长江中下游稻茬小麦超高产群体磷素积累、分配与利用特性

Accumulation,Distribution and Utilization Characteristics of Phosphorus in Super-high Yield Wheat Population under Rice Stubble in Middle and Lower Reaches of the Yangtze River

为给长江中下游稻茬小麦超高产(>9 000kg.hm-2)生产提供理论依据,以中筋小麦新品种扬麦20为材料,通过氮素运筹(氮肥使用量、施用时期和比例)和基本苗调控建立稻茬小麦不同产量水平群体,研究超高产小麦群体磷素积累、分配与利用特性。结果表明,不同产量水平小麦群体整个生育期磷素积累动态变化均可采用Richards方程拟合。超高产群体拔节期至开花期、开花期至成熟期、开花期、成熟期磷素积累量分别达28、22、46、68kg.hm-2,显著或极显著高于高产群体。超高产群体磷素吸收高峰出现在拔节期至开花期,其次为开花期至成熟期。开花期茎鞘、穗及成熟期颖壳+穗轴、籽粒中磷素积累量与籽粒产量呈极显著正相关,分别达21、8、9和45kg.hm-2以上才有利于实现超高产。花后叶片磷素转运量与籽粒产量呈显著线性负相关,茎鞘磷素转运量与籽粒产量呈极显著线性正相关,叶片磷素转运量低于9kg.hm-2,茎鞘磷素转运量高于15kg.hm-2才有利于实现超高产。超高产群体百公斤籽粒吸磷量为0.84～0.88kg,磷素利用效率为113.60～118.93kg.kg-1,磷收获指数为0.64～0.67。

Phosphorus is one of the essential nutrients for wheat production.It is very important to figure out what are the definite characteristics of accumulation,distribution and utilization of phosphorus in different wheat varieties,ecological environments,soil types or yield level populations,which have much theoretical and practical meaning to agricultural production.Using the medium gluten wheat Yangmai 20 as the material,a field experiment with different combinations of fertilizer and plant population was carried to investigate the accumulation,distribution and utilization characteristics of phosphorus in super-high yield（9 000 kg·hm-2） wheat population in rice-wheat cropping system.The main results were as follows： the phosphorus accumulation amount dynamics under different yield levels population could be modeled using Richards equation.In super-high yield wheat population,phosphorus accumulation amount（PAA） at the stages from jointing to anthesis and from anthesis to maturity,at anthesis and at maturity were significantly higher than that in high yield wheat population.For super-high yield wheat,the corresponding population PAA was 28 kg hm-2 from jointing to anthesis,22 kg·hm-2 from anthesis to maturity,46 kg·hm-2 at anthesis and 68 kg·hm-2 at maturity or above,respectively.The period with the highest phosphorus absorption of super-high yield wheat population was from jointing to anthesis,and then from anthesis to maturity.PAA in stem and spike at anthesis,and in rachis and hull and grain at maturity were linear correlation with grain yield.PAA was 28 kg·hm-2 in stem and 8 kg·hm-2 in spike at anthesis,and 9 kg·hm-2 in rachis and hull and 45 kg·hm-2 in grain at maturity or above,respectively,which was better to realize the super-high yield.The phosphorus translocation amount from leaf to grain was negatively correlated with grain yield.The phosphorus translocation amount from stem to grain was positively correlated with grain yield.The phosphorus translocation amount was below 9 kg·hm-2 from leaf and above 15 kg·hm-2 from stem,respectively,which was better to realize the super-high yield.For super-high yield wheat population,the phosphorus amount to produce 100 kg of grain,phosphorus use efficiency and phosphorus harvest index was 0.84~0.88 kg,113.60~118.93 kg·kg-1 and 0.64~0.67,respectively.