Abstract: To study the effects of cover crops on soil nutrients and bacterial community structure in organic kiwifruit orchards in Guanzhong plain,we used LEfSe analysis,random forest analysis,PICRUSt2 function prediction analysis,and other methods to determine the soil nutrients,soil bacterial community structure,and the indicators in the 0~20 cm soil layer of the organic kiwi orchard with Glycine max,Melilotus officinalis,and Lolium perenne. The results showed that the content of soil organic matter in the cover crop treatments was significantly higher than that of the clear tillage. The treatments of MO and GM significantly increased the total potassium,catalase,and urease content of the soil,indicating that cover crop treatment can effectively improve orchard soil nutrients. Meanwhile,cover crop treatments increased β diversity of soil bacteria and representative species,increased the abundance of soil bacteria carbohydrate metabolism and energy metabolism functional genes,and promoted soil nutrient cycling. In summary,planting LP,GM,and MO in organic kiwi orchards of Guanzhong plain can help to increase soil organic matter,nutrient content,and soil micro-ecological environment,and which could be used as a suitable orchard management mode.

Key words: Cover crops, Enzyme activity, Soil bacterial diversity, 16S rDNA high-throughput sequencing

摘要： 为探究果园生草对关中地区有机猕猴桃（Actinidia chinensis）园土壤养分及细菌群落结构的影响，本研究采用LEfSe差异分析、随机森林算法分析、PICRUSt2功能预测分析等方法，对秣食豆（Glycine max，GM）、草木樨（Melilotus officinalis，MO）、一年生黑麦草（Lolium perenne，LP）三种生草处理后的有机猕猴桃园0~20 cm耕层土壤养分及细菌群落等指标进行测定。结果表明：生草处理组的土壤有机质含量均显著高于清耕，草木樨与秣食豆处理显著提高了土壤全钾含量、土壤过氧化氢酶和脲酶含量，说明生草处理能够有效提高果园土壤养分。同时，生草提升了土壤细菌β多样性，改变了不同处理间差异代表物种，增加了土壤细菌碳水化合物代谢和能量代谢功能基因丰度，促进土壤养分循环。综上，在关中平原有机猕猴桃园间种植草木樨、秣食豆和一年生黑麦草有助于提高土壤有机质和养分含量，改善土壤微生态环境，是一种适宜当地条件的果园栽培模式。

关键词: 果园生草, 酶活性, 土壤细菌多样性, 16S rDNA高通量测序