水稻分蘖期是水稻从营养生长向生殖生长过渡的关键时期。为了获得足够穗数、培育丰产株型、减少植株倒伏和增强抗病能力,应做好水稻分蘖期的水肥调节工作。水稻体内含氮高峰出现在分蘖期,加之分蘖期氮肥利用率低和肥效期长,所以氮素化肥作追肥主要宜施在分蘖期。用硫酸铵作追肥,每亩应施30～35斤(分1～2次施入)。 Rice tillering stage is the key period of rice transition from vegetative growth to reproductive growth. In order to obtain enough spikes, cultivate high yielding plant type, reduce plant lodging and enhance disease resistance, water and fertilizer adjustment should be done at the tillering stage of rice. Nitrogen in rice peak appears in the tillering stage, combined with low nitrogen utilization efficiency and long tillering period, so nitrogenous fertilizer is mainly applied top dressing at tillering stage. Ammonium sulfate for topdressing, should be applied per acre 30 to 35 pounds (1 to 2 times applied).