Combining low-cost biochar, biogas, and cyanobacteria fertigation technologies with low-input crops for sustainable bioproducts in smart circular farming systems (CombiFarm)

The CombiFarm project develops living labs to demonstrate: (1) circular farming systems combining energy, carbon and nutrient recovery systems based on low-cost biochar, biogas, and microalgae fertigation technologies together with (2) sustainable cropping systems based on low-input crops (alfalfa, sorghum, aloe vera, aromatic crops, prickly pear cactus, salicornia, lentils, chickpea, durum wheat, pearl millet) and (3) solar-powered smart drip irrigation systems to generate (4) high-value bioproducts at local level. The project will develop and demonstrate the integrated systems in real conditions at selected pilot sites near Settat, Ait’Mhamed and Dakhla island, Morocco, as well as Mateur, Tunisia, and Ljubjana, Slovenia. Low-cost pyrolysis cookstoves of 30 L following Indian-type “Anila stove” batch Top-Lid Up-Draft design will allow combined production of biochar (soil conditioner) and heat (clean cooking solution from solid agro-industrial residues (to be deployed at pilot sites in Morocco and Tunisia). In Settat, a Chinese-type 10 m3 biogas reactor using local sustainable materials (brick walls and earth insulation) will be used. Downstream of the biogas reactor, a press filter will be installed for solid-liquid separation, which can be facilitated by biochar addition. Microalgae cultivation will take place in mixotrophic mode (microalgae operating in synergy with bacteria for bioconversion of organic matter) in different configurations: 1) on separated liquid effluent of the biogas reactor (in Settat, Morocco), 2) on aquaculture effluents (in Dakhla, Morocco), 3) on agro-industrial effluents, including olive oil processing residue and cheese whey (in Mateur, Tunisia and Ljubjana, Slovenia). Microalgae will not be harvested, but delivered to the test fields as fertigation with biostimulant effect, hence saving the costs of microalgae harvest. Furthermore, microalgae biofilms will be grown, allowing for direct harvesting as transportable biostimulants. Public access of pilot monitoring data will be ensured by linking IoT sensors to a cloud-based digital platform. The effects of biochar application as soil improver, as well as microalgae fertigation will be monitored. Additionally, the design and operation of smart solar-powered micro-irrigation systems will be optimized. The software will be delivered with the support of participating IT SMEs on a user-friendly multi-platform interface compatible with smartphones. Following an approach of user-centered design, visualization and testing of the software versions will be provided in open access at the project website. The quality and health benefits of farming products will be evaluated. The parameters of biofertilizer addition will be optimized in pot experiments prior to up-scaling in experimental fields. Following a living lab approach, local farmers and companies will be involved in the monitoring and co-development of the project through local farmer advisory boards at each pilot site, including delivery of feedstock, monitoring of the products, testing and optimization of software products, and co-creation of online lectures and training workshops to be provided to students, farmers and professionals at the end of the project. Socio-economic and environmental challenges affecting local farmers in the energy-agriculture nexus will be evaluated and good practices will be drawn, considering the effects of regional policies, barriers, and incentives. Additionally, a GIS mapping analysis will be included to evaluate local biomass availability for pyrolysis and biogas production. Based on these analyses, the exploitation potential for such an innovative farming system will be estimated. A staff exchange program will promote exchanges of students, experts and engineers for specific activities. The project involves 12 partners from 6 countries, including 5 partners from EU countries (with 1 SME), and 7 partners from the MENA region (with 2 SMEs).