India faces the risk of a decline in growth of crop yields

Environmentally unsustainable farm practices and weather variations are to blame. An innovative system based on indigenous and traditional knowledge that enhances the natural resource base while increasing productivity is what Indian agriculture needs.

Over the past 50 years, the developing world witnessed an extraordinary period of food crop productivity growth. Although populations had more than doubled, the production of cereal crops tripled during this period, with only a 30 per cent increase in land area cultivated. Dire predictions of a Malthusian famine were belied, and much of the developing world was able to overcome its chronic food deficits. The effort and outcome, popularly known as the Green Revolution, was characterised by introduction of high yielding variety (HYV) seeds, extensive use of fertilisers, herbicides, pesticides, and the spread of irrigation.

In India, for instance, the Green Revolution has brought much needed self-sufficiency in the production of foodgrains. In fact, cereals production has generally been greater than the domestic demand since the mid-1990s, leading to an increase in export of cereals. Over the past half-century, rice yield grew by 145 per cent and wheat, by 270 per cent. Despite these successes, overall agricultural labour productivity is less than a third of that in China and about 1 per cent of that in the frontier countries. Land productivity (measured as yield per hectare) in the case of rice, for example, is about 50 per cent of those in China and one-third of those in the US.

However, there is increasing evidence that the growth in yields has levelled off and there is a danger of future declines in yield growth on account of global climate change and unsustainable food production practices in view of environmental damage.

Weather impact

Weather is undeniably one of the most important sources of risk in Indian agriculture, and the looming threat of climate change further exposes this vulnerability. Consistent with models of climate change which predict increased variability in weather, in India, the number of dry days as well as days with extremely high levels of rainfall has increased.

The Economic Survey (2017-18) reports that between 1970 and 2016 the average annual temperatures have increased by around 0.48 degrees and average monsoon rainfall has declined by 26 mm. Perhaps the most obvious impact of weather risk is on crop yields and estimates show that an extreme temperature shock results in a 4 per cent decline in agricultural yields during the kharif season and a 4.7 per cent decline in rabi yields, resulting in a 4.1-4.3 per cent fall in farm income.

Resources stretched

Expanding food production have often come at a heavy cost to the natural environment. Important key resources like water, soil quality and land are moving in a very unfavourable direction. Constant use of chemical-based inputs like fertilisers, pesticides, herbicides and mechanised farming have led to overexploitation of natural resources, especially groundwater and soil to the extent that most of the farming enterprises have turned out to be environmentally unsustainable.

Water tables have declined at an alarming rate in Punjab and Haryana (States where Green Revolution technologies were originally introduced), especially under intensively cultivated rice-wheat systems. During 1993-2003, the water-table fall in the central districts of Punjab ranged between 0.3 and 1.0 metre annually. By 2006, the water table had sunk to depths as low as 28 metres.

With the intensive use of irrigation came the problem of salinity build-up and water-logging; increased incidence of micro-nutrient deficiencies (specially zinc); and soil toxicities (iron). All of these negative trends are accelerating in pace and intensity and have threaten the sustainability of food systems. The slowdown in yield growth in Punjab and Haryana that has been observed since the 1990s can be attributed, in part, to the above degradation of the agricultural resource base.

As India’s population is projected to increase to 1.65 billion by 2050, overtaking China as the world’s most populous nation, the above-mentioned trends undermine India’s capacity to meet its food needs. To address the issue, an innovative system based on indigenous and traditional knowledge that protects and enhances the natural resource base while increasing productivity is needed. Otherwise, Malthus may prove to be right for the wrong reason.