Farmers use livestock for transportation and land preparation, and livestock waste can be recycled into organic fertilizer

The agro-biodiversity within the rice-based system presents great opportunities for improved nutrition within rural communities, increased farmer income through crop diversification, and the protection of a wealth of genetic resources for future generations.

Due to the continued presence of fresh water, wetland rice fields are habitat for a wide variety of terrestrial and aquatic organisms. The potential to diversify food sources within these rice-based ecosystem is, therefore, quite high. For thousands of years, rural people have relied heavily on the existing biodiversity within rice-based ecosystems. Often, they enhance this biodiversity with cultivated plants, domesticated animals and aquaculture to secure their daily food supply and income.

They use fish, frogs, snails, insects, and other aquatic organisms derived from these ecosystems as their main source of animal protein and essential fatty acids. Aquatic organisms in rice paddies can either be natural components of biodiversity that are trapped in the paddies, or they can be introduced intentionally (e.g. tilapia, barb and carp species). Fisheries are particularly important for poor people - especially the landless - who may also earn modest incomes from marketing fresh or processed aquatic food and medicinal products.

Various kinds of livestock are supported by rice-based systems. Ducks feed on small fish, other aquatic organisms and weeds within the paddy fields, while buffaloes, cattle, sheep and goats graze on rice straw as their main food source in rice-producing areas. Rice bran (a by-product of rice milling) and low-quality and surplus rice grains also provide feed supplements for livestock. In turn, farmers use livestock for transportation and land preparation, and livestock waste can be recycled into organic fertilizer.

Rice fields also host many natural enemies or predators, which provide a mechanism to control harmful insects and pests, thus reducing the need for pesticides. Similarly, fish feed on weeds and assist in weed control. Other plant species have established a symbiotic relationship with rice. For example, Azolla, a nitrogen-fixing aquatic fern, can be grown in paddy fields to improve nutrient availability, to reduce weeds and to facilitate fish-livestock integration. Plant varieties are used by farmers for food and medicine and as feed for fish and livestock.