Integrated Rice + Fish Farming in the Homesteads of Arunachal Pradesh, Northeastern India: A Unique Example of Sustainable Natural-Resource-Management for Subsistence.

During the past 50 years, the Apatani tribe of Ziro Valley of Arunachal Pradesh in the Eastern Himalayan region of India has developed a unique land-use system of growing rice (Oryza sativa L.) and fish together on the same unit of land in their homestead farms. The 32 km² of cultivable land of the valley (elevation of 1,500 m asl) is surrounded by undulating hills, and the average farm size is about 1.5 ha. Faced with shortages of staple food items of rice and fish, the Apatani tribe of subsistence farmers developed an ingenious system of cultivating these commodities together – in preference to rampant shifting cultivation that is practiced by most other tribes of the state – by capitalizing on the region’s good water supply (annual rainfall of about 1,500 mm during April – October, supplemented by natural water flow from the hills surrounding the valley). The system consists of growing two crops of rice per year (March–July and July–October) and rearing fish in paddy fields especially during the first crop of rice. Other crops include millets cultivated on bunds between rice plots, and domestic animals include mithun (Bos frontalis), pigs, and poultry. Crop residues and animal waste are the sources of nutrients to crops; chemical fertilizers and insecticides are not used. Over the years, rice yield has been stable at about 3,700 kg ha^-1 year^-1(two crops per year). Recently, UNESCO has tentatively added the Ziro Valley to its list of “World Heritage Sites” in recognition of its “extremely high productivity” and “unique” way of preserving the ecology. The resilience and the sustainability of the system could be attributed to efficient nutrient cycling and possibly nutrient input through water seeping in from surrounding hills; these have not been, but deserve to be quantified.