节水灌溉条件下不同施磷量对冬小麦磷素吸收利用的影响

为提高节水灌溉条件下小麦磷素利用效率，以济麦22和石优20为材料，设置60、120和180 kg P₂O₅·hm^-2三个磷素供应水平（分别用P₆₀、P₁₂₀和P₁₈₀代表）研究了节水栽培下磷素（P）用量对小麦P吸收和利用特性的影响。结果表明，供试小麦品种在各生育时期植株干重均随施P水平增高而提高；低P（P₆₀）水平下石优20植株干重较大，在高P（P₁₈₀）水平下济麦22则植株干重较大。两小麦品种各生育时期植株P含量均以高P处理下较高，且石优20高于济麦22。随施P水平的增高，小麦植株P累积量增多， P累积速率增大，以开花至成熟期P累积速率较高，且施P水平对P累积速率有正向调控作用。成熟期，植株各器官的干重、P累积量和P分配比例均以籽粒最高，茎秆和叶鞘及叶片次之，颖壳和穗轴最低；各器官P含量以籽粒最高，茎秆、叶鞘、颖壳和穗轴次之，叶片最低，表明生育后期植株体内P素主要向籽粒转运、积累。低P和中P（P₁₂₀）处理下，石优20产量显著高于济麦22；高P处理下，石优20的产量较济麦22低。随供P水平的提高，植株花前的P转运量和P转运效率增大，但P贡献率、P利用效率和P肥偏生产力下降。不同品种相比，石优20植株的花前P转运量和营养器官P贡献率与济麦22相近，但石优20的P收获指数、花前P转运效率、P利用效率和P肥偏生产力较济麦22低。研究表明，节水条件下，小麦养分高效品种石优20在低P水平下具有较高P吸收能力和籽粒产量，适当施P可增强济麦22植株生育后期P的吸收、利用能力和高产潜力。

Effect of Phosphorus Fertilizer on Acquisition and Utilization of Phosphorus in Winter Wheat under Water-Saving Cultivation

Using Jimai 22 and Shiyou 20 as materials together with nutrient assay approach, the effect of phosphorus(P) fertilizer on acquisition and utilization of P in winter wheat under water saving condition was investigated in order to provide theoretical reference for wheat cultivation with high P efficiency.Results indicated that the plant biomass at various growth stages of the tested wheat cultivars were increased along with the increase of P application.Compared with Jimai 22, Shiyou 20 produced elevated plant dry mass under low P level conditions.In contrast, Jimai 22 obtained increased plant dry mass under high P level conditions.At various growth stages, the tested cultivars showed higher P concentration under high P treatment than those under low P treatment.Meanwhile, Shiyou 20 displayed higher P concentration than Jimai 22 at various growth stages.Along with the elevation of the P level, the plant accumulative amount and accumulation intensity of P were increased at various growth phases in the tested cultivars.In addition, plants behaved more P accumulation at late growth stage, showing increased P accumulative intensity from flowering to maturity under the high P level.Across treatments and cultivars, more dry mass and P accumulative amount as well as higher P distribution rate were allocated to grain at maturity, followed to stem, sheath, leaf, glume and axis.At maturity, grain possessed the higher P concentration, followed by stem plus sheath, glume plus axis, and leaves showed the lowest P concentration.These results indicated that the acquisition and internal storage of P in plants were largely transported to grains during the late growth stage.Under P₆₀ and P₁₂₀ treatments, Shiyou 20 showed higher yield than Jimai 22; however, under P₁₈₀ treatment, Shiyou 20 exhibited lower yield compared to Jimai 22.At maturity, compared with those under lower P level, plants under higher P level showed elevated transportation amount and transport rate of the pre-flowering P to kernel, but displayed reduced P contribution rate of vegetative tissues, lower P utilization efficiency, and decreased partial productivity of P fertilizer.Shiyou 20 and Jimai 22 exhibited comparable transportation amount of pre-flowering P and P contribution rate of vegetative tissues; however, Shiyou 20 had lower P harvest index, transportation rate of pre-flowering P, P utilization efficiency, and partial productivity of P fertilizer than Jimai 22.Our results indicated that Shiyou 20, a wheat cultivar with high P use efficiency, possesses strong capacity for nutrient taken up and yield formation under water-saving conditions.On the other hand, Jimai 22 exhibits improved acquisition and utilization of P and enhanced yield under sufficient-P level.