Researchers have studied 179 agricultural areas: Ideally, more than half of agriculture should be organic.

Økologisk Nu
Researchers have studied 179 agricultural areas: Ideally, more than half of agriculture should be organic.

In 2020, 9.1% of the EU's agricultural land was organic, and the goal is to reach 25% by 2030. It may sound ambitious, but the target is set too low when looking at the results of a new EU-funded research project. They show that the best balance between environmental considerations and yields is achieved when at least half of the farmland is organic. At the same time, the researchers found that high yields do not necessarily come at the cost of soil life and functions; higher yields on both organic and conventional fields did not necessarily result in lower biodiversity. Lead author Laura García-Velázquez, a researcher at the IMEM environmental institute at the University of Alicante, states in a press release that the results demonstrate that "diverse and well-functioning soils are not incompatible with high yields." Furthermore, she points out that "implementing organic methods on at least 50% of the farmland could be crucial for ensuring the long-term sustainability of our food systems." Areas in Eight Countries To assess how to achieve the best balance between soil biodiversity, multifunctionality, and high yields, the researchers examined 179 agricultural fields—primarily cereal crops—in eight countries across Europe, Africa, Asia, and South America. They measured six groups of soil organisms—from fungi and bacteria to springtails and nematodes—as well as 21 soil functions such as carbon storage, enzyme activity, and water absorption capacity. Yield data were obtained directly from farmers via questionnaires. Unsurprisingly, organic yields were lower than conventional ones; however, organic soils generally performed better in terms of biodiversity and multifunctionality. Using these data, the researchers ran 10,000 different landscape scenarios, and in the 100 scenarios with the best balance between environmental benefits and yields, organic farming accounted for an average of 52.2% of the fields—more than double the EU target. Even if only focusing on yield and disregarding other parameters, the optimal mix was about 39% organic, still well above the EU goal of 25%. "This target may not be sufficient and should be more ambitious if the sustainability of the food system is to be secured and global biodiversity goals are to be met," the researchers write about the EU's ambitions in the press release. A Conservative Estimate Santiago Soliveres Codina, a co-author and researcher at the University of Alicante, assesses in a detailed email to Organic News that the difference between organic and conventional cultivation's impact on soil biodiversity and functions is likely greater than the study indicates. Most of the fields studied used methods typically associated with organic farming. A full 93% had received organic fertilizer within the past five years, and the same percentage practiced crop rotation—regardless of whether they were organic or conventional. Asked whether this means the conventional fields in the study are more environmentally friendly than average, and thus the difference between them and organic fields is smaller in the study than in reality, Santiago Soliveres Codina confirms: "Yes, our calculations are somewhat conservative. Organic fertilizer is known to increase soil biodiversity and improve organic matter content, and crop rotation is widely recognized as a sustainable practice. Conventional fields relying solely on chemical inputs and monocultures would likely show much lower biodiversity and soil functions," he writes. The study does not examine ecotoxicity or pesticide contamination of drinking water, which Santiago Soliveres Codina says are being investigated further in a follow-up study. Start with the Worst Soil The benefit of conversion primarily depends on how degraded or exhausted the soil already is. On lightly degraded soils, organic farming mainly increased the number of soil organisms. On moderately to severely degraded soils, this effect disappeared, but soil functions were more significantly improved. The researchers recommend prioritizing conversion on weakened soils, as these typically also have lower yields. "From the perspective of farmers and society, it would reduce economic risk and increase environmental benefits to focus on converting these areas to organic," they state. Another important parameter is how the landscapes are arranged, explains Santiago Soliveres Codina. "It appears that smaller farms, preferably surrounded by hedgerows or flower strips, are best. Large, homogeneous farms tend to offer fewer habitats in the landscape and are more vulnerable to pests." The study also identified both conventional and organic farms that excelled in all three parameters: yields, soil biodiversity, and multifunctionality. "The next step is to understand what these farmers do to achieve high yields while maintaining healthy soil. They may choose other regenerative practices, such as reduced tillage, organic soil amendments, or maintaining permanent cover crops, or cultivating varieties adapted to local conditions," he says in the press release. The researchers also remind that the UN's Sustainable Development Goals aim to reduce water and soil pollution and decrease pesticide use, and for these reasons alone, organic methods should be promoted. Studied Wheat Fields in Denmark Denmark is one of the eight countries examined, and wheat fields were included. The Technical University of Denmark is among the 22 institutions involved in the study. The study is observational. The fields were selected to cover specific combinations of farming practices and soil degradation levels and are not randomly distributed. Soil samples were taken once between June and November 2022. For Cameroon, Thailand, and Argentina, data on soil fauna were missing, so the biodiversity index there is based solely on microorganisms. The study was published in the journal Nature Sustainability. The article was produced as part of the project "Robust Organic Crop Production – From Inspiration to Implementation," supported by the Plant Levy Fund.

