Effects of Nitrogen Fertilization on the Growth and N Uptake of Late-sowing Winter Oilseed Rape (Brassica napus L.)

施氮量对迟播油菜生长及氮素吸收的影响(英文)

[Objective] The aim of this work was to analyze the N fertilization on the vegetative growth and N uptake of different winter rapeseed varieties at wintering stage. [Method] In two consecutive years （2009-2011）, two winter rapeseed varieties （B. napus L.）, an early maturity variety Zhongyou 116 （ZY116） and a middle-late application maturity variety Zhongyouza 12 （ZYZ12） were employed. Field experiments with different N levels （0, 90, 180, 270, 360 kg N/hm 2 ） were designed. At the wintering stage, the dry matter weight, the nitrogen content and concentration of plants, leaf nitrate reductase activity （NRA） and seed yields were investigated. [Result] The shoot dry matter of ZY116 increased rapidly when N rate ranged from 0 to 180 kg/hm 2 , and it raised slightly when N rate ranged from 180 to 360 kg/hm 2 . The shoot dry matter of ZYZ12 were changed in a single peak curve; the peak of shoot dry matter appeared at 270 kg N/hm 2 . The N concentration and N content in shoot and root increased rapidly when the N rate changed from 90 to 180 kg/hm 2 . Moreover, the N concentration and N content root of in ZYZ12 were much higher than that of ZY116. Present study revealed that the changed trend of leaf nitrate reductase activities （NRA） were significantly increased at the N rate of 180 kg/hm 2 in ZY116 and ZYZ12 compared with the N rate of 90 kg/hm 2 in two years. [Conclusion] Optimal nitrogen application significantly increased the dry weights and N uptake at wintering stage as well as increasing the yield of winter oilseed rape.

[目的]分析氮肥对不同冬油菜品种越冬期营养生长和氮素吸收的影响。[方法]连续两年(2009-2011)田间试验,以早熟品种中油116和中晚熟品种中油杂12号为材料,设5种氮肥用量(0,90,180,270,360kg/hm2)。在越冬期对油菜干重,根系和地上部氮含量及比例,叶片硝酸还原酶活性进行测定,并对籽粒产量进行考查。[结果]中油116在施氮量从0增加到180kg/hm2时,地上部干重迅速增加;而在施氮量从180kg/hm2增加到360kg/hm2时,地上部干重缓慢增加。中油杂12号的地上部干重随施氮量的增加呈单峰曲线变化,在270kg/hm2时达到最大值。当施氮量从90kg/hm2到180kg/hm2时,地上部和根中的氮含量及比例均迅速增加,并且中油杂12号根中的氮含量及比例高于中油116。两个品种的硝酸还原酶活性在施氮量从90kg/hm2到180kg/hm2时增加最为明显。[结论]合理施用氮肥能够显著增加不同熟期油菜品种越冬期的干重及氮素吸收,并提高油菜产量。