施氮量对冬小麦氮素吸收、转运及产量的影响

2004至2005年在田间条件下,研究了施氮量0、105、2103、15.kg/hm2对冬小麦氮素吸收、累积、转运、产量及氮肥利用率的影响。结果表明,施用氮肥可显著提高冬小麦的子粒、秸秆产量及成熟期地上部总吸氮量,但过量施用氮肥对子粒和秸秆增产不显著;各施氮处理的氮肥利用率在34.2%～38.3%之间,随施氮量增加而略有降低。植株中氮素含量随生育期的延长而降低,氮素累积量总体呈增加趋势。施氮量对冬小麦氮素吸收有显著影响,同一生育时期,氮素含量和累积量都随着施氮量增加而提高。施氮可显著地促进氮素在子粒中累积,其中69%～87%的氮素是靠营养体的转运而来的。施氮量影响氮素的转运效率,随施氮量增加,转运效率降低。本试验条件下,冬小麦的合理施氮量应控制在105～210.kg/hm2之间。

Effect of N rates on N uptake, transformation and the yield of winter wheat

A two years field experiment was carried out to study the effects of N application on N uptake and accumulation,N transformation,yield and apparent N recovery in winter wheat(Xiao Yan 22) in high productivity field in Guanzhong Plain of Shaanxi province.Four N rates were employed(0,105,210,and 315 kg/hm²).The experiment design was the randomized complete block with four replications,the area each plot was 33.6 m²(6 m×5.6 m).70% of N fertilizer and total P(P₂O₅ 96 kg/hm²) and K(K₂O 208 kg/hm²) was used as basal fertilizer,and 30% of N fertilizer used as topdressing fertilizer during the growth stage of regreening.The results showed that N fertilization expect over(application) significantly increased grain,straw yield and total N uptake of shoot of winter wheat in maturity.The apparent N recovery of all N treatments was ranged from 34.2% to 38.3%,which decreased slightly with increasing of N application rates.N content in plant was decreased with the growth stages of winter wheat,but N accumulation in the tissue showed an upward tendency.N application rates influenced N uptake of wheat plant significantly,both N content and N accumulation was increased with N rates increasing in the same growth stage.N application promoted N accumulation in grain significantly,among which.69%～87% of N in grain was transferred from vegetative organs.N fertilization also affected N transfer efficiency,which decreased with N rates increasing.The recommendatory N rate for winter wheat should be controlled from 105 to 210 kg/hm² under the experimental condition.