Context

• According to the UN Food and Agriculture Organization, the world will have to increase its food production by 60 per cent by 2050 to feed an ever-increasing population. For this, soil health becomes vital.

Soil and its components

• • Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support the life of plants and soil organisms.
  • They serve as the backbone of agriculture , store water, and play an indispensable role in our ecosystem.

• Components of Soil

• Minerals – It is the largest component of soil which makes up approximately 45 to 49 per cent of the volume. The texture of a soil is based on the percentage of sand, silt and clay found in that soil.

• • Water –  It makes up approximately 2 to 50 per cent of the soil volume. Water is important for transporting nutrients to plants, soil organisms and for facilitating biological and chemical decomposition.
  • Organic matter – It is derived from dead plants and animals, and is found in soil at levels of 1 to 5 percent. The percentage of decomposed organic matter in soils is often used as an indicator of productive soil.
  • Gases – They make up approximately 2 to 50 per cent of the soil volume. Oxygen is essential for root and microbe respiration, which helps support plant growth.
  • Organisms – They are found in the soil in very high numbers but make up much less than 1 percent of the soil volume. The largest of these organisms are earthworms and nematodes and the smallest are bacteria, actinomycetes, algae and fungi.

Soil Health

• • It is defined as the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals and humans.

• Principles of Soil Health include,

• • Maximize Presence of Living Roots
  • Minimize Disturbance
  • Maximize Soil Cover
  • Maximize Biodiversity

Soil Health tests

• • These tests assess the physical, chemical and biological characteristics of soil.

• Physical Properties

• • Soil compaction checks the maximum dry density for a soil sample. Highly compact soil reduces water percolation, nutrient availability.
  • Structural stability checks how soil structure resists mechanical and water stress.
  • Wet Aggregate Stability measures the soil’s ability to resist erosion and check the soil’s water filtration ability.

• Chemical Properties

• • pH measures the soil acidity or alkalinity. If levels are too high or low, it leads to reduced crop yield.
  • Electrical conductivity measures the amount of salts in soil. High salt levels can dehydrate plants
  • Macronutrients such as nitrogen, phosphorus, carbon are essential for crop production
  • Micronutrients such as iron, zinc are needed for plant growth
  • Active carbon measures the share of organic matter that can serve as an energy source for microbes .

• Biological Properties

• • Microbial biomass measures the mass of the living component of soil organic matter.
  • Microbial respiration measures the carbon dioxide (CO2 ) produced by soil microbes. A high rate indicates high biological activities
  • Proteins are measured to see their share in the organic matter pool.

Benefits of Healthy soils

• • Flood Regulation – Healthy soil helps in better water absorption, retention and reduced erosion. Soils in floodplains also act as temporary storage areas during flood events.
  • Foundation for Infrastructure – Soil is used in construction of infrastructure because it serves as the foundation material for both natural and human-made structures, providing support and stability.

• Habitat for organisms – Several organisms from macroinvertebrates like earthworms, ants and termites to microorganisms like bacteria, archaea, and fungi inhabit the soil.

• • Carbon Sequestration – Soils are regarded as effective carbon sinks and help in sequestering carbon dioxide effectively.
  • Water Purification – When groundwater and surface water pass through soil, it is cleaned via physical, chemical and biological processes.

• Nutrient Cycling – Soil microbes decompose organic matter to release nutrients. They also trap and transform nutrients into the soil, which can be taken up by plant roots.

• Source of Pharmaceuticals and Genetic Resources – Soil is the major reservoir of microorganisms that produce antibiotics, such as bacterial genera Bacillus and Streptomyces and fungal genera Penicillium.

Conclusion

• Thus, incentivizing sustainable land management practices, and fostering collaboration across sectors are crucial steps toward building resilient agricultural systems and ensuring food security for future generations.