Nutrient supply from soil organic matter under different farming practices in the Central West of NSW

Abstract

Key findings »» Conventional tillage enhances soil organic carbon (SOC) turnover with the potential to simultaneously increase plant available nutrients [nitrogen (N), phosphorus (P), sulfur (S)] in the soil compared with no-till and perennial pasture. »» Across farming management practices and under ideal soil moisture, soil organic matter (SOM) could have supplied up to 45 kg N, 16 kg P and 19 kg S/ha in the absence of plant carbon (C) input. »» Over a longer period (126 days), particularly if there is a lack of plant C input (e.g. a normal fallow period), any P or S released via native SOM turnover over a shorter period (e.g. over 30 days) would have been immobilised by microorganisms and/or adsorbed to soil minerals, hence decreasing P and S availability for crop uptake.