The perennial constraints of food shortages and lack of a balanced diet due to poverty, significantly threaten human survival and overall development in sub-Saharan Africa. Within the East African region and especially Kenya, low and unreliable rainfall distribution and infertile soils largely account for low and unsustainable agricultural productivity. This is reflected in low seasonal crop yields at smallholder level, where the maize (staple) yields are frequently below 1 t/ha/season, a result of lack of adequate nutrients and related inputs. The low yields can be compared against the...