A NEW WEAPON IN THE CARBON FIGHT
Author: Sujatha Byravan
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Atmospheric concentrations of carbon dioxide have crossed 410 parts per million and oceans are already turning acidic. Soil, if used as a sink for carbon dioxide, can help solving this issue and our transition to a ‘zero-carbon lifestyle’.
Soil, the largest terrestrial pool of carbon, contains roughly 2,344 Gt (1 Gt = 1 billion tonnes) of organic carbon (called soil organic carbon or SOC). SOC comes from plants, animals, microbes, leaves and wood, mostly found in the first metre of earth or so. Conditions and processes that determine changes to SOC content include temperature, rainfall, vegetation, soil management and land-use change.
Benefits of increasing SOC:
- Improved soil health
- Agricultural yield (increase of just 1 tonne of SOC in degraded cropland soils can increase crop yield by several kilograms per hectare)
- Food security
- Water quality
- Reduction in need for chemicals
- Better environmental health and increase in bio-diversity (carbon sequestration in soils has the potential to offset Green House Gases emissions from fossil fuels by up to 15% annually)
Approaches to increase SOC:
- Reducing soil erosion
- No-till farming
- Use of cover crops
- Nutrient management
- Applying manure and sludge
- Water harvesting and conservation
- Agroforestry practices
Soil and Agriculture
Estimates suggest that SOC in India has reduced from 60% to 30% in cultivated soils compared to undisturbed soils.
After the green revolution, the crop yield has increased manifold, but there has been a significant increase in use of chemicals like pesticides, herbicides and fertilizers. These chemicals have led to degradation to soil thus affecting the yield negatively.
Adverse affects of industrial change on agriculture:
- Loss of biodiversity
- Elimination of beneficial microbes and insects
- Reduction in yield
- Contamination of water bodies and soil
- Increasing toxicity and deaths from chemical use in farm households.
As a remedy, following sustainable agricultural practices that are consistent with ecological practices may be followed:
- Natural farming (also called do-nothing farming)
- Organic farming
Many farmers in India have improved incomes and soil quality after adopting these practices. These farmers can be helpful in the related research and formulation of policy.
A number of rainfed farmers are organic by default as they do not have capital to invest in chemicals. The produce of such farmers may be used in addition to encourage new farmers to adopt organic practices.
Work needs to be done at the grass root level and especially for the farmers with smaller land holdings.
Not paying attention to the successes of our own farmers has partly contributed to the agrarian crisis the country now faces.
The amount of quality food produced in the country must match the pace of population increase and producing quality food is going to be a challenge with the weather conditions deteriorating rapidly.
Steps that must be taken:
- Steps like ‘soil health card scheme’ must be promoted aimed at measuring the heath of the soil.
- Revision of fertilizer subsidy and policy support of organic farming and other natural alternatives. The Parliamentary Standing Committee on Agriculture in its 2016 report recommended the same.
- Implementation of carbon sequestering at policy level.