Diversified farming benefits people and environment

Sustainable cattle farming in Meta, Colombia, shows that diversified agriculture increases milk production. Image: Juan Arrendondo.

A massive new study shows that mixing livestock and crops, integrating flower strips and trees, while carrying out water and soil conservation measures, shows positive effects all around the world - while negative effects are hard to find.

For the last four years, Laura Vang Rasmussen of the University of Copenhagen has served as the link between 58 researchers on five continents, and as lead author of a major agricultural study which gathered data from 24 research projects,

The hard work alongside her colleague Ingo Grass of the University of Hohenheim in Germany. has finally paid off. Their research article, just published in the journal Science, delivers a clear and well-founded message.

"Drop monoculture and industrial thinking and diversify the way you farm – it pays off," says Rasmussen. "Our results from this comprehensive study are surprisingly clear.

Strawberry growing in California - monoculture on the left, and diversified with wildflower strips on the right. Images: Claire Kremen.

"While we see very few negative effects from agricultural diversification, there are many significant benefits. This is particularly the case when two, three or more measures are combined. The more, the better, especially when it comes to biodiversity and food security," she explains.

The researchers see the greatest positive effects on food security, followed closely by biodiversity. Furthermore, social outcomes in the form of well-being also improved significantly.

Among the many strategies adopted, livestock diversification and soil conservation had the most positive outcomes.

Improved food security

According to Rasmussen, previous studies investigated either the socioeconomic or environmental effects of agricultural diversification. This study investigates effects across the board, with surprisingly positive results.

"Agricultural diversification has been accused of perhaps being good for biodiversity, but having a few negative aspects too – especially with regards to not being able to achieve sufficiently high yields. But what we actually see, is that there is no reduction in yield from diversified agriculture – not even when we include data from large-scale European agriculture," says Ingo Grass of the University of Hohenheim.

In fact, the figures demonstrate that in the case of small farms and farms with lots of cultivated land in the surroundings, more diversified agriculture can significantly promote food security.

"Drop monoculture and industrial thinking and diversify the way you farm – it pays off."

Laura Vang Rasmussen, University of Copenhagen

"One example is fruit trees planted in maize fields in Malawi, which can help farming families improve their food security through improved diet and nutrition. Partly because they eat the fruits themselves, and also because the trees generate extra income when their fruits are sold at market – income that provides small-scale farmers with purchasing power for other foods," says Rasmussen.

Win-win outcomes

All 58 of the study’s authors participated actively in its design to attempt a robust and credible interweaving of the many datasets spread across the world – including rubber trees in Indonesia, silvopastoral cattle farming in Colombia and winter wheat in Germany.

"The study unites many different situations from the many datasets that we used. In Malawi, we have data on food security expressed, for example, in the number of hungry months for small-scale farmers where they have been short of food.

"Such metrics are not used for, for example, large European farms, where we have yield data instead, such as winter wheat yields in Germany," explains Rasmussen, "but the point is that when we look across all datasets, our results show that applying more diversification strategies improved both biodiversity and food security, and didn’t have a negative effect on yields."

The researchers also investigated which diversification strategies result in 'pairs' of favourable “win-win” outcomes. Their data showed that strategies beneficial for biodiversity also improved food security. They also witnessed win-wins for biodiversity and people's wellbeing.

Landscape study

To investigate whether the surrounding landscape influences the effects of diversification strategies, the study also took three different types of landscapes into account: heavily cultivated areas with very little nature, an in-between 'simple' category with mixed landscapes, and areas where the landscape around farms is characterised by nature that is relatively pristine.

Until now, the thesis has been that diversified agriculture would only have a very good effect on biodiversity for in-between or simple type landscapes, which is also where the researchers recorded the greatest effects. In fact, the study shows that diversification strategies make good sense in many different contexts.

Even in landscapes with more nature, there are positive effects to be gained with regards to biodiversity.

"It's a simple message to be able to pass on to different types of farms – whether it is small farms in South America or Africa or advanced European agriculture, there are lots of positive effects to be gained by introducing these various strategies – and very little to fear. It is very positive that so many different things can be addressed, and that, in general, positive biodiversity outcomes seem to go hand in hand with wellbeing and food security," says Ingo Grass.

"This is an important achievement in bringing together some of the world’s foremost agricultural researchers to synthesise the data needed to back policy on driving the transformations that are needed in farming landscapes” says Professor Zia Mehrabi.

Professor Claire Kremen of the University of British Columbia says, “The study shines a light on real-world farming conditions in many different regions and contexts worldwide. With the clear positive outcomes of these diversification strategies it suggests that governments and businesses should invest more in incentivising farmers to adopt such strategies, which will in fact help them, while also promoting agricultural sustainability and planetary health.”

Unique study

With 58 researchers scattered around the globe, representing a total of 2,655 farms on five continents – the research project is quite unique.

"As far as I know, this has never been done on such a scale before," says Rasmussen. "Finding common indicators for these calculations, in so many different studies and diverse data, and in such a way that we were able to integrate them, has been hard work, but I think the approach may inspire future research."