增氧灌溉对平邑甜茶生长及根区土壤的影响

Effects of Aerated Irrigation on the Growth and Rhizosphere Soil of Malus hupehensis

【目的】研究增氧灌溉对平邑甜茶生长及根区土壤环境的影响,为探明该灌溉方法对大田模式栽培下果树的影响提供参考。【方法】分别以1年生、2年生盆栽平邑甜茶为试材,设置3种不同含氧量的灌溉水,探讨其对地上部生长的影响,并研究地下部根系对其响应,测定根区土壤酶活性和调查微生物群落的差异。【结果】灌溉水中的含氧量为(5±0.1)mg·L^(-1)的处理显著性最佳,1年生处理株高、地径、地上部干质量显著提高37.1%、35.0%、50.3%,2年生处理株高、地径、地上部干质量显著提高17.1%、16.4%、17.2%,并且均可不同程度改善植株叶片的光合性能与荧光特性,显著提高植株叶片氮、磷、钾、钙、镁、铁、锌矿质元素含量。灌溉水中含氧量为(5±0.1)mg·L^(-1)的处理,其根系长度、根系表面积、根尖数和根系呼吸速率均显著高于其他处理,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)等根系抗氧化酶活性也均高于其他处理;同时,该处理可显著提高土壤蔗糖酶、脲酶、磷酸酶活性,并使土壤微细菌、放线菌增加,真菌减少。【结论】灌溉水中的含氧量在(1±0.1)mg·L^(-1)~(5±0.1)mg·L^(-1)的范围内,含氧量越高,对改善盆栽平邑甜茶生长、根区土壤环境以及土壤微生物结构的效果越明显。

【Objective】The objective of this study is to explore the effect of aerated irrigation on the growth of Malus hupehensis and the rhizosphere soil environment,which would provide reference for the effects of this irrigation method on fruit trees under field cultivation.【Method】In this study,one-year-old and two-year-old potted M.hupehensis seedlings were used as test materials.Three kinds of irrigation water with different oxygen content were set up to explore their effects on the growth of aboveground part,and the response of root systems to the treatments,and the differences of enzyme activity and microbial community in the rhizosphere soil were investigated.【Result】The treatment with oxygen content of(5±0.1)mg·L^(-1) in the irrigation water had the best significance.The plant height,ground diameter and aboveground dry weight of one-year-old seedlings were significantly increased by 37.1%,35.0%and 50.3%,and those parameters of two-year-old seedlings were significantly increased by 17.1%,16.4%and 17.2%,respectively.This treatment promoted to different degrees the photosynthetic performance and fluorescence characteristics of plant leaves,and the contents of nitrogen,phosphorus,potassium,calcium,magnesium,iron and zinc were significantly increased.The root length,root surface area,root tip number and root respiration rate of the seedlings treated with oxygen content of(5±0.1)mg·L^(-1) in the irrigation water were significantly higher than those in other treatments.The activities of root antioxidant enzymes such as SOD,POD,CAT in the treatment with oxygen content of(5±0.1)mg·L^(-1)were higher than those in other treatments,and the treatment with oxygen content of(5±0.1)mg·L^(-1)significantly increased the activities of soil sucrase,urease and phosphatase,increased soil micro bacteria and actinomycetes,and reduced fungi.【Conclusion】The oxygen content in irrigation water ranges from(1±0.1)mg·L^(-1) to(5±0.1)mg·L^(-1).The higher the oxygen content is,the more obvious the effect on the improvement of potted M.hupehensis growth.The higher the oxygen content the more obvious the effect on soil environment in root area and soil microbial structure.