Michigan State University Extension
Soils & Soil Management - Fertilizer - 06029710
07/10/97
Fertilizer Recommendations for Field Crops in Michigan Extension Bulletin E-550A, March 1992
D. R. Christenson, D. D. Warncke, M. L. Vitosh, L. W. Jacobs and J. G. Dahl, Department of Crop and Soil Sciences
Applying organic materials to Michigan soils for crop production is an accepted agricultural practice. In addition to animal manures, other organic materials including sewage sludge, septage, food processing wastes, and fermentation wastes are applied to soils in Michigan.
It is highly desirable to recycle nutrients and organic matter contained in these materials. However, some potential hazards may be encountered when organic materials are applied to the soil-plant system for crop production if good management practices are not followed. These can include excessive additions of nutrients, additions of trace elements and trace organic chemicals, pathogens, soil physical problems, odors and insects which spread disease. The Department of Crop and Soil Science at MSU can help you evaluate the benefits/risks of applying a specific waste by-product to crop land.
The application of most organic materials to land in Michigan is regulated by the Michigan Department of Natural Resources (MDNR). Any land application program must be approved by the MDNR. However, this agency has not required livestock producers to obtain permits for land application of manures, except where poor manure handling and management have contaminated water. For more information concerning MDNR requirements, contact the MDNR Waste Management Division, PO Box 30028, Lansing, MI 48909.
Animal manure can be a valuable source of nutrients for crop production. However, the nutrient varies considerably from farm to farm, depending on many factors, including animal species, feed used, amount and type of bedding, and amount of water added. (Vis. 7) shows the wide range in nutrient composition of manures sampled from numerous farms. Due to this wide variation, average nutrient values can be very misleading. The recommended method to determine the nutrient content for manure is to sample the manure and send it to a laboratory for analysis. The results should include: percent dry matter, ammonium nitrogen (NH4-N), total nitrogen, phosphate (P2O5) and potash (K2O).
The manure analysis should then be used in conjunction with the rate of application to calculate the amount of nutrients supplied from the manure. By giving credit for nutrients supplied from manure, the risk of water pollution will be minimized and economic benefits will also be gained.
There are a number of management practices which are suggested for producers utilizing animal manure. First, fields receiving manure should be sampled and tested every three years. Use these results along with a realistic yield goal to determine the nutrient needs for the crops to be grown. Second, analyze manure for its nutrient content. Subtract the quantity of nutrients supplied from the fertilizer recommendations to determine need for additional fertilizer nutrients. Third, do not exceed the agronomic rate of nitrogen for crops by the amount of available nitrogen in the manure applied or in the manure plus fertilizer used. Fourth, follow soil and water conservation practices to reduce the risk of nutrients entering surface water. Practices used to control runoff and erosion for a particular site should consider factors such as type of manure, surface residue or vegetative conditions, slope, soil type and proximity to surface water. Fifth, keeping records of manure analyses, soil test reports and rates of manure and fertilizer application for individual fields helps identify land areas needed for effectively utilizing the nutrients contained in animal manures. Good record keeping demonstrates good management and may be beneficial if the producer's management practices are challenged.
See Extension Bulletin WQ-12, "Livestock Manure Management for Efficient Crop Production and Water Quality Preservation" for methods of accounting for nutrients supplied from manures. Additional recommended manure management practices can be found in "Generally Accepted Agricultural Practices for Manure Management and Utilization," as adopted by the Michigan Commission of Agriculture.
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| Range in nitrogen, phosphate and potash analysis for animal - 24K |
