Jonas Frei is an urban ecologist, landscape architect, author and passionate advocate of pulses. His work builds a bridge between urban sustainability and culinary innovation. Frei thinks of food not only as a pleasure, but also as a contribution to a sustainable future. Since 2018, he has been realizing projects in the fields of illustration, film, photography and as an author in his studio “foifacht, which he founded with Raphael Kleindienst. 2020 he won the German Garden Book Award for the book “Die Walnuss”. We talk to him about the role of legumes in the food system, the benefits for the soil and their immense diversity.
You have already published a book about hazelnuts and walnuts. Now you are focusing on legumes, among other things. What fascinates you about them?
The sheer endless variety. The legume family, the Fabaceae, is one of the most diverse, with around 20,000 species. Of course, not all of these species are of culinary value, but many more than we are aware of in everyday life.
And in addition to the wild species, there are countless cultivated forms and varieties. Many of these are of little importance in today's agriculture and need to be specifically preserved. Traditional bean varieties are therefore being saved in conservation projects around the world. More than 115,000 varieties of new world beans alone, Phaseolus, are currently stored in gene banks. A considerable number, especially compared to the few varieties that regularly end up in our dishes. The number of accessions of the second major bean genus, Vigna, is similarly high.
Although these large numbers are impressive, I find their aesthetics much more fascinating. The variety of beans is so colorful that some cultivars make you think of jewelry, rather than food.
Legumes are considered a climate-friendly source of protein. What role do you think they could play in Switzerland's or the global food system of the future to promote sustainability?
When it comes to the cultivation of legumes, opposing extremes often collide on a global scale. Ultimately, it depends on the agricultural systems in many regions—not just the crops themselves—whether production contributes to sustainability. For example, about 80% of the global soybean harvest does not end up directly on our plates; instead, it is used as animal feed in meat production or indirectly enters our diet in the form of milk and egg products. This type of production, often accompanied by long transport distances, deforestation of primary forests, and the use of total herbicides, is among the most harmful influences on our ecosystems. In contrast, the direct consumption of legumes—especially from regional cultivation and as a substitute for excessive meat consumption—provides an excellent opportunity to reduce negative emissions. Globally, we would need significantly less of the former and much more of the latter.
On a national level, I particularly think about niche production: dried beans rarely come from Switzerland anymore, and lentils or field beans have lost their significance in local agriculture, with often large import distances standing in the way of sustainability. Legumes are fantastic for soil health and help reduce chemical fertilizers.
It would also be wonderful to see beans more frequently in home gardens or on balconies. Doing something for self-sufficiency and preserving old varieties is a wonderful experience.
What advantages do you see in the cultivation of legumes compared to other crops, both for agriculture and for the soil?
Compared to other crops, legumes have the advantage of being able to bind atmospheric nitrogen with the help of nodule bacteria. In this way, they contribute to soil improvement and fertilization and can reduce the need for energy-intensive nitrogen fertilizers. Legumes are often sown as catch crops to improve the soil for subsequent crops. This is often done with alfalfa or clover mixtures. For the same reason, the mixed cultivation of peas or field beans together with cereals is also exciting. Today, however, there is hardly any direct use for such mixed crops in mechanized cultivation outside of animal feed production.
However, combined cultivation has long been a widespread and important form of cultivation in indigenous agriculture in North and Central America. Beans, maize and pumpkin are sown together as the “three sisters”. Beans provide nitrogen, the maize becomes a climbing aid and the pumpkin provides shade for the soil. This form of cultivation has survived regionally to this day. At the same time, they provided the basis for a rich, balanced diet. Today, however, such concepts are more likely to be found in gardens and alternative cultivation systems because they are not suitable for mechanical harvesting.
How could the increased cultivation and consumption of pulses help to reduce the carbon footprint of agriculture?
First of all, I see great potential in replacing industrially produced meat. A large proportion of the (soy) beans grown go directly into meat production as silage. Wherever cows and cattle are not on pasture but have to be largely fed from the field, this entails a whole slew of ecological problems.
In this logic, every soybean that ends up directly in our stomachs as edamame or processed as tofu is a step in the right direction. Pulses are very rich in protein and can therefore take on a similar function on the plate as traditional meat dishes. Be it in traditional bean dishes or processed as vegan meat alternatives. And, as already mentioned, pulses also help to reduce the use of nitrogen fertilizers, which would otherwise have to be produced using a great deal of energy.
There are rare legumes that are less known outside the usual varieties. At the Soil to Soul Symposium, you and Dominik Flammer will also be talking about lesser-known species and varieties at the talk “Legumes make soil good”. Which species and varieties do you find particularly promising, and why?
Here, too, it's primarily the diversity that appeals to me. I find the Lima beans, for example, whose wild forms grow in the Andes of South America, particularly fascinating. There are countless varieties that are hardly known here. Not all of them can be cultivated in our climate, but their diversity is enchanting. Or lupins, several species of which are not only fascinating ornamental plants, but also great sources of protein. I also see great potential in the forgotten faba bean, which was the most important bean species in Central Europe before the American garden bean was imported. It's time to rediscover them in our culinary world!
The potato, once exotic, is now an integral part of countless dishes with which we identify, such as “Rösti” and “Härdöpfelstock”. There is hardly a Swiss dish without pulses. How can we ensure that pulses become an integral part of our diet?
Pulses were once much better represented in the Swiss diet than they are today. Lentils were already being cultivated in Central Europe in the Bronze Age and field beans were also among the first plants to be used agriculturally in the Alpine region. Stews with various legume seeds were once widespread and dried beans have not been out of fashion for so long. Not even a century ago, fresh runner beans for self-sufficiency were a matter of course in every front garden. Today, lentils come in the form of dal, chickpeas in hummus and beans in chilli with international cuisine. In addition to traditional recipes that have the potential to be reinterpreted, I see this change in eating habits in particular as an important growth market for pulses. It would be great if we could increasingly meet this demand with regional production in the future.
What is your favorite dish with pulses in the leading role?
From the traditional dried beans on the Bernese platter to Indian dal or snake beans from the wok, pulses are an integral part of many dishes for me.
However, I am particularly fascinated by how many functions pulses can take on on the plate. As a vegetarian source of protein, if we think of lentils, for example. As a vegetable, such as snow peas, as a condiment, such as fenugreek seeds or soy sauce fermented from soybeans. As fresh sprouts, where alfalfa or mung beans are often used. As a high-calorie spread, such as peanut butter or baked beans in English and American cuisine. Or acacia honey, which comes from the nectar of the robinia or acacia tree and is therefore also a legume. And all this is just a small selection of the many uses of this exciting plant family.
