Urgent need for sustainable intensification in an explosively growing Africa

Helping to create a better world. This is what Katrien Descheemaeker, 45, always wanted to do from an early age. After leaving the Catholic University of Leuven in Belgium, she ended up in Africa. Her research into soil conservation and land rehabilitation was conducted within a larger collaborative partnership with Mekelle University in northern Ethiopia. She realised that her research had to contribute to finding answers to the questions that arose there, and not the other way around. Katrien’s work now extends beyond the soil alone. She now focuses on the farms. Her goal is to develop sustainable food systems that produce healthy food in sufficient quantities for the growing population. 

Whereas here in the Netherlands we are mainly concerned with sustainability in relation to issues such as nitrogen emissions, sustainability is primarily needed in Africa in the battle against hunger. Katrien explains: ‘There is a huge difference in the population pyramids for Europe and Africa. Although you can’t really call the one for Europe a pyramid anymore, as it is quite top-heavy. Its main focus is at the top, with the older groups. The pyramid for Africa shows the complete opposite. A huge group of young people will be having children in the next few years. And as large families are often the norm and the quality of health care is improving, the population will grow rapidly in the years ahead as a consequence.’ 

‘The population growth in Africa means that there will be many more mouths to feed. And if you want to meet this demand with the current agricultural systems, you will need to take measures,’ Katrien explains. ‘One possible measure is to import more food. But the food crisis that threatened to occur because of the situation in Ukraine is an indication of just how risky this is. Another measure could be to significantly expand the land area used for agriculture. However, this could lead to loss of nature or use of land not suitable for agricultural purposes. 

One example of sustainable intensification is intercropping. Katrien explains: ‘We know from research that this development can be successful here in Africa. In this solution, two crops, such as maize and a leguminous crop like beans, are grown together. Not only is this better for the soil but also for yield certainty. Let’s say that an infestation occurs that destroys maize plants. In that case, you would still have the yield from the beans.’ Intercropping does, however, require greater management, such as for weeding and harvesting. ‘We therefore listen carefully to the criteria given by the farmers. Not only are they interested in the yields but also in the amount of labour that something costs and the demand from the market. Furthermore, they consider it important that their livestock are partial to the crop residues.’ 

In Africa, farmers grow crops and also keep various species of animals. In contrast to what happens here in the Netherlands, meat and milk are usually by-products. ‘Farmers on smallholder farms in Africa mainly use livestock to plough the land, they spread the manure over the fields and they regard the herd as a form of capital and savings; often due to the lack of reliable financial institutions. A herd also contributes to a farmer’s status. In the search for sustainable solutions for both livestock and people, intercropping experiments were carried out together with farmers in Katrien’s projects, in which they grew food for people and livestock simultaneously. An article was written about these experiments by Gatien Falconnier, a PhD student at the time. 

Measures such as intercropping and diversification lead to more sustainable agricultural systems as they result in a larger and more stable yield, a better soil and less burden on the environment in the long term. To take advantage of these opportunities, you need to take the local situation as a starting point: what do the farmers need, what is the market like and how can you achieve a productive collaboration? Katrien explains: ‘The main driver for improvement is based on local cooperation. We may have the scientific knowledge relating to soil management and plant characteristics but the farmers are the ones who have to do it. They, in turn, have specific knowledge and know how to cope with the uncertainty of the weather. For this reason, “co-learning” is the key to success. Not only do we learn from one another but together we can arrive at different insights.’ 

Thanks to the experiments that have already been carried out, the Plant Production Systems group has managed to obtain useful insights and data. They also use models that enable them to estimate long-term consequences. In order to convert knowledge into opportunities, Katrien and her colleagues also focus on conveying this information. This is something they are already doing. For example, a postgraduate researcher is currently conducting research into effective knowledge transfer in Burkina Faso. Although the results are not yet in, they have already discovered that the use of metaphors works well. Such as to achieve a shared understanding of biophysical processes. Katrien tells us: ‘One example is to use the human body as a metaphor when explaining about the needs of plants. Just like a plant, a human body benefits from a variety of foods. We also employ this method of using metaphors to explain the importance of a healthy soil.’ 

Katrien is positive about the developments, and collaboration with local farmers is continuing to improve. But in order to achieve improvements on a large scale, it is also necessary to get policymakers involved. This is not always easy to achieve however. ‘It’s great that knowledge institutions in African countries have already been collaborating with their Dutch colleagues, such as WUR, for many years now. This is fruitful in several ways. For example, we still often work with African students who we met because of the exchange projects between universities. This helps us to expand our network. And this network makes it easier to come into contact with policymakers.’ 

African farmers are well prepared for unexpected circumstances. With climate variability a common reality, it is not always the highest yield that is important but rather yield certainty. Katrien explains: ‘But when you do need to increase yields in order to feed the growing population, you may make the system less robust. It’s all about compromises, with regard to the environment and the fight against climate change, as well as in relation to social aspects, such as the differences between rich and poor. It’s important to have a clear understanding of these compromises first before any solutions can be put forward at all.’ 

Katrien is in her place in Africa. She works mainly in the lowlands, where the soil is less suitable for growing potatoes. But the knowledge and experience she and her network gain can also be applied to growing potatoes. That is why Katrien Descheemaeker is keynote speaker at Potato Days 2022: 'I am looking forward to this, especially because we need each other. Because in the battle against hunger and climate change, we have no time to waste. '