Technologies- El Niño

(Agricultural Resources Management Sector)

  

Evaporation Suppressant

 


Description:

Evaporation suppressant is a non-toxic and biodegradable chemical substance that helps minimize water loss due to evaporation in rice fields, water reservoirs, lakes, and aquaculture ponds. It comes in the form of paste, slurry, and solution with organic solvent. The solution form is the most recommended for use in the field because the film spreads rapidly in the field.

Evaporation suppressant prevents water loss by forming a thin continuous film above the water surface. The most readily available evaporation suppressant is a cetyl-stearyl alcohol mixture prepared from coconut oil.

Advantages:

  • Saves up to 2M liters of water/ha per season. This amount of water can already irrigate almost ¼ ha of rice fields, and therefore gives additional rice yields
  • Maintains optimum water temperature needed for faster growth of rice plants
  • Reduces nitrogen loss while facilitating oxygen exchange
  • In rainfed rice fields evaporation suppressant minimizes water stress during 2-3 week dry spells
  • Environment-friendly and safe

Conditions in Technology Application: 

  • The solution form of evaporation suppressant should not be used at floodwater temperature below 20oC because of the tendency of the suppressant to solidify before it can completely spread
  • Evaporation suppressant should not be applied in running water because it will be dispersed instead of staying on the surface
  • For better results other complementary practices could be adopted such as establishing wind breaks and increasing the dikes’ spillway height to at least 10 cm from the ground level

Possible Areas of Application:

Applicable in rain fed and insufficiently irrigated lowland rice areas, water reservoirs, and aquaculture ponds

Evaporation suppressant can be bought at AGR Lotus, Agribusiness Division, Km 16 Republic Steel Tube, Alabang Zapote Road, Pamplona, Las Piñas City. Telefax (02) 827-7709

Sources of Technology:

Dr. Maximo W. Baradas (deceased), PhilRice Maligaya, Munoz, Nueva Ecija

Dr. Milagros M. Peralta, Institute of Chemistry, UP Los Baños

References:

Department of Agriculture- Philippine Rice Research Institute (DA-PhilRice). "Use of Evaporation Suppressant." Rice Technology Bulletin, 2001 No. 34.

PCARRD. "Evaporation Suppressant." Information Bulletin Series/Leaflet No. 84/1998
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