Farmers have been farming on flat land for a very longtime, but they sometimes face erosions on thier farms and floods too which destroys thier crops. They also loose crop yield due to severe leaching of soil nurients but has every farmer thought about using stone bunds or stone lines? As a farmer it is important not to stick to one side of farming technology alone but to know how important stone bunds are to your farm and its effective impact and good crop yield.
Operation and Maintenance
There is limited, ongoing repair required as the stones are not vulnerable to erosion. However, silting behind the stone bunds requires that the stones to be relaid from time to time. Care must be taken that overtopping of the bunds does not lead to erosion on the downstream face, with subsequent gully formation and undercutting of the bund.
Level of Involvement
Beyond the initial, demonstration project in Burkina Faso, the technology has expanded in use of its own accord. Thousands of hectares outside of the project area currently use this technology. It is entirely farmer managed. In some villages, land management committees have been set up to look at a variety of activities related to improving land utilisation in their respective areas.
Where stones are in short supply, there are increased costs associated with their acquisition and transport. This will be self-limiting for the technology.
Effectiveness of the Technology
Contour stone bunding is effective when judged by the acceptability of the technology by farmers. Farmers use stone bunds on fields currently under cultivation and to expand cultivation to new areas. Stone bunding is particularly attractive to farmers because of its ability to be implemented on fields already under cultivation. Yields in the first year have been increased by an estimated 40%. When barren fields are rehabilitated, yields of 1 200 kg/ha have been achieved in the first year. Application of fertilisers has only rarely been necessary, and the expected decline in fertility has not been observed although it is expected that, ultimately, there will be a need for a limited use of fertilisers.
The technology is particularly suited to semi-arid lands, where stones are available. In the areas of application of this technology, long term average rainfalls are over 700 mm, but during the 1980s, when this technology came into widespread favour, rainfalls have been below 600 mm. The technique has also been used in wetter areas of Mali to prevent erosion due to overgrazing, and, in addition, has produced profitable cash crops.
The technology has noticeable, positive environmental impacts, leading to the rehabilitation of degraded lands and reducing soil erosion.
Benefits to farmers have been evident, and the technology is simple to implement at the local level. Stone bunds do not readily wash away and, therefore, the technique is not vulnerable to unusual and variable intensity rainfall events. In Burkina Faso, the project has also resulted in increased attention to land use planning and the environment by villages.
The popularity of the technique has resulted in shortages of stones and, therefore, a higher cost for latecomers.
There is a long history of soil and water conservation on the Dogon Plateau. Likewise, farmers in the Yatenga Region of Burkina Faso have traditionally used stone lines on their fields. For this reason, the further development of the concept into installation of stone bunds has been readily accepted. Farmer-to-farmer extension has been shown to be an effective tool which is underrated in many projects.
Further Development of the Technology
A concern over the eventual disposition of silt-in of the bunded areas has not yet been addressed, but it has been suggested that the planting of perennial grass on the bunds will maintain their function of slowing and spreading water and help to retain deposited silt within the bund basins. Extension support is required amongst the Dogon in Mali who have not yet adopted. The improved methods based on the simple stone lines they currently use.