在半干旱区研究了基施氮肥量对春油菜生长发育的影响。结果表明，基施氮肥后，春油菜物候期及生育期随着施氮量的增加均出现推迟的趋势。苗期至现蕾期，干物质累积量缓慢，施氮量影响不大。抽薹期期至成熟期，干物质累积量较快，低施氮量(90～210 kg/hm2)范围内油菜全株干物质重随施氮量增加而增大，而高施氮量(240～270 kg/hm2)下油菜全株干物质重量随一次性施氮量增加而减小。株高、分枝部位、分枝数均随基施氮量增加而增加。全株有效结角数、角粒数、角果长度、千粒重、单株产量随施氮量增加均呈先增后减趋势。基施氮量210 kg/hm2时各经济性状指标表现最好，产量最高，达2 013.43 kg/hm2。

Through studying on single basal application of nitrogen in spring-planted rapeseed in dry area， the results show that with the increase of single basal nitrogen fertilizer， squaring and bolting and fist flowering， full flowering， end flowering and maturity are delayed， the whole growth period delays 3～5 days. The dry matter accumulation of different treatments is different in growth stages. From seedling to the bolting stage，with the increase of single base nitrogen， dry matter accumulation increases. The dry matter accumulation increase with the increasing of single nitrogen application in the range of low nitrogen(90～210 kg/hm2). While in the range of high nitrogen application(240～270 kg/hm2)， the dry matter accumulation of whole plant decreases with the increasing of nitrogen application. The plant height， the number of branches and branches site increase with the increasing of nitrogen application. Whole plant effective pod number， grain number， pod length， 1 000 seeds weight， yield per plant with single nitrogen increasing firstly increase and then decrease， application of N210 nitrogen showes the highest in the economic characters. The grain yield of rapeseed increases firstly and then decreases with the increasing of single nitrogen application. The economic characters showed the best performance when the basal nitrogen amount is 210 kg/hm2， and the yield is the highest, reaching 2 013.43 kg/hm2.

S565.4

国家自然科学基金项目(31260334)；甘肃省自然科学基金资助项目(1308RJZA205)；甘肃省农科院创新专项(2013GAAS16)；甘肃省农科院中青年基金(2015GAAS34)。