Vermicompost from Chula Zero Waste Cup and Rain Tree (Samanea Saman) Leaves

Abstract

To recycle waste including paper-cup waste and rain tree leaves, the objective of this study was to determine the appropriate ratio of paper-cup waste (Chula Zero Waste Cup) and rain tree leaves in a vermicomposting process that uses the earthworm species Eudrillus eageniae and combines cow dung and coffee grounds as bulking agents. The vermicomposting in this study was conducted for 60 days. From the analysis of physical and chemical properties, it was found that all treatments (T1 to T5) on the final vermicomposting had the values of pH, EC and C/N ratio in the range of 8.16–8.41, 1.24–1.55 dS/m and 2.36–2.71 respectively. The total organic carbon content and total organic matter content had the highest value in treatment: 4 (T4) was 33.47 ± 0.56% and 57.56 ± 0.96%, respectively, while the lowest value in treatment 3 (T3) was 32.09 ± 0.61% and 55.20 ± 1.06%, respectively. For the primary macronutrients, including total Kjeldahl nitrogen content available, phosphorus and exchangeable potassium content, the study found that the total Kjeldahl nitrogen content had the highest in treatment 4 (T4) and the lowest in treatment 1 (T1), with the value of 14.17 ± 0.46% and 12.24 ± 0.48%, respectively. Available phosphorus content had the highest in treatment 1 (T1) and the lowest in treatment 5 (T5), with the value of 1,418.08 ± 305.45 ppm and 472.69 ± 57.98 ppm, respectively. Exchangeable potassium content had the highest in treatment 1 (T1) and the lowest in treatment 3 (T3), with the value of 8,146.81 ± 739.40 ppm and 3,861.98 ± 1,024.56 ppm, respectively. In addition, the seed germination test found that the highest value in treatment 1 (T1) was 45.00 ± 10.00%, while the lowest value in treatment 2 (T2) was 31.67 ± 23.63%. In comparing these results to the compost quality standards of the Department of Agriculture (2005), we conclude that T1 to T5 can help improve the physical properties of the soil as an alternative method for waste utilization by vermicomposting.