超高产常规粳稻宁粳1号和宁粳3号群体特征及对氮的响应

Population Characteristics of Super Japonica Rice Ningjing 1 and Ningjing 3 and Its Responses to Nitrogen

2007—2008年对宁粳1号和宁粳3号的丰产示范方进行调查,2008年以宁粳3号为材料进行氮肥用量和前后比例试验,研究常规粳型超级稻超高产群体特征及对氮的响应。结果表明,常规粳型超级稻宁粳1号和宁粳3号抽穗后干物质积累占籽粒产量的70%～80%,茎叶等营养器官的表观转运率少,易高产稳产。足够的颖花量是高产稳产的保证,要达到11.0thm?2以上的产量,颖花数要≥42000m?2;要达到11.7thm-2以上的产量,颖花数要≥45000m-2,同时结实率≥90%,粒重≥26mg。超高产群体抽穗期适宜叶面积指数(LAI)为7.0～7.5,叶色呈"黑黄"节奏变化,后期生长速率(CGR)高,收获指数(HI)≥0.5。氮肥的适量施用和适当后移,不仅可以保证宁粳1号和宁粳3号生育期"黑黄"节奏变化,建立抽穗期适宜LAI的群体,还可以保持超高产株型特征,提高抽穗后LAI、叶面积维持期、CGR和HI,最终实现超高产量。

In order to study the super high-yielding population characteristics of super japonica rice and its responses to nitrogen, two field experiments with five N rate treatments and four N application ratio treatments of Ningjing 3 were carried out in 2008, the 6.7 ha demonstration fields of Ningjing 1 and Ningjing 3 in 2007 and 2008 were also investigated. Results showed that the dry matter accumulation of Ningjing 1 and Ningjing 3 after heading was 70–80% of the grain yield, and the apparent translocation ratio of dry matter from stem and leaves to grain was small, which resulted in the high and stable grain yield. Ample spikelets per square meter were the guarantee of super and stable high yield. To achieve the target yield of 11.0 t ha-1, the spikelets per square meter must be above 42 000 m^-2; to achieve the target yield of 11.7 t ha^-1, the spikelets per square meter must be above 45 000 m^-2, as well as grain filling rate and grain weight must be above 90% and 26 mg. For super high-yielding rice population, the optimal LAI at heading should be 7.0–7.5, crop growth rate （CGR） from heading to maturity should be higher and the harvest index （HI） should be above 0.5. The appropriate N rate and relative more N topdressed at panicle initiation stage could not only ensure the optimal LAI at heading, but also maintain the plant type characteristics of super high-yielding rice, improve the LAI after heading, leaf area duration, CGR and HI, therefore achieve the super high grain yield.