American agriculture has enjoyed a growth In technological productivity since the early 1900*s. Barely does one method of efficiency become commonplace before the newest "state of the art" technologies push their way to the forefront in our eagerness to improve productive efficiencies still faster. With this trend issues of environmental soundness have arisen. Agriculture has moved to fewer and larger production complexes. Livestock production has, like most other farm enterprises, become more concentrated. Concentration has given rise to animal waste disposal problems and their parallel environmental Impacts. Animal manure has typically been treated as a waste product to be disposed in the least cost way. Its value as a fertilizer has been overlooked.