Wasser in der Landwirtschaft - agriwaterpedia.info

come generating activities (including post-harvest activities such as processing, transport, trading, marketing)
which pose additional sources of livelihood.
In fish culture, notably in those systems focused at smallholders (termed by FAO as “rural aquaculture”),
activities should be distinguished between those of the individual household versus community-based
approaches. In selection of aquaculture sites, an important factor is either the location at the water source
(e.g. a stream or canal), or the need for conveyance over distances to the site of the pond, or through
pumping of water. In this regard, security and theft-prevention often is a significant issue.
The comparative water use efficiency in aquaculture can be significantly better than for other enterprises,
such as livestock, and needs to be evaluated within the local situational context. Water use in aquaculture
through existing water bodies and sources distinguishes between moving/flowing water (such as canals,
rivers) and stagnant water (such as ponds or floodplains). Often, aquaculture systems require management
measures such as conveyance, diversion or pumping.
In utilizing existing water bodies, the following categories are distinguished: waterways (rivers/streams,
canals), lakes and reservoirs (fishery, net cages), floodplains (trap ponds, fenced-in areas), lowlands or
“inland valleys” (rain-fed ponds, stream-fed ponds), urban wastewater-fed aquaculture, and refuges/
brushparks (canals, lakes, lagoons).
Aquaculture can take place before crop use, e.g. through irrigation of ponds above rice fields/terraces,
such as in traditional rice cultivation, or in intensive fish culture in large pond-like reservoirs, where
effluent is used to irrigate cotton fields. In classical rice-in-paddy field culture, fish are grown in the rice
field during the rice culture period, and usually provided refuge trenches or small pond-like excavations.
In many societies, other water-living organisms such as crabs, shrimp, snails, mussels, frogs and small wild
fish species occur naturally within rice fields, and have been collected and used for food. Initiatives for
aquaculture (and for irrigation management for agriculture in general) should strive to maintain these
important sources of food and income. However, in many cases, agricultural development has actually
eradicated them.
Integrating aquaculture into irrigation schemes would require a change in thinking of how the command
area of schemes is used, and what types of agricultural activities (such as aquaculture) are permitted. In the
past, ponds were specifically established below dams, and farmers from the scheme were expected to rent
them, operate them (requiring frequent travel from their often remotely located homesteads), and also pay
for water and other services. These pond clusters, designed by irrigation engineers did not consider the
needs of the farmers and therefore have not been adopted.
Rain-fed ponds with close integration into homestead
activities are widely adopted in some countries in Asia.
These often start off as rice-fish systems, or farm-ponds
close to the homestead, utilize existing on-farm wastes
and residues (avoiding off-farm inputs), and pose a lowrisk
entry-level for novice farmers.
In Africa, numerous initiatives for rain-fed and stream-fed
ponds have been tried in the past decades. Only in recent
years have some become successful, due to increasing
better market opportunities from declining natural fish
supply. Also, in some cases, sociocultural inhibitors have
disappeared and enabled entrepreneurial initiatives to develop, not only through aquaculture.
43