Weed control, biomass and microbial metabolism of soil depending on the application of glyphosate and imazethapyr on crop soybeans

Abstract

Studied the weed control and the changes of biomass and microbial soil properties at crop cultivated both genetically modified and non altered soybeans because of glyphosate or imazethapyr herbicide applications. Soybean cultivations were tested (BRS 244RR), genetically modified and BRS 154, non modified) and herbicides (glyphosate and imazethapyr), and control treatment with weed. Variables were evaluated for phytotoxicity to the crop, control of Raphanus raphanistrum (wild radish), Digitaria sp. (crabgrass) and Brachiaria plantaginea (alexsandregrass), total organic carbon (TOC), microbial biomass carbon (MBC), basal respiration (BR) and metabolic quocient (QCO₂). The herbicide glyphosate, applied as a single dose or sequentially, effectively controls the weeds wild radish, crabgrass and alexsandregrass and increases microbial activity, basal respiration and metabolic quocient. The microbial metabolism was not affected by the fact that the genotype or not genetically modified, but the use of the herbicide glyphosate.