【目的】研究膜下滴灌条件下，不同灌溉定额对土壤水盐时空分布特征、春玉米产量和水分利用效率的影响。【方法】在石羊河流域中游，通过2014—2015两年的灌溉试验，对春玉米生育期设置不同灌溉定额（4800、4200和3600 m3·hm-2），测定0—100 cm土层内，土壤水盐时空分布特征，春玉米播种前和收获后土壤全盐量在年内和年际间的变化，春玉米产量及其构成要素。【结果】随灌水定额的增加，0—60 cm土层土壤含水率增加明显，当灌水定额从420 m3·hm-2增加到480 m3·hm-2时，春玉米吐丝扬花期0—60 cm土层平均含水率可保持在24.52%以上。在作物需水关键期，当灌水定额为480 m3·hm-2时，能明显增加深层土壤的蓄水量。当灌溉定额低于360 m3·hm-2时，灌水量严重不足，土壤水分亏缺明显。在非灌溉期，土壤盐分随水分蒸发在表层耕作土壤中积聚。垂直方向上，在0—40 cm土层发生积盐现象，80—100 cm土层发生脱盐现象。在灌溉期，在垂直方向上，随着灌溉定额的增加，土壤淋洗深度呈增加的趋势。不同灌溉定额条件下，0—20 cm土层土壤发生脱盐现象，40—100 cm土层发生积盐现象。但0—100 cm土层内，土壤全盐量盈亏量总体基本平衡。在水平方向上，土壤盐分以滴头为中心向滴灌带两侧运移，滴头间土壤水分的交汇作用将原耕层的部分盐分迁移到滴灌带的湿润锋边缘处。各处理土壤含盐量均表现为滴灌带间较滴头间增加明显。不同灌溉定额对春玉米穗长、穗行数、行粒数影响不显著，对穗粗、秃尖长、百粒重影响显著。降低灌溉定额可增加春玉米的穗粗和百粒重，但对作物增产无显著作用。【结论】膜下滴灌条件下，春玉米耗水量受灌水量影响，适度水分亏缺能提高水分利用效率（WUE），但使春玉米产量降低4.45%—20.99%。春玉米全生育期灌水10次，灌水定额为420 m3·hm-2，灌溉定额为4200 m3·hm-2的灌溉制度节水、压盐、增产效益最优。%Objective] The objective of the experiment was to investigate the effects of irrigation quota on distribution of soil water-salt, yield and water use efficiency of spring maize under the condition of drip irrigation under film.[Method] In the spring maize growth period, field experiment were conducted with different irrigation quota (4 800, 4 200 and 3 600 m3·hm-2) in the middle reach of the Shiyanghe Basin in 2014-2015. Soil water and salt space-time distribution of 0-100 cm soil layer, the interannual change of soil salt content and spring maize yield and its components were measured.[Result] The more irrigation quota was , the more soil water content was in 0-60 cm soil layer. Increasing irrigation quota from 420 m3·hm-2 to 480 m3·hm-2, soil water content could be higher than 24.52% of average in 0-60 cm soil layer. In key water requirement period of crop, it could increase the deep soil moisture with 480 m3·hm -2 of irrigation quota. While it had a serious soil moisture deficit with 360 m3·hm -2 of irrigation quota. In non-irrigation period, soil salt accumulated in 0-40 cm layer and desalinated in 80-100 cm layer in vertical direction. In the irrigation period, desalt depth increased with increasing irrigation quota in vertical direction. Soil salt desalinated in 0-20 cm soil layer and accumulated in 40-100 cm soil layer, while total soil salt of 0-100 soil layer remained unchanged. In horizontal direction, soil salt migrated in both sides of drip irrigation belt, in addition, the effect of soil moisture movement migrated parts of soil salt which was been kept in arable layer to wetting front edge between the middle of the two drip irrigation belt in horizontal direction. Soil salt content in drip irrigation belt interval was higher than in drippers interval, irrigation quota had no significant effect on ear length, ear rows and rows grains of spring maize, while had significant effect on ear diameter, bald tip length and hundred-grain weight.[Conclusion]Under the condition of drip irrigation, water consumption of spring maize was mainly influenced by irrigation water. Water deficit in a certain extent could elevate water use efficiency (WUE), while yield of spring maize was reduced by 4.45%-20.99%. Irrigation schedule which had irrigation norms of 420 m3·hm-2 and 10 irrigation frequencies was recommended as the most optimal result of saving water, preventing soil salt from moving up and increasing yield of spring maize.
展开▼
