南疆免冬春灌棉田土壤水热盐时空迁移规律与调控研究

发布时间：2018-01-04 03:02

  本文关键词：南疆免冬春灌棉田土壤水热盐时空迁移规律与调控研究　出处：《中国农业大学》2017年博士论文　论文类型：学位论文

  更多相关文章： 免冬春灌 冻融作用 土壤水热盐 水热盐调控

【摘要】：膜下滴灌已成为新疆棉花产业发展的重大支持技术之一,并已显现出良好的经济和生态效益。随着南疆社会经济的快速发展,常规大定额冬春灌洗盐压碱模式难以支撑南疆水土资源的可持续发展。本文尝试将南疆膜下滴灌非生育期大水淋洗盐的水盐调控模式进行调整,探索免冬春灌条件下滴灌棉田全生育期土壤水热盐调控对策。通过2012-2015年4年田间长期定位试验、室内实验、定量定性分析和数值模拟,对南疆免冬春灌滴灌棉田水热盐时空变化进行了研究,主要结论有:(1)免冬春灌棉花生育期土壤水热盐时空变化特征0-30cm 土壤含水率随灌溉定额的增加而增大,苗期、蕾期、花铃期和吐絮期土壤含水率分别为 14.19%、16.37%、15.45%和 13.42%,40-100cm土壤含水率分别为 12.24%、15.50%、16.01%和13.41%,棉花生育期灌溉可使40-100cm土壤水分获得补给。0-10cm日均土壤温度免冬春灌分别比气温和春灌播前高7.17℃和1.86℃,播后高5.15℃和0.44℃。免冬春灌播前土壤含盐量0-30cm高于40-1OOcm。棉花生育期土壤盐分累积量小于播前盐分累积量。连续4年免冬春灌0-30cm 土壤范围年际间出现盐分积累,积盐率随灌溉定额的增加而减小,0-30cm 土壤含盐量年均增加23.50%,40-100cm 土壤含盐量年均增加13.82%,0-100cm 土壤含盐量年均增加19.41%。(2)滴灌棉田冻融期土壤水热盐变化特征0-100cm 土壤储水量冬灌玉米秸秆覆盖(WICM)比裸地(WIB)和留秆(WICS)分别多29.10%和10.36%,免冬灌玉米秸秆覆盖(NWICM)比裸地(NWIB)和留秆(NWICS)储水量分别多14.97%和2.21%。冬灌和玉米秸秆覆盖可有效平抑冻融过程土壤温度的变幅,影响程度随土壤深度的增加而减弱。免冬灌表层0-10cm 土壤温度升温快于冬灌处理。(免)冬灌土壤盐分出现表聚,0-30cm 土壤含盐量裸地最大,玉米秸秆覆盖最小。200mm冬灌定额0-100cm 土层范围WICM、WICS和WIB盐分淋洗率分别为34.86%、15.82%和7.26%;NWIB、NWICS 和 NWICM 积盐率分别为 10.11%、7.96%和 3.01%。(3)免冬春灌适宜节水控盐灌溉制度与水盐调控对策棉花非生育期采用留秆或玉米秸秆覆盖,苗期灌水定额0.25ET.,灌水2次,蕾期灌水定额0.60ET.,灌水4次,花铃期灌水定额0.85ET.,灌水7次,吐絮期灌水定额0.55ET0,灌水2次可作为南疆免冬春灌"一膜两带四行"棉花生育期水盐调控灌溉制度。对沙质壤土当土壤含盐量在2g/kg-3g/kg的植棉区3-4年进行一次冬灌,在初始含盐量为3g/kg-5g/kg的植棉区,可选择2-3年进行一次冬灌或采用冬灌和隔一年进行春灌相结合的方法实现棉田土壤水盐平衡。(4)冻融期土壤水热分布模型模拟SHAW模型对冻融期NWIB和NWICM处理土壤温度模拟效果优于土壤水分的模拟效果。
[Abstract]:Drip irrigation under film has become one of the important supporting technologies for the development of cotton industry in Xinjiang, and has shown good economic and ecological benefits, along with the rapid development of social economy in southern Xinjiang. It is difficult to support the sustainable development of water and soil resources in south Xinjiang by conventional large quota irrigation in winter and spring. This paper attempts to adjust the water salt regulation model of drip irrigation in the non-growth period of drip irrigation in southern Xinjiang. To explore the control countermeasures of soil water, heat and salt in the whole growth period of drip irrigation cotton field under the condition of no-winter and spring irrigation. The long-term field experiment, laboratory experiment, quantitative qualitative analysis and numerical simulation were carried out during 2012-2015. The temporal and spatial variation of water, heat and salt in drip irrigation cotton field without winter and spring irrigation in southern Xinjiang were studied. The main conclusions were as follows: (1) soil moisture content of 0-30cm soil increased with the increase of irrigation quota, seedling stage and bud stage. The soil moisture content in flowering stage and flocculation stage were 14.19 ~ 16.37% and 13.42 ~ 40 ~ 100 cm, respectively. The soil moisture content was 12.24%. 15.50% and 13.41%%. During cotton growing period, irrigation could recharge 40-100 cm soil moisture. 0-10 cm daily soil temperature was 7.17 鈩，

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