Dual inoculation of woody legumes and phosphorus uptake from insoluble phosphate rock

Abstract

Phosphorus deficiency limits crop production in Western Kenya, and there is need for more affordable sources of P for resource-limited smallholder farmers in the region. Indigenous phosphate rocks (PRs) from Uganda are abundant but unreactive, so some means of increasing their effectiveness is needed. We tested two agroforestry fallow species for their ability to grow in sand culture with P supplied as Ugandan Busumbu phosphate rock (BPR) or triple superphosphate (TSP), and with or without rhizobial and/or mycorrhizal inoculation. The test species were Crotalaria grahamiana and Tephrosia uogelii, two promising improved fallow species in western Kenya.