Less intensive management works better for agricultural soils, study discoveries

The less you manage the soil less intensely, the better the soil can work; For example, do not plow so often or use more grass locking mixtures as cover crops. These are the conclusions of a research team led by the Netherlands Institute of Ecology (Nio-Knaw).

Surprisingly, it applies both to conventional and organic agriculture. These important ideas to make agriculture more sustainable are published in the journal Science.

“It offers clear evidence to help farmers better manage soils,” said the research team.

Cultivate more sustainable food: what is the best way to do this? This is one of the major challenges: producing enough food without compromising the soil. After all, healthy soil has many functions – called multifunctionality – and for sustainable agriculture, these must be preserved.

“Multifunctional soil is essential for sustainable food production, because plants are drawing their food,” said researchers, Nioo and Wageningen University (Netherlands) and University Tübingen (Germany). “The soil also has essential roles in water storage, climate change management and the abolition of diseases.”

Organic vs conventional

Research on the farms of the Netherlands now shows that it is mainly the intensity of the work of the soil that determines whether the soil can maintain all its functions. Interestingly, the difference between conventional and organic agriculture has less influence. In both types of agricultural systems, many variations are found in soil work and management.

“The good news is that in conventional agriculture, which is the vast majority, there is a lot to win,” said the land environmentalist and the Nioo Wim Van Der Putten teacher. “In all farms, including organic products, it is important at this point not to cultivate the soil too intensively. For example: plowing less. The inversion of the soil during plowing is a very great disturbance in soil life.”

More than plowing less

Not only is less frequent plowing, but also more use of mixtures of herbs and plants from the bean family, such as clover, contributes to a healthy multifunctional soil. You can alternate them with growing cereals such as wheat, barley, spelled and rye.

The research team has removed samples and made measurements in more than 50 Dutch agricultural farms on clay and sandy soils. This has always been done in pairs: a farm with conventional agriculture plus a neighboring organic farm. The type of soil and other conditions were then very similar.

“In this way, we could compare them as twins,” clarifies researcher Guusje Koornef. With Sophie Van Rijssel, she directed her doctorate. Research on this subject.

Sustainable and productive

A wide range of soil properties has been measured and farmers shared the agricultural practices they applied. The organic carbon present in the soil has proven to be the best predictor of the multifunctionality of the soil, and for biological indicators, it was bacterial biomass.

Koorneef adds: “We have examined the sandy and sea clay soils. These are two very different types of soils in the Netherlands. And we see the same image in both types of soil.”

“The popular term” sustainable intensification “is contradictory with our results,” says the researcher contributing Kyle Mason-Jones, now working at the University Tübingen. “The more intensive soil management leads to a reduction in soil functions and is therefore less durable.”

Consequently, the researchers offer a new appropriate objective: “productive de-intensification. If it succeeds, you will obtain more functions from less intensively cultivated soil while retaining the yield of cultures as much as possible,” they declare.

These results are the final result of the vital soil project. The project was coordinated by Nioo and carried out with Wageningen University and Research. In addition to scientific partners, there were also several social partners involved: Eurofins-Agro, Bo Akkerbouw, Open Teelten (formerly PPO-AGV) and LTO-Noord.

Previous research using satellite imaging, in the same project, has measured the greenery of cultures in the field. This provided an estimate of production levels. He showed that the degree of greenery (the yield of cultures) did not suffer from a decrease in the intensity of management. Interestingly, organic farming could be as productive as conventional farming about 17 years after the transition.

“You do not necessarily need to have crossed the entire transition to organic farming to still have a positive impact on soil health,” explains Koorneef. “I find that it really promises that in conventional and organic farms, you can strengthen the functioning of the soil by working it less intensively.”