15 the Nin-Plus-Ultraâ„˘(17-20-0) [Calma et al, 1952]. Other fertilizers used since 1933 that are still existing to date are the Superphosphate (0-18-0) or Solophosâ„˘, and the sulfate of potash (0-0-50), the latter lately improved to give higher percentage of potassium (Muriate of Potashâ„˘, 0-0-60). When commercial fertilizers were introduced with better rice varieties in 1950s, the production was 28.3 cav/ha in fertilized 257,046 hectares compared with 25.1 cav/ha from unfertilized areas (Galang, 1952). Because of this increase, fertilization became common in rice fields. Crop year
Ave. yield (cav/ha)
Source: FG Galang.1952. The Agricultural Extension Service. pp147-153. In: A half-century of Philippine Agriculture. BA Golden jubilee committee. Graphics house. Manila. 463 pp.
From 1933 to 1941, several fertilizer rates and fertilizer sources were tested for varieties Elon-elon and Ramil. Although fertilizer rates used were low, palay yield was increased 91% to as high as 100 cavans (Calma et al, 1952). This have encouraged farmers to use commercial forms and also organic manures such as guano, copra cake, dried lye or algae and compost with a little amount (40 kg/ha) of commercial nitrogen fertilizer (Aquino and Subido,1952).
Published on Mar 21, 2011
July 2005 Philippine Institute for Development Studies Surian sa mga Pag-aaral Pangkaunlaran ng Pilipinas For comments, suggestions or furth...