不同种植年限设施芦笋土壤微生物群落结构与功能研究

Microbial Community Structure and Function in Greenhouse Soils of Asparagus

以上海某设施园艺场长期设施芦笋种植土壤为研究对象,采用常规梯度稀释混菌平板法和Biolog-Eco微平板反应系统,研究了芦笋设施种植1、3、5、8及11年棚土壤微生物群落结构及功能多样性。结果表明:设施栽培芦笋后,土壤细菌种群数量减少,真菌数量增加,细菌与真菌数量比(B/F值)降低;除11年棚表现特殊外,随种植年限增加,土壤微生物代谢活性逐渐下降,5年和8年棚AWCD值均仅为对照1年棚的15%左右;土壤微生物代谢类群多样性减少,5年和8年棚的土壤微生物丰富度指数(S)均仅为对照1年棚的72%左右,Shannon指数均为对照1年棚的82%左右,Mc Intosh指数则均为对照1年棚的90%;不同种植年限芦笋设施土壤中微生物群落的碳源代谢特征发生了明显的分异变化,主成分分析表明,这种变化主要体现在对6种碳水化合物和5种氨基酸碳源的代谢利用上;设施芦笋土壤微生物参数指标对土壤p H和EC值变化响应敏感,另外,土壤速效磷和速效钾含量也是影响土壤微生物代谢和区系分异的2个主要因素。

The structure and functional diversity of soil microbial communities of 1, 3, 5, 8 and 11 a asparagus shed were investigated with traditional dilution plate and Biolog-Eco system. The results showed that amount of bacteria decreased, fungi increased and bacteria/fungus ratio（B/F） decreased sharply after the cultivation of asparagus, which indicated a trend of soil microbe type translation from bacteria to fungi. Except for 11 a shed, microbial metabolic activities were decreased as the increase of planting year, the AWCDS of 5a and 8a shed were only 15% of control＇s（1 a shed）. Diversity of microbial metabolic communities decreased： the richness indexes（S）, Shannon indexes, Mc Intosh indexes of 5a and 8a were about 72%, 82%, 90% of control＇s（1a shed） respectively. The principal component analysis（PCA） showed the differences in metabolic characteristics of soil microbial community resulted mainly from the utilizations of six carbohydrates and five amino acids. The microbial parameters were sensitive to p H and EC of soil. In addition, the contents of available phosphorus and potassium in soil also affected microbial metabolism and soil system differentiation.