Water Resources Research Act Program

Details for Project ID 2008SD136B

Determining Soil Moisture and Temperature Condition Effects on Potential Run-Off for Cold Season Manure Application

Institute: South Dakota
Year Established: 2008 Start Date: 2008-03-01 End Date: 2010-02-28
Total Federal Funds: $37,594 Total Non-Federal Funds: $74,804

Principal Investigators: Dennis Todey, David German

Project Summary: This is a continuation of a currently funded USGS 104b proposal to determine risk of application of manure on frozen soils and to develop risk assessment indexes for the period of frozen soil and probability of rainfall on frozen soils. Currently NRCS guidelines for application of manure on frozen soils are being reviewed in South Dakota. Balancing the risk of application between producer needs and protection of water quality has been a major part of the discussion. Both producers and regulators have sought scientific data to support their cause. But lacking in the discussion has been specific data related to South Dakota based on South Dakota soils and climatic conditions. This project will continue the process of evaluating those conditions and help deliver some assessment of risk of application based on soil temperature and soil moisture conditions as well as the risk of water quality impairment by run-off from frozen soils. In addition, little work has focused on analyzing weather data to determine the risk of occurrence of conditions that are perceived as potentially detrimental to water quality from manure application on frozen ground. All economic development, whether agricultural, municipal or industrial, is carried out with the understanding of risks and implementation of policies and rules to minimize risks, especially with regard to human health and safety. There are three winter conditions that are expected to yield runoff: 1. Frozen soil and snowmelt that can not enter the soil; 2. Snowfall that insulates the soil from freezing but that is in excess to soil storage; and 3. Rainfall on snowpack or frozen soil. The benefit of this research will be a fundamental understanding of the risk of late winter/early spring conditions that lead to excess runoff. These risk assessments based on historical soil temperature and rainfall data will be the outcome of the current 104b proposal. In conjunction with the current 104b and this proposed 104b the PIs have a complimentary funding request pending to study several watersheds near Brookings for run-off from various manure applications using winter management strategies. These strategies are being chosen in discussion with a local advisory group to determine common manure management strategies. Equipment purchase and deployment for in-situ data gathering is the main focus of the parallel proposed project in addition to PI salary. Missing from the parallel proposal is funding for a graduate student to work on this project. For the purposes of this proposal a continuation of the 104b project is requested to fund a graduate student in soil, water, or climate to gather in-situ soil temperature, soil moisture and run-off data and develop statistical relationships of the run-off based on gathered soil data. The graduate student will work with the PIs to collect runoff data available, analyze the amount and type of run-off based on soil conditions and develop models of soil run-off based on soil type, soil moisture, soil temperature and management. The summarization of this data gathered from these combined experiments will begin to answer questions about the risk of manure application on frozen soils in South Dakota based on realistic in-field conditions and meet the following goals for the combined projects. 1. Complete an assessment of the risk of spreading manure on frozen soils, 2. Compare winter manure spreading practices in relation to location, timing and placement to determine which minimize impacts to water quality and develop BMPs, 3. Develop climatic risk factors using frequency of soil frost and rainfall events on the risk of manure application to assist livestock producers in timing manure applications during least risky time periods.