Management and coinoculation of microorganisms (Bradyrhizobium japonicum, Azospirillum brasilense, Bacillus subtilis and microbial metabolites) in soybean culture

Abstract

Soy (Glycine max (L.) Merrill) is one of the most important crops in the world economy. In Brazil, the inoculation of soybean seeds with atmospheric nitrogen-fixing bacteria is essential, and it does not require the need for supplemental fertilization with nitrogen, generating savings of approximately US $ 7 million for the country. The use of growth promoting bacteria in plants has been used in conjunction with Bradyrhizobium in order to optimize nodulation and generate positive responses in productivity. The objective of this work was to evaluate the effects of coadjulation by Bradyrhizobium japonicum, Azospirillum brasilense, Bacillus subtilis and Microbial Metabolites on biological nitrogen fixation, plant development and productivity. Two simultaneous experiments will be developed for each crop (2016/17 - 2017/18) of the same experimental design, one in the field and the other in a Greenhouse at UNESP - Faculty of Agronomic Sciences, located in the city of Botucatu (SP), with Experimental design of randomized blocks arranged in a 2 x 8 factorial scheme, with four replications, that is, two soybean cultivars (one with an early cycle and an indeterminate growth habit, the other with a late cycle and a determined growth habit), treatments (Bradyrhizobium japonicum (inoculated via seed, concentration of 2.8 million seed-1 cells), microbial metabolites (inoculated in seed path, concentration of 1.2 million seed-1 cells), Bacillus subtilis, Azospirillum brasilense (foliar spraying at the phenological stage - V4, dose of 300 mL / ha-1). The sowing will be carried out in December 2016 and 2017. The following will be analyzed: foliar nutritional contents, nodulation, direct and indirect evaluations of the root system, production components, productivity and biological nitrogen fixation activity. (AU)