The nutrient status and cultivation practices of the soils of the North-West wheat belt of NSW.

Abstract

A study has been made of the nitrogen, organic carbon, phosphate, and pH levels of the wheat soils of north-western New South Wales, and the cultivation practices adopted. They are found generally to be high in both total and available phosphate, and particularly high figures for available phosphate, over 1000 p.p.m., were found in limited areas. The nitrogen levels of the virgin chernozemic soils are distinctly higher than those of the red-brown earths and red solodic soils, but soils of all groups show a decline with cultivation, which is most rapid in the first 10 years. The introduction of periods under lucerne raises the nitrogen level, but the wheat/grazed fallow or wheat/grazing oats appear to cause the same nitrogen losses as are encountered under continuous wheat, in spite of the prevalence of stubble burning which inevitably accompanies this practice. The average yields of wheat on the chernozemic soils are distinctly higher than those obtained on the red-brown earths and red solodic soils, on some of which nitrogen appears to be limiting.