INCREASE WORLD FOOD PRODUCTION
The green revolution has tripled world grain production using
fertilisers and irrigation but has now come to limits like availability of
water, salinity, unsustainable mechanization, energy consumption, etc. 1
Billion people still experience hunger and the world population is growing
so new approaches are needed.
Barriers for small farmers
Some 75% of the farmers in developing countries have less than 5 Hectares
of land and a yearly income of 300 to 800US$. A single disastrous crop
failure can turn them into landless labourers or send them into the urban
ghetto. They have no access to technology like tractors or harvesters and
irrigation technology is expensive. (300 - 500US$ for a
motor pump for shallow wells. Deep Well pumps are more expensive).
Small farmers normally cannot afford these technologies and subsidies on
wells and irrigation schemes often have not worked or only reached bigger
Still the potential of small farmers to increase production by irrigation
is enormous and using the right varieties and technologies, food production
worldwide could be tripled, but as P. Polak of IDE states: "The most
important barrier is lack of affordable irrigation technology".
Low-cost irrigation from shallow wells
Modern irrigation technology has been developed to be used on a large scale
(25% of the world farmers). However there are promising developments for
small scale farmers.
For instance in Bangladesh and India there now is low-cost well drilling by
combined with a "Treadle pump" (a pedal pump, costing 10
- 30 US$).
With low cost of labour and rising cost of fuel, irrigating with this
Treadle pump is much cheaper than with a motor pump. The organisation IDE
informs that more than one million farmers already irrigate rice or
vegetables with Treadle pumps and so earn an additional income of 100US$ a
Low-cost irrigation from deep wells
The Treadle pump works in areas with water levels less than 8 meters deep,
but for lower water levels, a different pump technology is needed. For wells
down to 70 m. deep, the new Rope pump is now considered a good option.
Similar to the Treadle pump the Rope pump has low production cost and is
easy to install and maintain. Because its high efficiency
(40 l/min. 10 m well) the use of the Hand Rope
pump for small scale irrigation is increasing. For larger scale irrigation,
Rope pump models "powered by" wind, horse, pedals and electric or diesel
motors have capacities of 60 to 180 litres per minute. From wells of 10 to
40 meters deep, 2 to 0.5 Ha. can be irrigated with furrow irrigation. If the
newer low-pressure drip irrigation technology is used, irrigated areas could
Low-cost drip irrigation*
The USA based organization IDE has developed low-cost drip irrigation
systems for small farmers ranging from a 5 US$ Kit for home gardens to a 250
US$ microtube system to irrigate 1 arce. These technologies are reducing
water consumption and cost 40 to 60% compared to conventional drip systems.*
The pump capacity of a Hand Rope pump is 2.4 m3 per hour (10 m well),
enough to irrigate for instance 2000 tomato plants. The water outlet of
the Multi purpose model is high so a water tank can be filled directly.
Instead of a metal drum a cement tank may be used with the advantage that
costs per litre are much lower, long lasting material (no corrosion),
volume can be 500 to ..5000 litres, lower part can be used for some fish
production, and the tank can be constructed with local materials and
skills. For instance after a short training, users can make the tank
A cement tank of e.g. 800 litres consists of:
100 bricks, 1 kg of steel wire, 2 bags of cement, 6 bags of sand.
The tank is round and reinforced with steel wire on the outside of the
A simple filter is included in the tank and using PVC caps, no valves are
The height of 1 meter is enough for the drip irrigation to function.
The IDE drip system for 520 plants costs US$ 15-20(in Bangladesh), and a
similar system made of local materials (black hose and PVC tubes) costs
US$ 30 (in Nicaragua).
The irrigated area can be expanded to even 0.5 Ha., according to well
depth, plants or trees to be irrigated and hours of pumping.
Depending local situation the costs of a basic irrigation set is 70 to
140 US$ including:
|| Rope pump (for wells 1 to 40 m deep)|
|| Cément tank (800 litres)|
|| Micro drip system (for 120 sqm, 520 tomato