Andongan as a strategy for purifying agricultural irrigation water: case study of Subak Sembung, Bali

Farmers in Bali have for centuries applied local wisdom in the concept of andongan to obtain better water quality from Subak irrigation streams. The problem is that the implementation of andongan is starting to be abandoned because farmers do not understand the benefits and functions of andongan. This research aims to analyze the local wisdom in the andongan concept in Subak Sembung, Denpasar-Bali, and identify the plants used in andongan. The target is that the andongan concept can be revitalized so that it can be implemented again by farmers. Moreover, the idea of andongan in terms of its function, purpose, and how it works in principle is the same as phytoremediation technology. The case study method with a qualitative approach was used in this research to collect data through observation, interviews, and documentation. If examined closely, andongan is a water management system that reflects Balinese farmers' respect for water as a source of life. Water is respected as a vital element for producing food and maintaining the sustainability of the agricultural sector. Conceptually, andongan is a water purification innovation using plants commonly referred to as phytoremediation technology. The types of plants commonly used to purify water in andongan are water hyacinth (Eichornia Crassipes) and lotus (Nymphae sp.). The implementation of the Andongan concept in Subak currently faces challenges related to farmers' land ownership status. Tenant farmers who do not have permanent ownership of the land they manage are reluctant to build Andongan because they are worried that this will reduce the size of the planting area and result in a decrease in crop yields. Based on the results of the study, it can be concluded that farmers in Bali have been applying phytoremediation technology for centuries in a water management concept called Andongan. The plants used in andongan also have benefits as animal feed and for religious ceremonies.