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22 area although yield reduction of 19.8% was observed in the non-irrigated areas (average of the 2 barangays). Water management during the Green Revolution period. A remarkable change in rice production brought about by irrigation during this period was the second cropping of rice during the dry season. In as early as 1955-56, a second crop was already considered but was only given greater importance after 1967-68 when irrigation systems were increased and old systems were rehabilitated, coupled with the availability of nonphotoperiod sensitive high yielding varieties, the 40% increase in irrigated area, large increased use of fertilizer and improved cultivation practices. However the rate of yield increase (3.6% annual rate) from 1962-71 has grown rapidly while area harvested declined. The decline was reversed only in 1967-68 when profitable possibilities of high yielding seeds along with the large expansion of irrigated areas induced increased plantings (Mears et al., 1974). Massive investments in irrigation infrastructure in the late 1960’s became essential for the success of the Green ‘Revolution and for rapid growth productivity. With the construction of the Pantabangan Dam or Angat Irrigation Project in the late 1960’s, rehabilitation of old irrigation canals, and the establishment of the National Irrigation Administration-Upper Pampanga River Integrated Irrigation System (NIA-UPRIIS) in the late 1970’s, irrigation water became abundant in Central Luzon. Presently, however, the increase in population, urbanization and industrialization competed with agriculture for water resources. At the same time, the supply of irrigation water started to decline due to reduced spending on irrigation infrastructure, degradation

The Evolution of Rice Production Practices  

July 2005 Philippine Institute for Development Studies Surian sa mga Pag-aaral Pangkaunlaran ng Pilipinas For comments, suggestions or furth...