African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6574

Full Length Research Paper

Variation of soil enzyme activities and microbial community structure in peanut monocropping system in subtropical China

Peidong Li 1#, Chuanchao Dai1#, Xingxiang Wang2,3*, TaoIin Zhang2 and Yan Chen1
   1Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Science, Nanjing Normal University, Nanjing, China, 210046. 2Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China, 210008. 3Jiangxi Key Laboratory of Ecological Research of Red Soil, Experimental Station of Red Soil, Chinese Academy of Sciences, Yingtan, China, 335211.
Email: [email protected], [email protected]

  •  Accepted: 29 December 2011
  •  Published: 26 March 2012

Abstract

 

The changes in soil microbial community are supposed to be one of key factors for peanut yield decline in long-term continuous monocropping systems. A series of peanut fields, where peanut were continuously monocropped for 3, 6, 10 and 15 years in subtropical China, were selected to investigate the effect of continuous monocropping on peanut yield, soil microbial community structure and enzyme activity. Peanut yield, urease and invertase activities decreased with time, but the activity of polyphenol oxidase decreased in the first several years and then increased. The results of both culture dependent methods and phospholipid fatty acids (PLFA) analysis showed that bacteria (Gram-positive and Gram-negative bacteria) and actinomycetes decreased, while fungal colony-forming units (CFUs) increased with time. Canonical Correspondence Analysis (CCA) showed that with increasing peanut monocropping years, soil microbial structure became more correlative with fungi compositions. The proportion of bacteria in total PLFA decreased from 67.4% to 53.0%, meanwhile the proportion of fungi was increased from 16.9% to 32.8%. Denaturing gradient gel electrophoresis (DGGE) analysis indicated that bacteria diversity decreased and fungi diversity increased with time, and changes in fungi diversity were much greater than those of bacteria.

 

Key words: DGGE, enzyme activities, monocropping, peanut, PLFA, red soil.