Effect of zinc fertilization on accumulation and transportation of N,P,K and Zn after anthesis of wheat

In order to clarify the effect of zinc fertilization on the amounts of accumulation and transportation of N,P,K and Zn in above-ground organs of wheat,a field experiment with four zinc levels(ZnSO4·7H2O 0,11.25,22.5 and 33.75 kg/ha) was conducted on the Teaching and Demonstration Farm of Agricultural University of Hebei during 2001—2002.Two winter wheat cultivars 8901-11 and 4185 were used as experimental materials.The results showed that the concentration of Zn in various organs ranged from 4.14 to 54.18 mg/kg,with the order: grains >husks >leaves >stems at anthesis and early grain filling period,and the order of grains >leaves >husks >stems during late grain filling period.The amount of Zn required for 100 kg grain production ranged from 4.40 to 5.20 g.The accumulation of Zn at maturity was accounted for about 1/800—1/700 of N or K2O,and about 1/500—1/300 of P2O5 respectively.Zinc(application) could enhance the accumulation of N,P,K and Zn in above-ground organs.And the transportation rate to grains also increased due to the increase of zinc fertilization.However,excess zinc fertilization could lower accumulation and transportation of these nutrients.Nutrient uptake and accumulation patterns were different for those tow cultivars,4185 had a stronger N and P uptake capacity before anthesis,while 8901-11 had a stronger uptake capacity on N and P after anthesis.The K and Zn uptake capacity of those two cultivars show a reversed pattern with that of N and P uptake before and after anthesis.The accumulation of N,P,K and Zn in 8901-11 went up with the increasing zinc fertilization.The highest accumulation was observed when the application rate of ZnSO4·7H2O was 22.5—33.75 kg/ha.The highest accumulation by 4185 was observed when the ZnSO4·7H2O application rate was 11.25 kg/ha.Therefore,we can conclude,with enough macro-element supply,the optimum rate of zinc fertilization was 11.25 kg/ha for the cultivar 4185,but 22.5—33.75 kg/ha for the cultivars 8901-11.