It’s time to feed the worms: agriculture as a tool for promoting biodiversity

Today, December 5, World Soil Day (WSD, World Soil Day which has only been taking place since 2012) is commemorated, in part to reflect all the practices it sustains (such as c is the motto of this year) “Living soil, protecting biodiversity”. And it’s not just the power of organic farming, also intensive (industrial, if you will) farming has its tools to protect, enhance and bring the soil to life.

We are living in a vintage age, objects of a certain age that have been reassessed over time. Furniture, styles, clothes, formats and why not customs. Today, it is fashionable (but it goes beyond something temporary), to recover elements and practices that our parents or grandparents did. It ranges from listening to a pasta record, to setting up a living room with antique furniture or in the garden at home. Like that too, the field has regained an ancient practice, the so-called cover crops or green bridges which are now called service crops and allow the use of fewer pesticides while helping to fight weeds in close quarters.

In homage to the earth in its time, Clarín Rural consulted two specialists such as Luis Wall, doctor in biochemistry and researcher at Conicet, and José Camilo Bedano, doctor in biological sciences at the Institute of Earth, Biodiversity and Environmental Sciences (ICBIA), researcher at Conicet and the research group in ecology of terrestrial ecosystems (GIEET).

We invite you first to come back to the things that were done badly or, rather, as Wall prefers, the consequences of the things that were done. “Agriculture did not consider soil biology as part of the production processThe two agree. “From this point of view, excessive tillage with physical disturbances of the soil, the monoculture of soybeans and the use of an excess of agrochemicals are three aspects which have strongly harmed the biology of the soil”, summarized Bedano.

For Wall, “for this rather extractive agriculture, the soil is a support or a provider of fertility and structure”. However, the Conicet researcher does not crush the farmers: “It was not on purpose, Today we have a knowledge which allows us to think differently, before not“.

“Tillage is like a permanent earthquake in the ground, biology leaves the tillage area and the physical structure of the soil is lost and this generates erosion problems, but also, tillage combined with chemical fertilization which means that the plants do not finish taking advantage of what is generated with the activity and ends up being the cause of gas emissions greenhouse effect, ”Wall pointed out.

Why a change is important

Now, how important is this? Because even so, soil degradation has resulted in high yields … perhaps to the detriment of the soil itself. But until when? “The broader vision that we are proposing does not only consider yield as an indicator of production processes, we also propose the importance of soil biology from two angles: that which comes from biodiversity per se, where many live. organizations. represent 25% of the planet’s biodiversity, but, on the other hand, also a functional implication of soil biology which is important because it regulates and effects ecosystem processes such as nutrient recycling, carbon uptake or structure»Explained Bedano, who has no doubts:« A soil which has a good biological relation has more productivity ».

Wall is convinced that with rotations and service cultures Industrial agriculture could converge with agroecological models. The key is “to incorporate soil biology as part of any system, so that dichotomies can be left behind, and that’s an incentive for the future, microbial diversity makes a more interconnected and resilient system“.

“So we can think of agriculture as a tool to mitigate climate change rather than a source of harmWall said. And he added: “This crop rotation had a novelty in recent years, which is to save things that were done in pre-industrial agriculture, which are cover crops now called for service, they have been recovered. to control weeds but the additional benefits are very important “.

Another interesting problem mentioned by Bedano is that when these three aspects are improved, “the biological response is strong and rapid, in the short term”.

The legacy of worms

Earthworms, for example, are one of the most important groups of “earthworkers”. Bedano cited global studies showing that Worm soils increase the yield of a wide variety of crops by 25% compared to soils without them.

“When you change the management of a system and turn it into good practice, regardless of its label, it will increase the worm biomass per hectare,” Bedano said. And he quantified: “If the quantity of worms reaches 1000 kilos / ha, and knowing that a worm can consume up to 30 times its weight per day, we can deduce that it reaches up to 30 tons of soil per hectare consumed per day. “

This results in chemical and physical improvement of the soil. “The worm effect is seen in the increase of particulate organic carbon, which in turn, what the earthworm releases is more water-stable and improves soil structure, which we call earthworm plowing, ”Bedano said.

The other group they study are the oribatidae mites which are smaller than earthworms, more difficult to see with the naked eye but they do a great job of breaking up stubble. A process that bacteria and fungi then continue. “In well-managed soil, it can support a population of 143 million oribatida mites per hectare that consume up to 300 kilograms of corn stubble per day, with the benefits that this means,” Bedano said.

“We provide microscopic evidence of how soil fauna promotes the processes that later, scaled to lot level, are used by the producer as ecosystem services, ”Bedano summed up.

“I would add that there is a need to measure biological indicators, to develop new system indicators, parameters of biological soil quality, which are more complex, but not inaccessible,” Wall said. And he concluded: “It is even an opportunity for the development of the country, by making soil health diagnostics and teaching others to do it”.