Cuurently some nutrient management plans in the United States are based on live animal weight for a production unit. As the swine industry has intensified the size of the earthen manure storage has also increased. Newly constructed, larger manure storage facilities contain a higher total nitorgen level than smaller facilities, has resulted in cases where insufficient land was available to receive manure at the planned rate. Manure volatilization occurs at a very consistent rate of volatization, which keeps the total nitrogen at a fairly consistent level. Volatization rate will be dependant on several factors such as pH, temperature and lagoonm design. Therefore future nutrient management plans may need to incorporate design characteristics of the manure storage facility, rather than on animal weight alone.