2025 Volume 51 Issue 2 Pages 222-231
Soil amendments using household food waste products are becoming popular approaches for enhancing urban sustainability. In Japan, the increasing number of households produces BC (bokashi compost using sealed containers for composting food waste mixed with fermentation agent) and DF (dehydrated food waste using home appliances specialized for thermal dehydration), while there are few studies testing effects of those home food-waste products as soil amendments for urban greening. In the 4-week laboratory experiment using LED lights for recreating the sunny summer temperature of Tokyo, we measured thermal and hydrologic properties of substrate samples made by adding BC vs. DF to commercial green roof substrates using organic (wood bark) vs. mineral (expanded shale) base materials respectively. We found that the addition of BC to green roof substrates using mineral base materials, and the addition of DF to green roof substrates using organic or mineral base materials increased field capacity and plant available water respectively. The 40% addition of DF to green roof substrates using organic base materials increased evaporation. The addition of DF to green roof substrates using organic or mineral base materials increased substrate temperature for the entire experimental period. Further research is needed for understanding plants’ effects on stormwater retention and cooling potential for green roof substrates mixed with household food waste products, while identifying the initial decomposition periods having high decomposition rates.
