ABSTRACT
Sustainability likely has as many definitions as individuals who wish to define it, and the definition is normally biased toward the perception or goal of the one defining. A general definition is normally stated something like “Meeting the needs of the present without compromising the ability of future generations to meet their needs.” Developing a more specific definition and quantifying sustainability becomes difficult. Nutrient cycling and loss to the environment is an important issue in cattle production systems with the most important nutrients being nitrogen and phosphorus. The most common characteristics differentiating these two systems relate to the access to pasture, amount of grain fed, and the type of housing provided for the animals. Stage of life of the animal can also have an impact on the type of system utilized. The application of nitrogen in excess of crop needs can result in elevated concentrations of nitrate-nitrogen in soil, a form of nitrogen that can be lost to groundwater.
