持续干旱作用下东辽河流域土壤容重及水分空间变异特征分析

Spatial Variability of Bulk Density and Soil Water under Continuous Drought in Dongliao River

针对2009年发生的特大干旱,研究了持续干旱作用下东辽河流域的土壤湿容重和重量含水量的空间变异特征,以期为持续干旱作用下改善土壤质量,进而提高东辽河流域的粮食产量提供理论依据。对比分析2008年9月和2009年9月的野外采样数据可知,东辽河流域土壤湿容重变异不大,为弱变异性;土壤水分变异较大,为中等变异。由于受人类耕作的影响,10 cm深的土壤湿容重和重量含水量空间变异性明显高于30 cm深。从整体上看,2009年9月10 cm深和30 cm深的土壤重量含水量的变异系数均高于2008年9月。持续干旱作用下,10 cm深的土壤湿容重及其变异系数均减小,10 cm深和30 cm深的土壤重量含水量及其变异系数也减小。丘陵旱田土壤重量含水量最小值10 cm深为5.490%,30 cm深为4.575%;丘陵水田土壤重量含水量最小值10 cm深为11.619%,30 cm深为8.425%,明显小于农作物适墒重量含水量,已严重威胁到作物的正常生长,若干旱持续下去将影响东辽河流域的粮食产量。

The drought created serious effects in 2009.In order to improve the soil quality and increase the grain yield,the spatial variability of bulk density and soil water under continuous drought in Dongliao River was analyzed.This study has been carried out using the field experiments in September 2008 and 2009.It was found that soil wet bulk density has small variability,but soil water has moderate one.The spatial variability of wet bulk density and soil water in 10 cm depth was stronger than the one in 30 cm depth due to the influence made by human activities.In all,the spatial variability of soil water in September 2009 was stronger than the one in September 2008.The results showed that the wet bulk density and its spatial variability in 10 cm depth decreased under the continuous drought.Soil water and its spatial variability in 10 cm and 30 cm depth decreased too.The minimum soil water of hilly dry farmland was 5.490% in 10 cm depth,and 4.575% in 30 cm depth.The minimum soil water of hilly paddy field was 11.619% in 10 cm depth,and 8.425% in 30 cm depth.From these results it was concluded that the soil water in Dongliao River was disagree with the optimum soil water of the crop,which would affect the regular growing of the crop,than effect the grain yield in Dongliao River.