[Effects of binary coverage on soil water content in apple orchards during low-water-consumption growth period]

To investigate the effects of intercropped rape and film mulching on soil water content in dryland apple orchards during the low-water consumption period on the Loess Plateau, soil water content and soil water storage were measured with in situ field observations. The results showed that at the sprout period of apple trees, mean water content in 0-200 cm soil layer under apple trees with film mulching + intercropping 50% width rape (PR₁) and apple trees with film mulching + intercropping 100% width rape (PR₂) treatments increased by 7.9% and 6.9% compared with the control (apple trees without film mulching+row clearing), respectively. At the blossom period of apple trees, mean soil water content under these two treatments increased by 3.5% and 6.9%, respectively. At the sprout period of apple trees, soil water competition between apple trees and rape occurred in both PR₁ and PR₂ treatments, with the competition being most severe at the boundaries. At the sprout period, competition in the PR₁ treatment was less intense than that in the PR₂ treatment. At the blossom period, competition in the PR₁ treatment was not obvious, but the competition in the PR₂ treatment was significant. Moreover, at the sprout and blossom period, a low-soil-water-content zone was observed in the PR₂ treatment. Compared with the control, both PR₁ and PR₂ treatments increased soil water storage in 0-80 cm layer, and soil water was not deficit in the 0-200 cm layer. In conclusion, the implementation of PR₁ model is conducive to improve soil water availability in the dryland apple orchard on the Loess Plateau during the low-water consumption period.