不同有机物料对黄土高原治沟造地土壤水分运移的影响

为了改善黄土高原治沟造地土壤结构较差的问题,采用一维定水头土柱模拟试验,探讨了不同有机物料(生物有机肥、粉碎秸秆、50%粉碎秸秆+50%生物有机肥、尿素、对照)对治沟造地土壤湿润锋推移、累积入渗量、入渗速率和土壤水分蒸发特征的影响,并采用Green-Ampt模型、Philip模型和Kostiakov模型拟合分析土壤水分入渗规律。结果表明:(1)粉碎秸秆与有机肥均降低了土壤水分移动速率,增强了土壤持水能力;粉碎秸秆同时降低了土壤稳定入渗速率,与对照相比减小了17.65%;(2)湿润锋推进深度与累积入渗量呈良好的线性关系;通过对3种入渗模型拟合发现,Philip模型和Kostiakov模型的拟合效果较好,符合黄土高原治沟造地土壤入渗率和时间的动态关系;(3)土壤水分蒸发过程中,添加粉碎秸秆具有阻截和蓄积土壤水分,提高土壤含水量的积极作用。

Effects of Different Organic Materials on Water Movement in Gully Land Consolidation Soil on the Loess Plateau

Aiming at the problem of how to improve the gully land consolidation soil poor structure in the Loess Plateau, the vertical one-dimensional stable water potential infiltration experiments were conducted to explore the effects of different organic materials (bio-organic fertilizer, crushed straw, 50% crushed straw + 50% bio-organic fertilizer, Urea, CK) on gully land consolidation soil''s wetting front movement, cumulative infiltration, infiltration rate, and soil water evaporation characteristics. Green-Ampt model, Philip model and Kostiakov model were used to fit and analyze the regularity of soil moisture infiltration. The results showed that: (1) Crushed straw and bio-organic fertilizer both reduced the soil water movement rate and enhanced soil water holding capacity; crushed straw simultaneously reduced the soil stable infiltration rate, which was 17.65% lower than CK. (2) There was a good linear relationship between wetting front depth and the cumulative infiltration; by fitting the three infiltration models, it was found that the Philp model and Kostiakov model had the best fitting effect, which were more in line with the Dynamic relationship between soil infiltration rate with time in gully land consolidation soil on the Loess Plateau. (3) In the process of soil water evaporation, adding crushed straw had a positive effect on blocking and accumulating soil moisture and increasing soil water content.