Potencial de produtividade e produtividade explorável nas lavouras de arroz irrigado no Sul do Brasil

Abstract

In the search for the sustainable intensification of rice production, 349 production units (UDs) (10,182.9 ha) were carried out during the 2017, 2018 and 2019 growing seasons in the 6 irrigated rice producing regions in Rio Grande do Sul (RS), Brazil. The objectives were: i. determine how many % of the yield potential (Yp) the high yield fields are; ii. to determine the sowing date in the six riceproducing regions in Rio Grande do Sul that allow reaching high yield at field level; iii. Determine the increase in paddy rice production in RS, if all crops reach 80% of the potential yield. The UDs were divided into quartiles, the Yp was estimated for the first (low yields, BP) and fourth quartile (high yields, AP). The sowing date factor was determined by comparing the AP x BP through the t test or Mann-Whitney Rank and through the boundary function that the yield loss per day of delay in the sowing date. AP UDs are between 66 and 105% of Yp. The sowing dates of these crops are between 09/19 and 11/08 and varied according to the rice producing region. Yield losses as a function of sowing date ranged from 62 to 450 kg ha-1 day-1. With the use of good management practices, with the best sowing time and an 80% increase in Yp in all irrigated rice crops, it is possible to increase the production of paddy rice in RS by 4 million tons in the current area arable