Slurry dairy manure as corn nutrient source

Abstract

Application of slurry dairy manure were made on five different farms in the Piedmonts region of North Carolina for three consecutive springs and two falls. The manure supplied sufficient nutrients to produce corn (Zea mays L.) silage yields comparable with commercial fertilizer applications at soil test recommendations. The calculated availability of manurial N varied between farms. Yield was usually not significantly different for fall and spring applications of manure, but sometimes the spring manure application resulted in greater yield. The use of a nitrification inhibitor in fall-applied dairy slurry did not give significant yield differences when compared with similar fall treatments that did not receive this material. For maximum manure utilization efficiency application rates should be below 224kg N ha⁻¹ (80 m³ manure ha⁻¹). The slurry manure nutrient concentrations were found to vary considerably between farms and from season to season at a given farm, indicating the desirability of seasonal manurial analysis. Some test sites, due to previou manure and/or fertilizer applications, were found to be unresponsive to either manure or fertilizer applications. Nitrogen availability (NA) was found to vary with site; however, spring manure applications appear to give higher NA values.