Characteristics of herbaceous vegetation on abandoned fallow fields in south central Zimbabwe

Abstract

Fields abandoned to fallow, due to biophysical and socio-economic factors in communal areas of Zimbabwe, are used for livestock grazing. A study was conducted to characterise vegetation from such fields, and assess its grazing suitability across four agroecological regions (AER II – AER V) characterised by annual rainfall ranging from 750 mm to 400 mm, and five categories of fallow age groups (0-5; 6-10; 11-20, > 20 years and normal rangeland). Most fallow fields did not mature into woodlands but remained grasslands with or without sparse shrubs regardless of the period of fallowing and AER because of high stocking rates. There were no variations in palatability, ecological value, diversity, biomass and grazing capacity across fallow age groups. However, significant differences were observed across AERs. The quality of vegetation from fallows in AER II and III was poor but good in AER IV and V. The quantity of vegetation from fallows in AER II was higher than from other AERs. However, all fallow fields from the four AERs had low grazing capacity than expected from literature. We conclude that using fallow fields for uncontrolled grazing is unsustainable. There is need to investigate better management strategies for livestock production in fallow fields.

Keywords: agroecological region; fallow age; grazing suitability; uncontrolled grazing