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Asian Journal of Agriculture and Development (AJAD) - Call for papers!

Methods, Sources and Time of Nitrogen Application for Upland Rice

(Thailand), Master of Science (University of the Philippines Los Baños)

Thesis Abstract:

 

Field experiments were conducted at the International Rice Research Institute (IRRI), Los Banos, Laguna and at Cuenca, Batangas, Philippines, to determine the effect of methods, sources and time of nitrogen application on yield and yield components of C22 and IR1529-430-3 rice varieties grown under upland culture.

In both locations, IR1529-430-3, a semi-dwarf selection, produced higher grain yields, heavier grains and more tillers and panicles than C22, a tall variety recommended for rainfed upland areas.

The addition of nitrogen markedly increased the gain yield of both varieties, but the yield increment of IR1529-430-3 was higher than that of C22 in both locations, indicating that the former was more responsive to applied nitrogen.

Sulfur-coated urea (SCU) proved to be a better source of nitrogen than urea and ammonium sulfate when applied all at planted, either broadcast and incorporated or placed in band.

When urea and ammonium sulfate were the nitrogen source, however, split method was better than single application at planting particularly on sandy soils. Urea and ammonium sulfate applied in two equal split doses at 30 days after emergence (DAE) and at panicle initiation were similarly effective as SCU applied singly at planting, in increasing panicle number and grain of both varieties.