Integrated agriculture-aquaculture: A primer

The rice-fish ecosystem

by Ahyaudin Ali

Figure 1. Simplified nutrient flows

To understand the rice-fish ecosystem as discussed in this paper, here are some terms to note:

Fertilizer - input of simple nutrients to the system.

- organic - available also to fish, plankton, algae, soil, fauna and bacteria
- inorganic - available only to rice crops, macrophytes/algae/weeds, phytoplanktons and bacteria.

Photosynthesis

- produces food from simple nutrients using sun's energy;
- plants, algae and phytoplankton are food for fish, insects, zooplankton and soil fauna

Decomposed materials - add to the detritus layer
Bacteria - organisms which recycle materials back to simple nutrients
Fish - examples of various feeding groups

Figure 2. Ecosystem components

Conceptual food chain for fish in the system

Issues for further consideration

The ricefield environment is a specialized culture environment for fish that can be exploited best through certain types of polyculture.

Fish such as common carp, through their foraging behaviour, aerate the topmost sediment layer and enhance the aerobic bacterial decomposition process thereby ensuring the release of inorganic nutrients at a rapid rate.