In Bangladesh, 35% of children are chronically undernourished and their diets deficient in vitamins and minerals. Homestead gardening can provide a source of fresh fruit and vegetables to enrich diets. However, land for gardening is often not very fertile and commercial mineral fertilizers are expensive and difficult to dose. Urine is a highly efficient fertilizer, but underused because of odour. Biochar is a porous material with highly adsorptive properties that can soak up urine and transform it into an odourless solid fertilizer that increases soil organic matter, biological activity and water-holding capacity. It can be produced from crop waste in soil-pit kilns at village level. BUNCH2Scale will work with farmers to scale up biochar-based organic fertilizer production to 48 villages in rural Bangladesh. Collaborating with local NGO field workers and research institutions, HKI Bangladesh will evaluate the potential of this novel method for improving soils and increasing garden production.