. 70(4):1387-1397.
Jung, W., Kitchen, N.R., Sudduth, K.A. 2006. Relationship of soil profile strength and apparent soil electrical conductivity to crop yield. Korean Journal of Soil Science and Fertilizer. 32(2):109-115.
Kim, H., Sudduth, K.A., Hummel, J.W. 2006. Sensing nitrate and potassium ions in soil extracts using ion-selective electrodes. Journal of Biosystems Engineering. 31(6):463-473.
Kim, H., Hummel, J.W., Sudduth, K.A., Birrell, S.J. 2007. Evaluation of phosphate ion-selective membranes and cobalt-based electrodes for soil nutrient sensing. Transactions of the ASABE. 50(2):415-425.
Kremer, R.J. 2007. Deleterious Rhizobacteria. In: Gnanamanickam, S., editor. Plant-Associated Bacteria. Bordrecht, The Netherlands: Kluwer Academic Publishers. p. 335-357.
Martin, N., Bollero, G.A., Kitchen, N.R., Kravchenko, A.N., Sudduth, K.A., Wiebold, W.J., Bullock, D.G. 2006. Two classification methods for developing and interpreting productivity zones using site properties. Plant and Soil. 288(1-2):357-371.
Mungai, N.W., Motavalli, P.P., Kremer, R.J. 2006. Soil organic carbon and nitrogen fractions in temperate alley cropping systems. Communications in Soil Science and Plant Analysis. 37:977-992.
Patthra, P., Motavalli, P.P., Kremer, R.J., Anderson, S.H. 2007. Soil compaction and poultry litter effects on factors affecting nitrogen availability in a claypan soil. Soil & Tillage Research. 91(1):109-119.
Scharf, P.C., Kitchen, N.R., Sudduth, K.A., Davis, J.G. 2006. Spatially variable corn yield level is a weak predictor of optimal nitrogen. Soil Science Society of America Journal. 70:2154-2160.
Souza, E.G., Scharf, P.C., Sudduth, K.A., Hipple, J.D. 2006. Using a field radiometer to estimate instantaneous sky clearness. Brazilian Journal of Agricultural and Environmental Engineering. 10(2):369-373
Yildirim, S., Birrell, S.J., Hummel, J.W. 2006. Laboratory evaluation of an electro-pneumatic sampling method for real-time soil sensing. Transactions of the ASABE. 49(4):845-850.
Means, N.E., Kremer, R.J. 2007. Influence of soil moisture on root colonization of glyphosate-treated soybean by fusarium species. Communications in Soil Science and Plant Analysis. 38:1713-1720.