The latest IPCC results present an increasingly arid future for the Mediterranean, with less rain and more frequent and longer heat waves. For this reason, the United Nations has focused on solutions to be taken to combat land degradation, desertification, effectively and sustainably manage our water and take care of the land to prevent it from eroding. Under the motto ‘Land. Life. Legacy: From scarcity to prosperity’ the week of May 9 to 20, the fifteenth COP of the Convention to Combat Desertification was held, with several sessions to understand and address this crisis. What is being done about it in Spain? Why do we need healthy soil?
Uncontrolled dumping on our soils, massive logging, global nutrient imbalance and desertification These are some of the examples of the palpable effects of these crises on the land we walk on and inhabit.
Also biodiversity is related. Soils are home to 25% of the world’s diversity and more than 40% of living organisms in terrestrial ecosystems are associated with them. Thousands of organisms live in the subsoil that undergo all these changes, they take part in global life cycles that, therefore, must be managed on a global scale. Precisely, last year the FAO launched a report on the state of knowledge of soil biodiversity, in which the CREAF researcher Pilar Andrés participated as an expert.
What mechanisms do we have to promote good soil health? We present some of the solutions that we are studying at the Center for Ecological and Forestry Research (CREAF) to (re)live the planet’s soils.
1.Compost, from the brown container to nourish the soil
We eat a tangerine, remove the skin and throw it in the bucket that we have reserved for organic waste. Our life goes on and once or twice a week we will lower this fraction of the bucket to the brown container or to the door of the house. The material that we find inside is called FORM (Organic Fraction of Municipal Waste) and the Catalan Waste Agency monitors it, which will continue towards the composting plants. Over there These organic residues are decomposed through a controlled process that includes the action of microorganisms and the presence of oxygen for about 3 months. After this time, voilà! We get a good compound. “The compost obtained from FORM is a very valuable fertilizer, since it provides the soil with the three M’s it needs to be considered healthy: microorganisms, organic matter and minerals,” explains Meri Pous, from the Agència de Residus de Catalunya.
“The use of compost in the soil, insofar as it improves its quality and increases carbon sequestration, can be considered one of the solutions in the fight against climate change and soil degradation”, defends Vicenç Carabassa, a researcher at the CREAF. On the other hand, the use of compost in agriculture is also good news for dedicated people, since it greatly reduces the use of chemical fertilizers and, therefore, the expense that they entail.
2. Floors a la carte
Another restoration technique is the newly created soils, the so-called technosols. These are soils designed and planned to recover them with a specific objective, such as the reforestation of an old mine or the rehabilitation of an agricultural estate; they are in a certain way “soils à la carte”. To create these technosols, different organic materials are applied that improve the health of the soil, one of which is compost, and which are known as organic amendments.
From CREAF, “we have been studying these amendments with the Waste Agency for years, because we need to know in detail how they act on each soil, what doses are necessary to restore it, if it helps to retain carbon and improve the provision of ecosystem services in general” Carabassa explains. “In our team we have historically investigated it with sewage sludge, those that come from wastewater treatment facilities and that also serve as an amendment. We have studies of more than 25 years, which were initiated by Josep Maria Alcañiz, also a CREAF researcher and professor at the UAB, and this year we are expanding them with other organic and mineral waste in experimental plots in Garraf to restore landfill soil , quarries and other degraded land”.
Another of the materials that can be applied to the soils to be recovered is biochar or biochar, a material obtained from plant remains and biomass residues. It is applied to the soil directly, it does not burn like classic charcoal, and it improves its fertility and stimulates microbial activity.
3. Agriculture and regenerative livestock
“A country that does not have fertile land is not capable of producing food, nor deciding on its own agricultural and food policies. Recovering lost fertility makes it possible to promote food sovereignty and produce quality food for the whole of society without control by large external lobbies”, argues Marc Gràcia, coordinator of the European Polyfarming project. How we eat is clearly linked to the health of the soil where we live.
