Variabilidade temporal de variáveis climáticas, influenciando a produtividade de soja

Abstract

Currently, besides increasing productivity, grain production in Brazil has been increased with the inclusion of new areas, but even with all this advancement and adaptation, the climatic factor appears as limiting to the production increases, much because of its unpredictability, exerting great influence on crop productivity. The objective of this study was to study the temporal variability of climatic variables and their influence on soybean yield (Glycine max) in the city of Dourados-MS, Brazil, producing their respective maps through geostatistics and using them in analysis of the differences between the yields obtained from soybean, compared to the calculation of the potential productivities in the period. Data were provided by the National Institute of Meteorology (INMET) and refer to the time period between 2006 and 2015. Productivity, area planted and average yield were obtained from the website of the Brazilian Institute of Geography and Statistics (IBGE). Descriptive statistics and time dependence analysis of climatic variables were performed using the Minitab 17 and GS + programs, as well as the comparison of the average climatic data in the months of the crop cycle. The climatic data covered refer to the monthly total rainfall expressed as water depth (mm), monthly averages of air temperature (° C), relative humidity (%), wind speed (km h-1 ) and radiation (MJ / m2 / day). The soybean crop is directly influenced by climatic variables, influencing its productivity and management. It was observed that the variables are interrelated and have great influence in the planning, planting, development and harvesting of the crop. Although in some years there has been an increase in the area planted, this did not translate into increased production. The geostatistical analysis indicated that all variables presented temporal dependence, and the semivariograms models were well adjusted to the data, except for the solar radiation that undergoes great daily changes. Geostatistics is a very important tool because it helps to identify temporal distribution patterns and through the historical series of climate attributes of a region, it is possible to predict the characteristics of the site.