紫色土坡耕地耕层蓄水保土及耕性特征研究

发布时间：2018-02-24 08:07

本文关键词： 蓄水保土耕性耕层坡耕地紫色土　出处：《水土保持学报》2016年06期 　论文类型：期刊论文

【摘要】：通过对重庆合川和云南楚雄紫色土坡耕地野外调查和土壤物理力学性质分析,对比研究了紫色土坡耕地耕层土壤的蓄水、稳定性及耕性特征。结果表明:(1)紫色土坡耕地耕层土壤入渗速率随土层深度而降低,0—20,20—40,40—60cm耕层土壤稳定入渗率分别为5.80~9.58,2.81~4.35,0.98~1.96 mm/min;而相应深度土壤最大有效库容分别介于49.93~66.26,46.04~59.05,37.42~43.55mm范围,0—20cm土壤兴利库容高产耕层大于低产耕层;(2)不同类型紫色土坡耕地耕层土壤稳定性差异明显,土壤团聚体结构均以5,5~3,3~0.5mm 3个粒级为主,且0.25 mm水稳性大团聚体含量随耕层深度显著降低;0—20cm耕层土壤稳定性指数依次为烟草高产耕层(2.96)玉米高产耕层(2.55)烟草低产耕层(2.45)玉米低产耕层(2.38);20—40,40—60cm土层的玉米和烟草稳定性指数分别较0—20cm耕层降低0.44,0.64和0.66,0.71;(3)不同坡耕地耕层土壤抗剪强度和贯入阻力差异显著(p0.05),土壤抗剪强度依次为玉米低产耕层(36kPa)玉米高产耕层(29kPa)烟草低产耕层(25kPa)烟草高产耕层(21kPa),峰值出现在20—40cm;高产耕层的土壤贯入阻力在0.3~1.9 MPa,低产耕层则在0.5~2.5MPa变化,其峰值出现在40—50cm。紫色土坡耕地高产耕层具有稳定入渗率高、有效库容大、土壤持水性能较强、土壤结构稳定性高、表层土壤抗剪强度和贯入阻力较低的特征。
[Abstract]:Based on the field investigation of purple soil sloping land in Hechuan, Chongqing and Chuxiong, Yunnan, and the analysis of soil physical and mechanical properties, the soil storage in sloping layer of purple soil was comparatively studied. The results showed that the soil infiltration rate of tilling layer of purple soil decreased with the depth of soil layer 0 ~ 20 ~ 20 ~ 40 ~ 40 ~ 60 cm and the stable infiltration rate of 0 ~ 20 ~ 20 ~ 40 ~ 40 ~ 60 cm soil layer was 5.80 ~ 9.58 ~ 2.81 ~ 4.350.98 ~ 1.96 mm / min, respectively, and the maximum effective storage capacity of corresponding depth soil was between 49.936.26 ~ 46.04 ~ 37.42N ~ (43.55) mm / min, respectively. The soil stability of sloping cultivated land in different types of purple soil was significantly different from that of high yield tillage layer to low yield tillage layer in 0 ~ 20cm soil. The structure of soil aggregates was mainly composed of 3 grain sizes of 5 ~ 5 ~ (5) ~ (3) ~ (3) ~ (3) ~ 0. 5 mm. The soil stability index of 0 ~ 20cm soil layer decreased significantly with the depth of topsoil layer 0 ~ 20cm. The order of soil stability index was tobacco high yield tillage layer 2.96) maize high yield tillage layer 2.55) tobacco low yield tillage layer 2.45) maize low yield tillage layer 2.38 ~ 40 ~ 40 ~ 40-60 cm soil layer and tobacco. The soil shear strength and penetration resistance of different sloping cultivated land layers were significantly different (p0.05), and the soil shear strength was 36 KPA (low yield layer of maize) and 29kPa of high yield layer of maize (25 KPA) of low yield tillage layer of tobacco (P < 0.05), respectively, compared with 0-20 cm tillage layer (0.44%) and 0.666% (0.71 kPa) of tilling layer (P < 0.05). The soil shear resistance index of different sloping land layers was significantly lower than that of 0-20 cm tillage layer (P < 0.05). The peak value of soil penetration resistance in high-yield tilling layer was 20-40 cm, and the penetration resistance of high-yield tillage layer was 0.31.9MPa, while that of low-yield tillage layer varied at 0.5 ~ 2.5MPa. The peak value appeared in 40-50 cm. The characteristics of high yield tillage layer in purple soil were high stable infiltration rate, large effective reservoir capacity, strong soil water holding capacity, high soil structure stability, low shear strength and penetration resistance of surface soil.
【作者单位】：西南大学资源环境学院;重庆市水利电力建筑勘测设计研究院;
【基金】：公益性行业(农业)科研专项“坡耕地合理耕层评价指标体系建立”(201503119-01-01)
【分类号】：S157;S155.25

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