Grain yield of common bean (Phaseolus vulgaris L.) varieties is markedly increased by rhizobial inoculation and phosphorus application in Ethiopia

Abstract

A field experiment was conducted to assess plant growth, symbiotic performance and grain yield of common bean in response to rhizobial incoculation and phosphorus application at Galalicha in Southern Ethiopia during the 2012 and 2013 cropping seasons under rain-fed conditions. The treatments consisted of 2 released common bean varieties (Hawassa Dume and Ibbado), 3 levels of Rhizobium inoculation (uninoculated, inoculated with strain HB-429 or GT-9) and 4 levels of phosphorus application (0, 10, 20 and 30 kg P ha−1) using a split-split plot design with four replications. Here, phosphorus levels, Rhizobium inoculation and common bean varieties were assigned as main, sub- and sub-sub treatments, respectively. The results revealed marked varietal differences in plant growth, grain yield and symbiotic performance. Of the two common bean varieties studied, Hawassa Dume generally showed superior performance in most measured parameters in 2013. Rhizobium inoculation significantly (p ≤ 0.05) increased plant growth, symbiotic performance and grain yield. Applying Rhizobium strain HB-429 to bean crop respectively increased plant growth, %Ndfa, amount of N-fixed and grain yield by 19, 17, 54 and 48% over uninoculated control. Similarly, the application of 20 kg P ha−1 to bean plants respectively resulted in 36, 20, 96 and 143% increase in plant growth, %Ndfa, N-fixed and grain yield when compared to the control. These results clearly indicate that plant growth, symbiotic performance and grain yield of common bean can be significantly increased by Rhizobium inoculation and phosphorus fertilization in Ethiopia. Rhizobium inoculants are a cheaper source of nitrogen than chemical fertilizers and when combined with moderate phosphorus application can markedly increase grain yield for resource-poor farmers.

Productivity and Economics of Inoculated Common Bean as Affected by Nitrogen Application at Different Phenological Phases

“…Considering the average of the two cropping year (2017 and 2018), the GY of the inoculated treatment was about 10.2% higher than the N-fertilized ones. Although the literature still reports that inoculation alone is not able to reach the same levels of productivity of N-fertilization (Bertoldo et al 2015), our results corroborate to authors which found GY values of inoculated common bean higher than those of Nfertilization (Mercante et al 2017;Moreira et al 2017;Samago et al 2017).…”

Biological Nitrogen Fixation Response to Soil Fertility Is Species-Dependent in Annual Legumes

“…In general, plant growth is greatly influenced by soil mineral N, and in N-fixing plants, as soil mineral N levels increase, BNF rates decrease and the uptake of mineral N increases (Goergen et al 2009). However, under very low N availability, plant growth and BNF have been found to be limited by N uptake (Moreau et al 2008) or P availability (Smith 1992;Samago et al 2018). In our experiment, aboveground plant production increased with organic pools of N and P and with N mineralization processes that are only related to readily available forms of N and P (inorganic P, mineral N, and PMN) in the case of chickpea.…”

Microbial inoculants: reviewing the past, discussing the present and previewing an outstanding future for the use of beneficial bacteria in agriculture

“…However, there are limiting factors that restrict the use of inoculants in some areas. Biotic and abiotic stresses may affect the effectiveness of the product, making them inefficient in cases such as nutrient-poor or unbalanced soils, salinity, water stress, increasing temperatures, pests and diseases, among others (Bashan et al 2014; Das et al 2017; Khan et al 2017; Thilakarathna and Raizada 2017; Samago et al 2018). To circumvent these factors, several studies have been addressed to gain better knowledge on the intrinsic properties of PGPB, seeking at understanding their optimum growth conditions and interaction with the host plants (Flores-Félix et al 2018; Goulart-Machado et al 2018; Jiménez-Gómez et al 2018).…”