The rice azolla fish system features an ecological three-dimensional approach to agriculture.
Rice is planted on the ridge, azolla grown on the water surface, and fish raised in the water.
This new farming system was studied between 1984 and 1987. Experiments were conducted on two plots of land, each with an area of 0.2 ha and a 6-m2 fish pit. Growth of rice, azolla, and fish was recorded. The nutrient content of azolla and fish dung was determined by standard methods of analysis. Effect of different ridge widths on yields of rice, azolla, and fish.