大葱伴生甜瓜栽培对根际土壤酶活性和细菌群落的影响

Effects of Companion Planting of Melon With Onion on Enzyme Activities and Bacterial Community in Rhizosphere Soil

为解决设施栽培土壤恶化引起的甜瓜产量持续下降问题,本研究以大葱与甜瓜进行伴生栽培试验,基于传统土壤农化、土壤酶分析和现代高通量测序技术分析,探究伴生对根际土壤农化、土壤酶、土壤细菌群落结构的影响。结果表明,伴生栽培甜瓜根际土壤细菌数量低于甜瓜单作处理,但差异不显著,而伴生处理的Shannon指数显著高于甜瓜单作处理,表明伴生栽培虽然降低了根际土壤细菌数量,却显著提高了细菌群落结构的多样性。细菌结构分析表明变形菌门(Proteobacteria)等有益菌门是伴生处理中的优势菌门,在播种80 d后伴生处理中占比达到35.73%;鞘脂单胞菌属(Sphingomonas)等有益菌属是伴生处理中的优势菌属,在播种80 d后伴生处理中占比达到11.90%。通过对土壤农化、土壤酶分析可知,伴生处理中脲酶、蔗糖酶、漆酶等土壤酶活性和速效磷含量均显著高于甜瓜单作;相关性分析表明,pH值、速效钾含量、蔗糖酶活性、脲酶活性、漆酶活性和土壤细菌菌落在播种80 d后伴生处理中呈显著或极显著相关性。伴生栽培后的甜瓜果实除可溶性固形物含量、果实硬度外,单果重、单株产量以及亩产量均显著高于甜瓜单作。研究表明伴生栽培后土壤的细菌群落得到了改善,这为土壤微生态环境改良提供了理论依据,并为甜瓜生产的可持续发展提供了思路。

In order to deal with the problem of continuous decrease of melon yield which caused by the deterioration of soil, the companion planting experiment was carried out with green onion and melon. Based on traditional soil agro-chemistry, soil enzyme analysis and modern high-throughput sequencing technology analysis, the effects of companion planting on the rhizosphere soil agro-chemistry, soil enzymes, and soil bacterial community structure were studied. The results showed that the number of bacteria in the rhizosphere soil of the companion planting melon was lower than that of the monocropping treatment, but the difference was not significant, and the Shannon index of the companion planting treatment was significantly higher than that of the monocropping treatment, indicating that the companion planting reduced the number of rhizosphere soil bacteria but increased significantly the diversity of bacterial community structure, with the percentage of 35.73%;the analysis of bacterial structure showed that Proteobacteria was the dominant phylum in the companion planting treatment the dominant bacteria in the companion planting treatment was Sphingomonas, and it takes account for 11.90%. The analysis of soil agro-chemistry and soil enzymes showed that the pH value and organic matter content in the rhizosphere soil of the companion planting treatment were higher than those of monocropping, and the content of available phosphorus was significantly higher than monocropping;the activities of soil enzymes such as urease, invertase and laccase were all significantly higher than monocropping. Spearman correlation analysis showed that pH, available potassium, invertase, urease, laccase and soil bacteria colony were significantly or extremely significantly correlated. Except for the soluble solids, the fruit firmness, fruit weight, yield per plant and yield per mu of melon after companion planting were significantly higher than those of monocropping of melon. Therefore, the companion planting of green onions changed the physicochemical properties of melon rhizosphere soil. This study can provide a theoretical basis for improving soil ecological environment, and provides advanced ideas for the sustainable development of melon production.