Rice-fish system

A rice-fish system is a polyculture practice that integrates rice agriculture with aquaculture, most commonly with freshwater fish. This practice is highly valued as it was one of the first to be considered as a “Globally Important Agricultural Heritage System” according to FAO-GEF (Global Environment Facility). It is based on a mutually beneficial symbiotic relationship between rice and fish that is developed when introduced into the same ecosystem. Many benefits, including social, economic and environmental come with these systems. Cultivating rice and fish simultaneously is a practice thought to be over 2,000 years old. Ancient clay models of rice fields containing miniature pieces, and more specifically miniature pieces of fish such as the common carp, have been found in China. They were found in tombs dating from the ancient Han dynasty (206 BC – 220 AD). Even though the exact location of the first rice-fish systems is unknown, it is believed that the system originated somewhere in continental Asia in countries such as India, Thailand, northern Vietnam and southern China. The most common theory is that the process started in China since they are considered precursors of aquaculture with heavily developed systems for the time. Archaeological researches have found that the common carps were probably one of the first fish used in rice-fish systems. Wei dynasty records dating from 220 to 265 AD mention “a small fish with yellow scales and a red tail, grown in the rice fields of Pi County northeast of Chengdu, Sichuan Province, can be used for making sauce”. Liu Xun wrote the first descriptions of the system, with texts written during 900 AD during the Tang dynasty. Rice-fish systems may have evolved from pond culture in China, with one theory stating that the practice started when farmers decided to place excess fry in their ponds. After observing the improved growth of fish when placed in rice fields instead of ponds, farmers took to the habit of raising their fish in rice fields, which would later lead to the rice-fish system.