Inoculação de sementes de soja revestida com osmoprotetor em diferesntes pH do solo

Abstract

The demand for the viability of seed inoculation days before sowing has challenged scientists to develop technologies that do not affect the survival of inoculated bacteria and that contribute to increase the productivity of the soybean crop. Among the new technologies, the use of osmoprotectants stands out. The objective of this study was the viability of the inoculation with Bradyrizobium bacteria associated with the osmoprotective coating, performed on different pre-sowing days, as well as the effect of different soil pH conditions on the productivity components, Nodulation and grain yield of the soybean crop. Two experiments were carried out in two sowing seasons, in the 2015/2016 harvest, using two soybean cultivars (NA 5909RR and NS 6209RR), submitted to two soil pHs (5.3 and 6.5) and inoculation with bacteria Of the genus Bradyrizobium associated with the osmoprotective coating (on the day, 4 and 11 days before sowing, for the first epoch, on the day, 7 and 14 days before sowing, for the second epoch). The seeds of the cultivar NA 5909RG that were inoculated at four and seven days pre-sowing, using osmoprotect together with bacteria of the genus Bradyrhizobium, provided yields 10.8% and 8.3% higher compared to the treatments performed on the same days without osmoprotectant , In soil with pH 5.3. The osmoprotector together with the Bradyrhizobium inoculation is an alternative for use in soils with low pH, as it provides a greater number and dry mass of nodules and, consequently, higher yield of grains. Soil with lower acidity was responsible for higher grain yield, compared to the soil with higher acidity, when both were not inoculated. Principal component analysis proved to be efficient, highlighting the importance of maintaining the grain yield variable, due to its greater explanatory power and contribution to the variability in the experiment data.