Biochar and biosolids increase tree growth and improve soil quality for urban landscapes.

Urban soil quality is often degraded and a challenging substrate for trees. This study was conducted to assess the impacts of biochar (BC), biosolids (BS), wood chips (WC), compost (COM), aerated compost tea (ACT), and a nitrogen plus potassium fertilizer (NK) for improving three typical urban soils and tree sapling growth. Across the three soil types, the most significant changes in soil properties were observed with BS and BC.