How big a role does the monsoon play in India’s agricultural production?

It is a long-held consensus that agriculture in India is highly dependent on monsoon rains. To find out how true this is, we looked at historical data on the southwest monsoon in relation to the country’s foodgrain production.

Our analysis shows that the southwest monsoon (SWM), which is recorded from June to September, does have an impact on the country’s agricultural sector, especially in light of the fact that as much as 46 percent of India’s net sown area remains unirrigated (as of FY20). However, this is not the only factor that matters.

“Southwest monsoon is crucial as most of India gets its rains during the four month period. Kharif crops like paddy, soybean, tur and masoor are important for food security and cotton is important for textile industry and export,” said Siraj Hussain, a former Union Agricultural Secretary.

A RBI report released last month also highlights the importance of SWM rainfall. “Around 75 percent of India’s annual rainfall is concentrated during the four months of the SWM season, which is vital for the agricultural output during the kharif cropping season, as almost half of the country’s net sown area is still unirrigated,” said the report.

Historical data shows that in the years in which the amount of SWM rainfall fell below the threshold of normal rainfall for this period, there was a dip in the production of kharif crops. For example, both 2014 and 2015 received less than normal SWM rainfall, and both years saw a decline in the production of foodgrains.

To meet the criteria for a normal monsoon, the amount of rain received has to be within a margin of 10 percent from the long period average (LPA) of 880.6 mm. However, the IMD has modified this parameter from 2022, and the LPA now stands at 870 mm, with the margin of error at 4 percent.

Meanwhile, data shows that SWM rainfall is not the only defining factor behind foodgrain production in India.

The years 2016, 2017 and 2018 recorded lower SWM rainfall than the LPA, although it remained within the IMD threshold for a normal monsoon. Moreover, the monsoon rainfall received in the latter two years was also lower than the year before. However, foodgrain production continued to grow year-on-year (Y-o-Y) at a healthy pace during this period. Meanwhile, in 2012, which also saw a Y-o-Y decline in rainfall despite remaining in the normal monsoon threshold, there was a dip in foodgrain production.

The fact that SWM rainfall and foodgrain production didn’t move parallel to each other during these years points to the existence of other factors that we need to consider.

Rise in irrigation

Between 2000 and 2019, the net irrigated area in India has grown by 36.68 percent and the area covered continues to rise.

Data from 2016 to 2018, when there was growth in food production, shows that although the SWM rainfall saw a decline during these years, the net area under irrigation went up.

In a bulletin released in May last year, the central bank had said, “To meet the growing demand for water from the agriculture sector, irrigation infrastructure has expanded at a considerable pace, making India a food sufficient nation by reducing its dependence on monsoons.”

Rise in irrigation has a multiplier effect on agriculture. “Studies show that access to assured irrigation improves resilience of farms, and farmers make better decisions on crop, fertiliser, among others. On average, income of farmers with irrigation is higher than those whose farms are rain-fed. When farmers have assurance that their crops won’t wither due to variations in rain, they manage their resources better. So, irrigation has a multiplier impact on agricultural economy,” said Shweta Saini, an agricultural economist and co-founder, Arcus Policy Research.

However, according to Hussain, irrigation can only be seen as a supplement and not as substitute. “Higher irrigation coverage has meant that area under paddy has gone up. But it does not mean that it can compensate entirely for very poor rainfall. Irrigation water is a supplement not a full substitute for rainfall,” he said.

Net sown area

A more important factor that should be considered when it comes to agricultural production in India is the net sown area.

Out of the 14 times that the country has seen a decline of more than 0.5 percent in the net sown area since 1976, only twice has there been a growth in kharif foodgrain production. In the other 12 years, production of foodgrains saw a decline.

According to calculations released by the RBI in 2015, while a 34-percentage-point change in SWM rainfall could impact the growth of agricultural production by around eight percentage points, just a six-percentage-point change in the net sown area could have an impact of around seven percentage points in agricultural production.

In short, this means that changes in the net sown area play an influential role in determining agricultural production.

However, this may not be as straight forward as it looks. “Net sown area is influenced by factors such as past prices, predicted prices, access to irrigation, and timely and affordable access to other inputs like fertilisers, seeds. Further, it is also influenced by duration and amount of rainfall received. Hence, although variations in net sown area do impact agricultural production, it is not a variable that can be seen in silo and is influenced by many other factors,” said Saini.