Variabilidade da qualidade de grãos na produção de arroz de terras altas em segunda safra no médio norte de Mato Grosso : uma análise exploratória

Abstract

Rice cultivation in Brazil is carried out by two systems, rainfed (upland) and irrigated. The state of Mato Grosso is the main rice producer in the highlands and irrigated rice, with the largest share of production, is cultivated in the south of the country. It is a staple food for much of the world's population and, according to estimates, by 2050 there will be demand to meet twice as much as it is now. Thus, the objective of this study was to evaluate the quality variability of upland rice grains, produced in the Middle-North region of the state of Mato Grosso, considering aspects of soil attributes. The condition of the soil was related to the qualitative aspects of the grains, so the areas in the two plots studied, located on a property in the municipality of Tabaporã - MT, were classified into Low and High Apparent Electrical Conductivity of the soil (ECa), called Low 1 and 2 e, High 1 and 2. For the evaluation of soil conditions, samples were collected from cells of 2 hectares with at least 15 sub-samples, and the data were processed generating maps of soil attributes. The rice, cultivar AN Cambará, was produced in the 2nd crop of the 2018/19 agricultural year. In the rice harvest, from each area, 5 grain samples were taken from the harvester's bulk carrier, totaling 20 samples, which were analyzed for physical quality (bulk density and thousand grains weight), physiological (germination, accelerated aging, electrical conductivity of exudates), income and yield and classification according to type. From the results obtained, it was verified that there is qualitative variability of rice grains in the same production area. There was verified that there was an effect of soil ECa conditions on the physical and physiological properties of rice grains, where the product harvested in areas considered as High ECa presented superior quality. In terms of income and income, rice in the Baixa 1 area had the worst performance. When classified by type, only the rice produced in the Alta 1 area, which showed higher quality in all evaluated properties, was classified in Type 2, the others in Type 3.