Can we simultaneously decontaminate and cultivate? An urban cherry tomato story

Abstract

AbstractUrban planners are increasingly focused on integrating urban farming as a creative strategy for producing sustainable, local food in underutilized spaces, once occupied by polluting industries, in peri‐urban areas. However, before urban farming's contribution to local self‐sufficiency can be determined, it is crucial to gather quantitative data on the effectiveness of tailored strategies, including polyculture, and the suitability of different vegetables, to adequately assess the value of brownfields. This study aims to provide quantitative agronomic data on a copper‐contaminated urban garden with the dual objective of assessing its capacity for food production and mitigating the spread of soil contamination. Tomato (Solanum lycopersicum) plants were grown for one growing season in brownfield soils with different copper concentrations (up to 2000 mg kg−1), accompanied by different plant species assemblages typically used in phytoremediation (Achillea millefolium, Salix discolor, and Trifolium repens). The most successful assemblage yielded over 800 fruits per square meter with low copper concentrations (<5 mg kg−1), indicating that one square meter could satisfy the annual fresh tomato weight requirement of an average individual. Although some amendments can improve adaptability to local soils, the highest fruit‐producing assemblage consisting of S. lycopersicum, S. discolor, and T. repens also proved to be the one of the most effective for copper phytoextraction, removing over 30 g ha−1 from the contaminated soils. Overall, the data indicated that all assemblages phytostabilized copper. The quantitative results of this study provide a valuable benchmark for urban planners and researchers to implement large‐scale urban agriculture on brownfield sites.