Update overdue: Why climate change should be integrated into crop calendars at the hyper local level

India still sows according to a calendar created on the weather of the 1990s, though rainfall and temperature patterns have seen a major shift

By Shagun, Himanshu Nitnaware
Published: Saturday 10 September 2022

In 1996, the India Meteorological Department (IMD) created a first-of-its-kind calendar with district-wise weather information for crop cultivation.

It provided sowing and harvesting time, as well as weekly average rainfall and temperature during critical growth stages of the area's major crops.

Agriculture departments across the country used it to prescribe sowing dates to farmers. Over the years, the sowing schedule became India’s farming cycle, to the extent that at least two generations of farmers have now been following it.

However, rainfall patterns in the past two decades have seen substantial changes in the date of arrival, frequency as well as distribution. As a result, farmers who adhere to the crop calendar often face crop loss.

Sethpal Singh of Nandi village in Uttar Pradesh’s Saharanpur district has been in such a situation four times in the past decade.

“I always start preparing paddy nurseries by the second week of June. Twenty days later I transplant them. This is also the schedule that officials at the local Krishi Vigyan Kendra tell us to follow,” Singh, who owns over 12 hectares (ha), said.

“But if it does not rain in these 20 days, the saplings go to waste and we have to prepare them again. This is what happened this year too,” he added.

This year, Saharanpur received no rain in the first two weeks of June, seven per cent less than normal rain in the third week, and no rain in the fourth week, according to IMD data.

The district also saw 11 per cent and 52 per cent less than normal rainfall in the first two weeks of July.

All the farmers Down To Earth (DTE) spoke to in Uttar Pradesh, Madhya Pradesh, Maharashtra and Bihar narrate similar stories.

“At least three of the past 10 years have seen a significant delay in rainfall. In all those years, I had halved my acreage under paddy to cut my losses,” Swaroop Prasad, a farmer from Madhya Pradesh’s Rewa district, said.

Santanu Bal, principal scientist with the Indian Council of Agri-cultural Research (ICAR)-Central Research Institute for Dryland Agriculture (CRIDA), told DTE that the existing calendar would not help in decision-making for crop production in the backdrop of current climate variability.

“The crop calendar was set according to the onset of rain, its volume and distribution. For example, the monsoon reaches the Kerala coast by June 1. Crop sowing in the state has been set accordingly. It reaches Odisha by June 12-13, where, again, sowing has been set as per this date. Agriculture universities in the states developed the calendar according to the major crops and the monsoon,” Bal explained.

But the calendar is based on the assumption that the weather is “normal” and can no longer precisely suggest operations for rain-fed agriculture, he added.

DTE analysed IMD data for 30 years, from 1988 to 2018, covering 676 of India’s 730 districts in 28 states and the Union Territory of Jammu and Kashmir, to find that 420 districts in the country (62 per cent of the districts covered in the data) have seen a decrease in rainfall in June — the key month for sowing the kharif crop.

A total of 210 districts (31 per cent of the districts covered in the data) also reported an increase in the number of days with no rainfall.

Though 248 districts (36 per cent of the districts covered in the data) saw an increase in rainfall, it does not really help farmers because it still means unpredictable rainfall. For instance, a district could see heavy rain one day and then no rain for a long duration.

Growing a crop like paddy, which needs continuous flooding of fields up to 10 cm depth for two weeks at the transplantation stage, requires precise weather information.

Overall, 55 per cent of India’s net sown area (139.42 million ha) is rain-dependent and grows 34 of the country’s 40-odd major crops, according to a July 2022 draft policy paper of the National Rainfed Area Autho-rity (NRRA).

This signifies the pressing need for a relook at the crop weather calendar, which NRRA also states in the paper: “Long-term data for India indicates, that rainfed areas experience 3 to 4 drought years per decade. Of these, two to three are moderate and one or two are severe in intensity. Rain-fed crops are likely to be worst hit due to limited options of coping with variability of rainfall and temperature resulting in a shift in sowing time and shorter growing season, which may necessitate effective adjustment in sowing and harvesting dates. Increasing intra-seasonal variability of rainfall has become a major concern.”

False start

Bal highlighted another phenomenon, called “false start”, happening more frequently in the first monsoon month of June.

It refers to a situation where the first spell of rain is followed by dry spell lasting a week or more.

“June has been troubling. There is not much difference in the onset of rain but the major concern is the break in rain once you have sown. A break in monsoon has been happening more in June. For rain-fed areas, there is no other option because the sowing window is only till July 10-15,” Bal said.

“False start condition is very vital, because it leads to germination failure and re-sowing by farmers resulting in increased cost of culti-vation,” stated a paper published in Agricultural and Forest Meteorology journal on March 14, 2022.

Adapting to the changed rain pattern, farmers already have started to delay sowing.

Bharat Dighole, a Nashik-based farmer and president of the Maharashtra State Onion Grower’s Association, said many farmers had skipped sowing in June.

