包膜尿素对夏玉米产量、吸氮量和氮分配的影响

以施氮量调控氮代谢,提高氮肥利用率为目标,利用15 N研究了包膜尿素（CU100、150和225kg/hm2）和普通尿素（150和225kg/hm2）对夏玉米产量、生物量、氮肥利用率以及各器官氮分配的影响。结果表明：包膜尿素比普通尿素显著增加玉米从肥料中的吸氮量,显著增加地上部生物量;15N包膜尿素肥料利用率（15NU...

EFFECT OF COATED UREA AND NON-COATED UREA ON GRAIN YIELD,N UPTAKE AND N DISTRIBUTION IN DIFFERENT PARTS OF MAIZE

In order to regulate nitrogen metabolism with nitrogen application rate and to increase nitrogen use efficiency, an isotopic method was used to compare grain yield, biomass and nitrogen use efficiency of coated urea (CU) to those of non-coated urea (U) at the N application rates of 0, 100, 150 and 225 kg/hm2.Results showed that CU significantly increased maize N uptake from 15N fertilizer and aboveground biomass. The nitrogen use efficiency (15NUE) of CU was 13.3-21.4% greater than that of U. There was a significant difference of fertilizer 15N uptake between CU and U in maize parts. And N uptake of CU treatment followed the order of seed>leaves>straws>cob>husk, while N uptake of U treatment was in the order of seed>straws>leaves>cob>husk. The N uptake of maize parts by both CU and U followed the same order when non-isotopic method was applied. No significant variations were observed amongtreatments in N uptake, Nitrogen Harvest Index and grain yield. The reason maybe that low soil temperatures (<10℃) from the fourth week of October to next April reduced N uptake of winter wheat, therefore, residual NO3-N in cultivated soil layer was high after harvest. Thus, maize N uptake was more dependent on the shoot growth potential than fertilizer amount and types under high amount of available nitrogen.