【作者】 胡永翔；

【导师】 李援农；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2013， 博士

【摘要】 针对黄土高原地区生态环境脆弱、水土流失严重和主要特色果品生产技术落后等实际情况，为了保证黄土高原地区水土资源可持续利用，提高退耕还林区群众经济效益，满足农业现代化建设和改善区域生态环境条件，于2009-2011年在陕西米脂县孟岔枣树试验园进行了连续试验。试验以黄土高原地区特色果品枣树为研究对象，在枣树的不同生育期设置了不同亏水度的调亏处理，以不同灌水处理的土壤水分动态变化规律为基础，针对调亏灌溉对枣树需水耗水规律、生理生态指标、果实的品质指标、产量和水分利用效率的影响进行了详细分析，建立了基于熵理论的枣树调亏灌溉综合效益模型，探求了基于FAO-56水分胁迫系数的枣树园土壤水分估算方法，并制定了黄土高原地区滴灌方式下枣树的调亏灌溉制度，最终得到了黄土高原地区滴灌方式下枣树最优灌溉模式和作物系数，为黄土高原地区发展节水、稳产，优质、高效的可持续型枣树种植提供全面的理论依据。取得以下几方面成果：(1)通过对不同灌水条件下枣树土壤水分变化特性进行研究，发现生育期内不同亏水度处理间的土壤含水率存在明显差异，各调亏处理在水分亏缺期间的土壤水分消耗趋势均缓于对照。相同调亏程度的处理在不同生育期的土壤含水率状态差异显著：枣树在开花坐果期和萌芽展叶期的土壤含水率变化速率相对较快。(2)黄土高原地区枣树的各生育期作物系数(3年均值)从大到小的排列顺序为：果实膨大期(1.188＞果实成熟期(0.897)＞开花坐果期(0.655)＞萌芽展叶期(0.526))，并且作物系数和叶面积指数之间存在显著的二次曲线关系。各调亏处理在亏水的生育期中，作物系数都不同程度的低于对照处理，存在一个水分胁迫系数。不同调亏处理在亏水阶段的水分胁迫系数随着亏水程度的增加而减小，即重度调亏<中度调亏<轻度调亏。(3)通过对枣树各生态指标的研究发现，调亏灌溉对枣树各器官的生长有显著的影响，调亏处理的新梢长度、叶面积指数和开花坐果数均受到不同程度的抑制或促进效果。综合考虑各调亏处理对枣树营养生长和生殖生长的调控效果，萌芽展叶期进行适度的亏水能控制冗余生长，起到抑制枣树新梢生长和叶面积指数、增加开花数和坐果数的作用，尤其以萌芽展叶期中度调亏处理T2(M-P1)具有相对良好的效果，而开花坐果期不适宜进行水分胁迫，各处理均会降低开花数和坐果数，从而影响枣树最终的经济效益。(4)调亏灌溉对黄土高原地区枣树的生理指标有显著性影响，主要表现为亏水时和复水后的状态差异。亏水状态下的各调亏处理的净光合速率日变化曲线不同程度的低于对照处理CK，且随着调亏程度的增加而减小，即重度调亏处理<中度调亏处理<轻度调亏处理<对照；调亏后复水会显著提高净光合速率，并净光合速率日变化曲线的峰值时间前移。亏水时期调亏处理的枣树叶片气孔导度均有不同程度的下降，复水后各调亏处理的气孔导度值均有显著提高。在相同的天气条件下，叶水势的变化状况直接与调亏程度相关，随亏水程度的增加而减小。(5)不同生育期调亏灌溉对果实的物理品质指标有一定的影响：果实膨大期的中度和重度调亏处理使单果质量和体积显著降低；调亏灌溉会降低枣果实的含水率，坏果率，提高果实硬度，其中果实膨大期的调亏处理降低果实含水率和提高果实硬度的效果最显著，达到9.1%和10.3%；果实成熟期的重度调亏处理降低坏果率的效果最为显著，为20.1%。不同生育期调亏灌溉对果实的化学品质指标有较显著影响：其中果实成熟期的重度亏水处理降低枣的有机酸含量最为显著(P<0.05)，平均降幅25.5%；提高枣树果实维生素C含量的效果最为显著，平均增幅23.9%。开花坐果期中度调亏处理提高果实可溶性固形物的效果最为显著，平均增幅25.3%。而果实膨大期的重度调亏处理对可溶性蛋白的抑制作用最为显著，3年中平均降低了14.8%。(7)使用基于信息熵理论的模糊评判方法建立了黄土高原地区枣树调亏灌溉综合效益模糊评价模型。根据2009～2011年黄土高原地区枣树不同生育期不同调亏处理的试验资料，综合考虑果实物理指标、化学品质指标、产量、水分利用效率与经济效益等因素，对各调亏处理的综合效益作出了全面客观的评价。(8)通过使用基于FAO-56水分胁迫系数的计算模型，模拟了黄土高原地区滴灌条件枣树水分胁迫状态下土壤含水率的动态变化过程，分析了计算模型在枣树不同生育期的精度变化和误差形成原因。(9)建立黄土高原地区滴灌方式下枣树的最佳调亏灌溉制度，参考本试验中调亏灌溉对枣树各项指标影响的分析，以综合效益最大化的处理为模板，按照萌芽展叶期中度调亏，开花坐果期和果实膨大期尽可能保证充分供水，果实成熟期重度调亏的具体原则，结合不同水文年的降水情况和试验中已经实测的枣树耗水量，设计了黄土高原地区滴灌方式下枣树的调亏灌溉制度。更多还原

