An integrated agro-ecosystem
In the Ziro Valley of Arunachal Pradesh, at an altitude around 1,570 meters, the Apatani people practice a unique form of agriculture that integrates rice, fish, and forestry. This system, developed over centuries, functions without farm animals or modern machinery, relying entirely on human labor and a deep understanding of the local ecology. The valley floor is meticulously terraced into plots for wet rice cultivation. These fields are irrigated by a gravity-fed network of bamboo and wooden pipes that divert water from mountain streams. This complex system maintains a constant water level ideal for both rice and fish.
The core of the system is the symbiotic relationship between rice and fish, a practice known locally as Aji-Nguyi. Shortly after transplanting rice seedlings, farmers introduce fingerlings of fish, primarily Common Carp (Cyprinus carpio), into the flooded paddies. The fish thrive on plankton, algae, and insect pests that would otherwise harm the rice. Their movement aerates the soil, and their excrement is a natural fertilizer, boosting rice productivity by an estimated 10-15%. This method can yield an additional 350 to 500 kilograms of fish per hectare each season. To ensure the fish survive when water levels are low, a small ditch or refuge area is dug into each paddy.