The pressures of constantly increasing production have resulted in a persistent decline in soil fertility—a major challenge that Indian agriculture is facing.
Increasing penetration of agricultural inputs has helped Indian farmers achieve record foodgrain production. In fact, in 2016-17, the government estimates an all-time high foodgrain production of 272 million tonnes. However, this does not automatically imply that all is hunky dory on agricultural front. India’s land area is about 2.5% of the global land, and it supports more than 16% of total human population, along with 20% of global livestock population. The pressures of constantly increasing production have resulted in a persistent decline in soil fertility—a major challenge that Indian agriculture is facing. With rising population, limited availability of agricultural land, small landholdings 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 foodgrains 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 has resulted in overuse of chemical fertilisers, 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. Soil degradation is estimated to be severely impacting 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, there has been observed a gap between nutrient demand and supply including decline in organic matter status, deficiencies of micro-nutrients in soil, soil acidity, salinisation and sodification. If we do not take this disturbing trend into account and start acting, India might be saddled with vast swathes of land rendered infertile by lack of sagaciousness and long-term thinking. Experts say one of the ways forward is to make agriculture more sustainable and reviving age-old practices of soil regeneration, while balancing it with judicious use of agrochemicals. The agrochemical industry must invest in producing organic biological products that help improve soil health.
Apart from natural factors like floods, volcanoes and earthquakes, human-induced factors such as deforestation, ill-management of industrial wastes, overgrazing by cattle and urban expansion are also responsible for loss of soil’s productive capacity. Widespread land degradation caused by inappropriate agricultural practices has an adverse impact on food and livelihood security of farmers. These practices 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 by the Indian Institute of Soil Science (Bhopal), contrary to increasing food demands, the factor productivity and rate of response of crops to applied fertilisers under intensive cropping systems is declining. The current status of nutrient use efficiency is quite low for most nutrients—in case of phosphorus, soil’s nutrient use efficiency has been found to be a meagre 15-20%, for sulphur 8-12%, and for nitrogen 30-50%. Deterioration in chemical, physical and biological health of soil is to blame for this. 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 the decline in soil organic carbon (SOC) content to 0.3-0.4%, when it should ideally be 1-1.5%. SOC plays a key role in maintaining soil fertility by holding nitrogen, phosphorous and other nutrients for plant growth, holding soil particles, improving soil’s water holding capacity and providing gaseous exchange and root growth. It is a source of food for soil fauna and flora, suppresses crop diseases, and acts as a buffer against toxic and harmful substances, like sorption of toxins and heavy metals. As a result of human activities, the carbon pool in the atmosphere has increased and elevated carbon dioxide is considered to be a contributory factor to global warming and climate change. SOC is the largest component of terrestrial carbon pools, about 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 help alleviate the problem of climate change.
Investment in organic products
This brings us to the question of how can we ensure that India’s growing food grain needs are met while nurturing soil health. The answer lies in a focus on biological products to improve soil health, propagating judicious use of agrochemicals, reducing excessive dependence on fertilisers and pesticides, and 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 in biological products that can rejuvenate soil health organically. At the same time, farmers have to be educated about what they can do to improve the health of their nutrient-depleted soil by following good crop practices. It is pertinent to educate them about 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.
By: Rajesh Aggarwal
MD, Insecticides India Ltd