Instabilidade pluviométrica versus produção agrícola em áreas sujeitas a desertificação no semiárido cearense: os casos de Arneiroz e Miraíma

Abstract

Hydraulic instability causes instability over the production of rainfed crops, such as beans, cassava and corn, cultivated in the Brazilian semiarid, especially in municipalities that suffer from the effects of the desertification process. The present search aimed to study how rainfall distributions in the municipalities of Arneirós and Miraima behave in relation to what happens in Ceará State, as well as the behavior of the variables involved in the production of beans, cassava and maize in these selected municipalities because they are included in Areas. Subjected to Desertification (ASD). The variables studied are: rainfall, harvested area, and yield of beans, cassava and corn from 1974 to 2017. The climate of these municipalities were classified into three different rainfall regimes (drought, normal and rainy). The probabilities of occurrence of each regime, coefficients of variation and geometric growth rates for the variables related to the studied cultures were evaluated. In both municipalities, it was observed a higher probability of drought periods. Rainfall instability and the variables harvested areas, yields and crop yields also were high. In Arneirós only the geometric rates of growth of harvested area and productivity were negative in beans, cassava and corn. In Miraíma, it was observed that the areas harvested with beans showed negative growth rates between 1974 and 2017. The other variables were stagnant in that period. The research concludes that climatic instabilities translate to those associated with the production of beans, cassava and corn in the municipalities studied.