Syed Turab Raza1,2, Jia Liang Tang1, Zulfiqar Ali3, Zhiyuan Yao1, Hamidou Bah1, Hassan Iqbal4, Xiao Ren1. 1. Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, No. 9, Section 4, Renmin Road-South, Chengdu 610041, China. 2. International College, University of Chinese Academy of Sciences, Beijing 100049, China. 3. Laboratory of Environmental Health & Wildlife, Department of Zoology, University of the Punjab, Lahore 54590, Pakistan. 4. Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 100864, China.
Abstract
There is a huge potential for nutrient recovery from organic waste materials for soil fertility restoration as well as negative environmental emission mitigation. Previous research has found vermicomposting the optimal choice for converting organic waste into beneficial organic fertilizer while reducing reactive N loss. However, a great deal of the processes of greenhouse gases (GHG) and ammonia volatilization during vermicomposting are not well-documented. A field vermicomposting experiment was conducted by deploying earthworms (Eisenia fetida) with three types of agricultural by-products-namely, cow manure (VCM), pig manure (VPM), and biochar (VBC)-and crop (maize) residues compared with traditional composting (COM) without earthworms in the Sichuan Basin, China. Results showed that vermicomposting caused a decrease in electrical conductivity (EC) and total organic carbon (TOC) while increasing total nitrogen (TN). The greatest TN increase was found with VCM. The cumulative NH3 volatilization in COM, VCM, VPM, and VBC during experimental duration was 9.00, 8.02, 15.16, and 8.91 kg N ha-1, respectively. The cumulative CO2 emissions in COM, VCM, VPM, and VBC were 2369, 2814, 3435, and 2984 (g·C·m-2), while for CH4, they were 0.36, 0.28, 4.07, and 0.19 (g·C·m-2) and, for N2O, they were 0.12, 0.06, 0.76, and 0.04 (g·N m-2), respectively. Lower emissions of N2O, CH4, and NH3 were observed in VBC. We concluded that earthworms, as ecological engineers, enhanced reactive nutrients and reduced ammonia volatilization during vermicomposting in our test system. Overall, vermicomposting is proposed as an eco-friendly, sustainable technique that helps to reduce environmental impacts and associated health risks.
There is a huge potential for nutrient recovery from n class="Chemical">pan class="Chemical">organic waste materials for sclass="Chemical">n>an class="Chemical">oil fertility restoration as well as negative environmental emission mitigation. Previous research has found vermicomposting the optimal choice for converting organic waste into beneficial organic fertilizer while reducing reactive N loss. However, a great deal of the processes of greenhouse gases (GHG) and ammonia volatilization during vermicomposting are not well-documented. A field vermicomposting experiment was conducted by deploying earthworms (Eisenia fetida) with three types of agricultural by-products-namely, cow manure (VCM), pig manure (VPM), and biochar (VBC)-and crop (maize) residues compared with traditional composting (COM) without earthworms in the Sichuan Basin, China. Results showed that vermicomposting caused a decrease in electrical conductivity (EC) and total organic carbon (TOC) while increasing total nitrogen (TN). The greatest TN increase was found with VCM. The cumulative NH3 volatilization in COM, VCM, VPM, and VBC during experimental duration was 9.00, 8.02, 15.16, and 8.91 kg N ha-1, respectively. The cumulative CO2 emissions in COM, VCM, VPM, and VBC were 2369, 2814, 3435, and 2984 (g·C·m-2), while for CH4, they were 0.36, 0.28, 4.07, and 0.19 (g·C·m-2) and, for N2O, they were 0.12, 0.06, 0.76, and 0.04 (g·N m-2), respectively. Lower emissions of N2O, CH4, and NH3 were observed in VBC. We concluded that earthworms, as ecological engineers, enhanced reactive nutrients and reduced ammonia volatilization during vermicomposting in our test system. Overall, vermicomposting is proposed as an eco-friendly, sustainable technique that helps to reduce environmental impacts and associated health risks.