Belg. J. Zool., 135 (supplement) : 187-190
A Capture-Mark-Release study was carried out in Morogoro, Tanzania, from April 1999 to April 2001
to investigate the effects of land preparation methods and cropping systems on population abundance of Mastomys
natalensis in crop fields. Two land preparation methods (tractor ploughing; slash and burning) and two cropping
systems (mono-cropping with maize; inter-cropping with maize and beans) were included in the study. The experi-
mental design was a Complete Randomized Design with 2x2 factors, with two replicates. In slash and burn fields,
rodent population abundance and distribution were strongly influenced by vegetation cover regardless of the type of
cropping system. Higher rodent population peaks occurred in dense vegetation cover in slash and burn relative to
tractor ploughed fields. In contrast, there were no obvious associations between vegetation cover and population
abundance in the tractor ploughed fields, particularly in the mono-cropping system. A negative correlation between
vegetation cover and population abundance of M. natalensis was obtained in fallow land surrounding the crop fields
(r = -0.63; p ≤ 0.05). The results show that the effect of vegetation cover on population abundance of M natalensis
in crop fields is strongly influenced by the type of land preparation methods. Tractor ploughing and clearance of fal-
low land surrounding crop fields could be a useful method to reduce the invasion of crops by M. natalensis.