【作者】 王芳；

【导师】 胡笑涛；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2023， 硕士

【摘要】 人口的增加和气候的变化影响着区域的水文生态过程,加剧了农业生产用水供需矛盾和地下水水位的下降。由于降雨分布严重不均,我国北方干旱半干旱区域灌区普遍存在雨洪资源得不到有效利用而干旱季节缺水严重的问题,为满足用水需求过量开采地下水造成水位持续下降,影响了农业稳产,造成了水环境恶化,陕西宝鸡峡灌区问题更为突出。因此,在宝鸡峡灌区腹地的陕西杨凌开展深蓄储水灌溉与降雨叠加试验对夏玉米生长和产量的影响试验研究,探索不影响产量的前提下充分利用雨洪资源补给地下水的灌溉制度,对于提高雨洪资源利用效率、减少干旱季节灌溉用水具有重要意义。论文定量分析了不同调控深度的深蓄储水灌溉和降雨叠加对夏玉米生长发育的影响,取得如下主要结果:(1)揭示了深蓄储水灌溉与降雨叠加对土壤水分的调控作用丰水年深蓄储水灌溉10d后各处理在0—100,100—200、0—200 cm土层平均含水率可达20.99%～27.01%,平水年深蓄储水灌溉3d后使得各处理在0—100,100—200、0—200 cm土层平均含水率可达20.91%～28.01%;丰水年夏玉米拔节期计划储水灌溉深度为90cm的处理蒸散作用最强,较其他处理高1.57%～28.13%,平水年140cm调控深度蒸散量达到最大,较其他处理提高0.2%～25.42%;丰水年、平水年夏玉米全生育阶段补给深层土壤水量最大可达279.32、150.03 mm,说明深蓄储水灌溉可将地表水储存在深层土壤达到补给地下水的目的,也表明了利用汛期雨洪资源进行灌水的储水有效性。(2)阐明了深蓄储水灌溉叠加不同水文年型的降雨量对夏玉米形态指标的影响规律丰水年随着调控深度的增大茎粗、叶面积指数呈现出先增大后又减小的趋势,其他处理的株高、茎粗、叶面积指数分别较调控深度为60 cm、90 cm、150 cm的处理减小0.57%～2.98%、2.71%～21.96%、3.08%～11.34%,茎粗对土壤水分更为敏感;平水年随着调控深度的增大茎粗先减小后增大,叶面积指数、株高总体表现为先增后减的趋势,其他处理的株高、茎粗、叶面积指数分别较调控深度为180 cm、90 cm、90 cm的处理减小0.94%～5.54%、0.64%～8.22%、0.44%～5.39%;深蓄储水灌溉叠加降雨条件下夏玉米植株干物质积累量和生长天数之间的关系利用Logistic生长方程拟合效果良好,随着调控深度的增大干物质积累量表现为先增大后减小的趋势,丰水年、平水年分别在储水深度为90、120 cm的处理处达到最大;随着调控深度增大,深蓄储水灌溉可在一定范围内促进夏玉米根系生长,若超过土壤水分阈值会抑制根系呼吸进而抑制根系生长发育;叶片叶绿素累积量随着调控深度的增大呈现为先增大后减小的趋势,选择适宜的储水深度有利于夏玉米光合作用的进行。(3)获得了深蓄储水灌溉玉米产量构成特征,提出了最优深蓄储水灌溉制度灌浆过程中百粒累积增量呈抛物线曲线变化,深蓄储水灌溉可推迟灌浆峰值的到来,有利于提高生育后期的粒重,防止了生育后期早衰的发生;深蓄储水灌溉处理下两季夏玉米产量分别在调控深度为90、120 cm的处理最高,调控深度继续增大会分别致使减产1.05%～13.81%、0.09%～5.69%;深蓄储水灌溉有利于夏玉米积累更多的地上部生物量,但WUE较对照组下降,主要是由于土壤水分较高,叶片蒸腾和地面蒸发增强;可利用Logistic方程对深蓄储水灌溉处理下的蒸散量、籽粒产量、水分利用效率进行拟合预测;丰水年、平水年综合得分最高的深蓄储水灌溉制度对应的调控深度分别为90、180 cm,有利于有效配置区域雨洪资源。更多还原

