Dynamic of carbon in the sugarcane agrosystem: mathematical modeling and environmental implications

• Grant number: 05/50970-0
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2005
• End date: October 31, 2007
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Carlos Clemente Cerri
• Grantee: Carlos Clemente Cerri
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Sugarcane is an important crop in Brazilian agriculture, both for the generation of income and employment and for the generation of foreign currency through increasing exports of sugar and alcohol. The burning of the sugarcane straw, to facilitate the harvest and the transport of the stalks, has been practiced for centuries in Brazil. Nowadays, for economic and legal reasons, the no-burn harvesting of sugarcane, leaving the straw on the ground, has increased. Little is known, however, about the long-term effects of the presence or absence of straw on the carbon dynamic in the sugarcane agrosystem. Mathematical modeling could be an effective tool for understanding these processes and to estimate the potential of carbon sequestration in the soil under sugarcane cultivation. The sequestration of carbon has agronomic, environmental and economic importance, in the context of climate changes and the so-called “carbon market”. The objective of this study is to evaluate the effect of the management with and without burning on the carbon dynamic in the sugarcane agrosystem, with the view to mitigating the greenhouse effect, using the Century model. We will use areas in the São Martinho sugar mill in Pradópolis, São Paulo. Two chronosequences will be analyzed, that is, fields in which sugarcane has been planted eight, six, four and two years ago, in addition to native vegetation. The areas studied are located in the class of soil predominant in the region, red latosol. One chronosequence handled the harvest with biomass burning and another, without burning. Collections of soil will be gathered, for evaluation of the following attributes: pH, density, clay fractions, silt and sand, total C and N and C microbial biomass. The results of the chemical and physical analyses will be used in establishing the parameters of the model and subjected to multivariate statistical analysis. (AU)