黄土塬区降水变化对冬小麦土壤耗水特性及水分利用效率的影响

发布时间：2018-04-08 08:32

本文选题：土壤水　切入点：降水变化　出处：《干旱地区农业研究》2017年04期

【摘要】：采用人工遮雨棚和自流滴灌系统来实时人工干预降水,研究了黄土塬区不同降水条件即正常降水(CK)、降水减少1/3(R-1/3)和降水增加1/3(R+1/3)条件下,麦田0~4 m土壤水分变化、冬小麦耗水特性及WUE。结果表明:(1)降水变化改变了冬小麦对土壤水的利用和补给;降水减少,冬小麦对土壤水的利用增强,导致生育期和休闲期深层土壤含水量降低,且很难补充恢复;降水增加,冬小麦也会部分利用深层土壤水,土壤含水量在生育期呈降低趋势,在冬小麦收获后,土壤水得到补给,土壤含水量会逐渐恢复并高于前期土壤含水量。(2)冬小麦优先利用降水转化而来的土壤水,然后利用土壤前期储水;对于越冬~成熟期的总耗水量(ET)组成,R-1/3处理的冬小麦对降水和0~2 m土壤水分的利用增强,降水量(P)和0~20 m土壤贮水变化量(ΔW0-2 m)各自约占ET的40%;R+1/3处理P占ET的比例约是ΔW0~2 m的1倍多;CK处理P占ET的比例比ΔW0~2 m高15%左右;降水减少,降水占耗水量的比例降低,0~2 m土壤水占耗水量比例增加;降水增加,则有相反的结果。(3)降水减少,WUEbio(基于生物量的WUE)相对于CK处理降低了1.3%,但产量下降程度(7.1%)小于耗水下降程度(14.2%),WUEgrain(基于籽粒产量的WUE)反而增加;降水增加,相对于CK处理生物量减少5.3%而籽粒产量增加4.5%,但水分的消耗增加了11.4%,WUEbio和WUEgrain均降低。总之,降水变化改变了冬小麦对土壤水的利用、土壤水的补给、冬小麦的耗水组成以及生物量和产量的平衡,最终影响冬小麦WUE。
[Abstract]:Artificial rain shelter and self-flow drip irrigation system were used to intervene precipitation in real time. The soil moisture changes of 0 ~ 4 m in wheat field were studied under different precipitation conditions, I. E. normal precipitation, 1 / 3 R ~ (-1 / 3) decrease and 1 / 3 ~ (3) R ~ (1 / 3) increase in precipitation.Characteristics of Water consumption and Wue of Winter Wheat.The results showed that the variation of precipitation changed the utilization and recharge of soil water in winter wheat, decreased the precipitation, increased the utilization of soil water in winter wheat, and resulted in the decrease of soil water content in the deep layer of winter wheat during growth and leisure periods, and it was difficult to replenish and restore the soil water, and the precipitation increased.Winter wheat will also partly utilize deep soil water, and soil water content will decrease during the growth period. After winter wheat harvest, soil water will be replenished.The soil moisture content will gradually recover and be higher than that in the early stage.) Winter wheat will preferentially utilize the soil water transformed by precipitation and then use the soil water storage in the early stage of soil.For winter wheat with R-1 / 3 composition of total water consumption during wintering to maturity, the precipitation and soil water use of 0 ~ 2 m were increased.The change of soil water storage (螖 W 0-2 m) in precipitation (P) and soil water storage (螖 W _ (0-2 m)) were about 15% higher than that of 螖 W _ (0) ~ (2 m) in the proportion of P to et under the treatment of 40% R / 1 / 3 of 螖 W _ (0) ~ (2) m, respectively, and about 15% higher than that of 螖 W _ (0) ~ (2 m) in the treatment of CK.The ratio of precipitation to water consumption decreased, and the ratio of soil water to water consumption increased, and precipitation increased.There was the opposite result.) the decrease of precipitation WUEbiob (based on biomass WUEN) was 1.3% lower than CK treatment, but the degree of yield decrease was lower than that of water consumption decreased by 14.2U WUEgrain (WUEN based on grain yield); the precipitation increased,Compared with CK, biomass decreased by 5.3% and grain yield increased by 4.5%, but water consumption increased by 11.4% WUEbio and WUEgrain decreased.In a word, the change of precipitation changed the utilization of soil water, the recharge of soil water, the composition of water consumption, the balance of biomass and yield of winter wheat, and finally affected the Wue of winter wheat.
【作者单位】：中国科学院水利部水土保持研究所;中国科学院大学;西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室;
【基金】：国家自然科学基金(41371242,41530854) 中国科学院“西部之光”和中国科学院重点部署项目(KFZD-SW-306)
【分类号】：S152.7;S512.11

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