Irrigation - Spray head

Spray irrigation for urban market gardening in Mali. Photo: Netherlands Water Partnership.

Spray-head irrigation requires pressure from pedal or motor pumps. In West Africa, the spray-head is mounted on a lay-flat hose connected to a small petrol pump. Spray irrigation is an intermediate option between a watering can and more sophisticated sprinkler or drip irrigation. It has high water use efficiency and saves energy and labour.

Treadle pumps combined with spray-heads are promoted by Approtec in East Africa and Enterprise Works in West Africa.

Due to its simplicity, spray irrigation technology has spread spontaneously from farmer to farmer in West-African countries such as Mali, Niger and Togo. A recent survey in Bamako, Mali, among 80 market gardeners showed that more than 60% used this method.

Suitable conditions

Advantages

Disadvantages

- High water use efficiency. - Saves energy and labour. - relatively low investment cost per unit area - widespread availability of equipment - well adapted to situations with multiple low-yielding wells, requiring the equipment to be shifted every 15 to 30 minutes - possibly enhanced plant growth and yield - negligible problems of rodent damage or theft - no emitters, so no emitter clogging - African farmers quickly take up the technology

- labour requirement could be high

Construction, operations and maintenance

Options for optimization:

• reduce the price of equipment, including that of accessories, such as layflat hose;
• improve spraying head efficiency;
• improve pump efficiency;
• improve engine efficiency; and
• replace the petrol pump with a treadle pump.

Costs

US$ 2 - 5 for a spray-head. US$ 300 - 600 for a unit with petrol pumps.

Field experiences

Location: West Africa.

Manuals, videos, and links

• Small scale pumped irrigation. FAO.

Acknowledgements

• Efficiency, cost, optimization and spread of spray irrigation in West Africa.
• SmartWater Solutions: Examples of innovative, low-cost technologies for wells, pumps, storage, irrigation and water treatment or ([http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CFEQFjAA&url=http%3A%2F%2Fwww.nwp.nl%2F_docs%2Fpublicaties%2FSmart_Water_Solutions_ENG_2006.pdf&ei=tKv8T_e6IYTiqgHOy4iLCQ&usg=AFQjCNE9tTXI9rJyLrJCYiS2z9bWSPnK5Q&sig2=ErJBEzlYeSUQV5erv2BWcw alternative link). Netherlands Water Partnership.