Date of this Version
Great Plains Beef Cattle Handbook, 1991, 4 pages.
The application of animal manure to farmland is an appropriate and environmentally sound management practice for most feedlot operators. Land application returns nutrients from manure to the soil and helps build and maintain soil fertility. In addition to containing nitrogen, phosphorus and potassium, manure contains trace "elements such as calcium, magnesium, iron and zinc. Manure has also been shown to improve soil tilth, increase water-holding capacity, lessen wind and water erosion and improve aeration. Land application of manure should be viewed as a means to utilize crop nutrients present in the manure for crop production rather than utilizing the land as a means of disposal.
The economic value of feedlot manure as fertilizer is usually calculated on the basis of its N, P2O5, and K2O content. Manure containing significant amounts of runoff or dilution water may also serve as an irrigation water source where needed. Although the nutrient content of this water is usually low, it should be regarded as a fertilizer source. In such cases, calculation of the value of the manure and wastewater for crop production must include both the nutrient and water value.
A number of factors must be considered when determining the amount of manure each soil is capable of handling without damage to the soil and to the surrounding environment. These factors include soil type, topography of the land, cropping system, and the nutrient and salt content of the manure and wastewater to be applied.
The rate of manure and wastewater application depends upon whether one wants to maximize the recovery of plant nutrients or the amount of manure that can be applied per unit of land area. Where an adequate land base exists, all attempts should be made to maximize nutrient recovery by application rates consistent with crop utilization rates. However, where a large concentration of cattle is maintained on a relatively small land base, manure application rates may be designed to maximize the application rate while avoiding any deleterious effects on the land.