Effects of Rhizobium inoculum compared with mineral nitrogen fertilizer on nodulation and seed yield of common bean. A meta-analysis

Abstract

Common bean (Phaseolus vulgaris) is one of the most important legumes for human consumption. It is highly adaptable to different edaphoclimatic conditions, being an important crop in addressing global food security challenges. The common bean production segment has undergone an intense technological advance, with a focus on the use of technologies to increase the availabilityofnitrogen(N)andthecrops’ seedyield,whileenhancingeconomicandecologicalsustainability.Basedonthis,the present meta-analysis aimed to evaluate the effects of Rhizobium inoculation (RI), in comparison with mineral-N fertilization (NF), on the main nodulation characteristics, yield components, and seed yield of common beans. This study represents the largest assessment yet on this topic. We used data from peer-reviewed publications and, after extensive bibliographic research, analyzed68studiesfromsevencountries.WefoundthatRIincreasedseedyield(32.96%)butnottothesameextentasNF.The RIisonaverage12.31%lessefficientthanNF;however,whenwecategorizedthefactors,suchasthetimeofyearwhencommon beans were grown, the soil management system, and the soil physicochemical characteristics, the RI effects were more promising.Hereweshowfor thefirst timethatRI wasmoreefficient thanNFwhencommonbeans werecultivatedinthedryseason, under a no-tillagesystem, and in soils withhighorganic mattercontent,with a potentiallypositiveimpactonyields. In addition, the difference in the efficiencies of RI and NF was attenuated when common beans were grown in soils with a clay texture, eutrophic,withlowtoneutralacidity,andwithanadequatephosphorusavailability,andusingatleast10gofrhizobialinoculum per kg of seeds.