Factory tea waste is a high lignin and phenolic compounds-containing fibrous material generated in tonnes in tea manufacturing factories. In spite of its high nitrogen content, these physical and chemical properties limit its application as an organic amendment in soil. In this study, a novel technique was developed for extracting humic substrates by recycling factory tea waste and potential of those extracted humic substrates for improving soil properties and tea productivity was evaluated under field condition. Humic substrates are organic soil amendment that is often used for enhancing chemical and biochemical properties in soil. For extracting humic substrates, factory tea waste was processed through multi-step technique combined with easily available plant biomass like aquatic weeds. The method was suitable for extracting up to 25–30 L humic substrate solution containing 25.1 ± 3.8 g L−1 active constituent, 507.3 ± 11.8 mg L−1 total nitrogen and 2.91 ± 0.07 g L−1 total potassium by recycling each kilogram factory tea waste. The extract had shown fair similarity with standard humic acids. Under field condition, extracted humic substrates lead up to 6% increase in tea productivity and improved soil chemical properties. The residue remained at the end of this process was further vermicomposted to prepare organic amendment having total nitrogen content 1.34 ± 0.07 mg g−1 with C/N ratio 10.87 ± 0.92. In this study, the addition of pond sediment produced inferior quality humic substrate and vermicompost.
International Journal of Environmental Science and Technology – Springer Journals
Published: Jun 2, 2018