s:1002:"%T Nitrogen sourcing by fast - growing legumes in pure and mixed species fallows in western Kenya 
%A Gathumbi S M 
%X The major objective of the present study was to investigate the potentials of mixed fallow species compared with monoculture fallow species for enhancing and sustaining soil nitrogen. Field experiments were conducted in western Kenya while laboratory experiments were done in Wye College greenhouse. Fast growing woody and herbaceous legumes were evaluated for dry matter and N accumulation, subsoil nitrogen capture and their N contribution to the overall soil N economy in the fallow system through biological nitrogen fixation. The feasibility of using 15N isotope technique in estimating percentage N derived from BNF and tracing the subsoil N uptake by several legumes was assessed. The legumes included, cajanus, sesbania, crotalaria, tephrosia, macroptilum and arachis. The experimental details are presented and the results discussed. Recommendations are also presented. 
";