The impact of deep manure injection on water infiltration, nutrient distribution and corn yield

Manure application often results in accumulation of phosphorus at the soil surface where it is vulnerable to runoff. Deep manure injection may reduce this problem. Research was conducted in eastern South Dakota in 2004 and 2005. Water infiltration was measured with a sprinkle infiltrometer and a ponded (double-ring) infiltrometer. Inorganic N and Bray1-P levels were measured at four depths, and the nutrient distribution was measured by depth and distance from the manure slot. Corn grain yield was measured. Manure injection to 0.45 m (DI) either increased or did not influence water infiltration. Results from one site indicated DI lowered soil test P relative to 0.15 m manure injection at the surface. DI increased soil NO3--N one year after manure application. DI increased or did not influence corn grain yields. These results suggest that DI will decrease soil test P at the surface, increase water infiltration, and increase corn yields.