Understanding the Carbon Nexus: The Role of Vermicomposting in Sustainable Agriculture
Across India, a combination of farming practices having adverse environmental effects is causing a detrimental impact on soil, water, and air quality.
Additionally, these practices contribute to the emission of greenhouse gases, further escalating the long-term challenges faced by farmers and risking their livelihoods. Among the practices leading to these issues are crop burning and the widespread use of synthetic fertilizers. In 2019, India held the position of being the second-largest global producer and consumer of chemical fertilizers. By the year 2020–21, the consumption of chemical fertilizers (excluding single super phosphate) had reached 62.98 million tonnes, with a substantial growth of over 82.5% since 2000–01. Urea constitutes over 50% of the chemical fertilizers utilized in India. From the fiscal year 2000–01 to 2020–21, there was an 83% increase in the consumption of urea.
Additionally, per hectare, fertilizer consumption for 2020–21 stands at 161 kg, with a growth of 75 per cent since 2000–01. According to the International Panel on Climate Change (IPCC), around 12% of anthropogenic greenhouse gas (GHG) emissions are attributed to agricultural production which can escalate to 24%. Furthermore, the production of synthetic nitrogen fertilizers alone is responsible for about 2% of the world’s total energy consumption. The primary GHG emissions in agriculture are nitrous oxide (N2O), methane (CH4), and CO2, often accompanied by substantial releases of ammonia (NH3). It is approximated that agriculture contributes to over 80% of anthropogenic N2O emissions and 70% of anthropogenic NH3 emissions. These emissions predominantly stem from the application of livestock manure and inorganic fertilizer. Additionally, agriculture is responsible for approximately 40% of anthropogenic CH4 emissions, primarily originating from enteric fermentation.
Organic farming operates as a system that intentionally avoids or significantly limits the use of synthetic fertilizers, pesticides, growth regulators, and additives in livestock feed. The fundamental features of this approach involve several aspects.
Firstly, maintaining the enduring fertility of soils through the preserving organic matter levels. Secondly, encouraging the biological activity of soil, using judicious mechanical interventions, achieving nitrogen self-sufficiency via legumes and biological nitrogen fixation, ensuring efficient recycling of organic materials such as crop residues, livestock wastes, and weed control. In the pursuit of sustainable and eco-friendly agricultural practices, vermiculture and vermicomposting have emerged as valuable tools. It has proven effective in processing a variety of wastes, including cow dung, sewage sludge, urban debris, fish pond waste, paper remnants, textile mill sludge, by-products from the guar gum and sugar industries, residues from distilleries, waste from the leather industry, and remnants from the beverage industry.
This process results in nutrient-rich manure. Effective waste management strategies involve the handling of municipal solid waste (MSW), leaf debris, and the separation of bio-waste at its source. Subsequent treatment using vermicomposting proves to be among the most sustainable approaches for improving the physicochemical properties of the soil. Vermicomposting not only contribute to waste management but also play a crucial role in the carbon nexus.
The carbon nexus in sustainable agriculture refers to the interconnected processes that involve carbon sequestration, soil health improvement, and sustainable food production. Earthworms, particularly species like Eisenia fetida (commonly known as red wigglers), break down organic waste into stable organic matter, preventing the release of CO2 into the atmosphere. This process not only mitigates climate change by reducing GHG emissions but also enhances soil organic carbon (SOC) levels. Presence of organic matter improves soil structure, promoting better water retention, aeration, and nutrient availability. This, in turn, leads to improved nutrient cycling and overall soil fertility.
Moreover, earthworms in vermi-compost enhances microbial activity, fostering a healthy soil ecosystem. It also aids in biological nitrogen fixation, further enhancing the soil’s nitrogen content creating an optimal environment for plant growth. The enhanced soil structure allows for better root penetration and nutrient absorption. This reduces the dependency on synthetic fertilizers, aligning with the principles of sustainable agriculture. Vermicomposting aligns with the concept of a circular economy by converting organic waste into a valuable resource. It helps in reducing GHG emission by diverting organic waste from landfills, where it would generate CH4.
By incorporating vermicomposting into carbon credit programs, farmers can generate credits based on the carbon sequestration achieved through their sustainable practices. This creates a financial incentive, offering a dual benefit of waste management and carbon offsetting. Farmers who adopt such practices have the opportunity to seek financial support and subsidies for establishing vermi-compost units through various government initiatives. To maximize the impact of vermicomposting in carbon market, it is crucial to educate farmers and stakeholders through proper training programs and awareness campaigns.
Moreover, accurate measurement and certification of carbon sequestration also plays an important role in carbon markets. Collaborative efforts of agricultural scientists, environmental organizations, and certification bodies in establishing standardized protocols for measuring the carbon content would give a proper direction in the carbon credit programs. On the other hand, to elevate the scale of vermicomposting operations, challenges like scalability, quality control, and logistics must be effectively tackled.
The successful establishment of larger-scale vermicomposting facilities coupled with the continuous assurance of consistent compost quality is essential for attracting carbon market participants and ensuring the success of carbon marketing initiatives. Hence, in the pursuit of sustainable and eco-friendly agricultural practices the role of vermicompost becomes more pronounced in building a resilient and sustainable future for our planet.