Optimising stocking rates on livestock farms neighbouring wetlands for sustainable productivity and ecological stability

Abstract

Uganda’s wetlands, especially in south-western Uganda are increasingly being invaded by cattle herders, particularly during droughts. Such uncontrolled grazing is accelerating wetland degradation. The objective of this study was to assess seasonal forage availability on farms neighbouring Ekigaaga wetland in south-western Uganda, and to determine their optimum stocking for sustainable productivity and ecological stability. The grazed area on each side of the virgin wetland was taken as a block, giving two blocks. In each block, three square metre sampling plots were demarcated along a transect line cutting across farms adjacent to the wetland. Some of these plots were fenced and others were left open to grazing by livestock. Two months after setting up the study, vegetation samples were collected from the fenced and unfenced plots in each block once every month, for a period of six months. Livestock classes and numbers grazing on each block were established and standardised into Tropical Livestock Units (TLU); where one TLU is equivalent to a cow weighing 250 kg. During wet and dry seasons, Cynodon dactylon was the most abundant forage species in the unfenced plots in both blocks. Fencing increased the prevalence of Chloris gayana and Themeda triandra in block 2. Sporobolus pyramidalis was the most abundant weed in both blocks. Fenced and unfenced plots in block 1 had higher grazeable forage yields (488.05 and 399.97 kg ha^-1, respectively) than block 2 (432.08 and 371.97 kg ha^-1, respectively). The TLU that could be safely grazed on blocks 1 and 2 were 121 and 107, respectively compared to the TLU being grazed on blocks 1 (279) and 2 (381). Therefore, to sustain the productivity and ecological stability of these grazing areas, there is need to control weeds/thickets, improve forage resources by oversowing with quality forages, and to adjust livestock numbers to match with forage quantities available for grazing.