Impact of combination of vermicompost and insect frass on long bean growth and productivity at urban farming

Abstract

Purpose: Urban farming is experiencing rapid growth and is believed to be a potential solution to future sustainable food production needs. In tropical regions, highly nutritious legumes are a common crop in urban farming. However, most production still highly depends on synthetic fertilizers and manure with high carbon footprints. One possible solution to this issue is the application of fertilizer. This study aimed to find an alternative to synthetic fertilizer for legumes grown in containers in urban farming setups. Method: In this study, several fertilizers were applied to the long bean (Vigna sinensis L.) grown in a container at an urban farming setup. The fertilizers used included synthetic fertilizer, manure, vermicompost, insect frass (produced by black soldier fly larvae fed on municipal wastes), and a combination of vermicompost and insect frass. The parameters observed were the long bean's growth, productivity, and yield quality. Results: The application of insect frass improves the growth medium chemical, physical, and biological characteristics. However, applying vermicompost produced better growth, productivity, and yield quality than insect frass. Combining vermicompost and insect frass with a ratio 1:1 produced higher plant (281 cm), more average pod numbers per plant (17.33), and the highest average yield per plant (273.13 gram). Conclusion: Providing vermicompost and insect frass originating from municipal waste could replace synthetic fertilizer and manure to improve the sustainability of urban farming. Combining both materials could produce a synergetic effect, further enhancing the growth and yield of long beans. Research Highlights • Insect frass applied was originated from conversion of municipal wastes. • Insect frass has more major nutrient (nitrogen, phosphorous, and potassium) than vermicompost • The growth and productivity of long bean was better when applied with single application of vermicompost than single application of insect frass • There is synergetic effect of combining insect frass and vermicompost which furtherly improved the improvement of growth and productivity • Combination of insect frass and vermicompost could replace synthetic fertilizer and manure in urban farming system.

Keywords

• Carbon footprint
• Low input farming
• Municipal waste management
• Organic fertilizer
• Sustainable