Reinoculation moments of Rhizobium tropici on bean cultivation in implantation of no - tillage system

Abstract

The common bean (Phaseolus vulgaris L.) is a culture of great economic and social importance, mainly in developing countries. Among the most nutrients required by this plant the nitrogen is highlighted, being also a great generator of expenses in the productive chain, not only because of this high price, but also because its mineral utilization is only 45%, losing the 55%, either by leaching or volatilization. Another important matter is that, unlike soy, the management of the inoculation of nitrogen fixing bacteria in beans doesn't provide the necessary N throughout the crop cycle, manifesting a deficit in nutrient supply in a hight relevant phase for productivity, after flowering. Therefore a supplementation of mineral N in the crop is needed. Thus, the aim of study will be to evaluate the management of inoculation and reinoculation of nitrogen-fixing bacteria in a implantation of a no-tillage system, aim at a second nodule population, extending the FBN process for the period of grain formation and pods filling. The study will be carri out Selvíria / MS, in the UNESP experimental area in a no-tillage system implementation, during winter harvest of 2018. The experimental design used will be randomized blocks in 5x3 factorial scheme, with four replications. The experiment will consist of the combination of 5 treatments with nitrogen fertilization and inoculation (T1: Rhyzobium tropici + Azospirilum brasilense; T2: Azospirilum brasilense; T3: Rhyzobium tropici T4: Nitrogen fertilization of 70 kg ha-1 in coverage; T5: No nitrogen fertilization in coverage) with 3 levels of reinoculation (R1: no reinoculation; R2: reinoculation in V4 or R3: reinoculation in R5.Will be evaluated. dry mass of aerial part; plants population; number of nodules per plant and nodules mass; production components and grain yield, during the conduction of the experiment. It is expected the obtained results will contribute to reinoculation management adoption maintaining FBN for a longer time and promoting a more sustainable production system with greater economic viability.