NYANDO BASIN, Kenya (Thomson Reuters Foundation) – Research is under way in western Kenya to measure the greenhouse gas emissions from soil tilled by small-scale farmers – the mainstay of African farming – so that scientists can work out how to farm more efficiently while minimising emissions that contribute to climate change.
The project is aimed at filling gaps in knowledge about what levels of greenhouse gases small-scale farmers produce and enabling scientists to recommend the best ways to manage the land sustainably and increase farmers’ incomes.
The test site for the project is in the Nyando Basin in western Kenya, a region known for a variety of crops, wide differences in altitude and a high population density – in fact, one of the highest in the country – which makes for intensive smallholder farming.
The programme is a collaborative effort between a consortium of research organisations under the CGIAR (Consultative Group on International Agricultural Research) and Maseno University, and is called the Standard Assessment and Mitigation Potential and Livelihoods in Smallholder (SAMPLES) systems.
Nyando Basin is one of the most food insecure regions in the country, with poor soil and prone to alternating but frequent floods and droughts. It includes both the Kisumu lowlands and the Kericho highlands, where tea is grown.
These factors, plus its range of cropping systems, make it an interesting area to study, according to Mariana Rufino, a senior scientist at the Centre for International Forest Research (CIFOR), a CGIAR affiliate.
Nyando farmers cultivate maize, beans, sugarcane and bananas as well as tea and napier grass as fodder for their livestock. Maize and beans are annual crops that require land to be prepared every year, whereas napier grass is a perennial, which will continue producing crops once planted. Sugarcane, another perennial crop, is managed in rotation of five to seven years.
This range of crops means the soil is disturbed for planting at different times and with different frequencies, and the potential rate and amount of emissions differs, depending on the crop.
“With a relatively small research site of 10 square kilometres, we can learn about a much larger area,” Rufino said.
To judge carbon emissions for each crop, farmers are asked questions such as whether or not they use fertilizer, how much they use, when they plant each crop, and how often they weed.
“All these affect emissions because interruption of the soil system may raise or lower emissions. We can then try and see how best to minimize emissions,” explained Bernadette Nangira, a student of environmental chemistry at Maseno University.
Emmanuel Mambo Oduory, an analytical chemistry student at the university, said that gas samples collected at the sites are sent to a laboratory at the university to be analysed.
The variety of crops, altitudes and rainfall in the Nyando Basin enables scientists to explore a range of mitigation options and land management practices, such as using drip irrigation, growing crops and trees together, using greenhouses, and introducing drought-tolerant crops, Rufino said.
The aim is to find combinations of plants that make sense in curbing emissions and protecting livelihoods and incomes, and to study how people manage their farms “because they are the ones who are going to make decisions on how to manage the land,” Rufino said.
John Obuom, a father of eight from Kowala Village, in the Lower Nyando Basin of Kisumu County, is one farmer whose income has increased since he received training in ways of coping with climate change.
He is now rearing fast-maturing breeds of goats and Red Maasai sheep and practising agroforestry (planting nitrogen fixing trees alongside crops) which has reduced soil erosion, especially during floods, while enriching the soil.
His new dairy goats, he said, produce three times as much milk as the old variety, allowing him to keep two litres a day and sell four. His Red Maasai sheep fetch up to 15,000 Kenya shillings ($176) at market, three times as much as the local breed.
His training was part of the work of Climate-Smart Villages, model villages set up across West and East Africa and parts of Asia by the CGIAR Research Programme on Climate Change Agriculture and Food Security (CCAFS) to test a range of crops, technologies and farming methods and work out which are best suited for a particular community.