Effect of saline water on rice yields and soil properties in the Murrumbidgee Valley

Abstract

Rice was grown on a transitional redbrown earth for 3 consecutive seasons and irrigated with saline groundwater of salinities 0.25, 0.5, 1.0, 1.5 and 2.0 dS/m. A 4.0 dS/m treatment was applied in the final year. Grain yield was only affected by the 4.0 dS/m treatment, where a 25% yield reduction occurred. Soil salinities increased with increasing salinity of applied treatments, reaching equilibrium after 3 years. The higher salinity treatments resulted in significantly increased rice field water consumption, attributed to increased infiltration rates. The presence of high electrolyte levels in the soil surface prevented any detrimental effect of increased soil sodium levels on soil properties. However, the communal supply system with potential cultivation of salt-sensitive species such as soybean, along with the potential for higher groundwater accessions, suggests that the salinity of irrigation water should be maintained as low as possible.