II. Northland warm temperate, Kaikohe

Annual totals of N fixed by legumes in an intensively managed pasture on a podzol in Northland in 1974–75 and 1975–76 were 368 and 392 kg/ha. The pasture produced 11.4–14.1 t DM/ha, of which one third was white clover ( Trifolium repens L.). Variation in the rate of fixation was small within and between years, and seemed to be most influenced by soil moisture. The generally close correspondence between legume growth rate and N fixation rate, as well as periods of apparent N deficiency, suggest that rates of N mineralisation are very low at this site.