西南丘陵山区植烟土壤肥力空间分布及适宜性评价

Spatial Distribution of Tobacco-Grown Soil Nutrients in Southwest China Hilly Mountainous Areas and Their Suitability Evaluation

针对丘陵山区复杂地形条件对植烟土壤肥力空间分布带来的影响,以重庆黔江区6种主要植烟土壤肥力要素为研究对象,选择地形因子作为辅助数据,在GIS平台下采用回归克里格法分析该区植烟土壤养分空间分布特征并在此基础上利用模糊综合评价法对植烟土壤养分适宜性进行综合评价.结果表明:黔江植烟土壤pH、有机质、速效氮、速效钾和水溶性氯含量适宜,速效磷含量偏低.从总体趋势来看,黔江植烟土壤以酸性、弱酸性为主,pH值呈现出从南到北逐渐降低趋势;有机质含量较为丰富,从东到西逐渐降低;速效氮含量主要从南到北逐渐降低;速效磷含量从东向西逐渐降低,总体含量相对偏低;速效钾含量除中部零星地区偏低外,其余地区均相对较高;水溶性氯含量则呈现出东南、北部高于其他地区的趋势.结果表明,土壤养分适宜性指数为优的区域占研究区域总面积的9.35%,为良的区域占44.2%,为中等的区域占34.65%,为一般和差的区域仅占10.05%和1.74%.

The complicated terrain conditions the hilly mountainous areas of southwestern China have great influence on the spatial distribution of tobacco-grown soil fertility.In this study,nutrients in 5 tobacco-grown soils in Qianjiang District of Chongqing Municipality were investigated,and Regression Kriging method was employed to analyze the spatial distribution of regional soil nutrients with terrain attributes as auxiliary variables.Based on the results,fuzzy mathematics was adopted for fertility suitability evaluation.On the whole,the tobacco-grown soils in Qianjiang are acid and weakly acid and soil pH gradually decreases from the south to the north.They are relatively rich in organic matter,being higher in the east and lower in the west of the district.Readily available N is richer in the south and lower in the north.The spatial pattern of available P is higher in the east of the district and lower in the west.Except scattered areas in the central part,the content of soil available K in other regions are relatively rich.The contents of water-soluble Cl are higher in southeastern and northern parts of the district than in other regions.Soil nutrient comprehensive evaluation showed that the areas that belong to the highest grade,high grade and medium grade account for 9.35%,44.2% and 34.65% of the total,respectively,and the areas that belong to poor and poorest grades account only for 10.05% and 1.74%,respectively.