In fact, overgrazing and intensive agriculture are among the human activities that most harm the quality of the land. An alternative to these intensive practices is regenerative agriculture, focused on taking care of the soil and recovering its fertility. In this way, the food we generate will be sustainable, while improving the health status of agricultural farms. CREAF studies on Polyfarming show that the regenerative orchard absorbs up to 30 times more CO2 than the conventional one, improves the capacity to retain water by 20% and multiplies the amount of organic matter. We are facing a solution to progressively recover degraded soils and offset annual emissions from the agricultural sector.
Along the same lines, livestock must also be framed in a more responsible consumption and that is why we are involved in regenerative and/or extensive livestock projects. The Mediterranean landscape is increasingly homogeneous and this harms the state of the soil, which does not have a diversity of fauna and flora, is at greater risk of fires and loses its ability to retain water. Extensive grazing practices would be a way to reverse it, because they diversify the landscape and its needs and it would allow us to prepare for the greatest increase in temperatures that is expected in our basin. Furthermore, if you design it from a regenerative point of view, livestock farming would not only be used to recover the mosaic landscape that we need, but also to once again have fertile soil. “Through studies with the fields4ever initiative we are comparing in Menorca the biodiversity of fungi and bacteria found in soils with intensively managed grasses versus sustainable grasses to see how it influences carbon sequestration in the soil”, explains our researcher Pilar Andrés, project leader and expert in soil ecology.
4. Biodegradable donuts to reforest
From CREAF, and with a team of international experts, the effectiveness of biodegradable devices, with a circular shape reminiscent of donuts, has been proven to replant desertified or highly degraded areas. They are known by the name of cocoon and it is a method that has served to replant some 30,000 trees in the Mediterranean –Catalonia, the Valencian Community, Almería, Italy and Greece– and the Canary Islands with a high survival efficiency of the shoots. These cardboard donuts are buried in the ground filled with water and hydrate and protect the tree during the first year of life, the most sensitive, and then they decompose in the ground.
The results of recent years are very positive., since this method can become a good solution if you decide to reforest an area that has lost the quality of the soil and needs a boost. It must be taken into account, as we said at the beginning of the text, that episodes of extreme aridity will be more and more frequent and achieving good reforestation, programmed and focused on each region, will be very necessary. In Catalonia, for example, it has been tried to replant a burned area in El Bruc and it has been found that 60% of the trees have survived, twice as much as with traditional methods. Furthermore, economically, studies around the Cocoon have shown that they can be up to 4 times more profitable as well in comparison. The actions have been carried out with the support of the Cabildo de Gran Canaria and the company GESPLAN.
5.Collect mist
It seems incredible, but the last solution that we present is carried out by the mist water droplets. The LIFE Nieblas project collects the fog and dew from the humid environments of Gran Canaria with a collector and uses them to recover the forests and aquifers of 35 hectares of the island. The objective is to collect 215,000 liters of water and, once the effectiveness of this highly innovative technique has been demonstrated, implement it in the Mediterranean basin and in Portugal to combat desertification. The areas chosen to rehabilitate in Gran Canaria had been severely degraded by centuries of logging and massive extraction of water from the aquifers and a devastating fire. Once the project is finished, they will enjoy endemic species of the area and typical of the laurel forest, such as the Canarian beech and holm oak. Having good vegetation again in a degraded soil helps to maintain the structure of this soil, since the roots are firmly attached, generating a cycle of organic matter that can help them recover fertility. In addition, living soils in which diverse plants grow retain water better and help maintain optimal humidity always, even if it doesn’t rain.
However, even if we have five solutions in front of us to try to mitigate the effects of global warming on the earth, we should not trust them. Many environmental restoration studies are being carried out to recover the health of our soils, but they never return –or it takes many years– to be like a primary soil, so the key is still to take care of them and preserve their health to prevent them from “dying “.
Reference article: https://blog.creaf.cat/es/noticias/five-solutions-to-restore-the-land/
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Verónica Couto Antelo is a communication technician from CREAF, biologist and has a master’s degree in scientific communication.….
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