不同连作年限下土壤物理性质对土壤饱和导水率空间分布的影响

Effects of soil physical properties on soil saturated hydraulic conductivity spatial distribution under different continuous cropping years

土壤饱和导水率是影响农田土壤入渗地重要因素,也影响着土壤水分再分布。研究农田灌溉下土壤饱和导水率的空间变化规律,有助于定量估计土壤水分的空间分布和设计农田的精准灌溉管理制度。为了探究不同连作年限下土壤性质(如土壤质地、容重、土壤含水量)对土壤饱和导水率空间分布的影响,试验采用均匀网格10m×10m的方式,测定了0～40cm土层的土壤饱和导水率动态变化,分析了不同连作年限下土壤饱和导水率的空间分布规律以及土壤物理性质与土壤饱和导水率之间的相关性。结果显示,土壤容重与田间持水量呈正相关;土壤饱和导水率与田间持水量呈显著负相关;饱和导水率与土壤容重之间则无明显的相关性。研究结果将为农田土壤饱和导水率的空间变异规律以及土壤饱和导水率的空间变异对农田水分渗漏的影响提供依据,同时会提高农田水分空间入渗量导致灌溉后土壤水分分布的均匀性。

Soil saturated hydraulic conductivity is not only an important factor affecting farmland soil infiltration,but also affects soil water redistribution.It is helpful to quantitatively estimate the spatial distribution of soil moisture and to design the management system of precision irrigation for farmland irrigation by studying the spatial variation law of soil saturated water conductivity under farmland irrigation.In order to investigate the effects of soil properties such as soil texture,bulk density and soil water content on the spatial distribution of soil saturated water conductivity under different successive cropping years,uniform grid 10 m10 m was used in the experiment.The dynamic change of soil saturated water conductivity in 0~40 cm soil layer was measured.The spatial distribution of soil saturated water conductivity and the correlation between soil physical properties and soil saturated water conductivity were analyzed under different cropping years.The results showed that there was a positive correlation between soilbulk density and field water holding capacity,a significant negative correlation between field water holding capacity and soil saturated water conductivity,and no significant correlation between soil bulk density and saturated water conductivity.The results will provide the basis for the effect of the spatial variation of soil saturated water conductivity and soil saturated water conductivity on farmland water leakage.At the same time,increasing the spatial infiltration of farmland water results in the uniformity of soil water distribution after irrigation.