salinity, and low exchangeable K concentrations are common constraints in many cracking clays. Recommendations for ameliorating sodicity include applying gypsum alone or in combination with deep tillage. Potassium deficiencies are usually managed by applying mineral fertilisers, although many farmers are interested in using animal manures as substitutes. The objective of this study was to quantify changes to sodicityrelated soil properties and exchangeable K concentration due to applying gypsum, K fertiliser and cattle manure in a region with an erratic rainfall distribution. Soil was sampled from a rainfed trial in southern Queensland. Cattle manure improved potassium availability by 0.16 t/ha and decreased ESP. Gypsum and K fertiliser application also decreased ESP, and the latter increased exchangeable K, albeit to a lesser extent than manure. Decrease in ESP was not, however, sufficient to reduce dispersion and improve drainage. Gypsum application did not overcome the effects of sodicity. Crop yields were unaffected by gypsum, manure or mineral fertiliser application, suggesting that their application may not be economically rational in an environment where rainfall is erratic.