文献类型： 外文期刊

作者： Ling, Ning ¹ ; Sun, Yuming ¹ ; Ma, Jinghua ¹ ; Guo, Junjie ¹ ; Zhu, Ping; Peng, Chang; Yu, Guanghui ¹ ; Ran, Wei ² ; G ¹ ;

作者机构： 1.Nanjing Agr Univ, Key Lab Plant Nutr & Fertilizat Lower Middle Reac, Jiangsu Prov Coordinated Res Ctr Organ Solid Wast, Minist Agr, Nanjing 210095, Jiangsu, Peoples R China

2.Nanjing Agr Univ, Key Lab Plant Nutr & Fertilizat Lower Middle Reac, Jiangsu Prov Coordinated Res Ctr Organ Solid Wast, Minist Agr, Nanjing 210095, Jiangs

关键词： Mollisol;Long-term experiment;Soil particle size;Soil enzyme;Bacterial community

期刊名称：BIOLOGY AND FERTILITY OF SOILS （ 影响因子：6.432； 五年影响因子：6.332 ）

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收录情况： SCI

摘要： Particle-size soils were fractionated for evaluating changes in the composition of bacterial community and enzyme activity in response to 13 years of fertilization. This study focused on Mollisol and its particle-size fractions of 200-2,000 mu m (coarse sand sized), 63 to 200 mu m (fine sand sized), 2 to 63 mu m (silt sized), and 0.1 to 2 to mu m (clay-sized). Long-term chemical fertilization lowered the pH of all particle fractions, whereas organic fertilizer application mitigated soil acidification. Nutrient concentrations depended on both fertilizer treatment and particle fractions and enzymes were unevenly active throughout the soil. Generally, the highest enzyme activities were observed in the silt and clay fractions of control soil and the soil treated with chemical fertilizer (N, P, and K (NPK)) and in the sand-sized fraction of soil treated with manure and chemical fertilizer (MNPK). Except for acid phosphomonoesterase, the other tested enzyme activities in coarse-sized fractions of MNPK soil were significantly higher than those of the control and NPK soils. Fertilization and soil fraction interactively (p < 0.05) affected the enzyme activity. Denaturing gradient gel electrophoresis analysis showed that the bacterial community structure significantly differed in different particle sizes with a higher bacterial diversity in small-sized than in coarse-sized fractions. Dominant bands were excised and sequenced. We have found the following bacterial groups: Actinobacteria, gamma-proteobacteria, and Acidobacteria. In addition, enrichment of organic matter in coarser fractions was related to greater bacterial diversity than any other treatment. Principal component analysis showed a smaller variability among fractions of the organic amended treatment. Redundancy analysis showed that the tested properties significantly affected the composition of bacterial community with the exception of C/N and available P. No significant correlation between enzyme activity and bacterial community composition was detected, whereas positive correlations between other soil properties and enzyme activities were observed to various extents. Probably, enzyme activities might be affected by specific functional bacterial communities rather than by the overall bacterial community. We concluded that the long-term application of organic manures contributed to the increase of soil organic matter content of particles higher than 200 mm, with higher bacterial diversity and increases in most of the enzyme activities