India’s traditional agriculture in jeopardy

1 December 2023, by Lea Schröder

Photo: UHH/Schröder

Climate change is impacting agriculture in regions around the globe. Things will become especially difficult in areas like the Himalayas of Northeast India, where steep slopes and nutrient-poor soils already make farming a challenge. What are the prospects for the local population?

Clear a field, sow, reap, switch to a new field. In many farming regions throughout the Himalayas, shifting cultivation is employed – a traditional farming practice used predominantly for rice, but also for other grains and vegetables. In this approach, a section of forest is cleared and burned, which serves to destroy pests and to fertilize the soil with ash. After cultivating it for one or two years, the farmer moves on to a new field. Now the old field lies fallow, grasses and shrubs spread, and a new forest slowly starts to grow as the soil recovers. At Universität Hamburg’s Cluster of Excellence for climate research CLICCS, my team and I are working to explore how traditional farming methods like this one will be affected by a changing climate.

Shifting cultivation already under pressure

Climate change hasn’t just led to forest fires in Australia and dry periods in Germany – it’s also affecting farmers in Northeast India. In spring 2023, we traveled there to assess how much local agriculture was already impacted. The farmers told us that, for example, they’d been unable to plant corn that spring due to a lack of rain. And there are other challenges to be overcome: many young people are leaving their home villages, which means they aren’t there to pitch in. In other regions, commercial plantations are increasingly competing with traditional types of farming. This reduces the amount of available land, which can lead to shorter cultivation cycles.

What will happen between now and 2100?

But how will climate change affect fields in the Himalayas in future? To get a better idea, we fed information from soil samples and climate data into a computer model that simulates all processes connecting the atmosphere, plants and soil, e.g. the water cycle, plant growth and soil erosion. In addition, the model factored in when rice is sown in India, when it is harvested, and how long the fields lie fallow afterwards. This allowed us to estimate how the climate would affect Northeast India’s soils by 2100.

In the future, more intensive rain during the summer monsoon will wash away more of the fertile soil. Farming on steep slopes and intensively cultivated fields – i.e., those with short fallow periods – will be particularly hard hit, as rainfall will more easily erode the soil. In concrete terms, soil erosion could increase by more than 60 percent if the planet warms by 3 degrees Celsius as opposed to 1.5 degrees. Consequently, especially toward the end of the century, soil erosion will increasingly pose a problem for traditional agriculture in Northeast India.

Older generation still clings to shifting cultivation

Given these prospects, do farmers want to continue practicing shifting cultivation? Among the younger generation, many are abandoning agriculture. In contrast, older farmers tend to cling to shifting cultivation, both for cultural reasons and due to a lack of alternatives, even if it will mean having to adapt to new circumstances.

Longer breaks between the cultivation cycles could help; less of the fertile soil would be eroded. The nature of the field also needs to be borne in mind. In this regard, the rule of thumb is: the steeper the field, the longer it should lie fallow. Planting trees can also help; their roots help to stabilize the soil.