Increasing penetration of agricultural inputs has helped Indian farmers achieve record food grain production year after year. For the record, the Government estimates an all-time high total foodgrain production of 272 million tonnes in 2016-17. However, this does not automatically imply that all is hunky dory on India’s agricultural front.

India’s land area is about 2.5 per cent of the global land area, and it supports more than 16 per cent of the total human population along with around 20 per cent of the global livestock population.

Clearly, the pressures of constantly increasing production have in turn resulted in a persistent decline in soil fertility — a major challenge that Indian agriculture is currently facing.

With rising population, limited availability of agricultural land, small land holdings and declining soil fertility, India is under serious threat of losing its food surplus status in the near future. According to estimates, the demand for foodgrain is expected to increase from 192 million tonnes in 2000 to 355 million tonnes in 2030.

But, is our ‘fatigued’ soil healthy enough to meet these targets?

Excessive tillage takes a toll

Over the years, increasing pressure on limited agricultural land in India has resulted in overuse of chemical fertilisers on soil, excessive tillage, jettisoning of age-old organic soil revival practices and lack of appropriate crop rotation. This has resulted in soil degradation and loss of fertility, which are emerging as major challenges for Indian farmers.

Soil degradation is estimated to be severely impacting the 147 million hectares of cultivable land in India, causing a successive deterioration in its productive capacity. In recent years, experts have witnessed a worrying sign of declining total factor productivity and compound growth rates of major crops.

In several agricultural regions across the country, there has been observed a gap between nutrient demand and supply including decline in organic matter status, deficiencies of micronutrients in soil, soil acidity, salinisation and sodification.

If we do not take this disturbing trend into account and start acting now, our country might be saddled with vast swathes of land rendered infertile by lack of sagaciousness and long-term thinking.

Experts say one of the main ways forward is to make agriculture more sustainable and revive the age-old practices of soil regeneration, while balancing the same with judicious use of agrochemicals. The agrochemical industry must also rise to the occasion and invest in producing organic biological products that help improve the health of Indian soil.

What causes soil fertility loss?

Apart from natural factors such as floods, volcanoes and earthquakes, a number of human-induced factors such as deforestation, ill management of industrial wastes, overgrazing by cattle, and urban expansion, are also responsible for the loss of soil’s productive capacity. Widespread land degradation caused by inappropriate agricultural practices has a direct and adverse impact on the food and livelihood security of farmers. Inappropriate agricultural practices that contribute to this include excessive tillage, frequent cropping, poor irrigation and water management, and unscientific rotation of crops. Decline in soil organic matter causes limited soil life and poor soil structure.

According to a document prepared by the Indian Institute of Soil Science on the subject, contrary to increasing food demands, the factor productivity and rate of response of crops to applied fertilisers under intensive cropping systems are declining year after year. The current status of nutrient-use efficiency remains quite low for most nutrients. For example, in the case of phosphorus, soil’s nutrient-use efficiency has been found to be a meagre 15-20 per cent; for sulphur it is 8-12 per cent; and for nitrogen it is 30-50 per cent. Deterioration in chemical, physical and biological health of the soils are to blame for this condition.

Conventional practices followed by farmers such as leaving the land fallow for some time to allow it to regain its lost nutrition, and appropriate crop rotation have been junked in favour of continuous cropping which has led to a decline in Soil Organic Carbon (SOC) content to 0.3-0.4 per cent in the country when it should ideally be at 1 to 1.5 per cent. (Organic matter plays a key role in maintaining soil fertility by holding nitrogen and sulphur in organic forms and other essential nutrients such as potassium and calcium. The loss of organic matter is accelerated by frequent tillage.)

Organic carbon’s an enabler

Soil organic carbon plays a key role in maintaining soil fertility by holding nitrogen, phosphorous and a range of other nutrients for plant growth, holding soil particles together as stable aggregates improving soil properties such as water-holding capacity and providing gaseous exchange and root growth, playing an important role as food source for soil fauna and flora and even suppressing crop diseases, and acting as a buffer against toxic and harmful substances such as sorption of toxins and heavy metals.

As a result of human activities releasing carbon dioxide into the atmosphere, the carbon pool in the atmosphere has increased and the elevated carbon dioxide is considered to be a contributory factor to the danger of global warming and climate change.

Soil organic carbon is the largest component of the terrestrial carbon pools, approximately twice the amount of carbon in the atmosphere and in vegetation. If more carbon is stored in the soil as organic carbon, it will reduce the amount present in the atmosphere, and therefore help to alleviate the problem of global warming and climate change.

Going organic

All this brings us to the vital question of how we can ensure that India’s growing foodgrain needs are met while at the same time soil health and fertility are nurtured and improved.

And the answer lies in turning the focus on biological products to improve soil health, propagating the judicious use of agrochemicals, reducing excessive dependence on fertilisers and pesticides while also reviving practices such as intelligent crop rotation.

Enhancing sustainable food production through improved soil health is not just the job of the Government and cultivators. The agrochemical industry also has a responsibility to invest with renewed vigour in biological products that can rejuvenate soil health organically.

At the same time the need of the hour is to educate farmers about what they can do to improve the health of their nutrient-depleted soil by following practices such as crop rotation, and using organic manure boosters such as cow dung and dried leaves.

It is also pertinent to educate them about the judicious use of agrochemicals and attain a fine balance between chemical and organic products — both of which are critical to India’s food sustainability goals.

The writer is the MD of Insecticides India Ltd

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