1987年,我们以不同播种量、不同施氮水平、不同基本苗数、不同株行距为主要内容,对中熟高产新品种湘早籼4号进行了早稻栽培研究。试验设三种施氮水平、两种插植密度6个处理。三种施氮水平是:每亩施纯氮10公斤、12.5公斤、15公斤,均以60%作基肥,40%作追肥。除施氮水平不同外,磷 In 1987, we studied the early rice cultivation of Xiangzaoxian No.4, a medium-maturing high-yielding variety with different sowing rates, different levels of nitrogen fertilizer, different seedling numbers and different row spacing. Three nitrogen application rates and six planting density treatments were set up. Three nitrogen levels are: Nitrogen fertilizer per acre 10 kg, 12.5 kg, 15 kg, 60% are used as basal fertilizer, 40% for top dressing. In addition to the different levels of nitrogen, phosphorus