Clima e agricultura: o papel das precipitações na produtividade da soja no município de Capinópolis/MG

Abstract

The city of Capinópolis/MG has a tropical climate with seasonal characteristics, favoring the planting of annual crops, including soybeans, which stands out in productivity due to the envieonmental conditions provided by the location of the municipality. Agriculture is responsible for 29,88% of the Gross Domestic Product (GPD) of the municipality (IBGE) whuich demonstrates the importance of this work that favors farmers to know the climatic demands of the municipality and how their distribution affects the planting and harversting of the vintage. The main objectives of this study are to elaborate and analyze the water balance, define the beginning and end of the dry season and correlate the dry spells with soybean productivity in the municipality of Capinópolis. The analysis range included the years 1990 to 2018, a series of 29 years, with climate data collected from National Water Agency and data on soybean production, planted and harvested area were obtained from the Brazilian Institute of Geography and Statistics (IBGE). As a methodology to define the beginning and end of the dry and rainy seasons, Thornthwaite and Mather (1955) Water Balance proposition was used as a reference, which resulted in the definition of water surplus and water deficit in the study area. And to characterize the beginning and end of the dry seasons in the municipality of Capinópolis, the proposition of Assunção (2012) was used. The dry spells according to Assunção’s methodology (2006) were classified by classes according to their duration; Unappreciable ( 6 days); Weak ( 7 to 8 days); Medium (9 to 12 days); Strong ( 13 to 18 days) and Very Strong ( greater than 18 days). With the analyses of the collected data, important results were found, such as the precipitation pattern is not related to the harvest, but the episodes of dry spells detected influence the development of the plant. The rainy season was characterized between the months of October to March, with January being the month with the most precipitation in the municipality, and it is essential for the rural producer to avoid harvesting in this month. The dry period was diagnosed between the months of April to September with a total precipitation of only 13,5%, which had a great impact on soybean productivity. It is worth noting that investments in technology and good quality seeds are essential to succeed in the harvest during prolonged periods of drought or to harvest the crop more quickly if the precipitation is more intense at harvest time, these actions guarantee better productivity even by increasing the cost of farming. Finally, in this work, it was noted that climate monitoring is very important for agriculture in the municipality due to its variation and this knowledge wil guarantee actions by Capinópolis producers that will guarantee soybean productivity.