紫色土坡耕地土壤属性差异对耕层土壤质量的影响

发布时间：2018-06-06 15:29

本文选题：耕层 + 坡耕地　；参考：《生态学报》2017年19期

【摘要】：坡耕地是一个区域最易发生水土流失的土地利用类型,其严重的水土流失、面源污染和耕层退化现象直接威胁着坡耕地持续利用以及当地粮食安全、生态安全;耕层土壤质量对自然因素和人为耕作活动的影响较为敏感。以南方3个地点紫色土坡耕地耕层土壤质量为研究对象,从土壤属性角度,对比分析了重庆合川、江西兴国、云南楚雄不同耕层垂直深度土壤养分特征、土壤物理性质、土壤水库特征、耕作性能差异性及其形成原因。结果表明:(1)坡耕地耕层土壤有机质表现为云南楚雄(28.80g/kg)江西兴国(9.03 g/kg)重庆合川(8.80 g/kg);除全钾含量外,土壤全量养分和速效养分的含量表现为云南楚雄江西兴国重庆合川;坡耕地耕层速效养分垂直分布变化规律基本一致,主要表现为土壤速效养分主要在0—20 cm土层富集,而20—40 cm和40—60 cm土层无显著差异。(2)不同地点紫色土坡耕地耕层土壤物理性质差异明显,以重庆合川坡耕地土壤物理质量最差,表现为土壤砂粒含量60%、土壤容重最大(1.43 g/cm3)、土壤总孔隙度(45.97%)和毛管孔隙度(34.36%)最小;从坡耕地耕层土壤物理性质垂直变化特征看,耕作层(0—20 cm)优于心土层(20—40 cm)和底土层(40—60 cm)。(3)紫色土坡耕地耕层土壤初始入渗率以江西兴国坡耕地耕层最大(0.32 mm/min),而以重庆合川坡耕地耕层最小(0.19 mm/min);土壤稳定入渗率和平均入渗率均表现为云南楚雄重庆合川江西兴国;坡耕地耕层土壤最大有效库容以云南楚雄最好(873.311 t/hm~2),说明云南楚雄紫色土坡耕地耕层土壤具有较好的抵御季节性干旱能力;不同地点坡耕地耕层土壤总库容、死库容、兴利库容、滞洪库容、最大有效库容在垂直方向变化表现为耕作层(0—20 cm)大于心土层(20—40 cm)和底土层(40—60 cm)。(4)不同地点紫色土坡耕地耕层土壤抗剪强度和贯入阻力均呈现出相同变化规律,土壤抗剪强度表现为重庆合川(15.39 kg/cm~2)云南楚雄(14.74 kg/cm~2)江西兴国(10.66 kg/cm~2),而土壤贯入阻力值为重庆合川(424.83 k Pa)云南楚雄(252.50 k Pa)江西兴国(188.87 k Pa),这种土壤力学性能的变化说明重庆合川紫色土坡耕地耕层土壤具有较好抵抗剪切破坏的能力和较大耕作阻力。上述研究结果可为不同地点紫色土坡耕地耕层土壤质量诊断、坡耕地合理耕层评价提供理论依据和数据支持。
[Abstract]:Sloping farmland is the most vulnerable land use type in a region. Its serious soil and water loss, non-point source pollution and land degradation directly threaten the sustainable utilization of sloping farmland and local food security and ecological security. Soil quality of tilling layer is sensitive to natural factors and artificial tillage activities. The soil quality of sloping farmland in purple soil in three locations in the south of China was studied. From the point of view of soil properties, the soil nutrient characteristics and soil physical properties of different vertical depth in Hechuan, Xingguo, Jiangxi and Chuxiong, Yunnan Province were compared and analyzed. The characteristics of soil reservoir, the difference of tillage performance and the causes of its formation. The results showed that the soil organic matter in the cultivated layer of sloping farmland was 28.80 g / kg in Chuxiong, Yunnan Province, 9.03 g / kg in Xingguo, Jiangxi Province) 8.80 g / kg 路kg ~ (-1) in Hechuan, Chongqing, and 8.80 g / kg 路kg ~ (-1) in Hechuan, Chongqing, except for the total potassium content, the content of soil total nutrients and available nutrients was the same as that in Chuxiong Jiangxi, Yunnan Province. The vertical distribution of available nutrients in sloping cultivated land was basically the same, which mainly showed that the available nutrients were mainly enriched in 0-20 cm soil layer. However, there was no significant difference between 20-40 cm and 40-60 cm soil layers. (2) there were significant differences in soil physical properties of sloping farmland in purple soil in different locations, and the soil physical quality of slope farmland in Hechuan, Chongqing, was the worst. The soil sand content is 60, the soil bulk density is 1.43 g / cm ~ 3, the total porosity is 45.97) and the capillary porosity is 34.366.In view of the vertical variation of soil physical properties in the tilling layer of sloping farmland, the content of soil sand is 60%, the maximum soil bulk density is 1.43 g / cm ~ (3), and the total porosity of soil is 45.97%. The initial infiltration rate of tilling layer in purple soil was 0.32 mm / min in Xingguo, Jiangxi Province, and 0.19 mm / min in Hechuan cultivated land in Chongqing, and the lowest level was 0.19 mm / min in Hechuan, Chongqing, which was better than that in core layer (20-40 cm) and in bottom layer (40 ~ 60 cm 路m ~ (-1) 路m ~ (3). The stable infiltration rate and the average infiltration rate are both reflected in Chuxiong, Yunnan, Chongqing, Hechuan, Jiangxi, Xingguo; The maximum effective storage capacity of topsoil in sloping cultivated land is 873. 311 t / hmm2 +, which indicates that the tilling layer of purple soil in Chuxiong has better ability to resist seasonal drought, and the total storage capacity, dead storage capacity and beneficial storage capacity of tilling layer of sloping farmland in different locations. Flood detention reservoir capacity, The maximum effective storage capacity varied from 0-20 cm to 20-40 cm in the tilling layer and 40 ~ 60 cm 路L ~ (4) in the bottom layer in the vertical direction.) the shear strength and penetration resistance of the cultivated soil layer in the purple soil showed the same variation law. The shear strength of the soil is 15.39 kg 路cm ~ (2) in Chongqing) Chuxiong, Yunnan 14.74 kg / cm ~ (2) Xingguo, Jiangxi, 10.66 kg / cm ~ (2), and the soil penetration resistance is 424.83 k Pa in Chongqing) Chuxiong, Yunnan (252.50 k Pa) Xingguo, Jiangxi, 188.87 k Paa. The soil of sloping cultivated land in Hechuan purple soil in Chongqing has the ability to resist shear failure and the tillage resistance. The above results can provide theoretical basis and data support for the diagnosis of soil quality in sloping soil layer of purple soil in different locations and the evaluation of rational tilling layer for sloping land.
【作者单位】：西南大学资源环境学院;重庆市水土保持生态环境监测总站;重庆市水利电力勘测设计研究院;
【基金】：公益性行业(农业)科研专项(201503119-01-01) 重庆市水利局项目(2016)
【分类号】：S151.9

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