STUDY ON THE TRANSPORTATION PATTERN OF WATER AND SALT IN SOIL OF HIGH-DENSITY JUJUBE ORCHARDS UNDER DRIP IRRIGATION IN SOUTH XINJIANG

Abstract

To reveal the pattern of water and salt movement with drip irrigation of high-density jujube orchards in South Xinjiang, soil moisture and salt contents were examined in the horizontal and vertical directions in key growing phases of Chinese jujube. The results showed that the salt contents displayed a descending trend in 0-40 cm soil layers and increasing-decreasing changes in 40-80 cm, whereas water contents in each soil layer presented a smoothly descending trend throughout the growing period. Before the drip irrigation was applied, water and salt contents increased with the depth of soil, and soil moisture in 40-60 cm was the highest. After irrigation, water contents became much higher with the increase of soil depth to the extent of 0-80 cm, but soil-salt in 0-40 cm reduced and soil-salt in 60-80 cm increased. In the horizontal direction, the salt contents were higher in the remote area from the water dripper. Such trends with the increase of soil depth weakened gradually to the extent that salt contents in 25 and 50 cm far from the water dripper were similar to the soil layer of 40-80 cm. Our results indicated that salt contents were rinsed to the outer edge of the wet body with water movement starting from the drip emitter, which resulted in a low salt zone in 0-40 cm soil layer.