Conventional irrigation systems are capital-intensive and generally suitable only for large landholders. Small and marginal farmers like Wadi plot-holders have to use micro-irrigation systems for ensuing effective irrigation, at low cost, with optimal use of water.
Micro-irrigation systems promoted by BAIF-Wadi include pot or pitcher irrigation and drum drip irrigation.
These systems provide water to plants uniformly and frequently, resulting in good plant growth. Another advantage is reduced leaching of nutrients in soil and reduced runoff losses. Soluble fertilisers can be added directly to the irrigation water.
Traditionally, in many parts of the developing world that suffer from water scarcity, earthen pots are buried around plants, and water is poured in the pots every week. The water seeps out the pots at a slow and uniform rate, towards the root zone of plants. In this way, plants receive the minimum amount of water required for growth.
As earthen pots break easily, and may not be locally available in all regions, prefabricated, cylindrical pots made out of cement are used in BAIF-Wadi projects. The cylinders have tiny openings at the bottom. The volume of the cylinder is around 1.5 litres. Normally 3 cylindrical pots are placed around a fruit tree sapling. The pots are supplied free along with planting material.
In Rajasthan, pitchers known as gheds are used for the same purpose.
Mulching is done to prevent evaporation loss from soil and cover the pot.
This system can be used for growing vegetables over an area of 1.25 gunthas. A plastic drum of 200-litre capacity is used to store water. A 16mm pipe is fixed to the drum with valve arrangement for regulating the flow of water. Five lateral pipes of 12mm diameter are attached to the main pipe, to supply water to plants, through micro tubes.
Generally, on each lateral, 26 micro tubes are fixed; one micro tube supplies water to 4 plants. In all, 130 micro tubes are fixed on 5 laterals, meeting the needs of 520 vegetable plants.
The lateral pipes are laid with space of 2.0m. The drum is kept at a height of at least 0.50m.
Drum drip irrigation is being used for growing vegetables like brinjal, tomato and chillies. It is also useful for horticulture plants.
On a pilot basis, treadle pumps and cycle pumps have been distributed, for lifting water from farm ponds or jalkunds and supplying to drums.