How smallholder farmers in Zimbabwe are succeeding with irrigation and fighting climate change impacts
By Martin Moyo
In 2016 and 2017, Zimbabwe was struck by a double disaster: An already severe drought was exacerbated by the most extreme El Niño impact seen in the country during the past 75 years. In combination, the two events decimated food production, and led Zimbabwe to declare a state of disaster.
Unfortunately, such extreme weather is becoming more common. Droughts and accelerating climate change impacts are making life difficult for farmers in Zimbabwe, not least for the large majority who practice rain-fed agriculture. When frequent droughts are replaced with erratic floods, as was the case during the 2016-2017 El Niño season, rain-fed crops naturally fail.
That’s why small-scale irrigation is emerging as a top priority to boost food security, eradicate poverty and build resilience against climate change impacts. But irrigation is in itself not a silver bullet solution: irrigation schemes are complex socio-ecological systems and should be treated as such.
Smallholders are only able to succeed when they can manage their farm systems efficiently. New, easy-to-use tools and recently introduced opportunities to experiment and solve problems in collaboration with others allow farmers to become more efficient and their farms more profitable.
Persistent irrigation woes weaken agricultural development
Small-scale irrigation has been lauded as key to building climate resilience by changing Zimbabwean governments, yet it has often failed in the past. The reasons are plentiful, but low crop yields and under-performing agricultural markets carry part of the blame. When farmers either have very few crops to sell—or no one to sell crops to—they have little funds and incentive to invest in irrigation.
Another reason is poor water management. For example, water is not always shared fairly: some farmers, with plots located close to the water supply, may receive much more water than farmers with plots further away. Because water delivery and distribution is not predictable, farmers tend to over-water their crops, causing water scarcity, nutrient losses, waterlogging, land degradation and soil salinization.
During the past five years, I have been working with colleagues from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) and the CGIAR Research Program on Water, Land and Ecosystems (WLE) to solve these and other, interlinked challenges.
What’s new: technology and learning make a winning pair
First, we have introduced two easy-to-use tools that help farmers to apply just the right amount of water to their crops. One is a so-called wetting front detector: a small device buried in the soil with an indicator above the surface that shows how deep into the soil water has infiltrated, thus giving a good sense whether more irrigation is needed. Farmers can also extract water samples from the device and use those to measure the soil’s nitrate and salinity status, helping to reveal if over-watering is leaching out nutrients.
The second device, called the Chameleon, complements the wetting front detector, and consists of three or four sensors permanently installed at different depths in the soil. A hand-held reader shows blue light for wet soil, green light for moist soil or red light for dry soil. In combination, the two tools make it much easier for farmers to know whether their crops need more water.
But technology alone is not enough. We introduced these two tools within the context of agricultural innovation platforms—informal institutions that bring together farmers, government officials, traders, researchers and others. As these different types of people had the opportunity to share knowledge, new ideas about how to use these tools and improve the system as a whole emerged. We found for example that farmers learned from each other and were able to get market information that led them to grow new, higher-value crops.
Bigger yields with less water prepare farmers for climate change
We tested this approach in two places in Zimbabwe: Mkoba irrigation scheme in the central part of the country and Silalatshani scheme a bit further south. Both places receive little rain and experience frequent dry spells, droughts, and high temperatures.
In each scheme, we provided twenty farmers with the two tools described above, and we established agricultural innovation platforms that were open to everyone. After four years, farmers achieved a number of impressive results, with some of the most significant highlighted below.
- Farmers have decreased the amount of water they use for irrigation. In both places, farmers use about 30 percent less water than before, using the tools to avoid over-watering and thus saving scarce water resources.
- Despite this, yields have increased by 25 percent or more for 86 and 76 percent of households at Mkoba and Silalatshani, respectively. This means that water productivity has increased—farmers grow a lot more crops with a lot less water.
- What’s more, these benefits extended beyond the farmers who were supported by their new tools. Through the agricultural innovation platforms, farmers learned from each other, and even those without tools started irrigating less frequently.
- Finally, farmers are increasing their interactions with people outside the community, getting information about new value chains and markets, boosting the potential to make additional profit from their increased yields.
These are a few promising first steps on the path toward a beneficial cycle where increased yields lead to greater incomes that can be invested in irrigation equipment, food, education and health. Such investments increase communities’ resilience to external shocks, including extreme weather.
Achieving climate resilience at scale
Zimbabwean farmers are, like many other farmers in Southern Africa, facing the harsh reality that already scarce resources are becoming even scarcer as well as less reliable due to climate change impacts and climate variability. While there are still no easy solutions, the combination of farmer-friendly tools and opportunities for learning and networking could help build climate resilience.
That’s why we are now working with both the Zimbabwean Department of Irrigation and with multilateral African institutions to find out how to scale up and out these innovations via policy and practice. This way, Zimbabwean farmers may be better placed to tackle increasingly destructive disruptions brought on by climate change and variability in the future.