KOCHI: Kerala and monsoon have an intricate relationship. The state’s nature, character, and economy are deeply tied to the annual rains, which is essential for its sustenance.
However, long-term changes in monsoon patterns have started having a detrimental effect on the state’s economy and environment. Adversely impacted by the erratic rainfall, paddy farmers have switched from longer-duration indigenous rice varieties to shorter-duration types and also moved to crops like banana and areca nut.
Plantation crops like pepper, cardamom, rubber, tea, and coffee are highly dependent on the monsoon, with their production closely linked to the timing and amount of rain. Excessive rainfall can damage these cash crops, while a shorter monsoon period leads to reduced crop yields.
Kerala receives an annual rainfall of 3,000mm from the southwest monsoon and the retreating northeast monsoon. More than 68% of this rainfall occurs during the monsoon period from June to September.
S Abhilash, director of the Advanced Centre for Atmospheric Radar Research (ACARR), told TNIE that there have been long-term changes in monsoon patterns, with a decline in the number of rainy days and an increase in the intensity of rain spells.
“Distribution of rainfall has changed over the years, though the overall volume of rain has remained more or less the same. Gaps between rainfall events have also increased. Additionally, the onset of monsoon is being delayed due to increased cyclonic activities in the Arabian Sea,” he said.
Dr Gopakumar Cholayil, an agro-meteorologist, emphasised the crucial interplay between weather, climate, and crop distribution and production. Climate dictates a crop’s suitability to a particular region, while weather influences its yield attributes, he said. “There is a significant shift in agricultural landscapes, such as the decline of oranges in Wayanad, with paddy fields giving way to areca nut and banana plantations. Climate change has exacerbated various issues across Kerala, causing reduced rainfall, and loss of wetlands and biodiversity,” Gopakumar said.
Reports by the agricultural meteorology department of the Kerala Agricultural University indicate that physio-chemical changes occur in plants due to changes in monsoon patterns.
June is the rainiest month in southern Kerala, while the northern parts get more rain in July. The study states that for the past few years, monthly rainfall has been decreasing in June and July and increasing in August and September.
Gopakumar said acidity increases and sugar content decreases in coffee beans with changes in rainfall during June and July. In black pepper, the flowering is impacted, while in cardamoms, the tillering (growth of side shoots) is affected. The mortality rate of pepper vines can go up to 40% due to the absence of rain in June and July. Berry initiation and elongation also depend on a cloudy and overcast sky, which is becoming rarer. Rain in July is very critical for cardamom. Cardamom berries shrivel and fall off the plant, when the atmospheric temperature rises above normal during flowering season. Production of fresh leaves declines when dry conditions prevail.
According to Girigan Gopi of the M S Swaminathan Research Foundation, the biodiversity loss when farmers move away from paddy cultivation is significant. “We have lost several indigenous rice varieties due to the shift to shorter-duration types. Varieties like ‘navara’ and ‘pokkali’ possess unique characteristics and need to be conserved. Paddy requires standing water and the crops help maintain groundwater level after the rain. With farmers shifting to crops like banana and areca nut, groundwater has depleted in many regions,” he said.
Paddy fields act as human-made wetlands, playing a crucial role in groundwater recharge, water regulation, flood and drought control, and biodiversity conservation, in addition to its role in food production. Between 2000-01 and 2021-22, the area under paddy cultivation shrunk by 39%.
Gopakumar said the agriculture sector remains the primary source of livelihood for a majority of Kerala’s population. “Over time, significant changes have occurred in cropping patterns. The area under rice and cashew cultivation has declined, while the area under rubber and coconut has increased. Vanilla and cocoa were introduced, but vanilla has since disappeared. The area under cocoa too has declined,” he said.
Gopakumar said changes in monsoon pattern, though slow, are irreversible and could fundamentally alter the state’s socioeconomic structure.
‘Monsooned’ coffee
The long-term impact of climate change can be best illustrated by the fate of the famed Monsooned Malabar, a specialty coffee cured by the unique monsoon rain in the Malabar coast. The distinctive coffee boasts unique cupping characteristics. Upset by the fluctuating taste and fortunes of the bean, an exporting firm catering to Europe, commissioned a study to examine the reasons for the same. The study, which blamed it all on the monsoon, conclusively proved how erratic rain hits the quality of coffee.
Dr Gopakumar Cholayil, who was part of the study at the College of Climate Change and Environmental Science, Kerala Agricultural University, Vellanikkara, said the quality of the coffee is better if monsoon is heavy and continuous during July-August over Malabar region.
The genesis of the coffee is as fascinating as its taste. Coffee transported from the Malabar coast during the era of sailing ships underwent physiological changes in the damp confines of the wooden holds. Over the six-month journey, the beans would lose its colour and some of its quality. However, consumers developed a fondness for its mellow, less acidic profile.
In response to consumer preferences, coffee exporters devised the perfect process known as “Monsooning Coffee.” This process involves subjecting the beans to a specialised treatment during monsoon. Today, this coffee graces the menus of specialised coffee salons worldwide and is celebrated for its distinct characteristics including a robust body, mild acidity, pleasant aroma, and flavour.