【摘要】 目前对小分子有机物的研究主要集中在叶面肥方面,较少在土壤肥料的应用方面,而对土壤酶活性以及微生物功能多样性的研究就更少。以分别添加葡萄糖、甘油以及甘氨酸的土壤(25℃培养)为试材,采用酶活性(每15 d取样)测定方法与Biolog-Eco板技术(取培养45 d的土样),研究小分子有机物对土壤微生物及酶活性的影响。结果表明,3种小分子有机物处理土壤的4种酶活性在15～75 d内,变化规律基本一致;在45 d时葡萄糖处理土壤的过氧化氢酶活性显著高于清水对照(CK)、甘油以及甘氨酸,而碱性磷酸酶活性显著低于其它处理。与CK、葡萄糖以及甘氨酸相比,甘油处理土壤微生物平均吸光度值和功能多样性指标(除指数D外)显著提高,而CK、葡萄糖以及甘氨酸处理之间没有显著性差异。葡萄糖、甘油以及甘氨酸处理改变了土壤的微生物功能多样性以及碳源利用比分,其中甘氨酸和葡萄糖处理土壤胺类利用百分比(AM)几乎为零。土壤微生物多样性与酶活性冗余分析表明,碱性磷酸酶与微生物功能多样性指数S、U、H′、碳水化合物利用百分比以及AM呈显著正相关,相关系数分别为0.588、0.669、0.616、0.678及0.603,与指数D及蔗糖酶活性呈显著负相关,相关系数分别为-0.737和-0.741。由此可知,不同种类小分子有机添加物对土壤酶活性以及微生物功能多样性影响不一,其中甘油显著提高了土壤微生物代谢活性以及多样性指数(除指数D外),而土壤酶活性与微生物功能多样性的主成分分析表明甘氨酸与另外两种小分子有机物存在明显差别。更多还原

【Abstract】 The studies on application of low-molecular-weight organic substances in agriculture,mainly as foliar spray fertilizers promoting plant growth are widely known,there is little information on concurrent changes in soil microbial functional diversity and enzyme.Soil microbial functional diversity and enzyme activities can be impacted by soil additions,which in turn can alter soil fertility and quality.The objective of this study was to investigate the effects of them on microbial functional diversity and enzyme activities.Biolog-Eco plates(at 45 day)and methods in enzymology(sampling every15 days)were used to acquire the change of soil microbial functional diversity and enzymes with glucose,glycerol and glycine addition(at 25 ℃).The results revealed that during the period of 15 ～ 75 days,the changes of soil enzyme activity were basically the same with three kinds of low molecular weight organic substances.The catalase activity of glucose addition treatment was significantly higher than CK,glycerol and glycine addition,while alkaline phosphatase activity was significantly lower after 45 days.Compared with control,glucose and glycine addition,the AWCD of soil microbial community and the indices of soil microbial functional diversity(except index D)were increased by glycerol,while there were no significant differences among the with control,glucose and glycine addition.Percentage of utilized substrates of soil microbial communities were significantly affected by soil additions,especially,the percentage of utilized amines(short for AM)were decreased to almost zero by glycine and glucose addition.The redundancy analysis showed that the activity of soil alkaline phosphatase(at 45 day)was positively correlated with microbial functional diversity indices S,U,H’,CH and AM with the correlation coefficients of 0.588,0.669,0.616,0.687 and 0.603 respectively,and negatively correlated with D(-0.737)and the activity of invertase(-0.741).Hence,it revealed that different types of small molecule organic addition have different effects on soil enzyme activities and microbial functional diversity.In addition,compared with others,glycerol significantly increased soil microbial metabolic activity and diversity indices of soil microbial functional diversity(except index D).PCA analysis of soil enzyme activity and microbial functional diversity both showed significant differences between glycine and other low molecular weight organic substances.更多还原