Temporal changes in topsoil qualities of dairy pasture and maize cropping sites in the Bay of Plenty Region, New Zealand

摘要

Temporal changes in topsoil qualities of dairy pasture and maize cropping sites were monitored periodically over a ten-year period. Results indicate that for both sites, many of the topsoil quality parameters were being maintained and these are withinthe provisional target values set by Landcare Research New Zealand for production and/or environmental criterion. However, the steady increase in the levels of anaerobicaUy rnineralisable N and Olsen P in dairy sites is a concern. High values of anaerobically mineralisable N could potentially lead to increased nitrate leaching while high values of Olsen P could lead to P-rich sediments polluting water bodies.