U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Document Type
Article
Date of this Version
2002
Citation
Great Plains Soil Fertility Conference, March 5-6, 2002, pp. 61-65
Abstract
Manure can serve as an effective fertilizer source if used properly or can lead to environmental contamination if used improperly. Proper use of manure requires some know ledge of the availability of nutrients contained in the manure. To better understand how soil and environmental variables effect N mineralization in manure amended soils a laboratory study was conducted to measure N-mineralization rates as a function of soil texture, water regime, and temperature. This study is part of a national effort to develop a model to predict nutrient availability from various manure sources across a range of soil and environmental conditions. There was no consistent trend in the effect of soil texture on N-mineralization rates. Manure addition increased N-mineralization rates in all three soils. As temperature increased, N-mineralization rates also increased in control and manure amended soils. Subjecting the soil to wetting and drying cycles did not affect N-mineralization rates likely because the drying cycle was not severe enough to negatively influence microorganism activity. The percentage of manure N-mineralized during the experiment ranged from 60% in a fine sand soil to 129% in a silty clay loam soil. Results suggest that as soil temperatures increase, as they commonly do during the early part of the growing season, N-mineralization rates in swine manure amended soils will also increase. As crop demand for N increases, swine manure should be effective in meeting that demand.