Bio-based fertilizers derived from peri-urban wastes : exploring potentialities and agro-environmental impacts in peri-urban market gardening ; Produits résiduaires organiques issus de déchets périurbains : évaluation des potentialités et impacts agro-environnementaux en maraîchage périurbain

In densely populated areas, significant amounts of organic waste are generated, presenting an opportunity for peri-urban agriculture, particularly in the context of developing market gardening (MG) driven by evolving policies and the growing demand for locally sourced food. Despite this potential, the benefits and environmental impacts related to the use of bio-based fertilizers (BBFs) derived from these waste materials in MG and related crop successions remain poorly understood. Therefore, this study adopted a multifaceted approach involving farmer interviews, field and greenhouse experiments, and long-term simulation of BBF use to comprehensively explore these aspects.Findings revealed that the Saclay plateau (SP), a peri-urban study area near Paris, is experiencing an increase in market gardening activities. The most commonly used BBFs in MG currently include green waste compost and animal manure. Additionally, there is a growing interest in biowaste compost. Under specific safety conditions, there is potential consideration for the use of human urine and food biowaste digestate. According to estimates, the BBFs already present on the SP can significantly meet the soil amendment demands for MG. However, concerning BBFs with fertilizing value, the potentially available biowaste digestate and human urine could be of great interest as they are also capable of largely fulfilling the MG requirement.Experimental investigations demonstrated that the combined use of BBFs with amendment and fertilizing value resulted in lettuce or tomato yields comparable to synthetic fertilizers (SFs) and did not pose any risks associated with heavy metal uptake or pathogen contamination. Soil assessments highlighted the ability of BBFs to maintain soil pH and potentially increase soil organic carbon and nutrient stocks over the long term.Using the calibrated STICS crop model for lettuce, simulations involving BBF use within a lettuce-wheat rotation (a common practice around SP) over a 30-year period indicated significant increases ...