Effect of Annual Amendments of Compost on Nitrate Leaching in Nursery Stock

Abstract

Municipal solid waste (MSW) compost was applied at rates of 56 and 112 t/ha (incorporated) and 224 t/ha (mulch) to mitigate topsoil loss in nursery stock production. In two years, nitrate concentrations in ground water beneath all plots remained below 10 ppm with no significant differences between treatments.In another experiment, nitrate in ground water was measured beneath a high coductive sandy terrace soil amended with a variety of composts. In one experiment, spent mushroom compost (SMC) and chicken manure compost (CMC) were applied yearly at rates of 56 and 112 t/ha to provide all the fertilizer requirements for intensive vegetable production. Nitrate concentrations in ground water beneath all compost-amended plots remained below 10 ppm during the three-year study, while concentrations beneath the fertilized control reached 14.7 ppm in an unusually wet spring. After heavy rains, control plots were more susceptible to nitrate leaching than compost-amended plots in the first two years of the study. Th...