It’s called controlled-release fertilizers (CRF), or fertilizer materials with semi-permeable (penetrable) coatings that allow them to release nutrients needed by crops for specific growth.
Initial pot and field trials have been conducted in Pampanga by the Central Luzon State University (CLSU), with the DOST-Industrial Technology Development Institute (ITDI) determining the appropriate kinds and amounts of coating materials needed to produce quality CRFs.
Results of the PCARRD-fund project showed that applying 150-35-35 kg of nitrogen, phosphorus, and potassium (NPK) using CRF instead of conventional fertilizers increased rice yield from 3.73 t/ha to 5.6 t/ha.
For tomato, applying 120-60-90 kg or NPK/ha from CRF increased yield from 3.93 t/ha to 5.56 t/ha.
PCARRD’s Maria Teresa de Guzman reported that four types of CRFs have been developed: urea (CRF (37-0-0), di-ammonium phosphate (DAP) CRF (14-30-0), complete CRF (15-13-18), and muriate of potash (JCI CRF).
ITDI is currently producing CRFs at laboratory scale. — Rudy A. Fernandez