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通过室内和田间结合试验,研究了不同滴头流量、灌溉制度、滴灌年限对土壤盐分运移及累积特征的影响。结果表明:相同灌水量下,滴头流量越小,单点处及交汇区在土壤垂直方向上盐分含量越小;在土壤水平方向,滴头流量越大,土壤盐分随着距离单点或交汇中心越远而逐渐增加。在相同湿润层次上,交汇区的盐分要高于单点处的盐分,单点处土壤脱盐深度大于交汇区土壤脱盐深度。相同滴头流量下,灌水量大的土壤盐分运移距离较深,盐分累积层次下移。较短的灌水周期对土壤盐分具有较好的淋洗作用;灌水周期较长的处理,土壤盐分波动变化较大,生育期中出现返盐现象。灌溉定额3 300、3 900、4 500 m3/hm2的土壤盐分峰值分别出现在土壤深度60、80、100 cm处。随着滴灌年限的延长,土壤0～100 cm盐分呈逐渐累积的趋势,累积的层次渐渐向地表迁移,滴灌年限相差6～7 a的棉田土壤盐分差异达到显著水平(P<0.05)。
Through indoor and field experiments, the effects of different dripper flow rates, irrigation regimes and drip irrigation years on soil salinity transport and accumulation characteristics were studied. The results show that under the same irrigation volume, the dripper flow rate is smaller, and the salinity content in the vertical direction of the soil is smaller in the single point and the intersection area; in the horizontal direction of the soil, the greater the dripper flow rate, The farther the center increases gradually. At the same wetting level, the salinity in the crossing area is higher than that at the single point, and the desalting depth of the soil at the single point is larger than the desalting depth of the soil in the crossing area. Under the same dripper flow, the soil salinity with a large amount of irrigation was migrated deeper and the salt accumulation level was shifted downwards. Short irrigation cycles had a good leaching effect on soil salinity. When the irrigation cycles were longer, the variation of soil salinity fluctuated greatly, and the salt return phenomenon occurred during the growth period. Soil salinity peaked at the depths of 60, 80 and 100 cm, respectively, at the irrigation quota of 3 300, 900 and 4 500 m 3 / hm 2. With the extension of drip irrigation years, the salt content of 0-100 cm soil gradually accumulated, and the accumulated layer gradually migrated to the surface. The difference of soil salinity in cotton fields with drip irrigation duration of 6-7 years reached a significant level (P <0.05).