黄河三角洲中重度盐渍土棉田水盐运移规律研究

为充分利用黄河三角洲中重度盐渍土资源,通过前期微咸水压盐(2 g/L),选取中度(3.10～3.90 g/kg)和重度(4.60～5.70 g/kg)盐渍土,研究了不同程度盐渍化土壤棉花种植下土壤剖面水盐运移规律。研究结果表明:微咸水压盐后可以使剖面盐分处于相对均匀分布状况;覆盖促进了棉花对膜下水分的吸收利用,中度盐渍土棉花在苗期和蕾期主要耗水层为0～40 cm土壤表层,重度盐渍土棉花主要耗水层为0～30 cm土壤表层,后期由于作物生长引起深层水分(60～100 cm)消耗,且中度盐渍土深层水分吸收要高于重度盐渍土;生育期内中度盐渍土盐分上下土层波动范围为0.80～2.00 g/kg,重度盐渍土为2.00～5.60 g/kg,膜下土壤含盐量均要低于膜外土壤含盐量,至收获期中度、重度盐渍土剖面平均脱盐率分别为62.40%和55.83%,棉花产量分别为2 129.76 kg/hm2和823.66 kg/hm2。

Soil Water and Salt Transport in Medium and Heavy Saline Soils of Yellow River Delta

The medium and heavy saline soils in the Yellow River Delta are important reserved cultivable resources in China, exploring the laws of soil water and salt transportation is significant to use these resources effectively, but the relative study is still less, especially the heavy saline soil. In this paper, cotton was planted in medium saline soil (3.10-3.90 g/kg) and heavy saline soil (4.60-5.70 g/kg) and irrigated with leached brackish water (salt concentration is 2 g/L). It was found that leached brackish water made the distribution of soil salt more uniformly in soil profile. Mulch film improved the absorption and utilization of soil water under the film, the main water-consuming layer was 0-40 cm in medium saline soil in cotton seedling and bud stages, while was 0-30 cm in heavy saline soil, water in deep layers (60-100 cm) was consumed due to crop growth in the later stage, and water absorption in deep layer was larger in medium saline soil than in heavy saline soil. Salt fluctuated within 0.80-2.00 g/kg and 2.00-5.60 g/kg in medium and heavy saline soil profiles, respectively. Soil salt content was lower inside mulch film than outside mulch film. The average desalination rate was 62.40% for medium saline soil and 55.83% for heavy saline soil in the harvest period. Cotton yield was 2 129.76 kg/hm² for medium saline soil and 823.66 kg/hm² for heavy saline soil. In conclusion, mulch film changes soil water and salt transportation in saline soils, mulch film can reduce water consumption, and medium saline soil showed better than heavy saline soil.