Effect of Dairy Manure Injection on Soil Carbon and Nitrogen Cycling.

Effect of Dairy Manure Injection on Soil Carbon and Nitrogen Cycling

William W. Smith, Rory O. Maguire, Mike Strickland and Steve Hodges

Surface application of dairy manure leads to high levels of ammonia (NH₃) volatilization and nutrient losses in surface runoff, leading to eutrophication in sensitive aquatic environments. As a result of the NH₃ volatilization, less plant available N is available to crops such as corn, requiring a second application of chemical N fertilizer to meet crop N requirements. Manure injection is a technique that places liquid dairy manure below the surface by using a disk or chisel to open a trough for the manure, and closing disks or wheels to seal the trough, resulting in lower rates of volatilization and greatly reduced runoff nutrient losses. This presentation will focus on the differences between surface application and manure injection treatments in respect to N cycling and volatilization, and changes in soil carbon fractions and long-term mineralization.