EFFECT OF SOIL ACIDITY ON BARLEY PRODUCTION IN THE SOUTH-WEST OF WESTERN-AUSTRALIA .1. THE INTERACTION BETWEEN LIME AND NUTRIENT APPLICATION

The effect of soil acidity on barley growth in Western Australia and the role of aluminium toxicity and nutrient deficiencies were examined at 9 sites using 5 application rates of lime and 3 levels of supply of nutrients. Nutrient plant analysis was also used to assess the mechanisms involved in any response to lime. Lime application increased barley yields at 3 sites, by 9-30%, by alleviating aluminium toxicity. Nutrient treatments did not interact with the lime response. The largest reduction in grain yield (> 15%) that was due to aluminium toxicity occurred at the site which had the lowest pH (4.3 in 0.01 mol CaCl2/L) and the highest concentration of CaCl2-extractable aluminium (5-mu-g/g).