As EWF/Lignaverda is pioneering in Namibia, it is important that it acquires knowledge, particularly on (i) the effectiveness and applicability of water harvesting techniques under the specific soil and climate conditions of the target area (Kavango West region); and (ii) the carbon sequestration potential of different planted tree stands (mixtures).
We therefore suggest to split the plot into four experimental sites:
1. Native tree species. Soil would be prepared by scarification only; i.e. furrows at 5 m distances from each other, in which seeds are sown directly (copying the approach from Senegal).
2. Mix of native trees with commercial tree species (such as mango, avocado, etc.), at a density of e.g. 50 - 100 trees per ha. Same approach as in 1, but with commercial tree species seedlings obtained from nurseries. The rationale behind commercial species is that they may be more appealing and therefore better accepted by local communities for afforestation of communal land.
3. Assisted Natural Regeneration (ANR): soil is scarified, but no additional activity is done. Rains will activate (i.e. cause germination of) the prevailing seed bank.
4. Enhanced weathering: i.e. soil amendment through biochar and silicate addition: in collaboration with Antwerp University. Addition of biochar will provide organic matter, required for enhancing the soil Cation Exchange Capacity (CEC); weathering silicates will release calcium (Ca) and magnesium (Mg) to the soil, and during that process will absorb CO2 from the atmosphere (adding to CO2¬-removal by the trees on the land). Soil preparation and seeds or seedling types to be further defined.