Polímeros hidroretentores na cultura da soja em condições de solo argiloso na região norte do Rio Grande do Sul

Abstract

Hydroretentor polymers have been widely used to minimize problems related to drought and rainfall distribution irregularities, factors which affect significantly the development of crops. This study aimed to evaluate different doses of hydroretentor polymers in soybean in different positions on seeds in clay soil conditions in the northern region of Rio Grande do Sul. The experiment was conducted at the Federal University of Santa Maria – Campus of Frederico Westphalen – RS. The experiment consisted of completely randomized blocks, in a trifactorial scheme (2 x 2 x 4), including two agricultural crops (2011/2012 and 2012/2013), two management incorporating hydroretentor (Management 1: application with the seed; Management 2: application in the same position as the fertilizer at seeding line) and four doses of EMD SAP (0, 5, 10 and 20 kg ha-1), in six repetitions. The use of hydroretentor along with fertilizer promotes greater yield. The highest yields are predicted to be achieved with the use of 15 kg ha-1, which is promising for the increase of grain yield, thousand grain weight and average number of grains per pod.