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

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.

Saved in:
Bibliographic Details
Main Authors: Rangel-Vasconcelos,Lívia Gabrig Turbay, Zarin,Daniel Jacob, Oliveira,Francisco de Assis, Vasconcelos,Steel Silva, Carvalho,Cláudio José Reis de, Santos,Maria Marly de Lourdes Silva
Format: Digital revista
Language:English
Published: Sociedade Brasileira de Ciência do Solo 2015
Online Access:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000200377
Tags: Add Tag
No Tags, Be the first to tag this record!