Effect of Nitrogen Rate and Ratio of Base and Topdressing Fertilizer on Yield,Quality and Fertilizer-N Use Efficiency in Wheat Cultivar Jimai 20

A 15N-labelled experiment was carried out to study the effects of nitrogen rate and ratio of base fertilizer to topdressing on grain yield,quality,fertilizer-N use efficiency(FNUE) of strong gluten wheat(Triticum aestivum L.) under high-yield condition.The study used 15N isotope tracer in PVC cylinders(2.05 m length,Ф0.2 m,without bottom)with seven treatments,without applying N fertilizer(N0);N application rate of 168 kg/hm2(0.527 g/pot),ratios of base fertilizer to topdressing of 1∶1(N1),1∶2(N2) and 0∶1(N3);N application rate of 240 kg/hm2(0.753 g/pot),ratios of base fertilizer to topdressing of 1∶1(N4),1∶2(N5) and 0∶1(N6).The results showed that the amount of N accumulation in plant have no significant difference between treatments with applying nitrogen fertilizer.Fertilizer-N use efficiency(FNUE) of topdressing was markedly higher than that of basal nitrogen;reducing basal nitrogen amount and increasing topdressing nitrogen amount could appropriately enhance FNUE,of which treatment N2 was the highest.Appropriate N fertilizer rate with reducing basal nitrogen amount and increasing topdressing nitrogen amount such as in N2,N5 and N6 increased grain yield,protein content and improved grain processing quality.In conclusion,under the condition of this experiment,as grain yield,quality and fertilizer-N use efficiency were concerned,the most appropriate nitrogen fertilizer applying regime recommended is treatment N2 with nitrogen fertilizer rate of 168 kg/hm2 and ratio of base fertilizer to topdressing of 1∶2.