Cropping System and Type of Pig Manure Affect Nitrate‐Nitrogen Leaching in a Sandy Loam Soil

The application of livestock manure can result in the loss of nitrate‐nitrogen (NO3−‐N) and degrade surface and groundwater. A 3‐yr lysimeter study was set up to compare the effect of cropping system and nitrogen (N)‐ and phosphorus (P)‐based pig manure application rates on the loss of water and NO3−‐N below the root zone. The experiment was a split‐plot design with annual and perennial cropping systems as the main factor. Five nutrient management treatments were the subplots: N‐based liquid pig manure application; P‐based liquid pig manure application, N‐based solid pig manure application, P‐based solid pig manure application, and a control without amendment. The results showed that 40 to 60 kg NO3−‐N ha−1 was lost from the annual plots in 2010 and 23 to 60 kg NO3−‐N ha−1 in 2011, whereas a negligible amount of NO3−‐N was lost from the perennial (