Economic valuation of the nitrogen content of urban organic residue by the agricultural sector

- Recycling by agricultural spreading is relevant for urban organic waste disposal.
- Organic residues are valuable sources of nitrogen for agriculture.
- Benefits originate from the substitution of mineral to organic fertilization.
- Valuation ranges from €1.5 to 7 per tonne of raw matter in the Ile-de-France region.
- Long-term effect of organic matter spreading results in abatement of N2O emission.

Urban organic residues (UOR), often perceived as environmental problems, could be valuable for the environment and agriculture. Spreading of UOR on agricultural lands functions as a disposal solution as well as a source of organic nitrogen, thereby enabling cropping systems to decrease mineral fertilization. The study shows the beneficial effect of two types of UOR on crop yields and the abatement of greenhouse gases. It culminates in an estimate of the economic shadow value of UOR, according to its nitrogen content, while accounting for various farm system characteristics and UOR availability. It is conducted for the densely populated Ile-de-France region, which has large amounts of UOR and agricultural acreage. Per tonne valuation of raw UOR for farming system use ranges from €1.5 to €7. Mineral fertilizer demand decreases by 18% in the case of optimal UOR sharing between regional farming systems, which leads to an 8.7% reduction in agricultural N2O emissions. Moreover, the per hectare gross marginal output increases by €39 for the region's utilized agricultural area. We use an agricultural supply model, a crop model, and a tool for estimating changes in soil organic matter. The method can be easily extended to other regions of the European Union.