Yield and economic benefits of common bean (Phaseolus vulgaris) and soybean (Glycine max) inoculation in northern Tanzania

Abstract

On-farm experiments were conducted in farmers’ fields at 12 different sites in the 2 districts of Moshi and Rombo in northern Tanzania during the 2000–01 cropping season to study the effects of (brady)rhizobial inoculation in combination with P supply on growth and grain yields of soybean and common bean, and to assess the economic returns of these different technologies to farmers. A low level of N was included as an indicator of endogenous soil N status. The treatments included (brady)rhizobial inoculation, N fertilisation (30 kg N/ha as urea), P application [26 kg P/ha as triple super phosphate (TSP)], (brady)rhizobial inoculation + P fertilisation (26 kg/ha as TSP) and unfertilised uninoculated control. The study was conducted as a randomised complete block design with each of the 12 farmers’ fields as a replicate. At harvest, plant growth of soybean and common bean was significantly (P≤0.05) greater with (brady)rhizobial inoculation compared with N and P supply or uninoculated control in the 2 districts. Relative to uninoculated unfertilised plots, grain yields of common bean were markedly (P≤0.05) increased by 60–78% from inoculation alone, and 82–95% from inoculation + 26 kg P/ha; with soybean there was 127–139% increase in grain yield from inoculation alone, and 207–231% from inoculation + P. Thus, the combined application of bacterial inoculants and P fertiliser to field plants of soybean and common bean significantly (P≤0.05) increased biomass production and grain yield compared with the single use of N and P or (brady)rhizobial strains. From economic analysis, the increase in grain yield with inoculation translated into a significantly (P≤0.05) higher marginal rate of return and dollar profit for soybean and common bean farmers in northern Tanzania. With common bean, there was a 66 and 92% increase, respectively, in dollar profit with inoculation at Moshi and Rombo districts respectively relative to control; these profit margins rose to 84 and 102% with provision of supplemental P (26 kg P/ha). With soybean, however, the increase in profit with inoculation was much larger, about 140 and 153% at Rombo and Moshi, respectively, and these rose to 224 and 250% with P supply.

Growth, symbiotic and yield response of N-fertilized and Rhizobium inoculated common bean (Phaseolus vulgaris L.)

“…This seems to be an important reason for its low seed yield in Ethiopia. This constraint could be alleviated through seed and/or soil inoculation with the proper Rhizobium bacteria before or at planting to facilitate N-fixation (Ndakidemi et al, 2006). Therefore, to increase the productivity of the farmers, it is crucial to increase the awareness of farmers towards the utilization of improved agronomic practices that increase their production and accelerate food security through proper implementation.…”

Soya bean glycine max (l.) Merr. genetic resources in Tanzania, 1905-2013

“…Studies at Lyamungu on the lower slopes of Kilimanjaro in northen Tanzania also showed the benefits of inoculation but best yields were obtained when inoculation was combined with a dressing of 40 kg/ha of phosphorus and without nitrogen (Sachansky, 1977;Ndakidemi et al, 2006). In further experiments it was demonstrated that cultivars bred and selected in Tanzania were compatible with native Rhizobium spp.…”

Assessment of variable application rates of biological amendment substances on establishment and growth characteristics of maize plants

“…Thus, the recent industrial conversion of composted organic materials into value-added single product as plant growth promoter through a novel approach of enrichment or blending of bio-fertilizers with inorganic fertilizers or plant growth promoting rhizobacteria (Tahir et al, 2006), constitute an alternative strategy for increased use of organic fertilizers. The use of such biological growth promoter has been reported to considerably increase grain yield (Ndakidemi et al, 2006;Kutu and Asiwe, 2010).…”