Grounded - How Can Agriculture Return to Balance?

Climate change has many aspects. One is the call for adaptation through the cultivation of heat- and drought-resistant plants. Looking at the cause is another. Biodynamic agriculture is particularly climate-friendly.

The sight of the maize fields stressed by drought over the last two summers really made your heart stop. Evidently maize does not seem to withstand the changes in weather. Adaptation is only one side of climate change.
The other side focuses on the causes. And that is where arable farming is at the forefront. On the one hand there is the soil with its supply of humus, on the other there is fertilizing with too much nitrogen.

Nitrogen as a stimulant

Nitrogen is a valuable nutrient for plant growth and is applied to the fields via animal fertilizers, but also via synthetic mineral fertilizers or waste materials from bio-gas plants. The plants can only absorb a certain part of it. And the rest?
One part is washed out as nitrate or escapes into the air as ammonia, another part remains in the soil and is converted. Soil microorganisms play a central role in this process. Their volume per hectare corresponds approximately to the mass of 20 cows. Most living organisms are microorganisms, e.g. bacteria and fungi. They can only be seen with a good microscope, because they are so small. But their effect is enormous.

Microorganisms are the best recyclers

Microorganisms are the best recyclers, they recycle everything, straw, leaves fallen from trees, manure and slurry, and they transform them into valuable humus. They also recycle the remaining nitrogen. Unfortunately, this is not possible without losses: a small part of the nitrogen is converted into a gas, laughing gas, nitrous oxide chemically written N2O. They are only traces when compared with the most important greenhouse gas, CO2. But N2O is much more harmful to the climate.
In spring 2019, a scientific study  on the emission of harmful greenhouse gases (carbon dioxide, nitrous oxide, methane) was published from the long-term study DOK. The results are impressive: if we calculate the total emissions of conventional agriculture at 100 %, it is only 61 % for organic agriculture and a mere 44 % for biodynamic agriculture.

There is great potential

Excessive fertilization has caused a lot of damage by humans. But there is also great potential here, as agriculture can react promptly. On the one hand, each farm keeps only as many animals as it can produce fodder on its farm, i.e. it does not buy any fodder; on the other hand, it uses less fertiliser. However, this is only possible if farmers are paid a price for their products that covers their costs. In concrete terms, this means bringing very intensive arable farming, which has been optimised almost like a factory, back to a level where human dignity, animal welfare and the environment play an important role.

Humus is stored CO2

Research has shown that this works: Thanks to moderate fertilization, natural organic farmland not only releases less nitrous oxide than conventional farmland, it also produces less nitrous oxide. It is also more climate-friendly in other respects thanks to a much more soil-friendly practice. Here we come back to humus.
Humus is stored CO2. Humus is built up by a variety of plants, in arable farming by crop rotation, as well as by the introduction of organic material such as manure, straw or green manure. And humus decomposition is slowed down by soil-friendly cultivation. This means that machines are used less deeply and one tries not to turn the soil upside down, not to stand the earth on its head (also called ploughing). The combination of these measures makes the soil richer in humus.
A poor, denatured soil can thus recapture CO2 from the air and actively act as a new reservoir. Because humus is not only a good CO2 storage. Humus makes the soil permeable to water and air, improves its structure, can hold rainwater better and thus supply the corn plagued by drought longer. A soil rich in humus is therefore a priority climate target in several respects.

Dr. Maike Krauss PhD Agriculture and Dr. Paul Mäder PhD Agriculture, Dipl. ETH Zürich, Research Institute of Organic Agriculture (FiBL)