Perspectives

The cost of proper manure application may exceed the value of the increase in available nutrients compared with the current inefficient application methods. The effect of manure application methods on nitrogen loss, not including loss during storage, is 15-30% without incorporating manure into the soil, but when manure is incorporated into the soil soon after application nutrient loss sinks from 1-5% (National Research Council, pp. 151). Different storage and handling systems of manure have a large range of nitrogen loss (15-80%, National Research Council) depending on the stability of the system. Also, manure frequently is not applied at a time in the growing season that results in optimal use of the manure as fertilizer. Often systems are designed to dispose of animal waste as an undesirable by-product. Therefore, systems need to be developed so that animal waste will be used more efficiently. More research needs to be done to devise low-cost systems that will profitably store, handle, and spread manure. These systems would be better for the environment and more economical for the farmers.