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Bibliographic Data
Control Number45670
Date and Time of Latest Transaction20060619141817.1
General Information060619s2003 |||||||||b ||00|||
Cataloging SourcePCARRD-DOST
Main Entry - Personal NameMactal, Ariel G.
Main Entry - Uniform TitleEnglish
Title StatementEfficacy test of controlled-release fertilizer in lahar affected and coarse-textured soil Clarita P. Aganon, Nora Dominguez, Ariel G. Mactal, Josie Pontevida
Physical Description29p
General Note-(DOST-PCARRD-CLSU-ITDI Proj. 2)
Summary, Etc.The onslaught of lahar in agricultural farms around Mt. Pinatubo resulted to soils of marginal productivity. This was caused by the low nutrient and water holding capacity, sandy texture, and very low nutrient content. By virtue of its texture, lahar deposits allows intensive leaching of nutrients, a disadvantage to applied fertilizers. Conventional inorganic fertilizers are highly soluble in soil water and therefore nutrients are readily lost through leaching. Fertilizer formulations capable of releasing nutrients at a controlled fashion can overcome the problem. Controlled-release fertilizers (CRF) were produced at optimized conditions such as bottom spray coating method in fluidized bed with a temperature of 21-24oC. Spray volume was at 40-50 ml/minute. Outlet temperature was at 30oC to facilitate drying of coating solution. The outlet temperature was 19-23oC and air pressure was 0.4kPa. SEM analysis was used to determine characteristics of the surface of CRF coated with polysterene (PS), styrofoam (SF) and elemi gum (EG). Coating was at 5, 10, 15 and 20% by weight of the material. Twenty percent coating of PS produced the best coated material in terms of pore covering (completely covered, uniformity of the thickness of the coating material and hardness of the granule. Capsulated or CRF were evaluated for their nutrient release characteristics in the laboratory using dissolution method, lysimeter set-up with lahar and soil as media (submerged and upland conditions), pot experiment and field conditions. The length of time by which the nitrogen, phosphorus and potassium content were released was measured. Binders consisting of either bentonite and dolomite or bentonite + dolomite + zeolite had longer release duration. Under room condition, urea CRF released 90% of its N in 90 days; DAP CRF released 98% of its N and 100% P2O5 in 70 days; KCl CRF released 35% K2O in 65 days and complete CRF released 96% N and 98% P2O5 in 60 days and 85% K2O in 90 days. Nutrient release speed up with increasing solution temperature. Nutrients were released from CRF at longer duration compared to conventional fertilizers that solubilized for a period of 25 minutes to 5 days. DAP released almost 100% of its N content within 48 days in lahar and 37 days in soil under submerged condition, while under upland condition it took 60 and 40 days in lahar and soil, respectively, to release all its N content. Phosphorus content of CRF was not released in full inspite of 100 days incubation period. Nitrogen from coated fertilizer incubated under submerged condition was released within 52 days (98%). Conventional fertilizers solubilized under lowland condition from 4 to 26 minutes and 2 - 4 ½ days under upland condition. Nitrogen efficiency of CRFs (urea + complete) applied to onion grown in lahar increased from 13.25 (recommended inorganic fertlizer) to 77.18% (CRF supplying full RR). N efficiencies of 72.56 and 85.36% were realized from RR and full CRF treatments applied to tomato whereas, in rice N efficiency increased from 38 (recommended inorganic fertilizer) to 92% due to CRF application. As a consequence there was a tremendous increase in yield of CRF treated plants including that of ½ CRF treated ones. Net income of rice increased by about PHP 5,000 and PHP 10,000 with the application of ½ less of recommended rate and full recommended rate of fertilizer in place of conventional available inorganic fertilizers (CAF)
Subject Added Entry - Topical TermControlled release fertilizers
 Lahar
 Coarse-textured soil
 Nutrient release
 Efficiency
Added Entry - Personal NameDominguez, Nora
 Aganon, Clarita P.
 Pontevida, Josie
LocationDOST PCARRD REPORTS PCARRD/SLS PCR-05-0067 1 Others 0000-00-00
  
     
 
Physical Location
Department of Science and Technology
Philippine Council for Agriculture, Forestry and Natural Resources Research and Development
  
     
 
Digital Copy
Not Available
  
     
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