New agroforestry horizons in Myanmar: the challenge of slash and burn
Myanmar is opening to the world and its agricultural systems are beginning to feel the pressure. World Agroforestry Centre scientists will soon start helping farmers with agroforestry, says Cathy Watson
Helping farmers to find alternatives to shifting cultivation is an urgent priority in Southeast Asia. Without support, they often opt for monocultural agriculture, which can degrade the soils and other ecosystem services, expose farmers to the boom-and-bust cycles of a single commodity and render their crops more vulnerable to climate change and plant pests and diseases.
Myanmar, recently opened up to the world and so experiencing new drivers of change, may follow this same detrimental path if its slash-and-burn systems are not guided in how they become sedentary. The shift to settled agriculture inevitably occurs as populations increase. ‘Slash-and-burn’ and ‘swidden’ agriculture are synonyms for shifting cultivation.
In northern Viet Nam, fields of maize on steep hillsides bleed soil into the valleys. In Xishuangbanna in China, a study by the World Agroforestry Centre found that monocultural rubber plantations had replaced almost all swidden fields, dramatically depleting soil carbon. Land under rubber in Indochina is predicted to quadruple by 2050, replacing secondary forests and swidden fields.
‘Shifting cultivation is probably the oldest farming practice in the world’, said Centre scientist Dietrich Schmidt-Vogt, who is leading the entry of the World Agroforestry Centre into Myanmar. ‘Across Asia, we have seen the disastrous consequences of replacing it with forms of land use that are ecologically or economically less sustainable’.
One alternative is more stable and productive agroforestry systems, such as mango trees introduced in maize fields in Viet Nam and jungle or ‘green rubber’ systems, in which farmers grow other trees and crops among the rubber.
In Myanmar, Schmidt-Vogt is starting the search for how to help farmers make the transition from shifting cultivation to more agroforestry—trees mixed with crops and animals—later this year. Working alongside forester Dr San Win, who is also the Vice-rector of Myanmar’s University of Forestry, they plan to identify the country’s different forms of shifting cultivation and their capacity to be converted into more productive agroforestry systems.
‘We already know that nitrogen-fixing alder, Alnus nepalensis, grows in Myanmar and we want to see if it can play a role in keeping land healthy and productive’, says Schmidt-Vogt. ‘In Sikkim in India, farmers grow Alnus with cardamom. Both plants have very dense root systems and are excellent at stopping erosion. Where farmers have access to markets, this ancient agroforestry system is profitable’. Myanmar is known for agroforestry systems with short rotation teak as well.
In addition to tackling transitions out of slash and burn, the Centre hopes to study the potential of indigenous tree species to produce biofuels for domestic use from their oily seeds. Candidate species include Vernicia montana, Sapindus mukorossi, Pongamia pinnata and Scleropyrum wallichianum, which are native species with wide distributions and many traditional uses. Integrated food-and-energy systems ensure that production of biofuels does not compete with production of food but rather complements it.
Schmidt-Vogt says Myanmar is ripe for agroforestry. ‘It has experienced great destruction of mangroves as they were converted to charcoal. This is why Cyclone Nargis was able to cause so much damage when it smashed into the coastline in 2008. The upland areas which are losing tree cover are the source of rivers and linked to the hydrology of the lowlands’,
His research with Dr San Win is funded by the Livelihoods and Food Security Trust Fund (LIFT), a multi-donor fund established in Myanmar in 2009. LIFT’s vision is to be an effective mechanism for channeling aid to partners to achieve its goal of improving the food and livelihoods’ security of the poor and vulnerable in Myanmar.
Interestingly, Myanmar is the birthplace of one of the most famous forms of agroforestry: ‘taungya’. The term means ‘hill (taung) ‘cultivation’ (ya) and was coined in the 1850s by Sir Dietrich Brandis (1824–1907), a German forester who worked with the British Imperial Forestry Service in then Burma.
Under taungya systems, farmers were allowed to grow crops in newly established plantations. The system proved so efficient that teak plantations were established at little cost as villagers, given the right to cultivate food crops in the early stages of plantation establishment, promoted afforestation on the cleared land by sowing teak seeds. The taungya system spread throughout Asia, Africa, and Latin America.
The work in Myanmar is linked to the CGIAR Research Program on Forests, Trees and Agroforestry