【作者】 崔宁博；

【导师】 康绍忠；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2009， 博士

【摘要】 我国干旱半干旱区占国土面积的52.5%,西北半干旱区许多地区作物生育期内降水不足250mm,难以满足正常生长需水,灌溉对于该区作物稳产、增产具有不可替代的作用。该区灌溉水有效利用率较低,且近年来地下水过度开采、水土流失严重,生态环境十分脆弱,农业与生态用水矛盾突出。但该区光照资源丰富、昼夜温差大,是我国优质水果重要产区,梨枣是该区的特色出口水果,也是该区种植结构调整中重点发展的支柱产业之一,因此,如何高效利用有限的水资源进行科学灌溉,提高灌溉水有效利用率是当地枣业生产中急需解决的突出问题。针对西北半干旱区果业生产面临水资源紧缺的现实,论文以该区特色经济果树梨枣树为研究对象,在西北农林科技大学旱区农业水土工程教育部重点实验室、陕西省大荔县城关镇梨枣园分别开展了温室与大田试验,对调亏灌溉的梨枣树根区土壤水分动态变化特征、水分亏缺与复水环境下梨枣树用水过程、生理调控与气孔响应机理、不同生育期不同水平亏水处理对营养生长与生殖生长的影响及其调控机制等进行了较系统的研究,分析了各生育期不同亏水处理对梨枣耗水规律、产量、品质、作物系数、水分利用效率及经济效益的影响,取得了以下成果:⑴通过亏水处理与复水效应研究,进一步证实了适度水分亏缺可以有效调控梨枣树叶片气孔开度,降低叶片过多的蒸腾耗水,并刺激树体诱发补偿效应,初步揭示了调亏灌溉提高果树叶片水平水分利用效率的机理与水分亏缺引起的“干湿交替过程”对气孔的调控机理,从果树生理角度进一步证实了调亏灌溉的节水机理。⑵揭示了调亏灌溉对梨枣树生长发育的调控过程,初步阐明了不同生育期不同亏水处理对其营养生长与生殖生长、梨枣果实发育与产量形成的影响机制,为提高梨枣产量水平水分利用效率提供了理论依据。⑶分析了温室不同生育期亏水处理梨枣树液流在全生育期内的变化规律及其与参考作物蒸发蒸腾量、土壤含水率间的定量关系,表明不同亏水处理在显著降低灌溉水量的同时液流总量最大降幅仅为10.5%,且部分处理出现液流总量略高于对照的现象,表明亏水处理下梨枣树根区土壤“干湿交替”可诱发根系产生明显的吸水补偿效应;同时,利用液流液流—株间微型株间微型蒸渗仪法计算各亏水处理梨枣树的蒸发蒸腾量与水量平衡法计算结果具有较好的一致性,相对误差在-6%～17%之间,可用于灌溉制度的制定。⑷研究了梨枣树不同生育期不同水平亏水处理对果实品质的影响,分析了梨枣单项品质指标对水分调控的敏感性并通过熵权法与主成份分析法对梨枣综合品质进行了评价,在此基础上初步建立了基于梨枣树水分-品质响应机理的控水调质生产函数。⑸得到了温室与大田条件下不同水平亏水处理的梨枣树耗水规律和作物系数,结果表明,生育期内两者均呈单峰曲线变化,最高值出现在开花座果期与果实膨大期。⑹通过对温室与大田梨枣树不同生育期实施不同水平亏水处理,研究了叶片碳稳定同位素分辨率(△L)与相应时段叶片水平WUE(WUEi、WUEn)、最终产量、产量水平WUE(WUEy)间的关系,同时研究了果实碳稳定同位素分辨率(△F)与产量、WUEy和耗水量间的关系。结果表明不同生育期亏水处理对梨枣树△L、△F影响显著,不同生育期亏水处理的△L与WUEi、WUEn仅在果实成熟期均呈显著负相关(P<0.05),△F与WUEy、产量也仅在果实成熟期均呈显著负相关(P<0.05或0.01)全生育期所有亏水处理下△L对叶片水平WUE具有一定指示性,且对WUEn的指示性优于WUEi,△F对WUEy、ETc指示效果较为理想。⑺根据三年的试验资料,从优选梨枣树最佳调亏灌溉方案出发,构建了评估梨枣树调亏灌溉综合效益的多层次指标体系,利用多层次多目标模糊理论与方法,建立了调亏灌溉综合效益多层次多目标模糊评价模型,利用信息熵理论求得各层评价指标客观熵权,结合专家法的主观权重获得了模型各层评价指标综合权重,提高了模型评价可靠性。同时,运用该模型对3年温室、大田梨枣树调亏灌溉综合效益进行了评价。结果表明,在温室条件下,果实成熟期中度(灌水定额为对照1/2)亏水处理方案的调亏灌溉综合效益较好;在大田自然降水条件下,果实成熟期重度(不灌水)、中度(灌水定额为对照1/2)亏水的单阶段调亏灌溉方案及萌芽展叶期重度(不灌水)+果实成熟中度(灌水定额为对照1/2)亏水的复阶段调亏灌溉方案综合效益较为理想,符合生产实际情况。因此,基于信息熵理论的调亏灌溉综合效益模糊评价模型可为梨枣树最佳调亏灌溉方案的制定提供较为可靠的指导。⑻根据三年的调亏灌溉试验资料与当地降水资料,初步提出了西北半干旱区不同水文年型梨枣树调亏灌溉模式,同时还探讨了调亏灌溉在西北半干旱区推广应用的适用性和潜力。研究结果表明,在西北半干旱区梨枣园实施科学的调亏灌溉可以提高梨枣树叶片和产量水平水分利用效率,有助于节水、稳产、优质、高效的可持续型果业生产模式的形成,对促进该区果业健康发展具有重要的指导。更多还原

【Abstract】 The area of the arid and semi-arid regions accounts for about 52.5% of the total area of China, and the rainfall of the crop growth stages in most areas of the semi-arid region in Northwest is less than 250mm, which cannot meet the water demand for normal growing, so irrigation has a irreplaceable effect on the high and stable yield. The lower irrigation water use efficiency in the study area and irrational competitions for surface water between its upper and lower reaches have resulted in serious soil erosion, deteriorated ecosystem and serious conflict of water shortage for both agricultural and ecological water demand. However, this area is an important productive base of good quality fruit due to the abundant sunshine and large day/night temperature range. The pear-jujube which is the special local export fruit of this area and also one of the supporting industries should be mainly developed during the process of the planting structure adjustment. So, to use the limited water resources for efficient irrigation of these crops and to enhance irrigation water efficiency have become an important issue of this area.According to the scarce water resources the fruit industry in the semi-arid region of northwest are facing, this paper focuses on the characteristic economy fruit tree, pear-jujube tree, and developed on the experiments in the greenhouse and the oasis field respectively in Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University and in the pear-jujube orchard located in Chengguan Village, Dali Town, ShaanXi Provence. This paper has made systematic research about characteristics of soil water dynamic changes, water deficit of the root-zone of pear-jujube tree with regulated deficit irrigation, physiological control in the process of the water use and the stomal response mechanism of pear-jujube tree under the water deficit environment, and the effects of different deficit irrigation levels at different growth stages vegetative growth and repproductive growth of pear-jujube trees, and also its regulation mechanism.This paper also analyses the effect of water deficit on water use, yield, fruit quality, crop coefficient, water use efficiency and economical benefit, and achieved the followings:⑴The research of the water deficit treatment and rewater domino effect significantly test that proper water deficit can regulate and control stomal open degree efficiently, reduce the overtranspiration of leaves, stimulate the compensating effects. It also primarily reveals the mechanism of the regulated deficit irrigation which can enhance the leaf water use efficiency, the mechanism of regulation and control to the stomata caused by“dry-wet alternative process”originated from the water deficit, and also the mechanism of physiological water saving of the regulated deficit irrigation from physiology of the fruit tree.⑵It reveals the control process to the growth of pear-jujube tree which is caused by the regulated deficit irrigation, primarily illuminates the cause of the effects of different deficit irrigation levels at different growth stages on the vegetative growth and reproductive growth of pear-jujube trees, the fruit growth and the yield of the pear-jujube and offers a theory basis for the enhancement in the yield of the pear-jujube and of water use efficiency.⑶The dynamics of the sap fluxes of pear-jujube tree in the greenhouse under different deficit irrigation treatments at different growth stages and its quantitive relationship with reference crop evapotranspiration and soil water content, indicate that different deficit irrigation treatments not only can decrease the irrigation water amount significantly, but also make the maximum decrease of the sap flow amount just be only by 10.5%, and even the phenomenon that the sap flow amount is a little bit higher than the reference crops is observed, which illustrates that the“dry-wet alternative”in the rootzone of pear-jujube tree under the treatment of water deficit can stimulate the root to produce significant compensating effects of water supping.The results of combination method of sap flow and micro-lysimeter indicate that the evapotranspiration were in accordance with those of soil water balance method, with relative error ranging from -6% to +17%, which can be used to directed establish the irrigation schedule.⑷This paper sduty the effects of different deficit irrigation levels at different growth stages on the fruit quality, analyzes the sensitivity of the special quality index of pear-jujube tree to the regulate and control of water and makes a evaluation on the comprehensive quality of pear-jujube tree by the entropy method and the primary component analysis method, and primarily establish the regulated quality by control water production function which is based on water-quality response mechanism of pear-jujube tree.⑸The water consumption and crop coefficient of pear-jujube tree with different deficit irrigation levels treatment under the condition of the greenhouse and oasis field, indicate that the two above change as a single-peak curve the whole during growth stages, with the maximum appears at the flowering to fruit set stage and the fruit maturation stage.