Land change in Sri Lanka as famous tea loses out to vegetables
In the highlands of Nuwara Eliya, tea country since 1840, swathes of the perennial crop are being uprooted. On steep slopes and tea terraces, farmers are increasingly growing potatoes, leeks, carrots and other temperate vegetables.
Sri Lanka’s per capita income of $2910 and lower middle income status have triggered a dietary transition. Vegetables are much sought, particularly by urban dwellers, and profits are high. However, the shift from tea and loss of permanent dense foliage on in its largest water catchment is causing erosion.
The Mahaveli River is Sri Lanka’s lifeline, contributing more than 40% of the country’s hydropower from six dams and feeding its largest irrigation schemes. When electricity from dams falls, Sri Lanka compensates by burning more coal and diesel than usual.
February is always dry in this island nation, but this year the Mahaveli’s levels are perilously low. The vista from Nuwara Eliya shows wide fringes of bare red earth around the river tanks, which are experiencing siltation and sedimentation.
“These tea estates were once natural forest, which is best for river flow,” explains scientist DK Pushpakumara, who represents the World Agroforestry Centre (ICRAF) in Sri Lanka. “Tea with shade trees is next best. But this cultivation of vegetables threatens the heart of our water system.”
“Trees force water into the ground” explains Ravi Prabhu, who directs research for ICRAF. The proliferation of buildings is a concern too. “Water will just run off with little re-charging of aquifers,” says ICRAF chief scientist Meine van Noordwijk, who also notes that rains are increasingly fickle.
Sri Lanka is, in fact, an extensively tree-clad country. Intact forest makes up 28.2% (1,759,840 ha) and tree-rich agroforestry systems a further 24.4%. Rubber and tea cover 300,000 ha; coconuts 396,000 ha; and home gardens 900,000 ha. Agroforestry is the major source of sawlogs.
Human capacity is extensive too, with the investment in education paying off. The University of Peradeniya’s agriculture faculty boasts 45 PhD holders. Youth female literacy is 99% and population growth less than 1% a year. Compare this with African countries where yearly population growth can surpass 3% and densities in highlands 1000 people/ha.
If any country can solve its land challenges, therefore, Sri Lanka can. Just 8.9% of its people live in poverty. But there is no space for complacency. The Regional Resource Centre for Asia and the Pacific notes that one-third of the land suffers considerable erosion. “Poorly managed tea lands as well as abandoned tea lands lose sediments 15 times more than in a homestead, and 20 to 22 times more than in the wet zone forests.” See Sri Lanka: State of the Environment (PDF)
Degradation also threatens Sri Lanka as a global biodiversity hotspot. Home to 189 out of the world’s 377 plant families, its multi-strata home gardens are particularly rich repositories with up to 1000 trees per hectare of between 100 and 200 tree species, almost all of which are used in one way or another.
Such “high-density trees-outside-of-forests systems” sustain ecosystem services, and Dr Pushpakumara wants them strengthened. “In Sri Lanka we cannot think about environmental protection without keeping the agricultural landscape healthy. We need diversification and domestication of trees.”
Sri Lanka has over 230 fruit tree species, many underutilized. Jackfruit (Artocarpus heterophyllus) provides fodder for elephants and goats, dye for the robes of Buddhist monks, seeds for flour, and mesocarp flesh for curry and desert. “We call it the rice tree because of its place in food security,” says the professor at the University of Peradeniya.
In Colombo last week ICRAF staff met with Minister for Economic Development Basil Rajapakse, for whose strategy the country’s four million home gardens are a cornerstone. “Our green cover is mainly in home gardens. They guard the land,” said the veteran politician.
In addition, we met the Minister for Coconut Industries, Jagat Pushpakumara. “We need to optimize our systems,” said the minister. “Coconuts are our island’s dominant crop.” Climate change is particularly hard on coconuts; its flowers abort if temperatures rise too high.
ICRAF director general Tony Simons stressed to both ministers that “nothing is better than a tree for taking carbon from the atmosphere and adding it to the soil. While the world worries about a 2-degree C increase from global warming, we need to remember that tree cover cools crops by 2-4 degrees.”
Cathy Watson is the Head, Program Development Unit, World Agroforestry Centre (ICRAF)