本文關(guān)鍵詞：南疆免冬春灌棉田土壤水熱鹽時空遷移規(guī)律與調(diào)控研究　出處：《中國農(nóng)業(yè)大學》2017年博士論文　論文類型：學位論文

  更多相關(guān)文章： 免冬春灌 凍融作用 土壤水熱鹽 水熱鹽調(diào)控

【摘要】：膜下滴灌已成為新疆棉花產(chǎn)業(yè)發(fā)展的重大支持技術(shù)之一,并已顯現(xiàn)出良好的經(jīng)濟和生態(tài)效益。隨著南疆社會經(jīng)濟的快速發(fā)展,常規(guī)大定額冬春灌洗鹽壓堿模式難以支撐南疆水土資源的可持續(xù)發(fā)展。本文嘗試將南疆膜下滴灌非生育期大水淋洗鹽的水鹽調(diào)控模式進行調(diào)整,探索免冬春灌條件下滴灌棉田全生育期土壤水熱鹽調(diào)控對策。通過2012-2015年4年田間長期定位試驗、室內(nèi)實驗、定量定性分析和數(shù)值模擬,對南疆免冬春灌滴灌棉田水熱鹽時空變化進行了研究,主要結(jié)論有:(1)免冬春灌棉花生育期土壤水熱鹽時空變化特征0-30cm 土壤含水率隨灌溉定額的增加而增大,苗期、蕾期、花鈴期和吐絮期土壤含水率分別為 14.19%、16.37%、15.45%和 13.42%,40-100cm土壤含水率分別為 12.24%、15.50%、16.01%和13.41%,棉花生育期灌溉可使40-100cm土壤水分獲得補給。0-10cm日均土壤溫度免冬春灌分別比氣溫和春灌播前高7.17℃和1.86℃,播后高5.15℃和0.44℃。免冬春灌播前土壤含鹽量0-30cm高于40-1OOcm。棉花生育期土壤鹽分累積量小于播前鹽分累積量。連續(xù)4年免冬春灌0-30cm 土壤范圍年際間出現(xiàn)鹽分積累,積鹽率隨灌溉定額的增加而減小,0-30cm 土壤含鹽量年均增加23.50%,40-100cm 土壤含鹽量年均增加13.82%,0-100cm 土壤含鹽量年均增加19.41%。(2)滴灌棉田凍融期土壤水熱鹽變化特征0-100cm 土壤儲水量冬灌玉米秸稈覆蓋(WICM)比裸地(WIB)和留稈(WICS)分別多29.10%和10.36%,免冬灌玉米秸稈覆蓋(NWICM)比裸地(NWIB)和留稈(NWICS)儲水量分別多14.97%和2.21%。冬灌和玉米秸稈覆蓋可有效平抑凍融過程土壤溫度的變幅,影響程度隨土壤深度的增加而減弱。免冬灌表層0-10cm 土壤溫度升溫快于冬灌處理。(免)冬灌土壤鹽分出現(xiàn)表聚,0-30cm 土壤含鹽量裸地最大,玉米秸稈覆蓋最小。200mm冬灌定額0-100cm 土層范圍WICM、WICS和WIB鹽分淋洗率分別為34.86%、15.82%和7.26%;NWIB、NWICS 和 NWICM 積鹽率分別為 10.11%、7.96%和 3.01%。(3)免冬春灌適宜節(jié)水控鹽灌溉制度與水鹽調(diào)控對策棉花非生育期采用留稈或玉米秸稈覆蓋,苗期灌水定額0.25ET.,灌水2次,蕾期灌水定額0.60ET.,灌水4次,花鈴期灌水定額0.85ET.,灌水7次,吐絮期灌水定額0.55ET0,灌水2次可作為南疆免冬春灌"一膜兩帶四行"棉花生育期水鹽調(diào)控灌溉制度。對沙質(zhì)壤土當土壤含鹽量在2g/kg-3g/kg的植棉區(qū)3-4年進行一次冬灌,在初始含鹽量為3g/kg-5g/kg的植棉區(qū),可選擇2-3年進行一次冬灌或采用冬灌和隔一年進行春灌相結(jié)合的方法實現(xiàn)棉田土壤水鹽平衡。(4)凍融期土壤水熱分布模型模擬SHAW模型對凍融期NWIB和NWICM處理土壤溫度模擬效果優(yōu)于土壤水分的模擬效果。
[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，

本文編號：1376736