Guan'gai paishui xuebao (Jun 2024)
The effect of dual spring-summer irrigations on water and salt transport in saline- alkali soil and water use of sunflower in Hetao Irrigation District
Abstract
【Objective】 A pre-planting border irrigation in spring coupled with a drip irrigation in summer during crops growth season is an irrigation technique to reduce soil salinity and safeguard crops growth in the salt-affected soils in the Hetao Irrigation District in Inner Mongolia. This paper investigates the impact of different combinations of irrigation amounts in the dual irrigations on changes in soil water and salt, as well as the growth of sunflower. 【Method】 The field experiment compared two spring (S) irrigation amounts: 95 mm and 135 mm, and three summer (W) irrigation amounts: 68, 100 mm and 135 mm. In each treatment, we measured the spatiotemporal changes in soil water and salt, as well as crop growth characteristics. 【Result】 ① The soil water content in the S135W135 treatment was the highest among all treatments during the experimental period, with the average soil water content and saturation being 17.10% and 75.53%, respectively. The coefficient of variation of soil water content in the S95W135 treatment was 22.40%, the lowest among all treatments. ② Depending on the summer irrigation amount, the desalination rate of the 0-80 cm soil layer under S135 and S95 varied from 32.64% to 50.50% and 21.8% to 38.87%, respectively. Although the spring irrigation amounts did not significantly affect immediate post-irrigation salt content, the S135W100 and S95W135 combinations showed deeper leaching depths and higher desalination rates (40.77% and 33.37%, respectively) than other treatments. ③ Aboveground dry matter production was significantly higher in the S95W135 and S135W100 combinations than in other combinations, surpassing the S135W135 combination by 10.55% and 9.94%, respectively. The S135W100 combination achieved the highest water use efficiency at 21.59%, an increase of 13.03% compared to S135W135. 【Conclusion】 Reducing spring irrigation by 30% to 95 mm combined with a summer drip irrigation of 135 mm is the most efficient irrigation scheme for sunflower cultivation in the salt-affected soils in the Hetao Irrigation District.
Keywords
