超高产冬小麦对氮素的吸收、积累和分配

Absorption,accumulation and distribution of nitrogen in super-highly yielding winter wheat

为明确超高产（9000 kg/hm2左右）栽培条件下冬小麦的氮素营养特点，于2004~2005年、2005~2006年2个小麦生长季主要生育时期，取样分析小麦各器官氮的含量，总结出超高产冬小麦氮素的吸收、积累和分配特点。结果表明， 小麦全生育期各器官的氮含量为0.22%~3.55%（干重）。生育前期叶片中氮的含量和积累量最高，生育后期籽粒中氮的含量和积累量最高。小麦生育期间氮的总积累量为232.48~285.18 kg/hm2，每生产100 kg籽粒吸收氮2.63~3.13 kg。小麦吸收的氮孕穗期前主要分配在叶片中，一般都在50%以上， 成熟期氮在籽粒中的分配率最高，各品种均在80%以上。成熟期籽粒中积累的氮68.02%~73.31% 来自营养器官中氮的再分配。出苗到起身期、拔节到孕穗期、开花到成熟期都是小麦氮素吸收的重要阶段。根据小麦的氮素吸收积累特点，河北平原冬小麦实现9000 kg/hm2的超高产，需要土壤全氮不低于0.75 g/kg，秸秆全量还田后施N 260 kg/hm2左右。

In order to clarify the characteristics of nitrogen nutrition in winter wheat with yields of above 9000 kg/ha, field experiments were conducted in Gaocheng County, Hebei Province during 2004-2006 Eight winter wheat cultivars： Shimai14, Jifeng703, Shimai12 and Shixin828 during 2004-2005, and Temai1, Shimai12, Shixin531 and Shixin828 during 2005-2006, were used for the experiments. Plant samples were collected at 8 growth stages and the nitrogen contents in different parts of wheat were determined. The results showed that the N contents in the tested parts of wheat were in the range of 0.22%-3.35% （dry weight）. The highest nitrogen contents and accumulation were occurred in leaf blades during the early growing period and in grains during the mature period. The total amount of accumulated N in whole plants were in the range of 232.48 to 285.18 kg/ha, the amount of N needed for forming 100 kg of grain yield was in the range of 2.63 to 3.13 kg. Before booting stage, more than 50% of the absorbed N was stored in leaf blades, and in maturity stage, more than 80% of the N was stored in grains in all the cultivars. 68.02%-73.31% of the nitrogen in grains at maturity stage came from the redistribution from vegetative organs. From seedling emergence to erecting stage, jointing to booting stage, and anthesis to maturity stage are important for winter wheat to absorb nitrogen. According to the characteristics of nitrogen absorption and accumulation, it is essential for winter wheat to yield 9000 kg/ha in Hebei Plain that the soil total N be higher than 0.75 g/kg, and the total fertilizing N be about 260 kg/ha.