Sinergias entre as instabilidades pluviométricas e a produção de lavouras de sequeiro no semiárido cearense

Beans, cassava and corn are rainfed crops grown in the semiarid of the 184 Ceará State municipalities. Pentecoste and Sobral are municipalities located in the semi-arid areas susceptible to desertification in Ceará. Temporal and spatial instability of rainfall is characteristic of the semiarid. The research compares rainfall in Ceará and these municipalities between the years 1974 and 2018. It makes tests in order to observe whether the State and municipal rainfall can be classified in a pattern defined in the survey. Statistical tests are also developed to assess whether rainfalls interact with yields and production value per hectare of crops in the period studied in Ceará, Pentecoste and Sobral. Productivities and production values per hectare of beans, cassava and corn are aggregated using the factor analysis method. The data are from FUNCEME and IBGE. The results show that the state and municipal rainfall can be classified according to the tested standard. It is also observed that in Pentecoste and Sobral there was a higher incidence of years with drought than in Ceará. The general conclusion of the research is that there are synergies between the instabilities of rainfall and the productivity of rainfed crops in Ceará, Pentecoste and Sobral between 1974 and 2018.