Water Resources Research Act Program

Details for Project ID 2004MI50B

Use of Spatial Data and GIS in Evaluating Manure Application Risk Index (MARI)

Institute: Michigan
Year Established: 2004 Start Date: 2004-03-01 End Date: 2005-02-28
Total Federal Funds: $15,000 Total Non-Federal Funds: $30,541

Principal Investigators: Da Ouyang, Carrie Laboski

Project Summary: Proper manure management is essential to the profitability of livestock producers, and must also address environmental concerns about nutrients, microorganisms, and organic matter from manure/sediment potentially polluting water resources. The Manure Application Risk Index (MARI), as developed by NRCS specialists, is used by farmers and agency personnel to evaluate fields for winter spreading of manure in an environmentally responsible manner. The MARI is based on 12 weighted field factors, including soil groups, soil test P value, concentrated water flow, vegetative buffer width, and manure application rates and methods. Daily hauling of manure remains a common practice in the Midwestern region as an economically viable method for winter manure application. In addition, the cost impacts of alternative manure management options are significantly higher. Liquid manure management 8-month storage systems, for example, are 3-6 times more costly depending on operation size. The MARI is used in Michigan as a part of the state-recognized Generally Accepted Agricultural Management Practices (GAAMP). It has the potential for use throughout the region to assist livestock operators in evaluating areas to determine whether the level of environmental risk associated with manure applications is acceptable or unacceptable. However, wider use of the MARI approach requires additional, broad-scale field verification of its usefulness in various soil types, landscapes, and manure management systems to facilitate its application throughout the Midwestern region. In this study, we will use spatial datasets including digital soils and elevation data in applying MARI for several fields that are selected by NRCS-USDA in Michigan for evaluation. As this risk index is more extensively evaluated, policymakers will become increasingly cognizant of its value. Wider use of this risk index is expected to facilitate broader acceptance of manure application on soils throughout the year where data indicates it is safe to do so. The end result will be effective environmental protection and enhanced farm profitability.