Crop Availability of Phosphorus in Beef Cattle Manure for Corn and Soybean
An efficient utilization of beef cattle manure nutrients is important to improve the sustainability of animal and crop production systems and avoid unnecessary use of energy and non-renewable resources. Manure phosphorus (P) management differs from inorganic fertilizers for several reasons. There is large variation in P concentration, manure has organic and inorganic P forms, and manure handling is more difficult. Organic P forms may not be entirely or immediately available for plant uptake but may become available over time. There is uncertainty about the crop-availability of beef manure P, which is reflected by a wide range (60 to 100%) of estimated availability in Iowa (see Extension publication PMR 1003). Therefore, a study was conducted at the Northern Research Farm, Kanawha, Iowa, in 2012 and 2013 to assess the crop-availability of manure P from selected Iowa beef production systems.