【Abstract】 The condition of the Loess Plateau is special: the ecological environment is fragile, thesoil is eroded seriously and the production technology of the main specific fruit is backward.Considering that special condition, this research is to ensure the sustainable utilization ofwater resources in the Loess Plateau region, improve the economic benefit of people whohave returned farmland to forest, meet the agricultural modernization and improve theregionally ecological environment conditions; additionally, the research object is the specificfruit—jujubes—in the loess plateau region. In the different growth periods of jujubes, theresearch designs different water deficit treatments, which are based on the dynamic change ofsoil water. The research analyzes the affection of Regulated Deficit Irrigation (RDI) onjujube’s water need and consumption rule, physiological and ecological index, fruit qualityindex, yield and water use efficiency; additionally, the research establishes the entropytheory based on the comprehensive benefits model of jujubes under RDI and the estimationmethod of jujube orchard soil moisture’s FAO-56water stress coefficient, and establishes thejujube’s RDI system under drip irrigation in Loess Plateau region. The result of this researchgains the jujube’s optimal irrigation model and crop coefficient under drip irrigation in theLoess Plateau, which provides a theoretical basis for promoting sustainable jujubes withsaving-water, stable-yield, high-quality and efficient in the Loess Plateau.(1) According to the study of soil moisture distribution characteristics under differentirrigation conditions, it has been concluded that there is obvious difference between differentwater deficit treatments in the same growth period. The soil water consumption trend ofdifferent water deficit treatments is slower than CK. The same deficit degree in differentgrowth periods of soil moisture rate appears to be quite different: the soil moisture rates ofjujube’s flowering and fruit-setting period and sprout developing period are relatively higherthan in other growth periods.(2) The jujube’s crop coefficient under drip irrigation in the Loess Plateau is sequencedfrom large to small as follows: fruit developing period> fruit maturing period> flowering andfruit-setting period> sprout-developing period; additionally, there are two curves relationshipbetween crop coefficient and leaf area index. As the RDI treatments in water deficit growth period, crop coefficients are generally lower than CK, that is, there is a water stress coefficient.The water stress coefficients in the water deficit periods under different RDI decreases aswater deficit degree increases, that is the severe RDI<<moderate RDI<light RDI.(3) According to the study of jujube’s ecological indexes, RDI has significant effect onthe growth of jujube’s various organs. New shoot length, leaf area index and the number offruit blossom are all under different effects of RDI. Considering the effect of RDI on jujube’snutrition growth and reproduction growth, moderate RDI in the sprout developing period cancontrol the redundant growth to suppress jujube’s new shoot growth and leaf area index, andincrease the number of blossom and fruit bearing number. Especially the moderate RDItreatment T2(M-P1) in the sprout developing period has a relatively active effect; however,the flowering and fruit-setting period doesn’t suit for water stress, which can decrease thenumber of blossom and fruit, thus affecting the jujube’s economic benefits(4) Jujube’s physiological index in Loess Plateau has significant difference in response towater deficit and rewatering. In the condition of water deficit, daily curves of netphotosynthetic rate under each RDI treatment generally lower than CK; additionally, thechanges of curves decreases as the RDI treatment increases, that is, severe RDI <moderateRDI<light RDI <CK. After RDI, the rewatering significantly increases the netphotosynthetic rate, and the peak time of net photosynthetic rate curve moves forward. Duringthe water deficit period, jujube leaf’s stomata conductance under RDI treatment generallydecreases; after rewatering, the stomata conductance increases. In the same weatherconditions, change of leaf water directly connects with RDI degree, that is, it decreases as thewater deficit degree increases.(5) RDI treated in different growth periods has effect on fruit physical quality index. Themoderate RDI and the severe RDI treated in the fruit developing period significantly decreasefruit weight and volume. RDI can decrease fruit’s water content, bad fruit rate, increase fruithardness. Specifically, the RDI treated in the fruit developing period most significantlydecreases fruit’s water content and increases fruit hardness, reaching9.1%and10.3%; thesevere RDI treated in the fruit developing period decreases the bad fruit rate mostsignificantly reaching20.1%. RDI treated in different growth periods has significant effect onfruit’s chemical quality index. Specifically, the severe RDI treated in the fruit maturing periodmost significantly decreases jujube’s organic acid content(P<0.05), the average decreasingrange is25.5%; that most significantly increases fruit’s vitamin C content, the averageincreasing range is23.9%. The moderate RDI treated in the flowering and fruit-setting periodmost significantly increases fruit’s soluble solids, the average increasing range is25.3%.However, the severe RDI treated in the fruit developing period most significantly decreases soluble protein, decreasing of14.8%in3years.(7) Applying comprehensive optimum seeking method on different RDI treatment andbasing on fuzzy evaluation method of information entropy to establish the evaluation modelof benefit under RDI treated in jujube in Loess Plateau area. According to the test data ofdifferent RDI treated in jujube’s different growth period during2011~2009in Loess Plateauregion, considering fruit’s physical index, chemical quality index, yield, water use efficiencyand economic benefits, this research provide comprehensive and objective evaluation of RDItreatment benefit.(8) Applying the calculated model of FAO-56water stress coefficient to simulate thedynamic process of soil moisture content under water stress of drip irrigation jujube’s in theLoess Plateau region, and additionally analyzing the precision changes and error reasons ofjujubes in different growth periods calculated by computer model.(9) Establishing the optimum RDI system of drip irrigation jujubes in Loess Plateau,referring the analysis of RDI’s influence on jujube’s each index, applying the treatment ofcomprehensive benefit maximization as the model, according to the following rule—applyingmoderate RDI in the sprout developing period, insuring adequate water supply in theflowering and fruit-setting period and fruit developing period, applying severe RDI in the fruitmaturing period—considering the precipitation conditions of different years and jujube’swater consumption tested, this research has designed the RDI system of drip irrigation jujubesin Loess Plateau region.更多还原