Adapting to Climate Change: Small-Scale Farmers

In my previous blog, I explored the impacts of climate change on agricultural farmers through the changes of rainfall and temperature across Africa. In the recent COP22 negotiations in Marrakech, agricultural adaptation to climate change was put at the forefront by 28 countries; Ban-Ki Moon explains that “Adaptation is not a luxury. It is a cautious investment in our future” (AAA, 2016a). A positive product of these negotiations saw the development of an initiative called the ‘Adaptation of African Agriculture (AAA) Initiative’ where the importance of climate change impacts on African agriculture is raised. This initiative focuses on implementing specific projects to improve Africa’s agriculture on all levels, ranging from soil management, agricultural water control, risk management and capacity building (AAA, 2016b). Perhaps, this negotiation can prove to be a pivotal point in elevating the concerns regarding agriculture and water availability. In this blog I want to explore the ways in which these farmers adapt to climate change, specifically exploring the small-scale farming techniques and adaptive measures to changing rainfall patterns and water availability for irrigation.

Rainwater Harvesting – Soil Moisture Conservation

This clip below provides a brief insight into the impacts of climate change and a farmers’ response to short rainfall, intense heat and the drying of soils through rainwater harvesting. 

Agriculture in many countries across Africa is highly dependent on rainwater and so climate change threatens a significant number of people’s livelihoods (Yosef & Asmamaw, 2015). Rainwater harvesting through storage in the soil profile is a form of in-situ water conservation whereby rainwater is held in the place that it falls. The amount of water stored in the soil is limited by the soil holding capacity and rate of infiltration, and in arid and semi-arid areas where coarse soils and high hydraulic conductivity, the amount of water stored in the soil is extremely limited and thus may not be a useful adaptive method (Yosef & Asmamaw, 2015). However, soil practices can be used to change the condition of the soil and thus improve the soil moisture retention. For example, in the drought affected areas of Ethiopia, stone bunds of 30cm wide and a height of 0.74m stone bunds are used to reduce runoff and soil erosion, and to increase soil moisture (Biazin et al., 2012). Other techniques such as terraces and trenches are also effective in increasing soil moisture and was widely adopted in traditional agricultural practices in many African countries. In Burkina Faso, the depth of soil pits was deepened and compost/manure was applied, this changed the composition of the soils, thus enabling the conservation of more water in the soil (Baizan et al., 2012). A study by Birru et al. (2012) found that farm yard manure and mulching significantly enhanced soil moisture retention. Soil moisture storage with mulch treatments of 6 ton ha^-1 of mulch retained 216.11mm of water, 39.15mm more water than soil without mulch treatment. 4 ton ha^-1 of straw mulch treatment retained 215.40mm of water, which is similar to the mulch treatment, thus showing that the straw mulch treatment has higher soil water retention capacities greater than mulch treatment.

Rainwater Harvesting – Macro-catchment

Larger rainwater harvesting techniques consists of collecting rainwater or runoff and diverting this water to a storage structure and target area through a macro-catchment system (Biazin et al., 2012). A study by Lebel et al. (2015) explains that rainwater harvesting techniques can prove to be a ‘valuable adaption strategy to climate change’, more specifically for maize crops because these techniques can address large issues concerning water deficits in the future. The study predicts that under RCP8.5 climate scenarios (highest greenhouse gas emissions during 2050s), maize yields have the potential to increase by 14-50% due to rainwater harvesting techniques meeting the demands required for productivity in Africa. Although, this study notes that in semi-arid and arid regions, rainwater harvesting techniques are unlikely to mitigate the impacts of intense temperatures and lack of rainfall, so other adaptive techniques are required.
An interesting study by Recha et al. (2015) suggested that the adoption of these rainwater harvesting techniques depended on the number of livelihood options available to small-scale farmers in Tharaka, Kenya. Farmers who depended on crops for their livelihoods was more likely to use rainwater harvesting techniques, but other attributes such as the cropland size during the MAM rainfall season, or the number of children per household also influenced the adoption of rainwater harvesting techniques. This shows that certain conditions would influence the choice of using these techniques by farmers, only if it would maximise their productivity and optimise the use of rainwater which would in turn improve their livelihoods.

Irrigation

Other adaptive strategies gaining momentum are irrigation schemes. Burney et al. (2013) argues that small scale distributed irrigation schemes, such as community level catchments, tubewells, sprinklers and drip lines, has five-times the cost-benefit than large centralised irrigation schemes such as dams. Yol et al. (2011) found that the internal rate of returns for large-scale irrigation schemes averages to 7% whereas small-scale irrigation schemes have a rate of 28%. This is because small-scale irrigation can benefit more from areas with high rainfall potentials, unlike large-scale irrigation which may have lower rainfall rates. Other benefits of small-scale irrigation include being able to adapt these schemes to local needs and thus maximise freshwater use for agriculture, whereby many small scale farmers can access this resource.

Concluding Thoughts

There are many adaptive strategies that small scale farmers can adopt to mitigate the impacts of climate change on their agriculturally based livelihoods, ranging from soil based moisture conservation (mulching, manure, terracing and trenches), macro-catchment rainwater harvesting and irrigation schemes. These techniques have been adopted in indigenous practices and have long been sustaining the African population. But given the onset of climate change and the devastating impacts that it is predicted to have over Africa, the COP22 negotiations can elevate the importance of adaptive strategies to a higher level, which may attract investment and development of these adaptive strategies and farmer’s adaptive capacities.