Clay irrigation system challenging drip method

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For marginal and small farmers with small landholdings, having a mechanism for optimum use of water is a boon. At a time when the Prime Minister had announced setting up a task force to study the impact of drip irrigation in the country, Clay Emitter irrigation is vying with drip irrigation for select crops.

Shaped like a ‘gilli’ of the popular amateur street game ‘Gilli-Danda’, the clay emitter is an 8-cm long earthen tube tapered at both ends with 30-40 per cent porosity. This emitter is connected with rubber pipes on each sides thereby making a series of emitters connected through the pipes. This series once connected to a drum filled with clean water, and placed at a moderate height, serves as a mini water-grid for plants.

Continuous system

“The earthen emitter allows water to seep through the pores thereby providing optimum soil moisture for the plant. When water is drawn through the pores, it moves in all directions due to capillary and osmotic forces, and forms a spherical wet zone for the roots of the plant. The water withdrawn by the plant is immediately replenished making it a continuous system,” said Soham Pandya, Executive Director, Centre of Science for Villages (CSV), which developed the cost economics and design for the emitter irrigation.

Improvement over drip?

Pandya claims that the concept is an improvement over the drip irrigation system with 50 per cent less water needed because it waters the root zone of the plant directly and costs about 50 per cent less than the drip system as it is made of clay, and can be produced even by a local potter.

Depending on the soil type, a number of emitters can be placed around a plant. In dry soil, emitters with 30 to 35 per cent porosity release about 2-2.5 litres of water in a span of 24 hours. The shape and size of the wet zone around the emitters differs in different soils.

The model is best suitable for plant crops such as fresh vegetables, oranges, lemon and floriculture crops such as gerbera flowers. However, academic circles in the agricultural research field have raised several doubts about the success of the system over the widely-accepted drip.

“There have been concerns about clogging in the pipeline and emitters. Also, farmers need a rough-and-tough and easy-to-lay system like drip. This is more complex and delicate. Yes, for water-starved regions, clay emitter is an age-old and proven system. But commercial viability is a question today,” said VP Usdadiya, Research Scientist – soil and water management, Navsari Agriculture University.

The statistical calculations conducted by Pandya revealed that the total cost of fixing and laying the emitter network on a 0.1 hectare plot is ₹34,700, including the cost of emitters, pipes and labour.

“The system has a life of about seven years. A farmer, who takes up cultivation of gerbera flowers would earn anywhere between ₹1,65,000 and ₹2,00,000 from the crop. They can take multiple crops in a year,” he said.

 Source : Business Line