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Organic and regenerative agriculture:
a contradiction?

Regenerative agriculture is increasingly potrayed in the media as a seemingly new form of agriculture. The amazingly simple solutions and quick successes that are often proclaimed in this context are worth a closer look. A first Stock-taking from the perspective of organic farming. 

Werner Vogt-Kaute, Naturland e. V.

SERVICE & EXPERTISE

The approaches to the concrete implementation of regenerative agriculture are often very different. However, a common goal is always the build-up of organic matter (humus). Besides the term regenerative, the terms restorative or syntropic are also used and there is an overlap with permaculture. Regenerative generally means to restore something, so here above all: to rebuild the soil, mainly by increasing the humus content. It is an important concern, especially in times of climate change. 


Building up organic matter in organic farming today

The goal of building up humus is already well achieved in organic farming. In several comparative studies, the build-up of humus on organic farms has been well demonstrated in comparison to conventional farming. It is true that the organic standards – especially legal minimum standard according to the EU and the USA - also allow farming without humus build-up. In organic farming, for example, there are also farms with highly humus-consuming root crops that do not cultivate forge legumes as main crop. Some of these farms rely on intensive compost management and are thus able to maintain humus content. Although in such cases it would be helpful to specify the situation, overall, organic farming is in a very good position in terms of humus build-up.

Building up humus and ensuring long term soil fertility is a fundamental element of organic farming (Naturland).

What distinguishes Regenerative from organic agriculture?

Some "regenerative authors" proclaim that organic farming differs from conventional farming only in the exchange of chemical fertilisers for organic ones. Full stop. Conclusion. Regenerative agriculture, on the other hand, deals with the interrelationships. However, this view completely ignores the fact that the core of organic farming is a holistic approach, i.e. the whole system is always considered. Such a distinction may therefore be effective for advertising, but in reality it makes little sense.

However an interesting difference between organic and regenerative agriculture is that conventional farmers can also practise regenerative agriculture. But can the latter really implement its central concerns? Does it really make sense to add fungi to the plant and the soil with compost tea and then kill them again with a fungicide? Does it make sense to promote symbiosis with mycorrhizal fungi, which is important for soil development, and then break it up again with mineral N fertilizer? It is not "irrelevant for the overall system whether the farms are conventional or organic", as some actors in regenerative agriculture claim. Where are the "connections" when insecticides and fungicides are used? Critical voices therefore even see regenerative agriculture as an approach to "greenwashing" conventional systems.

Grazing cows play an important role in regenerative agriculture (pixabay.com-HOerwin56).

Cows at the Centre of Regenerative Agriculture

Regenerative agriculture is propagated worldwide. Internationally, the importance of animals (animal welfare) and fairness (to farmers and workers) are as important as regenerative soil management. Most pioneers of regenerative agriculture even put cows at the centre of the system. The cow's reputation as a climate killer can be well refuted by the humus-building effect of farming with cows. Grazing often takes the form of “mob grazing”, a form of portion grazing. Although there is no scientific evidence to date that this form of grazing leads to more humus build-up, it is clear that any type of grazing is superior to pure cutting systems in terms of humus build-up.

No-till systems

One of the most important elements in the international discussion on regenerative agriculture is the no-till system. This involves, for example, turning over a rye stand at the end of flowering and sowing soybeans with a no-till system without further tillage; a fascinating approach. However, this system can only work if there is sufficient heat and water across several rotation members. If this is lacking, only cows can make the system work again, e.g. by grazing intercrops. This is demonstrated by many pioneers of regenerative agriculture. The complete abandonment of tillage over a longer period is not feasible in organic farming in view of the weed problem on many sites. So here, too, different system considerations collide. Nevertheless, it is clear that completely dispensing with tillage, or even restricting it to a very shallow variant, can make a contribution to humus build-up, if this is the measure of all things. However, the extent is disputed among scientists. While some researchers have only found a redistribution of humus From bottom to top with the same total amount, an international group of researchers found more roots on no-till farms compared to normal conventional farms. However, root mass was even higher on organic farms. Roots are the most important source for building up humus.

How can more humus be built up in the soil?

