Farmers in Upper Tana store carbon by mixed cropping
Storing carbon in soil and vegetation provides rainfed farmers with an opportunity to participate in emerging carbon offset markets. The reward that rainfed farmers might be able to earn by storing carbon has now been calculated for the Upper Tana river catchment in Southeast Kenya.For a scenario that assumes sustainable management practices on 60 percent of the suitable land, ISRIC researchers have calculated that annual earnings of US$7-13 per hectare are feasible. The results of the study were published recently in Land Degradation & Development (8 Feb. 2012, online).
The Upper Tana river catchment has been overexploited. Despite an increase in the area under cultivation, food production per person has decreased due to erosion, declining soil fertility and lowered levels of soil organic matter. Land and water conservation practices such as mulching and terracing can mitigate these problems, but many rainfed farmers do not have the means for such practices. A carbon-offset market could provide a financial mechanism to stimulate these farmers. The calculations were part of the Green Water Credits project. This project promotes land and water conservation practices by developing another compensatory financial mechanism: farmers earn money from downstream water users who benefit from improved water quality and less erosion upstream.
Carbon fixing potential
ISRIC researcher Niels Batjes calculated the carbon fixing potential of the land and water conserving practices applied in the Green Water Credits scheme. Then he translated these projected soil carbon stock gains into potential financial benefits on a carbon offset market, where parties will pay for carbon storage as compensation for carbon emissions elsewhere. He used a simple model and a conservative price estimate of US$ 10 per ton of CO2 fixed.. Compensation prices now range from US$ 5 to 30 per tonne CO2 equivalent.
Potential carbon payment
If the carbon fixing practices were applied on 60% of the suitable soil area in the catchment (348,000 hectares), some 4.8 to 9.3 x 106 tonnes CO2 could be stored in the soil over a period of 20 years. This implies a potential annual carbon reward of US$ 7-13 per hectare for farmers. Higher market prices for CO2 equivalents will probably result in a quicker implementation of the CO2 mitigation measures in agriculture, Batjes concludes.
Experiments with rewarding systems
Several carbon-offset markets exist. and various countries are now experimenting with this environmental rewards system. Kenya was the first country to issue voluntary carbon unit (VCU) credits in a Reduced Emissions from Deforestation and Degradation (REDD) forest-protection scheme, which was implemented in 2011
Article: Batjes, NH 2012. Projected changes in soil organic carbon stocks upon adoption of recommended soil and water conservation practices in the Upper Tana river catchment, Kenya. Land Degradation & Development, doi: 10.1002/ldr.2141