Co-inoculation of Rhizobium tropici and Azospirillum brasilense in common beans grown under two irrigation depths

Amanda Ribeiro Peres²*,Orivaldo Arf,José Roberto Portugal,Ricardo Antonio Ferreira Rodrigues³,Daiene Camila Dias Chaves Corsini

doi:10.1590/0034-737x201663020011

Amanda Ribeiro Peres²*, Orivaldo Arf + Show 3 more

Open Access

https://doi.org/10.1590/0034-737x201663020011

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Journal: Revista Ceres	Publication Date: Apr 1, 2016
Citations: 22	License type: cc-by

Affiliation: Universidade Estadual Paulista (Unesp)

Abstract

ABSTRACT The alternative technique of co-inoculation or mixed inoculation with symbiotic and non-symbiotic bacteria has been studied in leguminous plants. However, there are few field studies with common beans and under the influence of the amount of irrigated water. Thus, the objective of this study was to evaluate the efficiency of inoculation and co-inoculation of common beans with Rhizobium tropici and Azospirillum brasilense under two irrigation depths. The experiment was carried out in the winter of 2012 and 2013, in Selvíria, state of Mato Grosso do Sul. The experimental design was composed of randomized blocks in split-plot scheme with two irrigation depths in the plots (recommended for common beans and 75% of the recommended) and five forms of nitrogen (N) supply in the split-plots (control non-inoculated with 40 kg ha- 1 of N in topdressing, 80 kg ha- 1 of N in topdressing, A. brasilense inoculation with 40 kg ha-1 of N in topdressing, R. tropici inoculation with 40 kg ha-1 of N in topdressing, and co-inoculation of A. brasilense and R. tropici with 40 kg ha- 1 of N in topdressing) with four repetitions. Co-inoculation increased nodulation in the second year of cultivation. None of the evaluated treatments increased the grain yield in relation to non-inoculated control with 40 kg ha-1 of nitrogen in topdressing, which presented average yield of 2,200 kg ha-1. The use of 75% of the recommended irrigation depth provides similar grain yield to the recommended irrigation depth in common beans cropped in winter.

Highlights

Brazil was the world’s third largest bean producer in 2014, surpassed only by India and Myanmar (Food and Agriculture Organization - FAO, 2014)
One of the most important agricultural inputs that results in the achievement of high bean yields is the nitrogen fertilizer
An alternative to reduce the need for nitrogen fertilizers is the biological nitrogen fixation, performed by a select group of bacteria, named diazotrophic (Reis, 2007)

Summary

Introduction

Brazil was the world’s third largest bean producer in 2014, surpassed only by India and Myanmar (Food and Agriculture Organization - FAO, 2014). Despite this distinction, bean crop in Brazil presents average productivity relatively low. One of the most important agricultural inputs that results in the achievement of high bean yields is the nitrogen fertilizer. In spite of being assimilated more quickly by the plants, nitrogen fertilizers are expensive, presents high cost of energy sources in its manufacturing, low use efficiency by plants, besides being related to environmental pollution (Hungria et al, 2007). Alternatives that reduce the application of inputs in the areas of agricultural production are highly searched. An alternative to reduce the need for nitrogen fertilizers is the biological nitrogen fixation, performed by a select group of bacteria, named diazotrophic (Reis, 2007)

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