Soil Acidification threatens Indian Soils

Context

A recent study has raised concerns about the impact of soil acidification on Indian agriculture and carbon sequestration. The study predicts that soil acidification could lead to the loss of 3.3 billion tonnes of soil inorganic carbon (SIC) from the top 0.3 metres of soil over the next 30 years

Key Findings of the Study

• Soil Acidification: Farm lands which are 30 percent acidic than normal are widespread in our country to be seen across the available cultivable lands. These people’s very incentive to grow plants acts as an inhibiting factor.
• SIC Depletion: Acidity has such a climate that the common cause of such leakage is the loss of SIC, which is a very stable and large pool of carbon that is necessary for soil functioning.
• Impact on Crop Growth: The acidic feature of the soil interrupts the absorption of the most basic plant nutrient, in the consequence of the plant producing fewer outputs.
• Carbonate Chemistry: In addition to responsible human activity, carbonate being dominant in the SIC is a fact that has to be taken into account for pH levels. Such a low pH level in an acidic soil dissolves solid carbonate (which transforms into the carbon dioxide gas) or it goes directly into the water.

Soil inorganic carbon (SIC)

SIC (Soil Inorganic Carbon), being a key element of the global carbon cycle, particularly in arid and semi-arid ecosystems, is where the carbon stock is regulated mostly.

• Formation: Soil Inorganic Carbon (SIC) theory suggests two environments for carbon stabilisation, involving cation migration from solid minerals to form soil carbonate minerals. This process occurs concurrently with various factors like atmospheric conditions, water application, land use, and soil characteristics.
• Types: There are three kinds of carbonates in soils: lithogenic or the primary source of carbonate in soil parent material; hydrogenic, which is produced by interaction with plants and; pedogenic either through biochemical processes or as a result of those processes. Pedogenic carbonates are formed during these processes and are generally natural solutions.

Details on Soil Acidification And Impact on Indian Soil

The topic of soil acidification is critical to my country because the amount of acidic soil is over 30% of the cultivated land, negatively affecting plants and their productivity.

• Geographical Spread: Highly acidic soils, mainly due to acid rain, are prevalent in the southwest and northeast foothills of India, with some areas in the northeast reaching extreme acidity levels of 95.
• Causes: Soil acidification in India is attributed to natural factors like rainfall and animal decomposition, as well as human activities such as industrial operations and excessive use of nitrogen-based fertilisers in agriculture.
• Impact on Soil Inorganic Carbon (SIC): Acidification from industries and intensive farming may result in a projected loss of 3.3 billion tonnes of SIC from the top 0.3 metres of soil over the next 30 years, leading to soil infertility and affecting soil health.
• Effect on Crop Growth: Acidic soils immobilise nutrients, hampering plant growth and productivity.
• Environmental and Agricultural Implications: Soil acidification disrupts the food chain, depleting nutrient levels and carbon storage crucial for plant growth and environmental stability.

Environmental and Agricultural Implications of Soil Acidification

The environmental and agricultural implications of soil acidification in India are profound and multifaceted. 

• Biodiversity Loss: Low pH triggers decline of species number and shifts their biomass allocation patterns affecting decomposition and nutrients cycles and soil biota equilibrium.
• Atmospheric Carbon: It is Soil Inorganic Carbon (SIC) loss that adds to the increasing amount of CO2 in the atmosphere, and, indirectly, to the worsening of climate change.

• Nutrient Availability: Acidic conditions limit plant uptake of essential nutrients like phosphorus, calcium, and magnesium, hampering plant growth.
• Toxicity: Acidic soils can release aluminium and manganese, which may harm crops sensitive to these elements.

Conclusion

It is vital to emphasise the biomass, SIC life cycle and contributions to soil health, closer look at ecosystem services, and generally sequestering carbon that should be our key policy goals in order to beat global warming. A full-scope research plan that can provide solutions and neutralise the negative impacts of agricultural activity on productive soil is an essential requirement.

Source: DTE

UPSC Mains Practice Question

Q.Soil acidification poses significant challenges to agricultural productivity and environmental sustainability. Discuss the causes, consequences, and mitigation strategies of soil acidification in the context of India. Assess the effectiveness of current policies and propose measures to address this issue, ensuring long-term soil health and agricultural viability.

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