?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Birech%2C+Rhoda&rft.aulast=Birech&rft.aufirst=Rhoda&rft.date=2007&rft.title=Effect+of+plant+biomass+and+their+incorporation+depth+on+organic+wheat+produc-tion+in+Kenya&rft.genre=proceeding