不同耕作制度下荒漠绿洲棉田土壤水分的时空变化

通过田问试验研究了不同耕作制度荒漠绿洲棉田土壤水分的时空变化.结果表明,0-120 cm土层免耕覆盖土壤容积含水量最高,免耕留茬次之,传统耕作和耕作覆膜最低.0-20 cm土层,免耕覆盖和免耕留茬土壤含水量高于传统耕作和耕作覆膜,0-5 cm差异最大,但随着深度增加差异减小,20-120 cm差异不大.传统耕作、耕作覆膜、免耕留茬棉田表层与底层土壤水分梯度明显,免耕覆盖不明显.头水前不同耕作方式棉田0-120 cm土壤含水量都随时间延长逐渐降低,前期免耕覆盖和免耕留茬与传统耕作和耕作覆膜差异较大,后期差异变小;头水后,免耕覆盖、免耕留茬高于耕作棉田.免耕覆盖和耕作覆膜棉田表层土壤水分状况比较稳定,免耕留茬和传统耕作变化幅度较大.

Spatiotemporal Variation of Soil Water in a Cotton Field with Different Tillage Modes in Oasis

A field experiment was conducted to study the spatiotemporal variation of soil moisture in an oasis cotton field with different tillage modes.Results showed that in 0-120cm soil layer,the maximum soil moisture content was observed for no-tillage with mulching stalk;the medium,for no-tillage with standing stubble;and the minimum,for conventional tillage and tillage with film mulching.Soil moisture contents for no-tillage with mulching stalk and no-tillage with standing stubble were higher than those for conventional tillage and tillage with film mulching in 0-20cm soil layer,being significantly different in 0-5cm soil layer and no difference in 20-120cm soil layer.There was an obvious gradient of soil moisture content in the depths for the three tillage modes.Soil moisture contents for the three tillage modes decreased significantly with time before irrigation.The difference between no-tillage and tillage was greater at the early stage than the later stage.High soil moisture content was observed in tilled field after irrigation.Soil moisture in top soil layer was steady for no-tillage with mulching stalk and tillage with film mulching and remarkably varied for no conventional tillage and no-tillage with standing stubble.