Biochar (Agriculture)
Biochar (Agriculture)
Why In News:
Recently, the potential of biochar technology to address two simultaneous challenges: farm stubble burning (which causes severe air pollution in North India) and soil carbon sequestration has been in the news.
What is Biochar?
Biochar is a charcoal-like substance produced by pyrolysis of organic material (biomass such as rice straw, sugarcane bagasse, crop residue) in the absence of oxygen or with limited oxygen.
Process: Pyrolysis (thermochemical decomposition at temperatures of 300-700 degrees Celsius). The process also produces bio-oil and syngas as co-products.
Key properties: High carbon content (60-90%), porous structure, high surface area, alkaline pH - all beneficial for soil amendment.
Benefits of Biochar
Carbon sequestration: Biochar is highly resistant to decomposition; carbon remains locked in soil for centuries to millennia, making it a powerful tool for negative emissions.
Soil improvement: Increases soil water retention, nutrient availability (especially in degraded soils), and microbial activity.
Stubble burning alternative: Converts rice/wheat straw (currently burned by farmers in Punjab, Haryana) into a valuable product instead of smoke.
Reduces need for chemical fertilisers: Improves soil health naturally, reducing dependence on urea and other inorganic fertilisers.
Key Facts for Prelims
National Policy for Management of Crop Residue (NPMCR): India's policy framework for addressing stubble burning. Promotes in-situ and ex-situ management of crop residue.
Paris Agreement and LULUCF: India's NDC (Nationally Determined Contributions) includes creating an additional carbon sink of 3.5 to 4 billion tonnes of CO2 equivalent through forest and tree cover. Biochar contributes to this target under Land Use, Land Use Change and Forestry (LULUCF).