冬小麦灌溉制度对土壤贮水利用的影响

Effect of the irrigation systems of winter wheat on the soil storage water utilization.

足墒条件下冬小麦播种时200cm土体总贮水量为619.6mm,有效贮水量为329.5mm。冬小麦播种～拔节期主要消耗0～100cm土层内土壤有效贮水;由于有效贮水能满足作物需水,因此拔节期不出现土壤水分亏缺。拔节～开花期对照(CK)耗水深度为200cm土层,起身期灌1水(Ⅰ-1)处理为160cm,其他处理为130cm;至开花期CK和Ⅰ-1处理0～60cm土层内已呈现一定程度的水分亏缺。开花～成熟期各处理200cm土体内土壤有效水含量均呈不同程度下降,但主要供水层为0～130cm土层;冬小麦成熟期除春后起身～孕穗～灌浆期(Ⅲ-1)、拔节～开花～灌浆期(Ⅲ-2)灌3水和起身～拔节～开花～灌浆期(Ⅳ)灌4水处理外,大部分处理0～80cm或0～60cm土层内均呈明显的水分亏缺。随灌水次数或灌水量的增加,土壤贮水利用率呈明显下降趋势。

At sowing date,there is 619.6mm soil storage water and 329.5mm available storage water in whole soil profile of 200cm. From sowing to jointing stages,the water consumed by wheat plants is main from 0-100cm soil layer,and there is no soil water deficit at jointing stage even in non-irrigated treatment (CK). From jointing to flowering stages,the consumed water came from whole soil profile of 200cm in CK,while the treatment irrigated at upstanding stage(I-1) from the 160cm layer and the others from 130cm layer. At the flowering stage, light soil water deficit appeared in 0-60 cm layer in CK and I-1. From flowering to ripening stages, the consumed water came from whole profile but the most of them from 0-130cm lay-er. And at ripening stage,serious soil water deficit appeared in the 0-80cm or 0-60cm soil layer of the non-,one- or two-irrigated treatments but the three- or four-irrigated ones. In a word, the more the water is irrigated,the less the soil storage water will be utilized.