Soil Properties as Influenced by Phosphorus- and Nitrogen-Based Manure and Compost Applications

Abstract

Manure or compost application based on N needs of corn (Zea mays L.) may result in soil accumulation of P, N, and other ions, since the manure or compost N/P ratio is usually smaller than the corn N/P uptake ratio. This study was conducted from 1992 to 1996 to evaluate the effects of annual or biennial application of N- and P-based composted and noncomposted beef cattle (Bos taurus) feedlot manure on soil properties. Fertilized and unfertilized checks were also included. Soil surface (0–15 cm) pH significantly increased with N-based manure (MN) or compost application (CN), but decreased with NH4–N fertilizer application as compared with the check. Soil bulk density was unaffected by manure or compost application. After 4 yr of manure and compost applications, soil surface (0–15 cm) C and N concentrations and quantities were greater for N- than P-based management systems. About 25% of applied manure C and 36% of applied compost C remained in the soil after 4 yr of application, indicating greater C sequestration with composted than noncomposted manure. No significant difference was observed between fertilizer and check plots for soil total C or N. Soil properties in the 15- to 30-cm increment were unaffected by the applied treatments except soil electrical conductivity (EC). Residual soil NO3 to a depth of 1.2 m was greater for inorganic fertilizer than manure and compost treatments in drier years. Soil property changes were greater for the annual or biennial N-based than P-based manure or compost applications, reflecting the differences in application amounts.