Using the Integrated Farm System Model to Improve Nitrogen Management

Converting the farm operation from daily haul to six months of storage with broadcast application did not substantially change N losses to the environment. However, switching to manure injection conserved ammonium-N and improved manure N use efficiency by crops even though it increased N leaching by 27% with six months of storage and 13% with 12 months of storage. Increasing manure storage from 6 to 12 months with manure injection reduced nitrateN leaching by 38% due to better timing of manure application to crop growth, but annual net returns were lowered. Overall, combining manure storage with injection was the best environmental and economic option.