Success in thirsty Sumba a challenge for researchers
Dryland tropical agroforestry is a little-researched area that is likely to be increasingly in demand as climate patterns change. Researchers on the island of Sumba in Indonesia are working hard and fast to meet the challenges.
Sumba’s nine-month-long dry season, rocky and sparsely-treed terrain and remote location on the southern edge of Indonesia’s eastern archipelago present huge challenges for local farmers. Many of the hamlets in the east of the island face regular, lengthy droughts and famines, alleviated only by outside assistance. Under these conditions, the World Agroforestry Centre (ICRAF) has begun work with farmers to rapidly assess the best ways of bringing deep-rooted perennials, that is, trees back into the landscapes to improve farmers’ livelihoods and food supply.
‘Sumba was once covered by forests, so we know that more tree-based livelihoods are possible than is currently the case’, said senior agroforestry scientist with ICRAF, James M. Roshetko. ‘However, the challenge is how best to achieve this given the decreasing rainy periods and low resource base of farmers. We are confident these obstacles can be overcome for the benefit of farmers here. Seeing success on Sumba will also mean that we have systems that could be applicable in other dry parts of Indonesia, Southeast Asia and the world’.
Working with Wahana Visi Indonesia (WVI) as lead of the project, ICRAF is deploying expertise gained in less-severe dryland landscapes in neighbouring Sulawesi island through the Agroforestry and Forestry in Sulawesi project, a five-year research-in-development project that is led by Dr Roshetko, funded by the Department of Foreign Affairs, Trade and Development, Canada.
In eastern Sumba, 30 existing agroforestry demonstration trials in seven hamlets are being assessed by ICRAF researchers, with corresponding experiments with intercropping fast-growing annual crops. Tree nurseries are being built with farmers to produce thousands of seedlings and facilitate the expertise to manage those seedlings and the resultant trees with limited water. All of this is being done rapidly owing to the likelihood of an even shorter wet season this year. Usually lasting just over three months, in 2016 the meteorological prediction is for only two months.
The agroforestry demonstration plots, which were planted by community members with WVI’s assistance, are typically located in low-lying areas, such as at the foot of slopes, where soil and water are likely to be more available, or next to a reliable water supply, often in the form of rainwater tanks provided by external agencies. The experimental plots of teak, mahogany, sandalwood, Gmelina and other timber species, such as the indigenous ‘indjuwati’, have been buffeted over the last few years by Sumba’s extreme conditions, with high winds, poor water management, hidden rock platforms beneath the thin soil and attack by wandering livestock all taking their toll. ICRAF’s researchers have been examining each plot tree by tree and talking with the managing farmers to assess exactly what have been the main challenges and how to overcome them.
While carrying out the plot assessments, the researchers have been identifying annual crops suitable for planting between the rows of trees, such as green beans and pineapple. This intercropping is intended to provide more food supply for households given that the tree plantings have been all of timber species. The plan faces the challenge of the shorter wet season, which threatens the viability of crop production, and so researchers must also identify if specific locations have better access to water supply, such as from tanks or springs. On the rocky plateaux inland from the thin coastal strip, wells are few and far between owing to the water table lying 1-to-4 km deep through solid rock.
At the same time as the plot assessments, ICRAF’s technicians have been showing farmers—both women and men—how to produce seedlings and how to build nursery shading to protect them from the harsh sun. Along with this, farmers are being introduced to grafting techniques, especially for fruit trees, that allow more productive varieties to be grafted to stronger local root stock, thereby, providing the basis for higher-yielding, better-quality and longer-lasting trees that will benefit farm households for many years.
Seeds and seedlings are being provided to farmers based on the results of a ‘priority tree species’ survey that was the first task conducted by ICRAF’s researchers. Each hamlet identified a range of timber and fruit species, with similarities and differences between hamlets. Each species requires different planting and management techniques to ensure not only that it survives but also flourishes despite the harsh conditions, which, while consistent across the eastern part of the island also vary in intensity or criticality from hamlet to hamlet.
‘We have seen success under similar conditions in Sulawesi and also in ICRAF’s sites in East Africa’, said Dr Roshetko. ‘So we are looking forward to adapting this knowledge to the unique situation on Sumba and sharing the success with those here who need it so much’.
More information about WVI: www.wahanavisi.org