Spatial and temporal variability of soil CO2 emission in a sugarcane area under green and slash-and-burn managements

Autor(es)

Panosso, A. R. ^[1] ; Marques, Jr., J. ^[1] ; Pereira, G. T. ^[1] ; La Scala, Jr., N. ^[1]

Afiliação do(s) autor(es)

^[1] FCAV UNESP, BR-14884900 Jaboticabal, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SOIL & TILLAGE RESEARCH; v. 105, n. 2, p. 275-282, NOV 2009.
• Citações Web of Science: 47
• Assunto(s): Geoestatística Florestas tropicais Cana-de-açúcar

Resumo

Soil management causes changes in physical, chemical, and biological properties that consequently affect soil CO(2) emission (FCO2). Here, we studied the soil carbon dynamics in areas with sugarcane production in southern Brazil under two different sugarcane management systems: green (G), consisting of mechanized harvesting that produces a large amount of crop residues left on the soil surface, and slash-and-burn (SB), in which the residues are burned before manual harvest, leaving no residues on the soil surface. The study was conducted during the period after harvest in two side-by-side grids installed in adjacent areas, having 60 points each. The aim was to characterize the temporal and spatial variability of FCO2, and its relation to soil temperature and soil moisture, in a red latosol (Oxisol) where G and SB management systems have been recently used. Mean FCO2 emission was 39% higher in the SB plot (2.87 mu mol m(-2) s(-1)) when compared to the G plot (2.06 mu mol m(-2) s(-1)) throughout the 70-day period after harvest. A quadratic equation of emissions versus soil moisture was able to explain 73% and 50% of temporal variability of FCO2 in SB and G, respectively. This seems to relate to the sensitivity of FCO2 to precipitation events, which caused a significant increase in SB emissions but not in G-managed area emissions. FCO2 semivariogram models were mostly exponential in both areas, ranging from 72.6 to 73.8 m and 63.0 to 64.7 m for G and SB, respectively. These results indicate that the G management system results in more homogeneous FCO2 when spatial and temporal variability are considered. The spatial variability analysis of soil temperature and soil moisture indicates that those parameters do not adequately explain the changes in spatial variability of FCO2, but emission maps are clearly more homogeneous after a drought period when no rain has occurred, in both sites. (C) 2009 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 08/58187-0 - Impacto das práticas de gestão sobre a emissão de CO2 do solo em áreas de produção de cana, Sul do Brasil
• Beneficiário: Newton La Scala Júnior
• Linha de fomento: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático