New Life for Biowaste as a sustainable Soil Improver

• The FENIX project, funded by the European Commission’s Horizon Europe program, will contribute to the recovery of abandoned poor soils for agriculture. It aims at improving EU’s soil quality and water retention capacity, while contributing to climate change mitigation and ensuring an independent energy supply and sustainable bio-waste management.

• The Edaphology and Agricultural Chemistry department of the “Universidad de Granada” (UGR) leads this initiative with 8 other partners from 4 different European countries.

Kick Off Meeting

Granada, June 7, 2023 - Last Wednesday 7th of June, the FENIX project was launched, coordinated by Universidad de Granada, and consisting of 9 partners with high competence in the thematic. The project aims to optimize a blend of biochar and digestate specifically designed to improve soil properties of poor agricultural soils. Over the next four years, researchers will investigate the ideal process conditions and product formulation to produce an optimised soil improver for different soil types and demonstrate the agricultural and economic benefits of such a soil product.

With a share of 34 %, bio-waste is the largest single component of municipal waste in the EU. To meet the EU target to recycle 65 % of municipal residues by 2035 its reconversion will be key. Exploiting bio-waste can make a significant contribution to establish a more circular economy by providing valuable resources such as soil-enhancing materials, fertilizers, and renewable energy in the form of biogas.

Biochar is a pure and carbon-rich type of charcoal derived from biomass like bio-waste. It plays a crucial role in soil regeneration by enhancing soil water-holding capacity, nutrient adsorption and carbon storage. Biochar can also stimulate soil microbial activity and diversity. Despite its multiple benefits, biochar faces barriers to become a widespread soil improver due to a lack of understanding and evidence of its agronomic benefits and economic returns.

Biogas from anaerobic digestion (AD) is a renewable energy source. Yet the cost of disposal of its effluents (digestates) reduces profitability and uptake of new AD projects, even though the digestate is rich in nutrients and can be used as a biofertilizer.

Recent research suggests that the combination of digestate and biochar creates a soil conditioner that exhibits enhanced fertility, improved stability, and outstanding soil regeneration capabilities including the potential to act as a carbon sink on agricultural lands. Additionally, biochar could be a powerful additive to enhance microbiological activity in AD plants.

Inspired by this recent research, the FENIX project will look for the best biochar and AD digestate mixture for different soil types. FENIX will demonstrate the agronomic and economic returns of its soil improver in field tests in three different countries in Western and Southern Europe. The project will also involve collaboration with partners who represent the entire value chain of the project and includes entrepreneurs who are prepared to implement the challenging outcomes.

Successful completion of the FENIX project will contribute to the recovery of abandoned poor soils, improve the EU’s soil health and water retention capacity, mitigate climate change, secure an independent energy supply, and ensure sustainable bio-waste management.

As part of the Horizon Europe funding program by the European Commission, the FENIX project consortium, led by Universidad de Granada (UGR) in Spain, consists of 9 partners from 4 different European countries. Universidad de Granada (UGR, Spain) will oversee all the work that is conducted during FENIX, maintain responsibility for the timely completion of the project tasks and also conduct the soil characterization and field testing in the south of Spain; TerraWatt (TW, France) will be the responsible for biochar production through pyrolysis and AD digestate mixture supply; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD, France) will prepare and select the best biochar for soil improvement for laboratory tests; Danmarks Tekniske Universitet (DTU, Denmark) will provide support in optimizing biochar as a bio-based material to enhance bio-methanation, soil properties and fertility; Institut National de Recherche pour l‘Agriculture, l'Alimentation et l'Environnement (INRAE, France) and its subsidiary INRAE Transfert (IT, France) will measure gaseous emissions and use validated soil and soil-crop models to simulate the environmental and agronomic long-term effects of the soil improver; Ellinikos Georgikos Organismos - Dimitra (ELGO, Greece) will test and select the best mixtures of biochar and digestate for improving soil quality; Eurofins Agroscience Services Regulatory France (EAS, France) will be involved in ensuring regulatory compliance and labelling strategies and; the technology transfer consultancy Inveniam Group (INV, Spain) will support the business strategy, impact monitoring and results dissemination.


UGR, Granada. Av. de Fuente Nueva, s/n, 18071 Granada


By: Júlia Gómez & Miriam Romero
Julio 2023