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Regenerative agriculture for healthier soil: identifying methods for a virtuous interaction

With the involvement of CREAF and the University of Lleida, IRTA has launched the AgriRegenCat and AgriCarboniCat research projects to improve the health and ecosystem services of Catalonia’s agricultural soils

Green roofs, organic fertilization and reduced tillage are among the methods whose effects on soil health and biodiversity will be monitored on a network of Catalan farms growing highly representative crops

The research is aimed at understanding the microbiological processes involved in carbon sequestration and developing predictive models for a cycle that is key to reducing greenhouse gas emissions

The projects will be financed through the Government of Catalonia’s Climate Fund, which receives 50% of the revenue from a tax on motor vehicle CO2 emissions and 20% of that from a tax on facilities with an environmental impact

Throughout agriculture, soil is the primary substrate from which crops and pasture obtain nutrients. And with suitable management, agriculture can return the fertility that sustains it to the soil and, consequently, combat climate change. Regenerative agriculture seeks to do just that: restore soil health, in terms of physical structure, biodiversity and chemical composition alike, through ecological processes. The formulae for such interaction vary from one context to another. With that in mind, in Catalonia this year the Institute of Agrifood Research and Technology (IRTA) has, with the participation of the Centre for Ecological Research and Forestry Applications (CREAF) and the University of Lleida (UdL), launched AgriRegenCat and AgriCarboniCat, research projects revolving around regenerative agriculture and carbon farming respectively. The two projects are complementary and share a line of research aimed at identifying the best farming practices for boosting soil ecosystem services with different crops and in Catalonia’s climate and agricultural conditions. “With projects like these two, we’re focusing on soil, something that has been largely overlooked until now,” says Josep Usall, IRTA’s managing director. AgriRegenCat and AgriCarboniCat involve recognizing what is being done well in rural settings, with methods such as organic fertilization, tillage reduction and proper management of pruning. “The impact of those methods on agroecosystems has hardly been quantified at all,” remarks Georgina Alins, an IRTA researcher and coordinator of AgriRegenCat.

The two studies are highly cross-cutting in their scope, involving a network of Catalan farms representative of the territory’s main crops, such as wheat, rice, apples, grapes, vegetable garden produce and pasture. The methods applied will differ for each crop, and their environmental, agronomic and economic viability will be evaluated. On plots of land owned by IRTA and commercial farms alike, many of the tests carried out will build on previous research projects. “This involves the whole of IRTA; a large number of researchers will be working on this,” remarks AgriCarboniCatcoordinator Maite Martínez-Eixarch. AgriCarboniCat will be monitoring effects on carbon sequestration, while AgriRegenCat will centre on aspects such as soil’s biodiversity, fertility and capacity to withstand extreme climate events. The use of green roofs, for instance, will be analysed with a range of crops and compared to standard practices. Other methods are more specific, examples being the fungal inoculation of soil in which vegetables are grown and circular bioeconomy methods involving compost made from cow dung, with extensive crops.

CREAF’s researchers have been implementing various regenerative agriculture and livestock farming practices on Planeses Farm in Girona for the last six years, and the Centre will be bringing the experience thus acquired to both projects. “This joint work between IRTA and CREAF is an opportunity to consolidate different regenerative agriculture methods in Catalonia,” according to Javier Retana, one of the participating CREAF researchers. Such methods, which are often absent from intensive farming, are key to protecting soil. The overuse of plant protection products and excessive tilling are detrimental to soil’s biodiversity (both on its surface and below) and, therefore, its natural fertility. The benefits of regenerative agriculture do not stop at soil productivity, however. A good structure makes soil more resistant to erosion and helps it retain water, two services that are essential for ecosystems. A lack of organic matter, on the other hand, makes soil more vulnerable. “In the Mediterranean basin, torrential rain erodes the most exposed soil; tonnes of it are lost per hectare and year,” states Alins. “If it disappears, our grandchildren won’t get it back in their lifetime; it isn’t renewable on a human scale,” she warns.

Burying carbon

Carbon is a central element in the agricultural sustainability equation. Absorbed from the atmosphere during photosynthesis, it is incorporated into the soil when plants die and is released by organisms that feed on and break down dead organic matter. Agricultural management can affect that cycle, and it is hoped that the practices being studied through AgriCarboniCat will do so. “We want to increase the amount of carbon in soil, make it difficult to break down and keep it underground,” says Martínez-Eixarch. “Our aim is for that to happen as a result of both the soil’s chemical nature and microorganism diversity,” she adds. “The more microorganisms have to compete with each other, the slower the degradation of organic matter will be.” IRTA’s project is intended to generate new knowledge about the processes of interaction between crops, the microbiome and soil, to which end a campaign involving sampling and qualitative analyses is to be carried out. “We want to know which organisms are involved in carbon dynamics in different agricultural conditions in Catalonia,” explains Martínez-Eixarch.

Changes in carbon levels are very slow processes. To understand them better, AgriCarboniCat will use data compiled in the field to create indicators and test predictive models. Working with the records available, and based on physical variables (such as the fragmentation of soil aggregates) and biological variables (microbial and fungal diversity), it could be possible to measure the evolution of carbon levels, something the project is seeking to integrate into food product life cycle analyses and carbon footprint calculations. Doing so is far from irrelevant: despite the slowness of such evolution, retaining and stabilizing carbon under crop fields is crucial to reducing carbon levels in the atmosphere. It is estimated that net carbon sequestration in agricultural soils could offset 4% of annual greenhouse gas emissions. “It isn’t just a question of preparing agriculture to adapt to climate change or lessen its effects, but also of combatting it directly,” declares Martínez-Eixarch.

About the projects

AgriCarboniCat and AgriRegenCat will end in 2025, following a best farming practice transfer stage involving sectoral conferences and public awareness-raising activities. IRTA is coordinating the two projects and CREAF is taking part in both, while the University of Lleida is participating in AgriCarboniCat. In total, 2.6 million euros have been made available to carry out the projects between 2022 and 2025 (2 million euros for AgriRegenCat and 600,000 euros for AgriCarboniCat). The source of that funding, in its entirety, is the Climate Fund of the Government of Catalonia’s Ministry of Climate Action, Food and Rural Agenda.

Created under Law 16/2017, of 1 August, on climate change, as an instrument for implementing policies and carrying out action geared to mitigation and adaptation, the Climate Fund is a public fund that receives 50% of the revenue from a tax on motor vehicle CO2 emissions and 20% of that from a tax on facilities with an environmental impact. The Government of Catalonia’s Interministerial Climate Change Committee establishes priorities for action and determines how the fund is to be distributed, based on the sums available, sectoral planning and cost-effectiveness analyses. The Committee has decided that research, business, local bodies, participation and singular projects are the priority areas for investment. On that basis, and with the Climate Fund being expected to receive 50 million euros per year, a total of 36 projects have been selected for funding in the 2021-2027 period, 11 of which, including AgriRegenCat and AgriCarboniCat, fall into the category of research and innovation.