EDAFOLOGÍA, VOL 13. (3), PP 139-150 2006

CARBON SEQUESTRATION RATES IN NO-TILLAGE SOILS UNDER INTENSIVE CROPPING SYSTEMS IN TROPICAL AGROECOZONESLA CALIDAD DE SUELOS COMO MEDIDA PARA SU CONSERVACIÓN

J. C.DE MORAES SÁ*, L. SÉGUY , E. GOZÉ2, S. BOUZINA. C2, O. HUSSON2, S. BOULAKI2, F. TIVET2, F. FOREST2, J. BURKNER DOS SANTOS
1Universidade Estadual de Ponta Grossa, Departamento de Ciência do Solo e Engenha- ria Agrícola, Av. Carlos Cavalcanti, 4748. Campus de Uvaranas, 84030-900, Ponta Grossa-PR, Brazil. E-mail: jcmsa@uepg.br
2Centre de Coopération Internationale en Recherche Agronomique pour le Développe- ment-CIRAD, PERSYST-UR SCV, TA B-01/07 Avenue Agropolis, 34398, Montpellier Cédex 5, France
3Josiane Burkner dos Santos, Universidade Federal do Paraná, PG Agronomia, Av. dos Funcionários s/n, Juvevê, Curitiba-PR, Brazil. *Correspondent author.

Abstract

The amount and quality of crop residues added through cropping systems with no-tillage (NT) soils is the key component to increase carbon (C) sequestration in agricultural land and mitigate car- bon dioxide (CO2) to the atmosphere. To compare conventional (CT) and NT systems associated with crop- ping systems, the soil organic carbon (SOC) stock and balance were assessed in four tropical sites - three in Cerrado region in Brazil, and one in the highlands of central Madagascar. The NT cropping systems in the sites were organized in randomized plots with three replicates and compared with CT under a monoculture. The mean C sequestration rate for NT was 1.66 Mg ha-1 yr-1 (from 0.59 to 2.60 Mg ha-1 yr-1). The regression fitted between C cumulative input and SOC sequestered showed a close relationship, and 14.7 percent of each additional Mg C input per hectare was sequestered as SOC. The C sequestration potential with adoption of intensive cropping system under NT can increase estimated decay rate by the first order differential equa- tion increased with the mean annual temperature and decreased when the C cumulative input increased.

Key words: No-tillage, cropping system, SOC balance, SOC sequestration rates