⑹By using various water deficit treatments at different growth stages on pear-jujube tree planted in both greenhouse and oasis field, we do some researches on the relationship between leaf stable carbon isotope discrimination(△L) and leaf water use efficiency at the same stage, the relationship between final yield and yield WUE, and also the relationship between fruit stable carbon isotope discrimination, yield, yield WUE and water use amount. Results indicate that water deficit had significant effect on the△L and the△F at different growth stages, and the△L under different water deficit treatments appear negatively related to WUEi、WUEn on fruit maturation stage(P<0.05)and the related relationship is not obvious at other growth stages(P>0.05),△F is significantly negatively related with WUEy and yield at fruit maturation stage. Thus the△L can indicate leaf water use efficiency over whole growth stage under different water deficit condition, and it indicated WUEn superior to WUEi,),and the indicated effect of△F to WUEy、ETc is also quite well.⑺From the view of selecting the best schedule of regulated deficit irrigation (RDI) for pear-jujube tree, a multi-hierarchy index system for evaluating the integrated benefit of the RDI was established using the field experimental data during 2005～2007. A multi-hierarchy and multi-objective fuzzy evaluation mode1 for evaluating the integrated benefit of RDI was also established using the multi-hierarchy and multi-objective fuzzy theory. The impersonality weights coefficient of all hierarchy evaluation index were obtained using the information entropy theory, then combined with the subjective weights given by experts, we obtained the integrated weights objective for the multi-hierarchy evaluation index, which can improved the reliability of the model evaluation results. At the same time, RDI integrated benefits (RDIIB) of pear-jujube tree with different water deficit treatments during 2005～2007 was evaluated and sorted using the model. Results show that under the greenhouse condition, the RDI integrated benefits (RDIIB) of pear-jujube tree with moderate water deficit (1/2 of full irrigation) treatments is better; Under the field condition the severe(no irrigation) and moderate water deficit (1/2 of full irrigation) treatments at the fruit maturation stage, the combined severe water deficit(no irrigation) at the bud burst to leafing stage and moderate water deficit(1/2 of full irrigation) at the fruit maturation stage had the better RDIIB,the result are in line with the actual production.Therefore, the RDIIB evaluation model based on information entropy theory can provide the reliable technical guidance for the optimal RDI scheme of pear-jujube tree.⑻According to the regulated deficit irrigation experiment data and local rainfall data in 3 years, the application model of the regulated deficit irrigation for pear-jujube tree on different hydrological years in the semi-arid region of Northwest China is primarily established, and the applicability and potential to apply and spread the regulated deficit irrigation for pear-jujube tree in the semi-arid region of Northwest is also discussed.The result of the research shows that the proper application of the regulated deficit irrigation in pear-jujube orchard in the semi-arid regions of northwest can enhance the yield and water use efficiency in leaves, contributing to form the continuable fruit produce model with stable water saving and high fruit quality, and give some important guidance to promote the scientific development of the fruit production in this region.更多还原