Effects of Alternating Sodic and Non-sodic Irrigations on the Build-up of Sodium in the Soil and on Crop Yields in Northern India
SUMMARYIn a field experiment, the effects of irrigating crops alternately with sodic water (high in sodium adsorption ratio and ) and good quality canal water were investigated for six years on a well drained sandy loam (Typic Ustochrept). The irrigation treatments included: irrigation with non-sodic canal water (CW), irrigation with sodic water (SW), CW irrigation alternating with one or two SW irrigations, and two CW irrigations alternating with one SW irrigation. The results showed that the use of sodic water increased the sodium saturation of the soil and decreased rice and wheat yields. The build-up of sodium depended on the number of SW irrigations during the season. The increase in sodium saturation and decline in crop yields were progressive over the years. The improvements in yield due to alternating sodic and non-sodic irrigations compared with the use of sodic water alone increased over the years. Alternating sodic and non-sodic irrigations could therefore be considered a practical way to alleviate the problems caused by sodic water. The number of sodic irrigations during a season should, however, be kept to a minimum and the build-up of sodium in the soil over time should be monitored.