The possibilities for building up humus in the soil are scientifically long and well researched. They range from cultivating legumes as the main crop (preferably with perennial clover-grass), to growing species-rich catch crops, under sowing, grassland sowing, perennial cereals, agroforestry, less intensive tillage and adding organic fertilisers, especially manure and compost. According to scientific findings, even with perennial clover grass, a maximum of about 1,000 kg C per hectare and per year can be made available for humus formation under optimal conditions, and about 100-250 kg C with catch crops and undersown crops. However, it is repeatedly claimed that regenerative agriculture builds up at least 3,000 kg C per hectare and per year. This would correspond to about 0.1 % more humus in the soil per year and would thus exceed previous humus research: Nitrogen is also necessary for humus build-up. With a typical C:N ratio of 10:1 in the soil, 300 kg N per year would be necessary for 3,000 kg C. However, this nitrogen would then have to be added exclusively to the soil.

Incooperating green manure into the soil can help to build up humus (W. Vogt-Kaute)

However, this nitrogen would then have to be available exclusively for humus formation and would thus be missing for the nutrition of the plants. Their needs would therefore be additionally covered - or they would have to pay the price with weak growth and yield. This aspect can also help to keep the realities in view. Yes, the search for methods that build up more humus is currently very important. However, scientifically recognised relationships should not be ignored.  

The role of fertiliser in humus formation

In the area of fertilisation, the approaches taken in regenerative methods range from complete self-sufficiency of the site to the use of very large amounts of purchased fertiliser. The basis for the purchase of fertilisers is often the Kinsey soil analysis, which is based on the work of the American researchers Bear and Albrecht from the 1930s and 1940s. The aim is to have the main nutrients calcium, magnesium, potassium and sodium in an ideal ratio in the soil. Fertilisation should establish this ideal ratio. In the USA, many research projects have dealt with this approach since the 1930s. So far, however, it has not been experimentally proven that under normal soil conditions a significant increase in yield is possible by balancing the nutrient ratios. Only in the case of extreme magnesium surpluses did antagonism to calcium and potassium come into play in nutrient uptake. The researchers ignored possible effects on plant health and soil parameters. However, these factors should be coupled with yield.

Soil type must always be considered in fertiliser and nutrient application. Calcium has the best effect on the soil structure, magnesium also plays an important role depending on the soil type. An excess of soluble potassium and especially sodium has a negative effect on soil structure. Yield-limiting factors in the trials were always an undersupply of nutrients. In organic farming, nitrogen is often also a yield limiting factor. Soil compaction can also lead to lower yields.

Important fungi and other specialized microorganisms can be spread through compost (Naturland).

What are the advantages of compost and compost tea?

While the use of bacteria does not play a role internationally, compost and compost tea are a big issue. A lack of bacteria is not to be expected in the soil - unless it is completely overgrown soil. If microbes are given food, they multiply at breakneck speed. If there is too much food, i.e. easily convertible organic material, and at the same time too little air, climate-damaging nitrous oxide can form. An exciting question, however, is whether there are enough fungi in the soil. Fungi are often specialists and tend to occur in acidic soils, e.g. in forests. More fungi and other specialised microorganisms are spread through compost. This should also be achieved through compost tea. However, there is no information yet on whether this happens to any significant extent and whether they survive or continue to multiply in the soil after application. There is evidence of a positive effect of compost in relation to various plant diseases; However, further research is needed on which type of compost tea or which extracts can also be expected to have a positive effect on which pathogens. An effect against weeds is not to be expected.  

Conclusion: Regenerative agriculture in organic farming

Many of the recommendations for regenerative agriculture are not new and have been implemented in organic farming for a long time: Examples include the strong emphasis on species-rich catch crops and mixed crops, and the high value placed on humus supply, soil life and microorganisms. Organic farming has also long recognised the importance of a more intensive approach to nutrient supply. Other suggestions or other forms of cultivation are unfamiliar at first, but can give organic farming systems impulses for further development. Many regenerative impulses are very welcome - as long as they stay grounded. 

This text is a translation. No guarantee can be given for the correctness.

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Author

Werner Vogt-Kaute
Naturland e.V.
Project management & on-farm research