基于土壤三相的广义土壤结构的定量化表达

Quantification of generalized soil structure based on soil three phases

以基于土壤固、液、气三相为研究对象的广义土壤结构为切入点,借鉴微观经济学中柯布-道格拉斯生产函数边际递减效益的思想,通过构建旱作土壤条件下土壤三相"投入"与土壤结构"产出"的土壤结构生产函数,定义了广义土壤结构指数(GSSI),GSSI=[(XS-A)XLXG]k。同时根据二维三系图中土壤结构相对理想三相点变化的趋势,计算了土壤三相结构距离(STPSD)。结合典型黑土区马铃薯耕地土壤深松整地前后土壤结构的变化与广义土壤结构指数和土壤三相结构距离的计算结果,验证了广义土壤结构指数可以有效反映土壤结构特征及其动态变化。在此基础上,采用281个旱作土壤样本数据对广义土壤结构指数与土壤三相结构距离之间的关系进行了拟合,二者之间存在极显著的线性关系(R2=0.86**)。可以认为,广义土壤结构指数与土壤三相结构距离均能作为定量描述土壤结构变化的综合指标,不仅为深入研究广义土壤结构提供了一种新方法,而且为定量研究土壤结构、功能与质量奠定了基础。

A generalized soil structure index（GSSI）was developed to predict the structure properties based on solid,liquid,and gas phases for dry land soil with the diminishing marginal productivity in the Cobb-Douglas production function for reference.GSSI is defined as GSSI=[（XS-A）XL XG]k,where A and K are the constants for dry land soil,the subscripts S,L and G denote solid,liquid and gas,respectively.Soil three-phase structure distance（STPSD）between the ideal 3-phase condition and that of a given soil was calculated in 2-D space.The GSSI was validated a typical black soil of Northeast of China producing potatoes both before and after subsoiling operation.Results indicate that the GSSI can effectively reflect subsoiling impact on this dynamic property.Based on this,281 soil samples were collected and used in the data-fitting of the relationship between GSSI and STPSD,giving a highly significant linear relationship,R2 = 0.86.It is suggested that GSSI and STPSD can be used as a quantitative index to describe soil structural change affecting soil quality.