小尺度滴灌棉田土壤硝态氮空间异质性研究

以1 m×0.8 m网格布点采集的土壤样为研究对象,从统计特征值、半方差函数和等直线图几个方面,对比分析3个时期土壤硝态氮养分的空间和时间变异特性。结果表明,各时期的变异系数受棉花的生长、田间作业影响较大。播前和收获期土壤硝态氮的空间结构符合球状模型,初花期则为线性模型,表明硝态氮含量变异是结构性与随机性共同作用的结果。硝态氮的空间变异性播前主要受结构因素影响;初花期主要受随机因素影响;收获后硝态氮含量的空间异质性变化人为因素大于结构因素。

Characters of Soil Nitric Nitrogen in Cotton Field with Drip Irrigation Spatial Variability in Small Scale

Data of soil used in this study were collected at 1 m ~ 0.8 m regular grid before sowing, early bloom stage and harvest statistical and geo statistical analyses were conducted to analyze and compare spatial variability of soil nitric nitrogen before sowing, early bloom stage and harvest. The correlation analysis indicated that different times＇ coefficient of variation influence was been affected greatly by cotton＇ s growth and the field work. Spatial structure of data of soil nitric nitrogen fitted very well with the spherical mode before sowing and harvest, while the early bloom fitted linear. It was indicated that content variation of nitric nitrogen was commonly influenced by constitutive and randomness. Spatial variability of soil nitric nitrogen was mainly affected by constitutive before sowing,then it was come from randomness in first flowering, while the influence of human was bigger than constitutive after harvest.