Crop and Soil Response to Application of Cattle and Swine Wastes.

Animal wastes are routinely applied to cropland to recycle nutrients, build soil quality, and increase crop productivity.  A field study was conducted in western Kansas to evaluate long-term applications of animal wastes on irrigated corn production and soil properties.  Swine (effluent water from a lagoon) and cattle (solid manure from a beef feedlot) wastes have been applied annually since 1999 at rates to meet irrigated corn P or N requirements along with a rate double the N requirement (2XN).  Other treatments were three rates of N fertilizer and an untreated control.  Application of cattle manure was greater with the N based than the P based treatment while application of swine effluent was greater with the P based than the N based treatment.  Corn yields were increased by application of animal wastes and N fertilizer.  Grain yields were 1.1 Mg ha^-1 greater following application of cattle manure than swine effluent when applied on an N requirement basis.  Yields were similar for all rates of cattle manure.  Yields were similar for all rates of swine effluent except for one year when the 2XN rate reduced grain yield.  After ten years of application, soil test P and organic matter in the surface soil were increased more by cattle than swine waste when applied at rates to meet crop N requirements.  Residual soil nitrate levels were greatly increased by application of swine effluent and cattle manure on a 2XN basis or swine effluent on a P basis.  When applied at rates to meet crop N requirements, residual soil nitrate levels were similar following application of N fertilizer or swine and cattle wastes.