EFFECT OF WATER AVAILABILITY ON SOIL MICROBIAL BIOMASS IN SECONDARY FOREST IN EASTERN AMAZONIA

Revista Brasileira de Ciência do Solo

Lívia Gabrig Turbay Rangel-vasconcelos¹  Daniel Jacob Zarin¹  Francisco De Assis Oliveira¹  Steel Silva Vasconcelos¹  Cláudio José Reis De Carvalho¹  Maria Marly De Lourdes Silva Santos¹ 

关键词: second-growth forest;    irrigation;    fumigation-extraction;    microbial C;    microbial N;    microbial C/N ratio;    capoeira;    irrigação;    fumigação-extração;    C-microbiano;    N-microbiano;    relação C/N microbiana;   

DOI  :  10.1590/01000683rbcs20140135

来源: SciELO

【 摘 要 】

Soil microbial biomass (SMB) plays an important role in nutrient cycling in agroecosystems, and is limited by several factors, such as soil water availability. This study assessed the effects of soil water availability on microbial biomass and its variation over time in the Latossolo Amarelo concrecionário of a secondary forest in eastern Amazonia. The fumigation-extraction method was used to estimate the soil microbial biomass carbon and nitrogen content (SMBC and SMBN). An adaptation of the fumigation-incubation method was used to determine basal respiration (CO2-SMB). The metabolic quotient (qCO2) and ratio of microbial carbon:organic carbon (CMIC:CORG) were calculated based on those results. Soil moisture was generally significantly lower during the dry season and in the control plots. Irrigation raised soil moisture to levels close to those observed during the rainy season, but had no significant effect on SMB. The variables did not vary on a seasonal basis, except for the microbial C/N ratio that suggested the occurrence of seasonal shifts in the structure of the microbial community.

【 授权许可】

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