Delineating Agroclimatic Zones for Deforested Areas in Para State, Brazil

Abstract

Agricultural exploitation in the Brazilian Amazon Basin, including Para State, is a controversial issue. It puts ecological concern with tropical deforestation against the need of a growing population for land for food production. The evaluation of climate in the form of agroclimatic zoning for corn, cowpea, and cassava, which are the basic staples of the Amazon Basin, is necessary in order to understand and predict these crops' response to the environment better. Climate and agroclimatic analysis was done in the study area for the period 1983-1986 and the results of analysis include spatial patterns of rainfall, computation of daily climatic water balance for 25 raingauge stations, climatic classifications, delineation of agroclimatic zones according to the growing season length, calculation of crop water balance and estimation of crop potential productivity related to soil moisture status. The results of agroclimatic analysis, although viewed as a second approximation, indicate that in the study area there are five agroclimatic zones with growing periods varying from 200 to more than 300 days and that all agroclimatic zones experience good potential for corn, cowpea and cassava. These results indicate that cultivation of annual crops in Para State deforested area can be diversified and made less environmentally damaging if adequate crop management is provided. Included in this study is a discussion of how agrometeorological research in the region could be developed in order to provide the minimum basic information for better characterization of sites in future agroclimatic studies.