The mission of the Land Husbandry component under Land Husbandry, Irrigation and mechanization Department of Rwanda Agriculture Board is to develop modern agriculture through natural Resources Management in a country where there is no soil or water loss.
The overall objective is to improve crop productivity through sustainable management of available land and soil conservation.
- Protection of hillsides and wetlands against soil erosion and floods,
- Restoration of Soil fertility,
- Improvement of land productivity.
The Land Husbandry component of the Department supervises all soil erosion control activities across the country. It also strengthens capacity of districts in soil conservation activities trough regular training to local government agronomists and all stakeholders involved in land husbandry issues. The overall objective is to increase year by year the proportion of arable area under erosion control and also the effectiveness.
As there were no reliable information on the progress of soil conservation in Rwanda, first of all a baseline survey was conducted in 2012 to account for the real estimate of soil erosion control structures and their efficiency. The output of this baseline was to provide data on soil erosion control in order to guide all interventions by providing districts annually targets for soil erosion control, the suitable infrastructure to be in place and their efficiency vis a vis to erosion control.
Soil erosion control baseline in Rwanda
After validating the new methodology which was developed for monitoring and evaluating soil conservation infrastructures, soil erosion control baseline for all 416 sectors was conducted. The key feature of this approach is the use of GIS, topographic maps and 0.25 m resolution orthophotos tools to the recognition of sites and areas to be assessed.
The baseline consisted of desk work to explore, understand and process the orthophotos with 0.25 m spatial resolution coverage, DEM 30 m resolution from ASTER Images band, The Land sat ETM+7 Satellite Images for land use classification to get the agriculture land and validated by the available orthophotos. Data were downscaled by sectors and then aggregated at District level. Also field data were collected thought observations, measurements and structured questionnaires.
In summary, results from the survey showed:
- The total cropped area for the whole country is 1,502,726 ha
- The total potential land area suitable to progressive terraces (calculated on the slope ranges of 3-25% and >55%) was 1,124,328 ha.
- The area covered with progressive terraces was 802,292 ha which represents a weighted national average of 75.2% of the national potential area suitable for progressive terraces.
- The total potential land area suitable to radical terraces (calculated on the slope ranges of 25-55% and soil depths >1.5 m and other related soil characteristics) was 245,163 ha.
- The progress for radical terraces establishment in Rwanda was 46,246 ha and represents a weighted national average of 18.96 % of the potential suitable radical terraces areas.
- The unprotected land area suitable to radical terraces was 198,917 ha.
- The total coverage of soil conservation structures was estimated to 848,538 ha representing 56.47 % of the national arable land. This total coverage included progressive terraces and radical terraces but without woodlots.
- The overall efficiency of soil conservation structures was 53%. This low value was due to inadequate design and management of progressive terraces. The efficiency varies from one province to another, being high in the Northern (68%) and Southern (57%) Provinces.