IMPLEMENTATION OF A MASS BALANCE APPROACH TO PREDICTING NUTRIENT FATE OF MANURE FROM BEEF CATTLE FEEDLOTS

Alivestock producer is faced with many decisionseach year, such as deciding when to purchaseanimals, what ration to feed, tacticalmanagement adjustments to counter the weather, when to sell, and a range of animal health and welfare issues. Cattle feedlot managers often produce grain as well, with additional decisions such as planting, tillage, fertilizer, irrigation scheduling, and other production related tasks. Expediency often dictates choices of convenience for waste management (the nearest field generally gets the most manure) or no decision at all until a problem occurs. Engel et al. (1990) pointed out the need for expertise in many domains to be an effective and efficient producer. Access to information relevant to the decisions and expertise in the manure management decision process is often difficult if not impossible to achieve. Schulte et al. (1994) noted that much technical information exists on the design and evaluation of manur