In 2020, 9.1 percent of the EU's agricultural land was organic, and the goal is to reach 25 percent by 2030.

It may sound ambitious, but the target is set too low when looking at the results from a new EU-funded research project. They show that the best balance between environmental considerations and yields is achieved when at least half of the agricultural landscape is organic.

At the same time, the researchers found that high yields do not necessarily come at the cost of soil life and functions; higher yields on both organic and conventional fields did not necessarily mean lower biodiversity.

Lead author Laura García-Velázquez, a researcher at the IMEM environmental institute at the University of Alicante, states in a press release that the results show that "diverse and well-functioning soils are not incompatible with high yields".

She also points out that "implementing organic methods on at least 50 percent of the farmland can be crucial to ensuring the long-term sustainability of our food systems".

Areas in Eight Countries

To assess how to achieve the best balance between soil biodiversity, multifunctionality, and high yields, the researchers examined 179 agricultural areas—primarily cereal cultivation—in eight countries across Europe, Africa, Asia, and South America.

They measured six groups of organisms in the soil—from fungi and bacteria to springtails and nematodes—as well as 21 soil functions such as carbon storage, enzyme activity, and water absorption capacity. The yield data were obtained directly from farmers via questionnaires.

Unsurprisingly, organic yields were lower than conventional ones—but overall, organic soils performed better in terms of biodiversity and multifunctionality.

With these data, the researchers ran 10,000 different landscape scenarios, and in the 100 scenarios with the best balance between environmental benefit and yield, organic farming accounted for an average of 52.2 percent of the fields—more than double the EU's target.

Even if one only considers yield and ignores all other parameters, the optimal mix is about 39 percent organic—still well above the EU's goal of 25 percent.

"This target may not be enough and should be more ambitious if the sustainability of the food system is to be secured and global biodiversity goals are to be met," the researchers write about the EU's ambition in the press release.

A Conservative Estimate

Santiago Soliveres Codina, a co-author and researcher at the University of Alicante, assesses in a detailed email to Organic Today that the difference in how organic and conventional farming affect soil biodiversity and functions is probably greater than the study indicates.

Most of the fields studied used methods typically associated with organic farming. As many as 93 percent had received organic fertilizer within the past five years, and equally many practiced crop rotation—regardless of whether they were organic or conventional.

Asked whether this means that the conventional fields in the study are more gentle than average, and that the difference to organic farming is therefore smaller in the study than in reality, Santiago Soliveres Codina confirms:

"Yes, our calculations are rather conservative. Organic fertilizer is known to increase soil biodiversity and improve soil organic matter, and crop rotation is widely recognized as a sustainable practice. Conventional fields relying solely on chemical inputs and monocultures would likely show a much lower level of soil biodiversity and functions," he writes.

The study does not examine ecotoxicity or pesticide contamination of drinking water. According to Santiago Soliveres Codina, this is something the researchers are now investigating further in a follow-up study.

Start with the Worst Soil

The benefit of conversion primarily depends on how degraded or exhausted the soil already is.

On lightly degraded soil, organic farming especially increased the number of organisms in the soil. On moderately to severely degraded soil, this effect disappeared, but the soil functions were more significantly improved.

Therefore, the researchers recommend prioritizing conversion on weakened soils, as these generally also have lower yields.

"From the perspective of farmers and society, it would reduce economic risk and increase environmental benefits to prioritize conversion to organic farming in these areas," they write.

Another important parameter is how the landscapes are arranged, explains Santiago Soliveres Codina.

"It appears that smaller farms, preferably surrounded by hedgerows or flower strips, are best. Generally, very large and homogeneous farms offer fewer habitats in the landscape and are more vulnerable to potential pests."

The study also found both conventional and organic farms that excelled in all three parameters: yields, soil biodiversity, and multifunctionality.

"The next step is to understand what these farmers do to achieve high yields while maintaining healthy soil. They may choose other regenerative practices, such as reduced tillage, use of organic soil amendments, or more permanent cover crops, or cultivate varieties adapted to local conditions," he says in the press release.

He also reminds that the UN's sustainable development goals aim to reduce water and soil pollution and decrease pesticide use, and for these reasons alone, organic methods should be promoted.

Studied Wheat Fields in Denmark

Denmark is one of the eight countries examined, and wheat fields were included. The Technical University of Denmark is among the 22 institutions involved in the study.

The study is observational. The fields were selected to cover specific combinations of farming systems and soil degradation, and they are not randomly distributed.

Soil samples were taken once between June and November 2022. For Cameroon, Thailand, and Argentina, data on soil fauna were missing, so the biodiversity index here is based solely on microorganisms.

The study was published in the journal Nature Sustainability.

The article was written as part of the project 'Robust Organic Crop Production – From Inspiration to Implementation' with support from the Plant Taxation Fund.