Soil erosion represents a downward spiral of degradation of the land — soil erodes, which means less fertile soil, which means plants grow less vigorously, which means less ground cover, which then means more erosion etc. On and on it goes.
In Chimene village, Rusape, gulleys — deep ditch or ravine — have become part of the soil erosion problem. Formed by mountain-side rainwater runoff, the Chimene gulleys have become a death trap for the local community and their animals. Road-side ditches have caused public transport to come to a halt.
Now, villagers are working to reclaim the deep channels, with assistance from Food, Environment and Enterprise Trust (Feet). John Nzira of Feet describes the danger associated with the gulleys of Chimene, created from prolonged water action on the loose, sandy soils of the rural village.
“Gulleys along the main road pose a serious hazard for travellers and many who live in the village are forced to walk long distances because vehicles simply cannot use the road,” said Nzira, himself a frequent visitor to Chimene village.
“The cars leave them about a kilometre or more away and they walk the rest of the way to go to their homesteads,” he added. After an interface with the village leaders and members, work to fix the galleys started in December last year.
With assistance from villagers, Nzira first surveyed the landscape to establish the source of the gulley-causing runoff water. The idea was also to work out a definite and feasible repair strategy that utilises locally available resources.
“Every year the water is coming from the mountain, taking the top soil and deepening the gulley, making it more and more difficult to repair each year,” observed the 56-year old conservationist.
“I realised that they (villagers) could apply water and soil management techniques to make sure that the water doesn’t continue to wash away the top soil into the river. That could help them maintain the natural systems,” he stated.
Nzira continued: “I introduced them to simple techniques for landscape management and we managed to build a (swale) contour ridge and an underground tank. The community contributed most of the required materials for the underground tank.”
In Zimbabwe, the equivalent of 58,000 square kilometres of soil — about 64 times the size of Harare — are susceptible to erosion, particularly in the areas where shallow Kalahari soils dominate, according to environment regulator EMA. The worst affected river catchments are Save, Umzingwane, and Sanyati, it says.
Experts blame poor farming practices and a lack of contour ridges in new and old resettlement areas as the single largest driver of soil erosion.
Contours are a practice in farming designed to prevent runoff from wandering aimlessly, taking with it treasured top soil. They are built with soil across fields contrary to the slope, running between 250 and 400 metres in length depending on soil type, and height of up to 20cm, creating ridges that help channel water away without chaos.
In Chimene, villagers have successfully restored the gulley, becoming an important feature for the community, according to Theo Mudzindiko of Pelum Zimbabwe, a farmer advocacy and conservation group.
Vehicles can now pass through the mountain-side roadway safely without damaging soil “in the gulley because they are driving through a contour line and that is important to conserve water and gullies in fragile areas.”
John Nzira, the Feet conservation expert explained: “The gulley was seen as a negative element in the community but we converted the gulley into a functional system and this functional system is now providing water throughout the year for both people and animals.
“Moreover, they are planting indigenous and fruit trees in the gulley, as well as grasses like vetiver and banner grass which provide good fodder for livestock as well as stabilising the soil.”
When rain falls it washes away that fine top-soil, as it runs off, depositing it into rivers and dams. Top-soil is very useful for agriculture, and for vegetation growth (which holds the soil together to prevent gulley formation).
God is faithful.