Hydrogel-a water bank
Hydrogel is becoming important in water conservation .It will not be wrong to call it as a water bank . Earlier, it was used in bio medical and hygiene sector .It is a white colour gel .Basically, it is cellulose based and has cross linkages. Pusa hydrogel is developed by IARI,Pusa ,New Delhi. The hydrogel absorbs and release the water . It looks like khaand (of jaggery) grains .When water is added then it give a appearance of halwa. It absorbed aqueous medium in their networked structure .when comes in contact with water it absorbs the water and swells
After one year of application, It is biodegradable in soil. Its Natural, Bio-degradable, non toxic and non Hazardous. . The gel after absorbing the water expands to 300 times its original size. It sticks to the roots of the plants .The gel sheds water to nourish the crop, as the soil moisture falls as the temperature rises. It works as an anti-drought mechanism and reduces the water requirement of plants. The gel helps crops store water for a dry spell and aids farmers to cope with the increasingly unpredictable monsoon seasons.
How effective is Hydrogel
The hydrogel is very effective in the sense that 1gm hydrogel absorbs 300 times more water .
The application of Hydrogel is done near the root zone of the plants . it should not be spread unevenly. It is used in dry form in mix with soil. The soil should be sieve first to remove unwanted particles . Later basal dose of DAP or any fertilizer as to be applied to the plants should be mixed . Care should be taken to apply in Dry form. Seed drill or pora can be used for seed sowing .So, a combination of soil ,fertilizer along with hydrogel is applied around the seed
It is placed 6-10 inches around and down the soil but never above the soil, as it may get washed away and hence wasted . 1-1.5 kg of hydrogel is sufficient for 1 acre area .for it aprrox 5-7 kg soil can be used .
How it works
When the gel get mixed with soil. It maintain a continuum with soil and water . It absorbs the water and releases it .
Where to use
It should be used in such places where there is limited source of irrigation infact, it is wise to use in irrigation deficit areas .but if used in areas having sufficient irrigation , it can saves 2 irrigation
Its application is good for one season only say for kharif or rabi i.e for different season ,the Hydrogel has to placed again
Presently in use
The farmers at itanagar in Arunacal Pradesh are taking benefits of Hydrogel for water conservation
The best benefit it , it slowly releases the water and hence provide a sustained supply of water/moisture. The application increase the biological activities in the soil and provide air availability to the root zone .All of these in turn helps in improving the physical properties of soil Its application increase the water holding capacity of soil and keep a check on leaching of nutrients in the soil