Economics of rhizobia and azospirilla co-inoculation in irrigated common bean in commercial and family farming

Abstract

The objective of this work was to evaluate the economic viability of the co-inoculation with Rhizobium tropici and Azospirillum brasilense in the Pérola cultivar of common bean (Phaseolus vulgaris), under sprinkler irrigation, in commercial and family farming in the states of Minas Gerais and Goiás, Brazil. For the analysis of economic viability, data from seven field experiments that evaluated the agronomic performance of common bean co-inoculated with R. tropici and A. brasilense, at six different sites, in three cropping seasons, were used. In these experiments, the treatments consisted of: non-inoculated control; N-fertilizer treatment; and different doses and forms of inoculum application. The economic analysis was performed based on market prices and indices as a function of the grain production of the different treatments. Economic viability was analyzed using the partial budgeting method. The best economic performance was obtained with the treatment R. tropici + three doses of A. brasilense sprayed on plants, which resulted in return rates of 90% in Goiás and 114% in Minas Gerais, for commercial farming, and of 13% in Goiás for family farming. For commercial and family farming, the production cost when using N fertilizer is 5.0 and 8.5% higher, respectively, than that with the co-inoculation of two doses of R. tropici and three doses of A. brasilense.