磷素营养对大豆磷素吸收及产量的影响

本试验以绥农14大豆为试验材料,利用砂培法,研究了不同供磷水平和不同生育时期断磷对大豆磷素吸收及产量的影响。结果表明:1）较高的供磷水平对大豆中前期植株磷浓度和磷素吸收促进作用明显,初花期（R1）,大豆植株磷素吸收量随供磷水平的提高而持续增加;鼓粒初期（R5）,当供磷水平达到51 mg/L时,再增加磷素营养已无明显促进作用;叶片和茎部磷浓度在磷素水平达到21～31 mg/L时,不再显著上升;到成熟期（R8）,供磷水平达到31 mg/L,对大豆磷素吸收促进作用不明显,达到41 mg/L时,根部磷浓度不再明显增加。2）大豆产量和单株大豆粒数随供磷水平的增加呈单峰曲线变化,供磷水平为31 mg/L处理产量最高,供磷水平为21 mg/L处理的粒数最多;供磷极低水平（1 mg/L）处理大豆植株处理粒数最少,节数也最少,百粒重反而最高。3）大豆鼓粒初期（R5）之前,磷素营养水平是产量形成的关键因素,之后是对磷素营养的非敏感期。V3～R1和R1～R5期间断磷,大豆节数和粒数减少,产量和磷素吸收明显下降,但对植株营养器官磷浓度无明显影响;R5～R7断磷处理影响大豆植株营养体、荚皮和子粒的磷浓度和磷素吸收量,而对产量无明显影响。

Effects of phosphorus nutrition on P absorption and yields of soybean

A soybean cultivar,Suinong 14,and the sand culture were used to study the effects of phosphorus(P) nutrition levels and without P on P absorption and yield of soybean at different stages.The results show that the promoting role of the higher P nutrition levels on the P concentrations and P absorption of soybean at early and medium stages is obvious,and soybean plant P absorption is increased continually under the increase of P nutrition at the beginning of blooming(R1).When the P level is 51 mg/L,the promoting role of the P nutrition is not obvious at the beginning of seeding(R5).When the P levels are from 21 to 31 mg/L,the P concentrations of leaves and stems are not increased obviously.When the P nutrition level is 31 mg/L,the promoting role on soybean P absorption of the P nutrition is not obvious at the full maturity(R8),and when the P nutrition level is 41 mg/L,the P concentrations of roots are not increased obviously.When the P nutrition level is increased,the soybean yield shows a single peak curve and the yield is the highest when the P nutrition level is 31 mg/L.When the P nutrition level is increased,the kernel number of a plant shows a single peak curve too,and the kernel number is the largest when the P nutrition level is 21 mg/L.When the P nutrition level is the lowest(1 mg/L),the kernel number and the node number are the least,while the weight of 100 seed is the largest.Before the beginning seeding of soybean,the P nutrition level is the key factor of forming yield,and after the beginning of seeding,the yield is insensitive to the P nutrition.The node number and kernel number are decreased under no P nutrition during V3~R1 and R1~R5 stages,while the vegetative of plant is not obviously affected,and the yield and P absorption are decreased obviously.The P concentrations of vegetative,pod skin and seed and P absorption of seed are exclusively affected under no P nutrition during R5~R7 stages,while the effect on the yield is not obvious.