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Climate change to worsen agricultural productivity in Maharashtra: Study

The state faces an increasing risk from rising temperatures, which are likely to impact the production of four major crops, soybean, cotton, wheat and gram, says a study by the Institute for Sustainable Communities

Maharashtra is India’s second-largest state by population, and third-largest by area. More than half of the state’s 11.42 core population resides in rural areas. The climate is generally characterised by hot summers, monsoon and then mild winters. Agriculture in the state is primarily rainfed, with only 18.2% of crop area irrigated. The net sown area for agriculture in 2018-2019 was 168.15 lakh hectares, or about 55% of the total geographic area. 

A majority of Maharashtra’s rural residents are dependent on agriculture for their livelihoods, but in the past decade only 11.7% of the Gross State Value Added came from agriculture and allied activities.  The 2015-16 agriculture census found the average size of an operational holding to be 1.34 ha with cereals, pulses, oilseeds, cotton and sugarcane dominating the categories of crops grown. 

Climate change impact on rainfall, temperature patterns

Current farming practices are set to the climatic patterns that have persisted now for several generations. However, in recent years, these patterns and trends are being redefined largely because of the effects of climate change induced by human activities. Increased greenhouse gases like carbon dioxide, methane, nitrous oxide and fluorinated gases are causing a warming effect that is changing rainfall and temperature patterns, which have a direct impact on agriculture. The sector is also facing increasing population pressure, declining land and water availability and declining soil fertility. But climate change is a new stressor for our cropping systems.  As crops suffer, farmers and workers who depend on these crops are increasingly at risk. 

About the study

This increasing risk from climate change is likely to impact Maharashtra’s production of major crops grown in the state. The Institute for Sustainable Communities study on “Climate Change Impacts on Maharashtra Agriculture” examined week-wise 30-year averages of historical data (covering the years 1989-2018) and predicted (covering the years 2021-2050) rainfall and temperature data for eight districts across Khandesh, Marathwada and Vidarbha regions of the state. These regions primarily grow kharif crops of soya bean and cotton and rabi crops of wheat and gram. The analysis mapped climate modelling and projections, with crop phenology, looking at the optimal conditions across each of the growing stages for a crop coupled with community based participatory assessments to understand the impact on the farmers and farming.

What it found

The study predicted a mismatch in rainfall and temperature patterns with crop phenology across the monsoon (kharif) and winter (rabi) season. Late onset of monsoon and intermittent dry and wet spells have impacted the germination of soybean and cotton. Excess rainfall during the mid-kharif season will lead to an increase in fungal diseases, weeds, and pests. This is likely to impact the production of pods in soybean and boll formation in cotton. Waterlogged soil and humid conditions will promote rot, leading to a loss of soil nutrients and fertilisers from the soil. The overall impact of excessive rainfall during the fruit formation and maturity stage for both the kharif crops studied–soybean and cotton–will be on the yield and quality of the produce.

The biggest challenge for wheat cultivation is likely to be from the high temperatures at the time of grain ripening. Grain weight goes down with a rise in temperature, and temperatures during the time of grain filling are predicted to increase. Gram cultivation will see a sudden increase in temperatures during pod filling, causing pods to fill less. 

There is very little or almost no rainfall predicted for the rabi season, thereby making the crops entirely dependent on irrigation. With groundwater being a major source of water for irrigation, the pressure on aquifers will increase. The impact of high temperatures, rainfall and humidity will make outdoor work difficult for the farmers. Increased incidences of heat stress and humidity will have a bearing on farming operations like weeding and harvesting. 

The importance of data to mitigate climate change impacts

Reducing the impacts of changing climate on agriculture will require efforts in generating granular climate data. This data will need to be integrated in informing farming decisions, improving quality of inputs, enhancing knowledge on better cultivation practices, and adopting better management practices for resource conservation, amongst others.

While our findings link climate events and their impact on the developmental stage of a crop, it is difficult to make definitive quantitative statements on how much yields will drop, or what percentage of crops will be affected, because the effects of climate change on crops are complex and inter-related. Many factors from the variety of plants used, to the slope of the land, to the planting date and fertiliser use affect how climate will impact a crop, and these are difficult to untangle without access to exhaustive data on all aspects of the crop. 

Future research needs to focus on quantitative data on climate. This should include variables such as humidity, rainfall and temperature indices, pest attacks, variety used, planting date, soil characteristics, fertiliser use, labour use, irrigation details, and other such factors.  These factors will then have to be correlated to yield in order to better inform farmers on potential risks to crops in the future. 

**Romit Sen is Associate Director and Chaiti Bhagawat is Program Assistant at Institute for Sustainable Communities.

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