opinion | carbon sequestration in the soil


Covid-19 has been terrible for this world. But there’s something worse we could be facing: a full-blown climate crisis. If you want to understand what kind of damage climate change will do, as Bill Gates puts it, look at Covid-19 and spread the pain over a much longer period of time. The loss of life and economic misery caused by this pandemic would be much less compared to the damage caused by carbon emissions.

The world has not done enough to prepare for the pandemic. We can avoid the same mistake with climate change. There is no silver bullet to stopping climate change, but increasing soil organic carbon (SOC) has been recognized as one of the best, most cost-effective and environmentally friendly options for climate change adaptation and mitigation, as well as combating food insecurity, desertification and land degradation.

SOC is a complex mixture of carbon compounds consisting of decomposing plant and animal tissues, microbes (protozoa, nematodes, fungi and bacteria) and carbon associated with soil minerals. Carbon can remain stored in the soil for thousands of years or be quickly released back into the atmosphere. Climatic conditions, natural vegetation, soil conditions, and drainage all affect the amount and duration of carbon storage.

Through the process of photosynthesis, plants absorb carbon and release some of it into the atmosphere through respiration. The carbon left as plant tissue is then consumed by animals or added to the soil as waste as plants die and decompose. The primary way carbon is stored in soil is as a SOC.

The degradation of a third of the world’s soil has already released up to 78 gigatonnes of carbon into the atmosphere. Conventional farming, or highly mechanized farming with monoculture crops and extensive use of chemical fertilizers, herbicides, fungicides and nematodes to encourage crop growth, has led to the degradation of more than 30 percent of the world’s soil, according to the UN Food and Agriculture Organization.

If soil degradation and business-as-usual agricultural practices continue, more carbon is likely to be released into the atmosphere than can be stored in the soil. Carbon dioxide is the main greenhouse gas contributing to global climate change, so it needs to be sequestered.

Carbon sequestration is the long-term storage of carbon in oceans, soils, vegetation (especially forests), and geological formations. It involves the removal of carbon dioxide from the atmosphere in the form of SOC.

Regenerative agriculture or traditional farming practices help increase soil carbon. Some recommended management practices (RMP) that result in soil organic carbon sequestration are mulching, conservation tillage, agroforestry, diverse cropping systems, cover crops, and integrated nutrient management, including the use of manure, biosolids, improved grazing, and forest management.

Improved soil organic carbon is best for plant growth and increased food production: it’s a win-win for both world food security and global climate change.

We therefore see a close relationship between soil carbon storage and world food security that can neither be overemphasized nor ignored.

It is said that the carbon pool in the soil is 3.3 times the atmospheric carbon pool and 4.5 times what animals and plants can store. Also, soil has the potential to offset 5-15 percent of global fuel emissions.

There is an urgent need to transform our current land management practices and conventional agriculture into sustainable land management and regenerative organic farming practices so that our soils become fertile and healthy.

Healthy and fertile soils can store the maximum amount of carbon and contribute to climate change adaptation and mitigation. Soil scientist and World Food Prize winner (2020) Rattan Lal says carbon in soil is like water in a cup. If we drink some of it, we can refill the cup.

The author is a student at the Institute of Forestry, Pokhara Campus


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