摘要
以常规籼稻为供试材料,通过不同的基蘖肥用量处理研究了前中期氮(N)肥分配对直播早稻群体特征、N素吸收利用、产量形成以及经济效益的影响。结果表明:相同落谷量、总N量和穗肥N量下,基肥用量增加降低了出苗率和前期分蘖速度,最高分蘖数和有效穗数在N肥用量不足或过高时表现为随基肥用量的增加而降低,适宜施N量下则表现为先升后降的趋势;基肥用量增加降低了水稻生育后期功能叶的叶片含N量和叶面积指数,从而降低了水稻成熟期的植株N积累量以及穗部的N分配系数,N农学效率和N回收效率明显降低,N素转运率与基肥用量则存在着二次曲线关系;增加基肥用量使产量降低,净收益下降。本实验条件下,施N量为180 kg/hm2,基肥-蘖肥-穗肥的比例为35-40-25时,直播早稻的产量和经济收益最佳。
A field experiment was carried out to study the effects of different basal and tiller nitrogen rates on the population dynamics, nitrogen uptake and utilization, yield formation and economic benefit of direct seeding early rice （Zhongxuan 181） in 2008 at Yujiang City, Jiangxi Province. Under the same seeding rate, total N rate and panicle N rate, the increase of basal nitrogen rate decreased the seedling emergence ratio and the tilter emergence rate at 38 days after seeding （DAS=38）. The highest tillers （DAS=54） and effect panicles decreased under the lower and higher N rate, while first increased then decreased with the increasing basal N rate under the optimum N rate. LeafN concentration and LAI of top three leaves at and after heading reduced by the increase of basal N rate, thus the plant N accumulation and the ratio of N allocation to panicle at maturity decreased, and N agronomic use efficiency and recovery use efficiency decreased significantly. The increase of basal N rate decreased the rice yield and net economic benefit. The optimum yield and economic benefit was achieved at the N rate of 180 kg/hm2 and the ratio of basal, tiller and panicle N of 35：40：25.
出处
《土壤》
CAS
CSCD
北大核心
2010年第5期815-821,共7页
Soils
基金
中国科学院知识创新工程重大项目(KSCX1-YW-09-08)
国家水体污染控制与治理科技重大专项(2008ZX07101-005)资助
关键词
直播早稻
基蘖肥用量
产量及其构成
氮素吸收利用
经济效益
Direct-seeding early rice, Basal and tiller nitrogen, Yield, Nitrogen utilization, Economic benefit
