Trends in some soil test data over a 14‐year period in New Zealand

摘要

Abstract To establish long‐term trends in soil fertility in New Zealand pasture lands, data for Olsen phosphate (Olsen P), pH, and QuickTest (QT) calcium (Ca), magnesium (Mg), and potassium (K) from 246 000 soil samples submitted to a commercial soil sampling laboratory from 1988 to 2001 were analysed. Each record was categorised according to year, land use (dairy, sheep/beef including deer), soil “group” (sedimentary, volcanic, pumice, peats, rest), and regions. Olsen P values were, on average, higher on dairy farms than sheep/beef farms and lower on sedimentary soils than other soils (P > 0.05). Sedimentary and volcanic soils had higher QT K than pumice and peat soils (P > 0.05). Regional differences were largely explained by differences between land use and soil group distribution. However, given this distribution, average Olsen P values were higher in the Waikato, Bay of Plenty/Taupo and Taranaki regions, the east coast of both islands generally had higher average pH, K, and Mg soil test values, and t...