Recycling local organic waste in peri-urban horticulture: a casestudy in the Parisian region

In France, there is a growing demand of locally produced vegetables from urban consumers. Meanwhile, cities and their peri-urban areas are a source of organic wastes (OW) that can be recycled as amendment or fertiliser in agriculture. Our research objective was to investigate the current and prospective uses of OW by market gardeners and fruit growers in three peri-urban areas near Paris (France). We carried out semi-structured interviews with thirty market gardeners and/or fruit growers to study their current fertilisation practices and their perception regarding the potential use of diverse OW available (or probably available in the future). It turned out that the most common OW were green waste compost and horse manure, used mainly as soil amendment. Besides, most farmers used commercial organic fertilisers. Farmers’ perception regarding the potential use of biowaste compost was good, as well as for shredded green waste. However, the farmers were more reluctant to use digestate from biowaste anaerobic digestion and human urine, although they would be suitable OW for the substitution of commercial fertilisers (thanks to a high N availability). This reluctance was mainly explained by sanitary risks, legal barriers, logistic problems or fear of consumer perception. We showed that for farmers, OW had to be considered not only for their fertilisation or amendment role but also for other farming objectives such as mulching. The rates of OW application greatly varied among farmers but were higher than what was usually applied in field crops in Paris region. Based on these figures, we extrapolated the required acreage to recycle all composted organic wastes from private households at the scale of the Ile-de-France (Paris) region. This showed that market gardening and fruit production could play a significant role in recycling OW from cities at the regional level.