My research interests are mainly related to examining nutrient use efficiency and overcoming the soil constraints of water repellence and aluminium toxicity in the cropping system of Western Australia. My main research activities in agricultural production are in the field of nutrient management (nitrogen-N, sulphur-S, phosphorus-P and potassium-K). I have done work defining soil test–crop response relationships and developed models for making fertilizer and lime decisions. I have examined how lime and gypsum can be used to manage subsoil aluminium-Al toxicity. I have developed a surfactant seed coating technique that is effective in overcoming water repellent soils.