Exploring effects of Rhizobium Strains on performance of common beans (Phaseolus vulgaris): Experiences from Demonstrations held in Kiambu District, Central Kenya. KARI-ETC-LEI INSMAP Report.

Abstract

Soil fertility is closely linked to productivity and is a function of individual soil variables (inherent and influenced) such as climate, management and slope. There is a belief that soil fertility is declining in East Africa as evidenced by appearance of widespread distribution of soil deficiencies in major macro-nutrients and micronutrients ascertained from commensurate crop responses and soil analyses and local soil quality indicators; widespread appearance of plant species which thrive under low soil fertility such as striga and poverty grass; changes in soil colour and texture associated with low fertility; and widespread negative nutrient balances (Nandwa and Bekunda, 1998; Nandwa, 2003). Emerging evidence points to the fact that a reversal of soil fertility decline requires the adoption of Integrated Nutrient Management (INM) as a pragmatic and feasible approach to overcome the limitations of past research approaches (Deugd et al., 1998). As a holistic approach to soil fertility management, INM embraces responses to the full range of driving factors and consequences, namely biological, physical, chemical, social, economic and political aspects of soil fertility decline. The approach also addresses nutrient deficiencies; inappropriate germplasm and cropping system design; pest disease interaction with soil fertility; linkage between land degradation and poverty and global policies; incentives as well as the role of institutions in soil fertility management (Bationo, 2003).