胡麻/大豆间作体系下施氮对胡麻干物质积累和产量的影响

摘要

To optimized nitrogen management on oil flax/soybean intercropping system,field experiment was carried out to investigate N effect on dry matter accumulation and yield of 2 crops. 3 different N rates(0,75 and 150kg/hm2 )were applied on monocropping and intercropping respectively. Results showed that fitted logistic equa-tions of oil flax dry matter accumulation were significant at P﹤0 . 01 . The maximum rate of dry matter accumulation of monocropping oil flax occurred at flowering stage. It moved to fruiting stage under 150kg/hm2 N on intercropping oil flax. Under monocropping,total dry matter accumulation and grain dry matter accumulation were increased with N application,and reached the highest under 150kg/hm2 treatment(T3). Under intercropping in contrast,75kg/hm2 N application(T5)led to the top dry matter accumulation. Compared to monocropping,the maximum inter-cropping oil flax yield(as 3 204. 80kg/hm2)was obtained due to higher translocation of dry matter(before anthe-sis),higher dry matter accumulation( after anthesis),and higher contribution rate of dry matter assimilation to grains. Additionally,mutually beneficial effect was greater than competition effect in oil flax/soybean intercropping system. In conclusion,half N application(75kg/hm2 N)under flax/soybean intercropping obtained high yield of 3 204. 80kg/hm2 flax seeds.%为改进胡麻产量和发展胡麻/大豆间作技术，采用随机区组试验，设单作模式下不施氮（ T1）、施氮75kg/hm2（T2）、施氮150kg/hm2（T3）和间作模式下不施氮（T4）、施氮75kg/hm2（T5）、施氮150kg/hm2（T6）6个处理，研究了施氮量和种植模式对胡麻干物质积累规律、产量及产量构成因子的影响。结果表明，拟合的胡麻全生育期干物质积累Logistic模型均达到极显著相关水平。单作胡麻最大干物质积累速率出现在盛花期，间作种植模式下过量施氮时峰值会转移至子实期。在单作模式下，胡麻总干物质累积量和籽粒干物质累积量均随施氮量的增加而增加，以施氮量为150kg/hm2处理（T3）最高；而在间作种植模式下，施氮量为75kg/hm2处理（T5）显著高于不施氮处理（T4）和施氮量150kg/hm2的处理（T6）。在同一施氮水平下，间作种植模式下各处理开花前贮藏同化物的转运量、花后干物质积累量和花后干物质同化量对籽粒的贡献率均显著高于单作各处理，以施氮量为75kg/hm2处理（T5）最高；各处理以T5的产量最高，为3204.80kg/hm2，且胡麻与大豆间作中得到的互利效应大于受到的竞争效应。因此，胡麻与大豆间作，即便减量施氮（75kg/hm2）仍可获得高产。