Effects of ridge planting on crop seedlings under saline water drip irrigation

Abstract

AbstractA field experiment was conducted in northwest China to study the effects of different irrigation water salinity levels on the emergence and growth of corn, sunflower, summer squash, and cowpea. Two tillage systems (flat and ridge planting) and five salinity levels (at 1.7, 4.0, 6.3, 8.6, and 10.9 dS/m) were tested. Compared with flat planting, the soil salinity within 30 cm horizontally from the drip tapes decreased by 15% in the ridge planting system. Ridge planting significantly improved the emergence and growth of crops, which was mainly manifested in higher emergence rates, reduced emergence time, and increased dry biomass, especially under high‐salinity conditions (electrical conductivity of irrigation water >4 dS/m). The electrolytic conductivity of the saturation extract threshold at which corn, sunflower, summer squash, and cowpea endured without reduced emergence rates was 5.8, 5.8, 4.8, and 4.0 dS/m, respectively. Above this threshold, the relative emergence rate decreased by 11%, 16%, 14%, and 20%, respectively. Our results indicate the agronomic benefits of ridge planting, and the soil environment was improved by ridge planting with saline water drip irrigation. In addition, we discuss the crop responses in terms of emergence rates and relative seedling dry biomass in relation to soil salinity. Suggestions for the secure and efficient use of saline water for irrigation in arid regions have been put forward.