Soil health

In news: In 2014, the United Nations Food and Agricultural Organization (FAO) declared December 5 as ‘World Soil Day’.

• The day was chosen as it coincides with the birthday of Thailand’s king, HM King Bhumibol Adulyadej, who led the programme and made it happen.
• It aims to draw people’s attention to the importance of healthy soil for the environment and for life.

Importance of soil:

• Provides plants nutrition to grow and foothold for their roots.
• It filters rainwater, recharges groundwater, regulates the discharge of excess rainwater, preventing flooding and it can store large amounts of organic carbon.
• Soil can help regulate emissions of carbon dioxide and other greenhouse gases.
• We build with soil — and on it — from mud brick houses to buildings, highways and more.
• It is a habitat for billions of organisms (including microorganisms) and about 25 per cent of the planet’s biodiversity.
• The soil microbes help break down organic matter and extract vital nutrients plants can use.
• Soil’s capacity to hold water varies according to the soil type (clay holds more water than sandy soil) and organic matter content.
• Each one per cent increase in soil organic matter helps the soil hold 20,000 gallons more water per acre.
• Healthy soils are the foundation of the food system.
• It is estimated that 95 per cent of our food is directly or indirectly produced on our soils.
• A healthy soil helps sustain life — plants, insects and microorganisms; withstand climate events like droughts, floods and erosion; and provide other ecosystem services.
• The microorganisms and larger organisms turn minerals into plant nutrients, which improve crop production.
• Healthy soil can help mitigate climate change by increasing its carbon content – soil removes about 25 per cent of global fossil fuel emissions from the atmosphere each year.
• Healthy soil has the right chemical composition of macro- and micro-nutrients such as nitrogen, phosphorus, potassium, calcium, magnesium, sulphur, iron, manganese and others, which plants get from the soil.
• Healthy soils store carbon and other greenhouse gases in soil organic matter (SOM).
• Globally, 10-14 per cent of total carbon emissions come from the intensive agricultural production system.
• Soil management is an essential element of regenerative agriculture, which helps regeneration.

Intensive agriculture:

• It includes promotion of monocropping, regular and over-tillage and use of chemicals.
• Chemical fertilisers and pesticides reduce beneficial soil organisms, which are necessary for soil health, making it less productive, reducing its water retention capacity and making it more susceptible to erosion, according to estimates.
• A third of the world’s soils are degraded.
• In India, around 29.7 per cent land is degraded, according to the ISRO Atlas published in 2021.
• Soil erosion and land degradation pose a major threat to global food security and to the achievement of the United Nations-mandated Sustainable Development Goals, compromising the well-being of at least 3.2 billion people around the world.
• The loss of a few inches of topsoil has the potential to lower crop yields by 50 per cent and it can take hundreds of years to rebuild the soil.

Soil carbon sequestration:

• Soil carbon sequestration is a process by which carbon dioxide is removed from the atmosphere and stored in soil, through processes like photosynthesis or the conversion of CO2 found in air pockets in soil into inorganic carbonates.
• This is possible with regenerative agriculture, which may result in more SOM in the soil.
• In fact, nearly 80 per cent (2,500 gigatonnes) of all carbon in terrestrial ecosystems is found in soil.

• The Intergovernmental Panel on Climate Change indicated that carbon sequestration will be a critical part of the strategy to fight global warming.
• Organic matter increase can help with carbon sequestration, while also improving the soil’s microbial population.
• This is possible through reversative agriculture (organic or natural farming) — a low-cost approach to reducing greenhouse gas emissions.
• Organic farming does not use chemicals, but it does increase organic matter content, microorganism population and plant availability of both micro- and macro-nutrients.
• With only about 60 years of topsoil remaining under current practices, regenerative agriculture is the solution.
• Farmers’ transition to adopt regenerative farming must include measures such as capacity building, incentives, seed and input availability as well as a mission-mode programme will have a long-term benefit for soil health and carbon sequestration

Source: DownToEarth

Previous Year Questions

Q1.) With reference to the circumstances in Indian agriculture, the concept of “Conservation Agriculture” assume significance. Which of the following fall under the Conservation Agriculture? (2018)

1. Avoiding monoculture practices
2. Adopting minimum tillage
3. Avoiding the cultivation of plantation crops
4. Using crop residues to cover soil surface
5. Adopting spatial and temporal crop sequencing/crop rotations

Select the correct answer using the code given below:

1. 1, 3 and 4
2. 2, 3, 4 and 5
3. 2, 4 and 5
4. 1, 2, 3 and 5