Use of Water Absorbent Polymer in Onion

Krishi Vigyan Kendra, Babhaleshwar is implementing NICRA project in Nirmal Pimpri village in Ahmednagar district of Maharashtra. The source of irrigation in this village is tubewell. Irrigation facility in the field crops is limited during only good rainfall year. Farmer generally prefer growing short duration onion crop during rabi with average rainfall. However during prolonged dry spells there is water stress to crop leads to poor onion bulb development and poor yield. The water absorbent polymer is a long chain cross linked sodium acrylic based absorbent gel crystalline powder that absorbs and retains water 300 to 400 times its weight. The material is suitable in light to medium soils where water retention is poor and organic matter is poor. Under such conditions the soil is mixed with water absorbent polymer @ 4kg per acre helps to retain water and simultaneously releases water at appropriate stage of development of osmotic pressure in capillaries, thereby maintaining field capacity and promoting optimum growth. The product is highly stable, non-reactive and does not leave any residue.

Demonstrations on use of water absorbent polymer in onion for water saving in inseptisols soils led to improved water retention and reduced frequency of irrigation.  This method gave higher bulb yield (182.3q/ha) with more net return (Rs 100987.5/ ha), 7.6 irrigations under demonstration and with a B: C ratio (1.49).