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通过野外采样和室内实验相结合,对渭干河-库车河三角洲绿洲农田表层土壤的粒度变化规律及其影响因素进行了深入分析。结果表明:1研究区农田表层土壤机械组成以粉粒和砂粒为主,土壤质地较轻,粘粒和砂粒含量属于弱至中等变异强度;2就各土地利用类型而言,粘粒含量果林地最高,混合作物地最低;粉粒含量混合作物地最高,棉花地最低;砂粒含量棉花地最高,谷物地最低;3各连作年限棉田而言,粘粒含量连作15年棉田最高,连作20年棉田最低;粉粒含量连作15年棉田最高,连作25年棉田最低;砂粒含量连作25年棉田最高,连作15年棉田最低;4从总体上来讲,渭干河、库车河、塔里木河冲洪积物交汇处粘粒和粉粒含量较高,而砂粒含量较低,由绿洲中心往外,以粘粒和粉粒含量逐渐降低,而砂粒含量逐渐增加;5土壤母质属性、地貌地形、气象气候等结构性因素是控制研究区农田表层土壤粒径变异的主要因素,人类的农业生产活动等随机性因素加剧了农田表层土壤粒径的结构变化。
Through the combination of field sampling and laboratory experiments, the variation of grain size on the topsoil and its influencing factors in the oasis farmland of Weigan-Kuqa River Delta were analyzed in depth. The results showed that: 1 The mechanical composition of the topsoil in the study area was dominated by silt and grit, the soil texture was light, and the clay and grit contents were weak to moderately variable; 2 For each land use type, Highest in cotton field and the lowest in mixed crops. Grain flour content was the highest in mixed crops and lowest in cotton field. The content of cotton was the highest in grain and the lowest in grain. In terms of continuous cropping years, the content of clay was the highest in cotton field for 15 years, The lowest is in the cotton field; the content of silt is the highest in cotton field for continuous cropping in 15 years and the lowest in cotton field in continuous cropping for 25 years; the content of sand grain is the highest in cotton field for continuous cropping in 25 years and the lowest in continuous cotton field for 15 years; 4 Generally speaking, The contents of clay and silt are higher in the intercourse and the content of sand is lower, which is from the center of the oasis to the outside, and the content of clay and silt gradually decreases while the content of sand increases gradually. 5 The characteristics of soil parent material, topography, weather and climate Structural factors are the main factors controlling the variation of surface soil particle size in farmland. The randomness of human activities such as agricultural production aggravates the structural changes of soil particle size in farmland.