grading of soil meaning in Chinese

土壤级配

For the study of the relations between crops and water condition , an experimental program was carried out in 1999 and in 2000 at the agrometeorological experimental station in the nanjing institute of meteorology . seven different grades of soil moisture were kept on wheat and cotton at every stages
本文在1999年和2000年对棉花和小麦进行7个不同等级土壤湿度试验的基础上，客观地分析了棉花和小麦全生育期的耗水特征和规律，并建立了定量模拟模型。
Soil hydraulic characteristic parameters can be estimated accurately using the pedo - transfer functions ( ptfs ) depending on soil fundamental parameters which are easy to get such as grading of soil , organic content and bulk density . pedo - transfer functions ( ptfs ) have been developed by two methods in this paper with data measured at keerqin sandy land
然而可以通过容易得到并能保证试验精度的土壤基本物化特征参数，如：颗粒级配、有机质含量和土壤容重等，利用土壤传递函数( ptfs )可以较准确地估算出土壤水力特性参数。