耕作方式对农田土壤水分变化特征及水分利用效率的影响

Effect of Different Tillage Methods on Soil Water Content and Water Use Efficiency in Cropland

探讨耕作方式对土壤含水量及水分利用效率的影响,对于高效利用自然降水,提高自然降水利用效率,增加作物产量具有重要的理论与实践意义。因此,采用铝盒称重法测定不同年份、季节、土壤剖面及冻融前后土壤含水量,研究不同耕作方式对土壤含水量及作物水分利用效率的影响。结果表明:在特定时期内土壤含水量随土层深度的增加而减少,特别是土层40cm以下尤为明显,而且随季节呈波动性变化且受降雨影响较大;季节冻融作用明显降低土壤含水量,但深松较其他处理土壤含水量增幅为0.93%~2.23%;土壤贮水量随季节呈先增后降的趋势变化,且生育前期明显高于生育后期;不同耕作方式对田间耗水量和耗水系数无显著影响,但深松耕作显著提高作物水分利用效率,并且水分利用效率与产量的相关性达到极显著水平(r=0.76**)。综合分析认为,保护性耕作结合深松是有效改善耕层结构,增加土壤含水量,提高自然降水利用效率的有效耕作方法。因此,该研究可为东北雨养农业区留茬深松保护性耕作技术的推广提供理论依据。

Investigation of the influence of different tillage methods on soil water content and water use efficiency have important theoretical and practical significance for the utilization efficiency of natural precipitation and the increase of crop yield.The gravimetrie soil moisture that soil samples were stored in metal cans,and oven dried at 105 ℃ for 6 hours was applied to determine the soil water content of soil from different years,seasons,profiles,and freeze-thaw.The influence of different tillage methods on soil water content and water use efficiency was assessed.The results showed that soil water content of different tillage systems decreased with the increase of soil depth,and it was significant when the soil depth was under 40 cm.Moreover,soil water content of different tillage systems was influenced by the precipitation and changed with season.The seasonal freeze-thaw decreased the soil water content of different tillage systems,however,soil water content of spacing tillage was increased from 0.93% to 2.23% with comparison of other tillage systems.Meanwhile,soil water storage was increased firstly then decreased with change of seasons,and was higher in the beginning of crop growth than in the end of crop growth.Influence of different tillage systems was on water consumption and water use coefficient was not significant;however,spacing tillage enhanced water use efficiency significantly,and the correlation between yield and water use efficiency was significant（r=0.76＊＊）.Spacing tillage is an effective tillage system to improve the soil structure,increase soil water content,and enhance water use efficiency.Therefore,this study will provide a theoretical basis for the application of the conservative tillage technology for deep loosening tillage in the Northeast rain farming area.