不同施氮量对钵苗机插水稻产量形成及氮素利用率的影响

Effects of Different Nitrogen Rate on Yield Formation and N Use Efficiency of Bowl Mechanical-transplanting Rice

[目的]寻求钵苗机插水稻的适宜施氮量,以期为当地钵苗机插水稻的合理施氮提供理论依据,促进钵苗机插技术的推广与应用。[方法]在统一钵苗机插条件下,以常规粳稻武运粳24和籼粳杂交稻甬优2640为试验材料,设置6个不同的氮肥水平N0(0)、N1(187.5kg/hm^2)、N2(225.0 kg/hm^2)、N3(262.5 kg/hm^2)、N4(300.0 kg/hm^2)、N5(337.5 kg/hm^2),研究不同施氮量对2个水稻品种产量形成及氮素利用率的影响。[结果]2个品种产量随氮肥水平的提高均呈先增后减的趋势,在N4水平下最高;移栽至拔节与拔节至抽穗阶段的干物质积累量均随氮肥水平的提高而增加,而抽穗至成熟阶段干物质积累量呈先增后减的趋势,其中N4处理最大;2个品种的氮素吸收利用率均随施氮量的增加呈先增后减的趋势,其中常规稻品种在N4水平下吸收利用率最高,杂交稻品种在N3水平下最高。[结论]在氮肥用量为300.0 kg/hm^2时,2种钵苗机插水稻各项群体指标较优,干物质积累多,有效穗数足,产量较高,氮素吸收利用率较大。

[ Objective ] To find a proper nitrogen applying level, thus to provide theoretical basis for local bowl mechanical-transplanting rice planting and promote the nutrition bowl mechanical-transplanting application. [ Method] Under the condition of nutrition bowl mechanical-transplanting, taking conventional rice Wuyunjing 24 and hybrid rice Yongyou 2640 as materials, setting six nitrogen levels 0, 187.5,225.0, 262.5, 300.0, 337.5 kg/hm^2, marked as N0, N1, N2, N3, N4, N5, the effects of different nitrogen levels on the rice yield formation and N use efficiency were studied. [ Result] With the increase of nitrogen applying, the yield of different rice increased first and then decreased, the highest yields were all in the level of N4. The dry matter accumulation during transplanting to jointing and jointing to heading increased with the increase of nitrogen level, while at heading to mature reached highest at N4 and then decreased significantly. The N utilization rate increased first and then decreased with the increase of nitrogen level, the conventional rice was highest at N4 level while the hybrid rice was highest at N3 level. [ Conclusion] When the amount of nitrogen is 300.0 kg/hm^2, the population index of nutrition bowl mechanical-transplanting rice is excellent, and it can make more dry matter accumulation, enough effective panicles, high yield and larger nitrogen absorption and utilization.