How nutrient-deficient are Indian soils?

According to a recent Centre for Science and Environment (CSE) report ‘The State of Biofertilizers and Organic Fertilizers in India’, about 85% of soil samples are deficient in organic carbon.

• The levels of organic carbon and macronutrients in Indian soils are either “very low”, “low” or “medium”.

• Organic deficiency: 85% of soil samples are deficient in organic carbon. Of the total sample, about 15% contain very low levels of organic carbon, 49% contain low levels of organic carbon and 21% contain medium levels of organic carbon
  • Organic carbon deficiency is widespread across the country—24 states and Union Territories (UTs) have, at least, half of their soil samples deficient in organic carbon.
  • Out of these, seven states have more than 90% deficient samples.
  • Haryana’s soils are the most deficient in organic carbon, followed by those of Punjab, Uttar Pradesh, Rajasthan, Tamil Nadu, Mizoram, and Andaman and Nicobar Islands.

• Nitrogen deficiency:Similarly, 97% of the samples are deficient in nitrogen—out of these, 45% of the samples show very low levels of nitrogen, 36% low levels of nitrogen and 16% medium levels of nitrogen.
  • 32 states and UTs have nitrogen deficiency in at, least, half of their soil samples.
  • Of these, 27 states and UTs have more than 90% deficient samples.
  • Fifteen states and UTs have nitrogen deficiency in almost all of their samples—Andaman and Nicobar Islands, Dadar and Nagar Haveli, Daman and Diu, Bihar, Delhi, Haryana, Kerala, Madhya Pradesh, Manipur, Mizoram, Odisha, Puducherry, Rajasthan, Tamil Nadu, Uttarakhand and Uttar Pradesh.
• Phosphorus deficiency: The report found that 83% of the samples are deficient in phosphorus—17% reveal very low levels of phosphorus, 31% reveal low levels and 35% medium levels.
• Potassium deficiency: About 71% of the samples are deficient in potassium. Of these samples, about 5% have very low levels of potassium, 14% low levels and 52% medium levels.
• Other deficiencies (micronutrient): Indian soils are also deficient in micronutrients with more samples showing deficit in boron, iron, sulphur and zinc and a lesser number in copper and manganese.

What decides soil’s fertility?

• Soil is a complex mixture of minerals, water, air, organic matter, and countless organisms—all of which come together to form a fertile substance that can grow and nourish saplings.
• These microorganisms provide essential nutrients for crop plant growth such as nitrogen, phosphorus, sulphur, potassium, calcium, magnesium and micronutrients.
• Soil fertility is also greatly dependent on biological components of soil like bacteria, fungi, or algae.
• The presence of diverse soil microbes protects the plant from harmful pathogens. Moreover, the presence of rich microorganism enhances the fertility of the soil, and therefore, gives out better yield.

Why soil is essential?

• Ecosystem service: Soil provides ecosystem services critical for life: soil acts as a water filter and a growing medium; provides habitat for billions of organisms, contributing to biodiversity; and supplies most of the antibiotics used to fight diseases.
• Food security: For healthy food production, soil health is essential. It provides essential nutrients, water, oxygen, and root support, all of which aid plant growth and development for food production.
• Home for biodiversity: Soils are habitats for beneficial soil microbes; these organisms are nature’s hidden helpers.
• To combat climate change: Soil is known as carbon sequester, and therefore, it can help combat climate change. It is estimated that the soil can store about 2,500 gigatons of carbon.

What is killing soil?

• Farming practices such as tilling break up the soil and destroy its natural structure, killing many of the vital bacteria.
• Agricultural chemicals can alter the physiological, metabolic and biochemical behaviour of microbiota in the soil. This can disrupt the relationships between plants and microbes, decreasing nutrient bioavailability.
• Pressures of population growth, food insecurity and agricultural intensification are leading to widespread soil degradation. This degradation can take many forms.
  • Soil degradation
  • Soil erosion
  • Soil Acidification
  • Soil Salinization
• Burning of crop residues
• Land misuse and soil mismanagement
• Climate change

What can save the soil?

• Replenishment
• Organic practice: Recycling of organic matter or biomass can be done through the application of organic fertilisers and practices like growing green manure crops or mulching. Some other practices that help regain nutrients include:
  • inter-cropping
  • mixed cropping
  • Practicing crop rotation allows different plants to grow in an area of soil every year. This allows the soil to replenish itself of nutrients that are lacking after the growth of one type of plant.
  • Agroforestryinvolves growing crops around trees and other plants such as hedges.
  • Permaculture is a form of sustainable farming that respects nature and its design
• Biofertilizers

• Communities, farmers and corporations can be educated about sustainable practices to promote respect and responsibility for nature and reduce their carbon footprint.

Government Interventions

• Pradhan Mantri Fasal Bima Yojana (PMFBY)
• Soil Health Card Scheme
• Soil Health Management Scheme
• Pradhan Mantri Krishi Sinchayee Yojna (PKSY)
• Per Drop More Crop
• India is signatory to achieving Land Degradation Neutrality by 2030.

Concluding thoughts

The dirt beneath our feet is getting poorer and on many farms worldwide, there is less and less of it. And if nothing is done to increase microbial activity in the soil in the next 10 years, there may be no going back. And not just would the lives of future generations be at peril, but it could also lead to unimaginable food shortages.

And it must be done urgently, for the clock is ticking on India’s soil health.