As part of the Ebro Basin Demonstration Site, the demo partners have established a coordinated framework to evaluate the agronomic and environmental performance of the bio-based fertilizers (BBFs) produced within the project.
Within this collaboration, the Ebro River Basin Authority (CHE) provides the 1-hectare plot where the field trials are being conducted, while CAYC is responsible for all on-site activities, including base fertilization with solid products, barley sowing, crop management, and the subsequent application of liquid fertilizers. GEST supplies the BBFs to be tested (digestate, pig slurry, and ammonium sulphate), and CIRCE oversees and coordinates the overall design, implementation, and monitoring of the activities.
The field experiment consists of five different treatments: the three BBFs produced within the project (digestate, pig slurry, and ammonium sulphate), a conventional inorganic fertilizer used as a reference, and a control plot with no fertilization. Each treatment is replicated three times to ensure statistical robustness and reliable comparison of results.
The demonstration monitors a full barley growing season, with detailed measurements to assess nutrient behaviour in soil, crop performance, and potential environmental impacts on water, air, and soil. Continuous tracking of climatic conditions, particularly rainfall and temperature, is also being carried out to evaluate how weather variability may influence nutrient availability, crop development, and the mobility of nitrogen in the soil.
Since the trial is located in a Nitrate Vulnerable Zone (NVZ) heavily influenced by intensive pig farming, a key objective is to demonstrate the potential for livestock-derived by-products to be valorised as sustainable fertilizers, contributing to improved nutrient management and reduced environmental pressures in the region. Additional environmental assessments will be conducted later in the season during the application of the BBFs in liquid form, allowing for a broader evaluation of their behaviour and impacts under real field conditions.
