南疆长期滴灌红枣根际环境效应及与根系抗寒的响应关系研究

With the adjustment of agricultural structure in southern Xinjiang , Acreage of jujube further expand, oasis agricultural water consumption is increasing which irrigation water Source originated from Tarim river, This is leading to severe water shortages , water-saving technology application is imperative. Our previous studies has shown that drip irrigation technology was more suitable for jujube irrigation with dwarfing and closely spaced planting, but local farmers worry that the long-term drip irrigation cause cold hardiness degradation and production cuts with fertilizer supply shortage of jujube tree, resulting in drip irrigation technology promotion difficult..The project takes for long-term drip irrigation jujube as the research object in the desert oasis of southern Xinjiang, through the outdoor field, potted and indoor freezing test, researches on the long-term drip irrigation which impact on environmental factors alienation process, root development and root hardiness in jujube rhizosphere. Base on biostatistics, root water uptake kinetics, root fractal theory, theory of solute transport in soil,Screens the major environmental factors in root rhizosphere which affect the root development and cold hardiness, reveals the variation law of environmental factors in jujube rhizosphere under long-term drip irrigation, in-depth to explore the mechanism of the dominant factors affecting on root cold hardiness,builds definite correlation between mutation of rhizosphere environmental factors and root cold hardiness, builds models of leading environmental factors of rhizosphere affect on the performance of root hardiness under long-term drip irrigation ,looks for the regulatory mechanism inside and outside between roots and rhizosphere of jujube tree. This research will provide a theoretical basis and technical support for the promotion and application of jujube drip irrigation technology in southern Xinjiang.

随着南疆农业结构调整，红枣种植面积不断扩大，以塔里木河为水源的绿洲农业用水量日益增加，水资源严重短缺，节水技术推广势在必行。前期研究表明滴灌技术较适用于矮化密植红枣，但当地农户担心长期滴灌后红枣抗寒性能下降造成减产，使滴灌技术推广困难。.以南疆沙漠绿洲区滴灌红枣为研究对象，通过大田、盆栽和室内冷冻试验，对滴灌红枣根际环境因子异化过程、根系发育、根系抗寒性能开展研究。以生物统计学、根系吸水动力学、根系分形理论、土壤溶质运移理论为基础，筛选影响根系发育和根系抗寒性能的根际环境因子，揭示长期滴灌红枣根际环境因子的变异规律；深入探讨主导因子对根系发育和抗寒性能的影响机理，明确根际环境因子异变与根系抗寒指标的响应关系，构建长期滴灌红枣根际主导环境因子对根系抗寒性能的影响模型；寻找根系与根际间的内外调控机制，提出针对长期滴灌红枣的节水抗寒调控模式。为南疆红枣滴灌技术的推广应用提供理论基础和技术支撑。

以南疆沙漠绿洲区滴灌红枣为研究对象，通过大田和室内试验，对滴灌红枣根际环境因子异化过程、根系发育、根系抗寒性能开展了研究。主要研究结果如下：①研究表明灌溉方式对土壤碱解氮的空间异质性影响较小，对硝态氮、有效磷的影响较大。②滴灌和有机肥的联合应用可以显著提高土壤有机碳储量和土壤养分含量，同时保持较高的作物产量和品质；长期施用矿物肥料可以降低土壤有机碳含量，而长期施用有机肥可以增加土壤有机碳储存量；滴灌和有机肥的长期联合施用显著降低了根区的土壤盐分；SOC对果实产量的相对贡献率最高；灌溉对盐度有显著影响。③滴灌枣树的一级根系、二级根系以及毛细根系与漫灌处理相比多集中于浅层土壤，且毛细根系在各土层的分布差异性小于漫灌。漫灌处理各层土壤的一级、二级侧根及毛细根干质量均显著大于滴灌处理。滴灌对一级侧根和毛细根根长的影响最大各类根系的垂直分布均符合三次曲线模型；滴灌处理浅层土壤的根系活力显著大于漫灌。④漫灌处理的电解质渗出率均大于滴灌；滴灌处理表层土壤中根系的过氧化氢酶活较低；滴灌处理各层根系的超氧化物歧化酶活均高于漫灌；深层土壤根系对糖分的累积率较高，但滴灌表层根系的可溶性糖含量显著大于漫灌；滴灌处理各层根系细胞中的丙二醛含量低于漫灌。滴灌导致枣树根系附于表层土壤，且根系生物量严重减少，但却能显著提高枣树表层根系的抗寒性能。⑤施肥方式对各项抗寒指标都具有显著的影响,而灌溉方式只对过氧化氢酶和超氧化物歧化酶有单独的影响；灌溉方式和施肥类型仅对超氧化物歧化酶和丙二醛有显著的交互影响。电解质渗出率和丙二醛与土壤养分指标呈现负相关关系，而与土壤pH呈现正相关；过氧化氢酶活、超氧化物歧化酶活及可溶性糖和土壤养分呈正相关关系，而与pH呈负相关。提高土壤磷含量有助于枣树根系的抗寒性。⑥提出了生育期湿度调控+环周式调根减蒸滴灌模式+有机肥+秸秆覆盖等枣树节水抗寒管理模式。