摘要:
利用多蘖小穗型常规品种空育131和少蘖大穗型品种超级稻龙粳21,设置3个用氮水平及4个基蘖肥与穗粒肥用氮比例,研究了氮肥施用方式对寒地水稻分蘖动态特征的影响.结果表明,随着施氮水平的提高,群体茎蘖数增加,高峰苗数显著增多,多蘖小穗型常规品种空育131增加幅度较大,而少蘖大穗型超级稻品种龙粳21增加幅度较小.基蘖肥比例增加,群体茎蘖数增多,随着穗粒肥比例的提高,高峰苗数有减少的趋势.氮肥总量与运筹互作对群体茎蘖动态有较大的影响,低氮(115 kg/hm2)水平下氮肥后移降低群体茎蘖数的效应明显高于高氮(161 kg/hm2)水平下的效应.随着施氮总量的增加,两品种的群体最高茎数、最高分蘖数、分蘖穗数和分蘖穗比例有逐渐增加的趋势,有效分蘖率和成穗率逐渐降低.少蘖大穗型超级稻品种龙粳21以基蘖肥与穗粒肥施用比例7:3处理的有效分蘖率和成穗率较高,多蘖小穗型常规品种空育131以8:2处理有效分蘖率和成穗率较高.在低氮水平下,增加穗粒肥施入比例可明显降低多蘖小穗型常规品种群体茎蘖数,导致群体收获穗不足.在中高氮水平下,适当增加穗粒肥施入比例将有利于提高少蘖大穗型超级稻品种群体有效分蘖率和成穗率.%Utilization traits of different types of rice, more tillers and smaller panicle variety Kongyu131 and less tillers and bigger panicle variety Longjing 21 were used in this study. Four base-tiller nitrogen to spike-grain nitrogen application ratios of 10:0, 8:2, 7:3, 6:4 were used with three N levels of 115, 138, 161 kg/ha. The results showed that the tiller number of plant population and the maximum tiller number of more tillers and smaller panicle variety Kongyu131 were more than those of less tillers and bigger panicle variety Longjing 21, with the increase of nitrogen supply level. Increase of the base-tiller nitrogen led to the increase of stem and tiller number in the population, and increase of the spike-grain nitrogen led to the decrease of peak seedlings number. Effect of nitrogen fertilizer postponing on stem and tiller number in the population under low nitrogen level was higher than that under high nitrogen level. With the increase of nitrogen rate, the highest stems num-ber(THSN), the highest tillers number (THTN), tillers panicle number (TPN) and tillers panicle proportion (TPP) in popu-lations of two rice varieties increased, but effective tiller number rate and panicle rate decreased. When the nitrogen applica-tion ratio was 7:3, the less tillers and bigger panicle variety Longjing 21 had higher effective tiller number rate and panicle rate. Whereas the more tillers and smaller panicle variety Longjing131 had higher effective tiller number rate and panicle rate when the nitrogen application ratio was 8:2. Under low nitrogen level, increase of spike-grain nitrogen application led to the decrease of population stem and tiller number of more tillers and smaller panicle variety, and further resulted in insufficient population spike. The suitable increase of spike-grain nitrogen application would be helpful for improving effective tillering rate and panicle rate of the less tillers and bigger panicle variety under middle and high nitrogen level.