氮肥施用量对覆膜菜用大豆根系生长的影响

在田间以新鲜豆1号为材料研究了6种不同施氮量对根系生长的影响规律.结果表明:覆膜栽培大豆单株结瘤数增加快,单位面积根系干质量比露地栽培高30.45%~53.47%;施氮肥能够显著减少单株根瘤数,但同时却能促进根量的增长和根系下扎,增加根冠比,提高根系活力;除高氮处理(N120+30)外,其余处理单位面积根干质量均在结荚期达到峰值后迅速下降;高氮处理(N120、N120+30)抑制开花至结荚期间根系的生长,但减缓了结荚期至鼓粒期间的根系干质量的降低;施氮量为90 kg/hm2时,根系综合性状优良,产量最高.

Effect of nitrogen on root growth of vegetable soybean under film mulching

Taking the fresh vegetable soybean No.1 as the testing material,the effects of six different levels of nitrogen fertilizer volume on root growth of the vegetable soybean cultivar were studied in the field.The result showed that nodule number per plant under film mulching cultivation increased very fast,and the root dry weight per unit area of vegetable soybean film mulching increased by 30.45 %～53.47 % compared with open field.In different treatments,application of nitrogen fertilizer was significantly decreased for the formation of nodule number per plant,but application of appropriate nitrogen fertilizer could promote root weight growth and root system penetration,increase root dry weight/ aerial parts dry weight and improve root activity.The root dry weight in unit area of the other nitrogen treatment reached its maximum at the pod-setting period and then began to quickly decrease expect for the high nitrogen treatment(N 120+30).The high nitrogen treatment(N 120,N 120+30) inhibited root development from flowering to pod-setting stages,but it alleviated the root dry weight per unit area to decrease between pod-setting and pod-filling stage.Considering the vegetable soybean fresh pod yield and root system comprehensive characters,90 kg/hm2 N-fertilizer was proper.