Introduction
The Tank (wewa), the Paddy Field (ketha), and the Temple (dagoba) made up the central concept in traditional Sri Lankan rural society. While the Temple handled spiritual as well as administrative issues within village communities and the Paddy Field ensured food security, the Tank was the vital core of the rural society. Sri Lanka is two third dryland area; irrigation was and remains crucial to agricultural activities. Therefore, the triangle of Tank, Paddy Field and Temple was the foundation of traditional agricultural society in dryland Sri Lanka. However, modernization processes have abolished the integrity of this socio-technological concept, often with adverse effects to small farmers and rural populations, as will be demonstrated in the paper.
The irrigation technology of the ancient Sri Lankan hydraulic society was based on an intricate, highly integrated cascade system of tanks and channels. This system served the population of the dryland well until the collapse of the Polonnaruwa Kingdom in the 13th century. Parts of the ancient irrigation system continued to be functional thereafter, but during the British colonial era, most village-level tanks fell into disrepair and traditional knowledge regarding irrigation practices was disregarded by the authorities in charge. In modern dryland Sri Lanka, water supply is controlled through state-led development mechanisms. Large-scale multi-purpose technologies are implemented, for instance in the context of the Mahaweli Development Program (MDP), which is based on the countries' largest river. Government-sponsored settlement programs and the use of "Green Revolution" technology (chemical fertilizers, pesticides and mechanized agriculture, innovative seeds) have shaped the nature of agricultural life in dryland Sri Lanka since independence.
The social structure of rural life in the areas under research is today characterized by small-scale agriculture (paddy cultivation and chena, a form of slash-and-burn vegetable farming) on relatively fragmented plots. The majority made up by the social group of Sinhalese Buddhist paddy farmers appear to be relatively homogenous. However, modernization processes and intensified social mobility in the context of globalization compromise social coherence. Furthermore, Sri Lanka's status as a post-conflict society after decades of ethnic civil war continues to shape social relations and political perspectives in civil society.
The arena of political contest between stakeholders is made of by questions over water allocation, subsidies of agricultural inputs, price stabilization mechanisms and social services. Climate change is projected to become a serious future challenge to small farmers' livelihoods and economic security. The inquiry seeks to identify socioeconomic and political questions in connection to environmental change and technological shifts in dryland Sri Lanka.
Methods/ Materials
This paper is based on field research in May 2013 in Horrowpothana DS, Anaradhapura District, North Central Province, Sri Lanka and March/April 2014 in Kantale DS, Trincomalee District, Eastern Province, Sri Lanka. It is amended by official statistics from government sources and international organizations. Within field research, qualitative research methodology was applied. This included participant observation as well as semi-structured interviews with experts and stakeholders in dryland agriculture: Small farmers, representatives of the local administration, members of NGOs.
The paper follows a political ecology approach, which means that it enquires the way how socioeconomic dynamics and power relations alter and dominate ecological processes. Political ecology seeks to explain environmental change through a political economy of natural resources. Accordingly, the research was focuses on the political, social and economic interactions in the field of irrigation agriculture in dryland Sri Lanka.
The political ecology approach relies on interdisciplinary; in the case study research at hand, insights from archaeology, geography, ecology and agronomy were combined with political science and economics, in the overall context of anthropologic methods. Adequate communication between experts of different fields remains one of the great methodological challenges in this kind of multidisciplinary research.
Results and Discussion
Interviews with small-scale farmers and government officials identified a major threat to the well-being of rural populations in the quasi-epidemic occurrence of chronic kidney disease of unknown etiology (CKDu).The high frequency of CKDu is accompanied with fatalities of mid-aged persons, economic hardship for the communities and families of deceased, and an overall sense of angst concerning the environmental security of rural life. Different strands of explanation to the CKDu epidemic were observed in the population, but almost all pointed towards unsafe drinking water. Current socio-medical research implicates the impacts of agricultural modernization, specifically the use of chemical fertilizers and pesticides, as responsible for the high occurrence of CKDu. Arsenic (As) poisoning stemming from residues of chemical inputs seems to largely cause CKDu, with the occurrence of a certain type of soil (Reddish Brown Earth, RBE) as a contributing factor. As an immediate measure, government has banned the pesticide glyphosate, to the dismay of many peasant farmers relying on the use of pesticides in their agricultural practices. Agricultural officers point towards what they describe as overuse of pesticides.
However, the use of chemical input is part of an integrated system of modernized agriculture that relies on both state intervention and market mechanisms in combination with a set of technological and organizational principles. Although many stakeholders speak of the need to change the system in order to ensure livelihoods, health and wellbeing of rural communities, there is hardly any coherent alternative ready for implementation. The rural Sinhalese Buddhist population of dryland Sri Lanka makes up an important power base for the ruling nationalist party alliance.
However, government policies so far fail to address some of the most serious socioeconomic threats that face rural communities. This could lead to serious conflicts over agricultural and social policies and water allocation in the future. Conclusion The overuse of pesticides impairs drinking water safety in dryland Sri Lanka, a semi-arid region already affected by water scarcity, possibly leading to high occurrence of potentially fatal CKDu. What looks like a classic "tragedy of the commons" is in reality caused by complex interactions between a market-based agricultural sector, government interventions in the scope of development policies, and global dynamics affecting food systems and agricultural production.