Improvement of soil fertility by improved fallows of Cajanus cajan, Sesbania sesban and Tephrosia vogelii at Gairo in Morogoro, Tanzania

Abstract

This study was carried out at Gairo in Morogoro Tanzania to evaluate the effects, of fallow  periods and fallow types on soil fertility improvement. A split-plot experimental design with three replications was adopted. Three fallow periods (i.e. 1, 2 and 3 years) were involved in this study. Soil pH, EC, OC, total N available P and total P were significantly (P < 0.05) affected by fallow periods and fallow types. Greater improvement in soil fertility was achieved by the improved fallows of S. sesban, T. vogelii and C cajan than the natural fallow. Soil fertility was found to increase with increasing fallow period from 1 to 3 years. Continuous cropping for 3 years resulted in greater decline in soil fertility. It is therefore concluded that improved fallows of S.sesban, T. vogelii, and C. cajan have the potential of improving soil fortility and so reduce the problems associated with a decline in soil fertility Based on the findings of this study, it is recommended that the species be tested on farm and further investigations be carried to examine nutrient dynamics and sustainability of maize crop yield after fallow .

. Keywords: fallow period, fallowtype, natural fallow, oontinuouns crop

Tanzania J. Agric. Sc.(2001) Vol. 4 No. 2, 45-54