湘西烟区土壤肥力状况分析与综合评价

为综合评价湘西烟区植烟土壤适宜性，选取有代表性的龙山县和凤凰县的371个土壤样品，采用隶属度函数对数据进行处理，并运用主成分分析法确定了各土壤养分指标的权重，通过估算土壤适宜性指数（SFI）对湘西植烟区土壤肥力进行了综合评价。结果表明：(1)湘西烟区土壤土壤有机质含量适宜，pH部分偏低，大量元素氮磷钾含量丰富，碱解氮含量偏高，中量元素交换性钙镁和有效硫含量适宜，微量元素有效锌、有效铜、有效铁、有效钼含量丰富，有效硼含量缺乏，有效锰含量偏高；(2) 湘西烟区土壤适宜性指数平均值为0.57，变幅较大，为0.17~0.76，变异系数较小为15.11%；(3)根据SF1大小将全省土壤肥力分为高、较高、中等、较低和低5个等级，有64.69%土壤样本土壤适宜性指数在0.2~0.6之间。

Analysis and Comprehensive Evaluation of Soil Fertility Status for Tobacco-Growing Areas

In order to evaluate the soil fertility of the North-west of Hu’nan province, based the 371 soil samples of the representative locations of Longshan and Fenghuang counties. The data was done with member function and the weights of soil nutrients were definited with principal component analysis by means of estimating SFI to evaluate the soil fertility. The results indicated that: (1) The organic matter content in the north-west of Hu’nan tobacco-growing areas was suitable; pH was partial low; The macro elements of nitrogen, phosphorus potassium content were abundant; But the hydrolytic nitrogen content was on the high side; The secondary elements of exchangeable calcium and magnesium and the available sulfur content were appropriate; The microelements of available zinc, copper, iron, molybdenum content were rich, but the available boron content was deficient and the available manganese was high. (2) The SFI ranged from 0.17 to 0.76 with the mean of 0.57 and coefficient variation of 15.11%. (3) The soil fertility was classified into 5 groups of higher, high, medium, low and lower based on the SFI, and SFI was in the extent of 0.2 ~0.6 for 64.69% of the soil samples.