“Cotton, soybean, bajra (pearl millet) and corn are among the major kharif crops grown in the region. For the past five years, we are not sowing in June due to high risks that come with uncertain rains. The farmers understand that the timing is not optimal for the crops and voluntarily push the sowing to July. June sowing in Nashik is only about 5 per cent; the majority of the sowing happens in July,” Dighole said.

Farmers in Nandi village too have shifted their kharif crops to July-August to minimise losses due to a failed June and a weak July monsoon.

“Apart from paddy, our other major crops are moong (green gram) and urad (black gram) in pulses and mustard and sesame in oilseeds, which are sown and harvested between March and June. But their season has shifted by two months to July-August since the last four years. We have seen a positive yield because of this,” Vinod Kumar, a farmer from Nandi, said.

Singh remembered that in 2021, there was heavy rainfall during the months of March and April that affected the short-duration zaid crops that are sown in March and harvested by May.

This turned into a vicious cycle. Zaid got prolonged till the kharif sowing season which led to delay in sowing and harvesting of kharif and, in turn, delayed clearing of the land for the rabi crop of wheat.

Farmers from other villages have also reported skipping the crop season. “I sow sesame and paddy in kharif every year in June. Since it did not rain, I could not sow these crops. Had I sown late, my rabi pea crop, which is my main source of income, would have been delayed,” Ajit Pratap of Jalaun district, Uttar Pradesh, said.

Kharif lag

As of August 12, 2022, kharif sowing lags by 3.76 million ha (mha) compared to the corresponding period in 2021, according to data on the website of the Union Ministry of Agriculture & Farmers’ Welfare.

Area under paddy—the main kharif crop—is short by 4.38 mha (12 per cent), compared to the 2021 data. The gap between “normal” paddy sown (calculated as an average of sown area between 2017-18 to 2021-22 during the corresponding week) during this time and the current sowing is much more at 21.9 per cent. The “normal” sown area for this time of the season is 39.7 mha.

This coincides with a deficit in rainfall in important paddy growing states of Uttar Pradesh, Bihar, Jharkhand and West Bengal. June had ended with a rain deficit of 8 per cent, with 18 states staring at a “large rainfall” deficit.

DTE analysed area under paddy till the second week of July in the last 10 years and found that there are fluctuations almost every year. In six of the 10 years, the area decreased when compared to the previous year’s figure during the same period.

‘Normal’ revised

IMD has taken note of the erratic nature of the monsoon. In April this year, it lowered the average normal value for June-September by 12 mm. The new normal of 868.6 mm is based on 1971-2020 data and replaces the earlier figure of 880.6 mm based on 1961-2010 data. This is reason enough for a re-look into the conventional sowing dates and practices followed across India.

In July 2020, Bal and other ICAR-CRIDA scientists started creating a dynamic crop weather calendar for 10 crops in 25 locations across the country. “The existing crop calendar is static. In the dynamic one, when you change an input — for instance, the monsoon arrival date or the average temperature in a particular month—the sowing and harvesting dates are optimised accordingly,” Bal said.

Nabansu Chattopadhyay, a former deputy director general of the agricultural meteorology division of IMD, is of the view that IMD’s rain data and its translation for use to meet agricultural needs are two different things.

“Land warming takes away the moisture from the soil, and heavy or excess rainfall does not allow it to retain the lost moisture because the soil does not get enough time to absorb it. Such scenarios occur when there are long breaks between the rain spells during monsoon,” he said.

Determining the onset of the crop growing season using this “soil-water balance” approach is important because it takes into account the amount of rainfall needed to build up the soil moisture and loss of soil moisture through evapotrans-piration. A dry spell of over two weeks after sowing could lead to crop failure or yield reduction because topsoil dries out.

New indices

ICAR scientists have tried to see the length and impact of a dry spell and have defined a new index called the dry spell index (DSI) in a paper published in the journal Agricultural and Forest Meteorology in December 2021. The index can be used to recommend area-specific crops based on new rain patterns.

The research finds that DSI is better in quantifying the reduction in yield due to a dry spell, as compared to the Standardised Precipitation Index (SPI), widely used by government agencies to monitor soil moisture levels. It takes into account the cumulative seasonal rainfall, not the length and impact of dry spells.

The paper quantifies the cumulative impact of dry spells during the kharif season on six major rain-fed crops in Rajasthan, Gujarat, Maharashtra, Karnataka, Telangana and Andhra Pradesh in 2012-16.

The analysis showed that the impact of dry spells on yields was higher in comparison to total rainfall indicated by the Standardised Precipitation Index. The productivity of all the crops was significantly influenced by DSI in over 65 per cent growing regions.

“The information on continuance of dry spells in a season is vital in deciding a particular crop or crop variety, and to breed varieties of various crop durations for a specific location and deciding adaptation strategies, supplementary irrigation and field operations in agriculture,” the paper said.

Granular assessment

Climate change should be integrated into crop calendars at the hyper local level, Abinash Mohanty, programme lead in the risks and adaptation team at Council on Energy, Environment and Water (CEEW), a non-profit in Delhi, said.

“We cannot have a straight cut fit for the whole of India because the monsoonal pattern is not the same or uniform across Indian districts,” he said, adding that the risk assessment and contingency plan also need to be synchronised.

