不同种植年限设施菜地土壤微生物量和群落结构的差异  

Changes in Soil Microbial Biomass and Community Structure with Cultivation Chronosequence of Greenhouse Vegetables

作　　者：宋蒙亚[1,2] 李忠佩[1,2] 吴萌[1] 刘明[1] 江春玉[1] 

机构地区：[1]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,南京210008 [2]中国科学院大学,北京100049

出　　处：《中国农业科学》2015年第18期3635-3644,共10页Scientia Agricultura Sinica

基　　金：国家科技支撑计划(2012BAD05B04);国家自然科学基金(41171233)

摘　　要：【目的】研究不同种植年限设施菜地土壤微生物量和群落多样性变化规律,探索高度集约利用下土壤质量退化的根本原因和机理,为设施菜地土壤可持续利用提供理论参考。【方法】采集江苏省常熟市由稻麦轮作农田转变为设施菜地种植3 a、6 a和10 a等3个不同年限0—20 cm表层土壤,以周围种植水稻/小麦的农田土壤作为参照,分别测定土壤理化性质、微生物量和微生物群落多样性等指标。【结果】由稻麦轮作农田转变为设施菜地种植3 a的土壤微生物活性较强,养分含量较高;种植6 a后微生物活性明显降低,速效养分含量积累。种植年限从3 a到10 a,速效氮含量升高66.1%,速效磷含量升高97.2%。种植3 a以内p H接近中性,而种植6 a以上p H降低至酸性。土壤微生物量碳和微生物商在种植3 a均最高,种植6 a和10 a后显著降低。微生物群落的碳源利用指纹(BIOLOG)分析表明,种植3 a平均吸光值(AWCD)和微生物多样性指数(Shannon、Simpson和Mc Intosh)均最大,对碳源的利用能力最强,种植6 a和10 a明显降低,其中AWCD和Shannon指数分别比种植3 a降低了96.1%、15.4%和89.7%、17.6%。磷脂脂肪酸(PLFA)分析表明,种植3 a PLFA总量及细菌、真菌、放线菌PLFA含量均最大,而种植6 a和10 a以上指标均明显降低,其中,种植10 a土壤的PLFA总量及细菌、真菌、放线菌PLFA含量分别比种植3 a降低27.4%、21.8%、42.7%、49.4%(P<0.05)。【结论】随着设施菜地种植年限增加,土壤微生物量和群落结构发生了明显变化,设施菜地种植3 a土壤微生物活性和群落结构稳定性明显增强,而种植6 a以上土壤微生物活性和群落结构稳定性明显降低,土壤生物质量显著退化。[Objective] This paper mainly studied the changes in soil microbial biomass and community structure with cultivation chronosequence of greenhouse vegetables, and explored the reason and mechanism of soil degradation under highly-intensified land use. The results would provide a scientific basis and practical guidance for soil quality maintenance and sustainable utilization of farmland. [ Method ] In this study, 0-20 cm soils were collected in 3 a, 6 a and 10 a greenhouse vegetable cultivation converted from rice-wheat rotation farmland in Changshu city, Jiangsu Province, with the adjacent nee-wheat rotation farmland as control. Soil nutrients, microbial biomass and microbial community diversity were measured. [Result] Soil in 3 a greenhouse vegetable cultivation converted from rice-wheat rotation farmland had rich microbial diversity and high nutrient contents. While soil in 6 a greenhouse vegetable cultivation showed significant acidification and microbial diversity decrease and nutrient accumulation. From 3 a to 10 a greenhouse vegetable cultivation, the available nitrogen increased by 66.1% and the available phosphorus increased by 97.2%. Soil pH in 3 a greenhouse vegetable cultivation was neutral, while that in 6 a cultivation wassignificantly to be acidic. Soil microbial biomass C and microbial quotient in 3 a greenhouse vegetable cultivation were higher than those in 6 a and 10 a cultivation. BIOLOG analysis showed that AWCD value and microbial diversity index in the soil of 3 a greenhouse vegetable cultivation were the highest among all treatments, which means the maximum absorption and utilization for carbon sources. PLFA analysis showed that soil in 3 a greenhouse vegetable cultivation had highest total PLFA concentrations in microorganisms and bacteria, fungi, actinomycetes, while those in 10 a cultivation significantly decreased by 27.4%, 21.8%, 42.7%, and 49.4% （P^0.05）, respectively. Principal component analysis showed that the diversity of microbial community structure had changed significantly.

关 键 词：土壤养分 微生物量 微生物商 微生物群落结构 

分 类 号：S154.3[农业科学—土壤学] S626[农业科学—农业基础科学]