The integrated rice-field irrigation system of Bali, Indonesia, has been awarded World Heritage Cultural Landscape status by UNESCO. It has maintained agricultural ecosystem services for over 1000 years but might not survive its popularity, says Elizabeth Kahurani
With over 2 million visitors a year, the Balinese subak rice-field irrigation system is in danger of being loved to death.
‘The landscape and its cultural traditions are so popular, farmers are selling their rice fields to developers, taking out of production about 1000 hectares a year’, said Steve Lansing, an ecological anthropologist who has been studying the system since 1974. ‘Because the entire system is integrated, when a few terraced fields are sold, the taxes on neighbouring farms increase, putting pressure on more farmers to sell, which threatens the viability of the whole. At the current rate of loss of rice fields, all subak are under threat and unless something is done in the next few years, the entire system could collapse’.
To prevent this from happening, in the UNESCO plan developed by Lansing and his Balinese colleagues a bottom–up model used by the subak themselves is being adapted for their protection. A Governing Assembly consisting of elected heads of villages and subak will manage the world heritage area. The Assembly will decide which aspects of the landscape visitors should engage with, collect fees from their visits, and use this revenue for the benefit of all.
‘This will be the first UNESCO site in Asia to be managed locally and not by government’, noted Lansing, who spoke at the 6th Annual Ecosystem Services Partnership Conference in Bali, 26 August 2013. ‘We hope that the councils will be able to act quickly enough to stop the threat to their own existence’.
‘An important development to note here is the preservation not just of the rice terraces but also of the management system’, said Meine van Noordwijk, Chief Scientist at the World Agroforestry Centre and head of the conference organizing committee. ‘The subak manage their own specific irrigation system that is intimately linked to all the others. This is unique to UNESCO heritage sites in Asia where the requirement normally is to first set up a management system that has a top–down approach’.
The system was earlier put to the test as a consequence of the Green Revolution of the 1970s when the Government of Indonesia introduced a technology package of new rice varieties, chemical fertilizers and organic pesticides. Farmers were urged to plant rice as often as possible with the new fertilizers and pesticides, which bypassed the controlled pattern of the water temple systems that provided natural fertilizer and pest control.
Lansing explained: ‘The results had unintended consequences because the absence of synchronised fallow periods led to an explosion of pests. Substitution with high technology affected other aspects of the ecosystem because use of fertilizers in the already nutrient-rich water meant that the fertilizer was washed into the sea via the rivers, causing growth of algae that covered and killed the coral reefs. Today, the water temples are in control again but problems caused by excess fertilizers persist’.
In Bali, the ancient system of water temples enables the subak to coordinate their activities along entire river systems. Inscriptions issued by Balinese kings in the 11th century describe subak and water temples, some of which are still functioning today. Irrigation water is regarded as a gift from the goddess of the volcanic crater lakes. Each subak performs ritual offerings to the goddess and other deities in their own water temples. These temples also provide a venue where farmers meet to elect leaders and make democratic decisions about their irrigation schedules. Groups of subak that share a common water source form a congregation of regional water temples, where all subak agree on watershed-scale cropping schedules.
‘In this way, each village temple controls the water that goes into nearby rice terraces; regional temples control the water that flows into larger areas’, explained Lansing. ‘The control of water is key to rice growth, in two main ways. First, the water flows over volcanic rocks rich in mineral nutrients, such as phosphate and potassium. The rice paddies are effectively artificial ponds in which the fertility of the water creates an aquarium-like effect; the processes in the water help the rice grow through providing the necessary nutrients. Second, the upstream subak ensure that water flows to their downstream counterparts. This brings about a synchronized planting and harvest pattern that has turned out to be an excellent pest control and management system, providing benefits for all’.
By synchronising irrigation schedules across neighbouring subak, pest populations are controlled when the fields are harvested and flooded, depriving the pests of food and habitat.
‘The subak have achieved such success by getting the right scale of coordination through a system of controlling and sharing water that forms an integrated irrigation system in Bali, which has enabled them to maintain the ecology of their rice terraces for over 1000 years’, said Lansing.
Lansing will be speaking on the topic at the Kongres Kebudayaan Bali, 24–25 September, and at the Ubud Writers and Readers Festival, 12–13 October.
Edited by Robert Finlayson