Cost-effective urban farming with alternative water sources treated by nature-based solutions: A critical review of global practices
Niloofar Shoja Razavi, Kefeng Zhang, Veljko Prodanović
Agricultural Systems
Urban Farm DB summary
This review assessed the agronomic suitability and contaminant profiles of five alternative water sources (greywater, blackwater, groundwater, rainwater, and stormwater) for urban crop irrigation. Four nature-based solution (NBS) technologies (constructed wetlands, biofilters, green roofs, and green walls) were evaluated as pre-treatment systems, with hybrid systems demonstrating over 97% removal efficiency for contaminants. Economic viability was highly dependent on crop selection; high-value crops like tomatoes and sweet peppers irrigated with treated groundwater showed the greatest profitability, while faba beans remained unviable regardless of treatment. Policy analysis identified substantial governance gaps, including inconsistent enforcement, limited public acceptance, and minimal regulatory guidance specific to urban agricultural water reuse.