Climate, Change, Water Management and Aquaculture in Malawi
Farmers tend to crops grown in the bottom of a dried pond in Chingale, Malawi.
The increasing variability of climate is a challenge for small-scale farmers in Chingale, Malawi. Changing weather patterns mean that farmers are unable to fully prepare their cropping calendars for optimal harvests, and irregular rainfall is causing unpredictable crop yields. With small land sizes of less than 0.2 hectares, small-scale farmers need to make full use of their available land in order to have enough food for their families and surplus for sale. To adapt to these challenges, farmers are integrating fish farming and crop irrigation to their farming practices, which are providing extra food and income.
However, the growth of irrigation-fish farming has increased the demand for water, and subsequently created conflicts over access to water sources. In Chingale, there are conflicts over water that are exacerbated by current low water levels. Farmers in Chingale have begun to divert water from streams and rivers for irrigating crops and ponds for fish farming.
In order to make informed decisions about water management and allocation, WorldFish, the International Water Management Institute (IMWI), and the University of Osnabruck, in collaboration with national partners in Malawi, Zambia and Mozambique, have conducted a collaborative research project called, “Enhancing adaptive capacity to climate change impacts through well managed water use for aquaculture integrated with small scale irrigation in the Chinyanja Triangle in Africa”.
Funded by Bundesministeriumfür Wirtschaftliche Zusammerbarbeit und Entwicklung (BMZ) administered by the GIZ, the project aimed to examine the benefits of integrating fish farming and small-scale irrigation by identifying improved water allocation and management strategies in the face of climate change. The water resources in target catchments were assessed under current and future climate scenarios and the water demands for different crop and fish production scenarios were modelled.
When the results were presented to farmers in Chingale, they felt that they have a role to play in ensuring that the effects of climate change are mitigated.
A local model for water allocation
Realising the need to share the limited water resources, local leaders have taken a leading role in sharing water equitably. Villages that have the water, but don’t have enough land for irrigation, share with those that don’t have water but have the land. In this regard, the farmers allocate each other a piece of land so that every farmer with an interest in fish farming or irrigation can benefit.
However, as the number of farmers in this arrangement grows, the demand is exceeding the supply of water. The farmers that own ponds are leaving their ponds undrained for longer periods as a source of water for irrigation. This resulted in stunted fish growth as fish compete for space and food, over-breed and cross-breed. When the water levels in the ponds become too low for fish growth, farmers harvest the fish and plant crops inside the ponds to utilise the residual moisture.
To cope with unpredictable rainfall, farmers have started increasing their water storage area by constructing deeper ponds with an average depth of 2 meters. The ponds support fish growth, and help in the harvesting and storing of rainwater. They also help to reduce pressure on other water sources, like streams and rivers.
Adjusting farming practices and water management
The farmers feel that they need to adopt farming practices that help to conserve moisture in the face of climate change. Farmers are also adopting other conservation agriculture techniques like making ridges in the ground to reduce the speed of runoff. Those farmers with irrigation are planting their crops earlier to utilize the residual moisture. This practice reduces the water, needed to irrigate crops from channels and streams.
Natural resources management
Chingale has many streams and rivers originating from the Zomba and Malosa Mountains. However, most of these rivers are now seasonal as the trees that covered them were cut down for charcoal, fuel wood and timber. Without trees to create shade, the water evaporates quickly from the stream, and siltation and erosion become major problems. The farmers now know that if their aquaculture and irrigation activities are to be sustained, they need to reclaim these rivers by planting the right tree species to help conserve water. They have also come to realize that growing crops close to the rivers is a practice that is promoting siltation of the rivers.
Through sharing research and best practices, the project has equipped the farmers of Chingale with the knowledge they need to take a leading role in protecting and managing the water resources they depend on.
Written by Asafu Chijere, a Technical Assistant at WorldFish