Response of Haricot Bean (Phaseolus Vulgaris L.) to Lime Application and Rhizobium Inoculation on Nitosols at Bench-Maji Zone, Southwestern Ethiopia

Haricot bean (Phaseolus Vulgaris L.) is one of the most economically important legume crops cultivated in Ethiopia. However, its productivity has never reached its full potential of production that it has in supporting income of resource poor farmers in the nation. This is partly due to infertility caused by acidic soils which have low nutrient contents including calcium. The present study was conducted to evaluate response of haricot bean to liming and Rhizobium inoculation in the vicinity of Mizan-Teferi, Bench-Maji Zone in Southwestern Ethiopia. The experiment comprised a factorial combination of four lime levels: 0, 1025, 2050 and 3075 kg ha-1; and Rhizobium leguminosarum biover phaseoli inoculation - with and without inoculation. The experiment was laid out in a randomized complete block design with three replications. Data on nodulation yield and yield component parameters were collected and analyzed. The result revealed that the interaction effect of lime and Rhizobium inoculation had a significant influence on the majorities of parameters tested except pod number per plant and thousand seed weight. Higher values of nodule number per plant, nodule weight per plant, pod length, number of seed per pod and yield of haricot bean were obtained at Rhizobium inoculated treatments receiving lime rate of 2050 and 3075 kg ha-1. However, further increases in rate of lime beyond 2050 kg ha-1 even got worsen with respect to seed yield. Therefore, lime at a rate of 2050 kg ha-1 in combination with Rhizobium inoculation might be tentatively recommended to be used as a bio-fertilizer in the studied area. Further research must be needed to confirm the result presented from this finding.