“CEEW has been studying extreme weather events at the district level. We have conducted a granular risk assessment for the past 50 years and found that 75 per cent of the districts show a swapping trend, which means that the traditional flood prone areas are becoming drought areas and vice versa,” Mohanty said.

Contingency plans

Ideally, district-wise contingency plans for agriculture should be put into action depending on the rainfall deficit. In 2010, ICAR-CRIDA prepared a contingency plan for all the districts.

The plan includes information about the district’s agro-ecological zone; rainfall, irrigation and land use patterns; crops cultivated and the sowing window, among others. It also lists the kinds of emergencies the district is prone to and strategies to counter them.

For example, in Uttar Pradesh’s Aligarh district, which has received 52 per cent deficit rainfall between June 1 and August 19, the contingency plan advises farmers to plant early-maturing varieties of pearl millet such as Composite-ICTP-8203 and Raj-171 Hybrid-Pusa-23 and 322. It recommends cultivating moong bean varieties like Samraaat and Meha and sorghum varieties like Composite-CSV-13, CSV-15 and Vijeta Hybrid-CSH-16 and CSH-14.

The contingency plan for Bihar’s Aurangabad district, which has faced 47 per cent deficit rain between June 1 and August 19, recommends replacing normal crop varieties to early-growing varieties of traditional crops like rice, wheat, pigeon pea, lentils and chickpea.

However, in a July-end meeting between the Union agriculture secretary and officials of Bihar, Uttar Pradesh, Jharkhand and West Bengal, which had seen deficit rainfall by then, the officials said the states were not in a position to implement contingency plans because seeds of alternative crops were not available, a government official on condition of anonymity, said.

“They said that they do not keep a reserve of seeds in such large quantities. What will they do of those seeds if monsoon was normal,” the official said.

Still, contingency planning and adapting to changing climate could be a possible solution, V K Singh, director at ICAR-CRIDA, said. “We have identified 650 districts across India that are vulnerable to climate change. An updated plan for over 350 is already in place. Farmers need to adapt by culti-vating drought-resilient varieties of crops. They could diversify by choosing horticulture and growing grains,” he noted.

States want an update

Some states have recognised the need to align their cropping cycles with the erratic nature of the monsoon. Assam has requested ICAR-CRIDA to do a revision of the crop calendar of the whole state. Following this, ICAR formed a committee under Bal to look at the change in rainfall and temperature in the state and to work on the best way to revise the calendar.

In Bihar too, the state government, in its Climate Resilient Agriculture Plan formed in September 2019, talks about an “improved climate resilient variety which is suitable for the cropping system and crop calendar”.

Scientists also make a case for reclassifying agro-climatic zones that have been in use since 1979, when imd had first identified them to develop location-specific strate-gies for agricultural development in the country. “Agriculture needs re-oriention. There is a need to reclassify agro-climatic zones,” Chattopadhyay said.

Chhatopadhyay and three scientists from IMD-Delhi, IMD-Pune, and the Indian Institute of Tropical Meteorology, Pune, documented this in a paper published in the journal Current Science in 2019.

The paper observed significant changing trends in weather parameters like temperature, rainfall, heavy rainfall and rainy days at various agro-climatic zones in the northeastern states, Gujarat, hilly areas of the country, and central and peninsular India.

“This definitely indicates change in climate from pre-90 to post-90s,” the paper stated, and added that the climate change may be reflected in the agro-climatic zones as well and ultimately affect the criteria of their classification based on climatic parameters.

It argued that any change in climatic parameters, particularly temperature and rain, in the agro-climatic zones will have a significant bearing on the existing agro-climatic classification as well as on crop production.

IMD agrees

For the first time, IMD also has recognised the need to revise the crop weather calendar. “Studies suggest that variability is incre-asing in certain areas. It is leading to more floods and more droughts. There is a change in the distribution of rainfall and we are finding the frequency of high rainfall events increasing due to climate change,” Mrutyunjay Mohapatra, director general of meteorology, IMD, said.

After ICAR-CRIDA prepared dynamic crop calendars for 25 districts, IMD has asked the organisation to prepare a dynamic crop weather calendar for all districts in the country, Mohapatra said. The work has been completed for 75 districts as of now, he added.

Studies also say that when farmers are able to access better advisories, changing sowing dates is one of the most beneficial climate change adaptation measures for them.

A four-year intervention study on 11,250 farmers in 75 villages of Uttar Pradesh, Bihar, and Madhya Pradesh said that 43 per cent of the respondents found change of sowing dates as the most useful impact from efficient advisory services.

In the four years of the project, the farmers were able to access climate resilient agricultural technologies and best practices. The project was undertaken by the US Agency for International Development-India along with CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) to scale out resilient agricultural interventions.

For now, the dynamic crop weather calendar is running in a project mode and has helped farmers, Bal claimed. But there is a dire need to extend it to all the districts for all the crops in the forms of more effective advisories.

(With inputs from Vivek Mishra and Anil Ashwani Sharma)

This was first published in the 1-15 September, 2022 edition of Down To Earth

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