不同灌溉方式对枣树根系生长及抗寒性能的影响

Root Growth and Cold Resistance of Jujube Tree Under Different Irrigation Treatments

以南疆矮化密植枣树为测试对象,采用三维根系发掘法研究了滴灌(DI)和常规灌溉(漫灌,FI)方式下枣树根系生长状况和根系抗寒性能。结果表明:滴灌枣树的一级根系、二级根系以及毛细根系与FI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FI处理。FI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DI处理。DI与FI处理相比,10~40cm土层死根干质量较高,占该土层总根质量的11.17%,FI处理则仅占2.30%;除0~10cm外,FI处理各土层一级、二级侧根及毛细根的总根长及根长密度均大于DI处理;与常规灌溉相比,滴灌对一级侧根和毛细根根长的影响最大。DI处理0~10cm土层毛细根根长密度比例最高,FI处理20~40cm土层最高,分别占58.02%和65.55%;DI处理二级侧根根长密度所占比例随土层深度增加呈降低趋势,而FI处理则呈升高趋势;各类根系的垂直分布均符合三次曲线模型;DI处理浅层土壤的根系活力显著大于FI处理。根系抗寒试验表明,FI处理的电解质渗出率均大于DI处理;DI处理20~40cm以上的土层过氧化氢酶(CAT)活性均大于FI处理。表层土壤中根系的过氧化氢酶活性较低;DI处理各层根系的超氧化物歧化酶(SOD)活性均高于FI处理;深层土壤根系对糖分的累积率较高,但DI处理0~10cm土层根系的可溶性糖含量显著大于FI处理;DI处理各层根系细胞中的丙二醛(MDA)含量低于FI处理。表明与漫灌相比,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。

The aim of this study is to provide the theoretical basis for the popularization of drip irrigation technology in dwarfing and planting of jujube in southern Xinjiang.The root growth status and cold resistance of jujube trees under drip irrigation（DI）and conventional irrigation（flood irrigation,FI）were studied by using three-dimensional root excavation method in the desert oasis agriculture area of southern Xinjiang.The results showed that the primary root system,secondary root system and capillary root system of drip jujube were concentrated in shallow soil compared with FI,and the distribution difference of capillary root in each soil layer was less significant than FI.The dry weight of primary,secondary and lateral roots of FI were significantly higher than DI.Compared with FI,the dry weight of dead root in the 10-40 cm soil layer of DI was 11.17% much higher than 2.30%of FI.Except for 0-10 cm,the total root length and root length density of the first,second lateral roots and capillary roots in soil layers of FI were higher than in those of DI.Compared with conventional irrigation,drip irrigation had a significant effect on the lateral root and capillary root length.Capillary root length density ratio were highest in 0-10 cm soil layer of DI and 20-40 cm soil layer of FI,accounting for 58.02%and 65.55%respectively.The proportion of root length density of secondary lateral root of DI decreased with the depth of soil layer,while FI showed an increasing trend.The vertical distribution of the root system was in accordance with the cubic curve model.The root activity of shallow soil of DI was significantly higher than that of FI.Root cold test showed that：the electrolyte permeate rates of FI was greater than that of DI.The activity of catalase（CAT）in soil layer above 20-40 cm was higher than that of FI.The activity of superoxide dismutase（SOD）in the root system of DI was higher than that of FI.The accumulation rate of sugar in the deep soil roots was higher;however,the soluble sugar content of root in 0-10 cm soil layer of DI was significantly larger than that of FI.The content of malondialdehyde（MDA）in root cells treated with DI was lower than that in FI.In summary,the results showed that DI could cause roots of jujube to float on the surface of soil,and it could seriously reduce the root biomass,but on the other hand,it could significantly improve the cold resistance of jujube root.