Location: National Soil Erosion Research2017 Annual Report
Objective 1: Quantify short- and long- term impacts of drainage water management, cover crop and manure application on soil and water quality, and greenhouse gas emissions of the Eastern Corn Belt. Objective 2: Assess climate change impacts on erosion and water quality for the Eastern Corn Belt using projected climate scenarios with the WEPP and SWAT models.
1. Monitor and assess changes in soil and water quality and greenhouse gas emission under different drainage water management, cover crop and manure applications at university research farms as well as farmer fields as a part of the Long-Term Agro-ecological Research (LTAR) network for the Eastern Corn Belt. 2. Downscale global climate change scenarios for the Eastern Corn Belt and perform simulations using the Water Erosion Prediction Project (WEPP) model Soil and Water Assessment Tool (SWAT) to assess the climate change effects on erosion and water quality at the region.
Field sites at Purdue University Davis Farm in central Indiana and 3 paired farm fields in northeastern Indiana have been instrumented for different drainage water management, cover crop and nutrient management research. Water quality samples are being collected for these sites. One specific paired farm fields are designated as a part of the Long-Term Agro-ecological Research (LTAR) network for the Eastern Corn Belt. The commonly used weather file generator in climate change research (MarkSim) was used to evaluate the impact of long-term conservation practice implementation on runoff, sediment, pesticide and nutrient losses in northeastern Indiana. The Soil and Water Assessment Tool (SWAT) model was used to test current and future estimates of climate conditions on effectiveness of no-tillage, vegetative filter strips, grassed waterways, blind inlets, and nutrient management. Manuscripts are being prepared for publicaiton.
1. Different soils erode differently. Purple and Loess soils are main sources of sediments in two largest rivers in China, i.e., the Yangtze River in the south and the Yellow River in the north. Despite many past research efforts in quantifying the erosion potential of these two soils, there has not been an experiment that these two soils are compared together. ARS scientist at West Lafayette, Indiana and Chinese cooperators measured erosion in rill channels under concentrated water flow found a general trend of a decreased detachment was decreased as either sediment concentration or rill length were increased. Nevertheless, the Purple soil was less erodible and reached a maximum sediment level much quicker than the Loess soil. The important message from this study is that different soils may have similar erosion trends, but have different specific responses depending on properties of the particular soil. More importantly, identical erosion research techniques need to be used when assessing erosion potential of different soils.
2. Timing of manure application is critical in water quality protection. The increased confined animal production systems have triggered an increased land application of liquid manures. Liquid manures do have plant nutrients, but improper timing of its application may cause nutrient runoff and affect water quality. ARS scientists at West Lafayette, Indiana and Brazilian cooperators measured runoff, sediment and nutrient losses from rainstorms one and seven days after manure application on soil blocks from no-till and conventionally-tilled fields in Indiana. The conventional tillage system produced greater runoff, sediment and nutrient losses than those from the no-till system. Rainfall occurred one day after the manure application resulted in higher losses in both conventional and no-till systems as compared to those from a rainfall event 7 days after manure application. Therefore, it is important to use weather forecast in making decisions on when to apply liquid manure to obtain agronomic benefits and avoid risk of water pollution.
Chen, X., Huang, Y., Zhao, U., Mo, B., Mi, H., Huang, C. 2017. Analytical method for determining rill detachment of purple soil as compared with that of loess soil. Journal of Hydrology. 549:236-243.
Cherobim, V.F., Huang, C., Favaretto, N. 2017. Tillage system and time post-liquid dairy manure: Effects on runoff, sediment and nutrients losses. Agricultural Water Management. 184:96-103.
Mamedov, A.I., Huang, C., Aliev, F.A., Levy, G.J. 2016. Aggregate stability and water retention near saturation characteristics as affected by soil texture, aggregate size and polyacrylamide application. Land Degradation and Development. 28:543-552.
Wallace, C.W., Flanagan, D.C., Engel, B.A. 2017. Quantifying the effects of conservation practice implementation on predicted runoff and chemical losses under climate change. Agricultural Water Management. 186:51-65.