生草栽培对桃园土壤养分特性及细菌群落的影响

Effects of Sod Culture on Soil Nutrient Characteristics and Bacterial Community in Peach Orchard

为了研究生草栽培方式对土壤养分特性及细菌群落多样性的影响,探讨桃园生草栽培的土壤生态机理,在浙江杨渡桃园培育区设计了套种黑麦草、套种毛苕子和清耕杂草（对照）3个处理,并采集不同样地表层土壤进行分析。结果表明,在套种黑麦草、毛苕子8个月后,桃园土壤（0~20cm）的有机质、全氮、速效钾和速效磷等指标,没有随着套种带来的土壤养分竞争增加而减少;相反,有机质、全氮等出现增加的趋势。同时,通过变性梯度凝胶电泳（DGGE）技术,对不同生草桃园土壤细菌群落多样性表征得到,与清耕杂草土壤管理方法比较,套种牧草后土壤细菌群落多样性有所提高,优势菌群数量增加幅度明显,尤其是套种毛苕子。研究表明,黑麦草、毛苕子套种对维护桃园土壤肥力、减少土壤中养分元素淋失和提高土壤的细菌生物多样性等方面都具有重要的作用。

In order to study the effect of sod culture on soil nutrient characteristics and the diversity of soil bacteria and explore the ecological mechanism in peach orchard, three treatments： interplanting ryegrass, interplanting hairy vetch and cleaning tillage weed were established in the area of Yangdu County, Zhejiang Province and then the topsoil of different treatments were collected and analyzed using correlation methods. The results showed that： for the 0-20 cm soil depth, the organic matter, total nitrogen, available K and available P did not reduce with the increased competition of soil nutrients induced by inter-planting after eight months. On the contrary, there were increases in the organic matter and total nitrogen. The diversity of soil bacteria was characterized by the molecular biology techniques of PCR-DGGE. Compared with the management method of cleaning tillage weed （CK）, the diversity of bacterial community among two interplant treatments somewhat improved and the increase in some dominant bacterium group was significantly greater than non-dominant bacterium group. The effect of inter-planting hairy vetch was more apparent. As a result, sod culture played an important role on maintenance soil fertility, reducing the leaching of nutrient elements in the soil and improving soil bacterial biodiversity.