Análise do desenvolvimento e produtividade econômica do arroz irrigado por pivô central

Abstract

The agricultural environment is constantly growing, searching new technologies enabling the production increase of crops, in conjunction with population growth and food consumption. Rice is one of the main nutritional sources for human food. In rice farming the surface irrigation method is the most used, however, it has a higher growth capacity in irrigation through central pivot sprinkler irrigation. Besides, the reduction of production cost is an extremely relevant factor for the producer. Thus, the objective of this work was to evaluate the response of rice under central pivot irrigation, aiming for greater water productivity and economic return. To meet the objective of this work, the experiment was conducted in the field in the 2020/21 crop year. The crop was planted in October/2020 in an experimental area granted by IRGA - Uruguaiana - RS, under a no-tillage system and a completely randomized experimental design, divided into three irrigation treatments with different soil tensions, with twenty repetitions each, divided into T1 - keeping the soil saturated, T2 - 15 kPa, 20 kPa irrigation during the vegetative phase (E to R1), and 15 kPa during the reproductive phase (R1 to R9); and T3- continuous flooding (witness). During the crop cycle the following growth parameters were determined: leaf area index, plant height, number of tillers, number of panicles, panicle length, and at the end of the cycle the yield components and grain production. Water productivity (WP) was determined for the irrigation strategies. The highest water productivity was obtained by the continuous flooding treatment, due to the fact that the IRGA 424 RI cultivar obtains good yields in flooded soil, thus, to obtain high values of water productivity, the cultivar cannot have soil humidity below saturation. The increase in soil water tension in the Western Frontier directly affects the development and production of the crop, leading to losses in production. Economic efficiency; Water productivity; Agronomic performance.