【Abstract】 The increase in population and climate change are affecting the hydrological and ecological processes of the region,exacerbating the contradiction between water supply and demand for agricultural production and the decrease in groundwater levels.Due to the severe uneven distribution of rainfall,there is a common problem of ineffective utilization of rainwater and flood resources in irrigation areas in arid and semi-arid regions of northern China,resulting in severe water shortage during the dry season.Overextraction of groundwater to meet water demand has caused a continuous decline in water levels,affected agricultural stability,and caused water environment deterioration.The problem is even more prominent in the Baojixia Irrigation Area in Shaanxi.Therefore,conducting a deep storage water irrigation and rainfall superposition experiment on the growth and yield of summer corn in Yangling,Shaanxi,in the hinterland of the Baojixia Irrigation District,exploring an irrigation system that fully utilizes rainwater resources to recharge groundwater without affecting yield,is of great significance for improving the efficiency of rainwater resource utilization and reducing irrigation water use in dry seasons.The paper quantitatively analyzed the effects of different regulation depths of deep storage water irrigation and rainfall superposition on the growth and development of summer maize,and obtained the following main results:(1)Revealed the regulatory effect of deep storage irrigation combined with rainfall on soil moistureAfter 10 days of deep storage irrigation in high water years,the average moisture content of each treatment in 0─100,100─200 and 0─200 cm soil layers of each treatment can reach 20.99%～27.01%,soil layers can reach 20.99%～27.01%.After 3 days of deep storage irrigation in normal water years,the average moisture content of each treatment in 0 ─ 100,100 ─ 200 and 0 ─ 200 cm soil layers can reach20.91%～28.01%.The treatment with the planned irrigation depth of 90 cm for water storage in jointing stage of summer maize in wet year had the highest field evapotranspiration,1.57%～28.13% higher than other treatments,and the evapotranspiration at the control depth of 140 cm in normal year reached the maximum,0.2%～25.42% higher than other treatments;The maximum amount of water that can be replenished to the deep soil during the full growth stage of summer corn in the year of abundant water and flat water can reach279.32 and 150.03 mm,indicating that deep water storage irrigation can store surface water in the deep soil to replenish groundwater,and also indicating the effectiveness of using rainwater and flood resources during flood season for irrigation.(2)Clarified the impact of deep storage irrigation combined with different hydrological year types on the morphological indicators of summer maizeIn rainy years,with the increase of regulation depth,the stem diameter and leaf area index showed a trend of first increasing and then decreasing.The plant height,stem diameter,and leaf area index of other treatments decreased by 0.57% to 2.98%,2.71% to21.96%,and 3.08% to 11.34% compared to the treatments with regulation depth of 60 cm,90 cm,and 150 cm,respectively.The stem diameter was more sensitive to soil moisture;As the depth of regulation increases,the stem diameter first decreases and then increases in the normal year,and the leaf area index and plant height generally show a trend of first increasing and then decreasing.The plant height,stem diameter,and leaf area index of other treatments decrease by 0.94%～5.54%,0.64%～8.22%,and 0.44%～5.39% compared to the treatment with a regulation depth of 180 cm,90 cm,and 90 cm,respectively;The relationship between dry matter accumulation and growth days of summer maize plants under deep storage irrigation and rainfall conditions was well fitted using the logistic growth equation.As the regulation depth increased,the dry matter accumulation showed a trend of first increasing and then decreasing.In high and low water years,it reached its maximum at treatment depths of 90 and 120 cm,respectively.As the depth of regulation increases,deep storage water irrigation can promote the growth of summer maize roots within a certain range.If the soil moisture threshold is exceeded,it will inhibit root respiration and thus inhibit root growth and development;The accumulation of chlorophyll in leaves shows a trend of first increasing and then decreasing with the increase of regulation depth.Choosing an appropriate water storage depth is beneficial for the photosynthesis of summer maize.(3)Obtained the characteristics of corn yield composition under deep storage irrigation,and proposed the optimal deep storage irrigation systemDuring the grouting process,the cumulative increment of 100 grains follows a parabolic curve.Deep storage irrigation can delay the arrival of the grouting peak,which is beneficial for improving the grain weight in the later growth stage and preventing the occurrence of premature aging in the later growth stage;Under deep storage irrigation treatment,the yield of summer maize in two seasons was highest at the control depth of 90 and 120 cm,respectively.Continuing to increase the control depth would result in a yield reduction of 1.05%～13.81% and 0.09%～5.69%,respectively;Deep storage irrigation is beneficial for summer maize to accumulate more aboveground biomass,but WUE decreases compared to the control group,mainly due to higher soil moisture,enhanced leaf transpiration and ground evaporation;Logistic equation can be used to fit and predict evapotranspiration,grain yield and water use efficiency under deep storage irrigation;The deep storage irrigation system with the highest comprehensive score in high and low water years corresponds to a regulation depth of 90 and 180 cm,respectively,which is conducive to the effective allocation of regional rainwater and flood resources.更多还原