A national database on land degradation prepared by the Indian Space Research Organisation in 2016 showed that 36.7 per cent of India’s total arable and non-arable land suffers from various forms of degradation, water erosion being the chief contributor (68.4 per cent). Micronutrient deficiency in Indian soils has increased at a rapid scale in recent years. Initially, the country’s soil was more deficient in nitrogen and phosphorus.

Now our soils are greatly deficient in Zn and other micronutrients. Scientists from Indian Institute of Soil Science, All India Institute of Medical Sciences (Bhopal) and ICAR (Delhi) conducted a study under the All India Coordinated Research Project on Micro- and Secondary Nutrients and Pollutant Elements in Soils and Plants (AICRP-MSPE) in April, 2018. They analysed 0.2 million soil samples collected from 28 states and territories.

Their findings published in Indian Journal of Fertilisers, 2018 (shown alongside) reveal that Indian soil truly is in distress. It appears from the statewise assessment that Rajasthan’s soils have some of the highest deficiencies in all micronutrients, excluding Boron. Other states with highest deficiencies in almost all micro – nutrients are Tamil Nadu, Punjab, Haryana, Odisha and Goa.

Trace soil minerals are a critical determinant of both crop productivity and the mineral concentration of crops, therefore potentially impacting the nutritional status of human populations relying on those crops. Both macro and micro nutrients are transferred via roots from the soil to the plants and then to human beings via food. Plants provide minerals and other nutrients such as proteins, carbohydrates, fats, vitamins which are synthesised by plants for human body growth and development.

The relationship between soil health and human health could be well established once roles played by some mi cro – nutrients present in soil are appreciated. Functions of Zn and Fe have already been mentioned. Cu is essential for collagen production, neurotransmitter synthesis, myelination and neural connection, it supports immune cell formation and also acts as an antioxidant. Mn is necessary for bone formation, wound healing. It supports neurotransmitters and also acts as an anti oxidant. Boron plays an important role in osteogenesis and its deficiency has been shown to adversely impact bone development and regeneration.

Health experts opine that micro – nutrient deficiencies are never singular. Deficiency in one micronutrient indicates a high likelihood of poor levels in others as well. However, it has been established that plants show deficiency symptoms or enter into hidden hunger conditions when the concentration of mi – cronutrients falls below their respective critical concentrations. Rice and wheat are the foundation of food and nutritional security for India and other parts of the world. A study conducted under the Indian Council of Agricultural Research (ICAR) has for the first time found alternations in grain nutrient density of rice and wheat cultivars bred. It is also observed that crops are losing their ability to take up nutrients like calcium, iron, phosphorus, zinc and copper from the soil along with nickel and silicon.

A more worrisome finding of the study published in the Journal Scientific Reports in November 2023 is that with the downward trend in nutritional quality there is an upward trend in taking up of toxic elements like arsenic and aluminium. Fortification of food with mineral micronutrient as also micronutrient supplementation are widely adopted keeping in view the urgency to fight hidden hunger.

But focus has now been intensified on agronomic biofortification. It is the means to increase the concentration of a target mineral to food crops and improve human mineral dietary intake. It is a time-tested, cost-effective and sustainable process. There are several techniques like nutripriming, foliar application, soilless activation and mechanised applications. Soil health is proportionally linked to our health. It is aptly said that “We are only 15 cm away from our annihilation”, this 15 cm being our top soil (storehouse of micronutrients).’ Soil is in distress because of alarming degradation.

Land resources are finite and therefore their conservation, development and management have played a determining role in sustaining life and civilisation. Mahatma Gandhi had very poignantly said in 1946, ‘To forget how to dig the earth and tend the soil is to forget ourselves.’

(The writer is a retired IAS officer)