Exploring Potentials of Rhizobium Inoculation in Enhancing Agro-economic Performance of Cowpeas in Mbeere District, Eastern Kenya

Abstract

Declining soil fertility is a major constraint to crop production in most parts of Mbeere District. According to Sanchez and Palm (1996) soil fertility depletion in smallholder farms is the fundamental biophysical root cause of declining per capita food production in the region, and its replenishment should be considered as an investment in natural resource capital. The declining soil fertility in smallholder farms has been attributed to continuous cropping, removal of field crop residues, overgrazing between cropping seasons with little or no use of external inputs and soil erosion (Smaling et al., 1992; Sanchez et al., 1997). Although inorganic fertilizers have been recommended as a means of improving soil fertility, these fertilizers have often been perceived by farmers as expensive. According to studies conducted By Heisey and Mwangi (1996) and Bashir et al. (1997), transport costs for agrochemicals make the use of inorganic fertilizers on staple food crops uneconomical for most smallholder farmers.