Nitrogen availability and leaching front soil amended with municipal solid waste compost

Beneficial use of municipal solid waste compost depends on identifying a management strategy that supports crop production and protects water quality. Effects of compost and N fertilizer management strategies on corn (Zen mars L.) yield and NO3--N leaching were evaluated in a 3-yr study on a Hubbard loamy sand soil (sandy, mixed, Udorthentic Haploboroll). Two composts were each applied st either 90 Mg ha(-1) yr(-1) from 1993 to 1995, or at 270 Mg ha(-1) in one application in 1993, The compost and non-amended plots were sidedressed annually with N fertilizer as urea at 0, 125, and 250 kg ha(-1). Biochemical properties of the compost as well as compost management strongly affected crop response and fate of N, Compost increased grain yield with no significant yield response to IV fertilizer with the single compost application in Year 1 and the annual compost application in Year 3. Plant N uptake increased with N fertilizer rate, except in the 270 Mg ha(-1) compost treatments in Year 1, Over the 3-yr period, NO3--N leaching with the 270 Mg ha(-1) compost application was 1.8 times greater compared to that with the annual application. The estimated N mineralization ranged from 0 to 12% and 3 to 6% in the annual and single compost addition, respectively, Under the conditions of this study, annual compost application with reduced supplemental N fertilizer was the best management strategy to reach optimum crop yield while minimizing NO3--N leaching losses.