土壤肥力评价方法探讨

Discussion of Evaluation Methods on Soil Fertility

总结了土壤肥力的评价方法,探讨了土壤肥力评价的流程。土壤肥力的评价流程如下:首先选择最小指标数据库,其次对指标进行标准化,最后将所有指标综合成一个土壤肥力指数。指标标准化时,根据土壤指标与作物生长之间的关系,可分为"S型曲线"、"反S型曲线和"抛物线型曲线"。评价方法包括多变量指标克立格法、土壤质量动力学方法、土壤质量综合评分法等。在某地区评价土壤质量时,要仔细查对各种土壤质量评价方法的优缺点,选出适合本地区土壤质量的评价方法。

The main aim of this present study is to summarize methods of soil fertility assessment, which have widely been used in the world, and to let everyone know the process and methods of soil fertility assessment. The process is divided into three parts： firstly, to select minimum indexes to compose a database; secondly, to standardize all indexes of database; thirdly, to integrate all indexes into a number indicating soil fertility. On the basis of the previous studies, three types of standardized scoring functions typically used for soil quality assessment can be generated： （1） ‘More is better＇, （2） ‘Less is better＇, （3） ‘Optimum＇. The equation defines a ‘More is better＇ scoring curve for positive slope, a ‘Less is better＇ curve for negative slope, and an ‘Optimum＇ curve in which a positive curve is reflected at the upper threshold value. The methods of soil fertility assessment generally include three types： （1） MVIK （multiple variable indicator kringing）, （2） dynamics method of soil quality, （3） integrated score of soil quality. In fact, merits and shortcomings exist in every method of soil fertility assessment. When local soil fertility is evaluated, the best appropriate method should be selected to be suitable for the local conditions.