Changes in soil nitrogen following different establishment procedures for Townsville stylo on a solodic soil in north-eastern Queensland

Abstract

The effect of the legume Townsville stylo (Stylosanthes humilis) on soil nitrogen status was studied under mown plots with different conditions of establishment and fertilizer application on a solodic soil in north- east Queensland. Increase in soil total nitrogen 0-7.5 cm of 180 kg N per ha and total nitrogen accession (plant and soil) of 460 kg N per ha was measured over a four year period where the legume was sown into existing spear grass and fertilized with superphosphate at 375 kg per ha per year. Soil nitrogen increases did not occur until the pasture was legume dominant and main increases took place where superphosphate was applied. Under these conditions there was also a dry season accumulation of soil nitrate nitrogen.