水稻抽穗开花期,幼穗体积增大,植株茎叶繁茂,光合作用增强。这时,水稻植株仍然需要较多的水肥,以满足花粉粒发育、受精完全、提高成粒数和继续增加淀粉积累的需要。为此,应在水稻齐穗期(辽南应在8月15日以前,中部地区应在8月10日以前,北部和东部山区应在8月5～10日以前)追施齐穗肥,每亩施硫酸铵10～15斤。灌水应采取3～0厘米 Rice heading and flowering, panicle volume increased, plant lush stems and leaves, photosynthesis increased. At this time, rice plants still need more water and fertilizer to meet the pollen grain development, fertilization is complete, increase the number of grains and continue to increase the need for starch accumulation. To this end, should be topdressing rice in the full (southern Liaoning should by August 15, the central region should be August 10 in the north and east of the mountain should be in August 5 to 10) Ammonium sulfate per acre 10 to 15 pounds. Irrigation should take 3 to 0 cm