Uniformidade de Distribuição da Uréia com Distribuidor Centrífugo sobre Taipas na Cultura do Arroz Irrigado

Abstract

Rice (Oryza sativa L.) is one of the most produced crops in the world, being the basis of the diet of thousands of people. Commonly, in irrigated rice crops, the distribution of solid fertilizers is carried out with the use of centrifugal distributors. However, there are few studies evaluating this distribution in conditions on taipas, it is necessary to study the effectiveness of this type of equipment. Thus, the objective of this work was to evaluate the regularity of solids distribution with a centrifugal distributor on different work surfaces and in contrasting coupling shapes. To this end, an experiment was carried out whose treatments were composed by the variation of the type of surface displacement in relation to the taipas (parallel, 45o and 90o), and two forms of coupling (mounted on the tractor's three-point hitch and dragged along the drawbar). It was observed that for 20% of the (CV) coefficient of variation the working widths found were small since, according to the manufacturer of the distributor, the minimum width is 16 m and the maximum is 30 m for the product used (urea). The transverse distribution profile in the terrain with taipas where the mechanized set if moved with an angle of 45o presented as the worst profile among those studied, in the two forms of coupling (mounted and dragged). It was analyzed that in the chosen working width of 23 m all (CV%) found were above the recommended for granular materials. It is concluded that the coupling form altered the cross-sectional distribution profile and the coefficient of variation, and for terrain with taipas the mounted coupling expressed a better cross-sectional distribution profile, and for terrain with taipas, the best form of displacement is with an angle of 90°. Key-words: distribution profile, nitrogen fertilization, rice paddies.