叶面不同施氮量对大豆氮素吸收与分配的影响

Effects of Leavse Nitrogen Application Rate on Nitrogen Uptake and Distribution in Soybean

为研究大豆叶面氮素吸收与分配规律,以黑龙江省三江平原大豆主栽品种合丰50为试验材料,采用15N示踪法在大豆R5期进行叶面施氮处理,研究大豆不同器官对氮素同化吸收及积累分配情况。结果表明:当施氮量超过4.5kg·hm-2(N3)条件下,大豆植株各器官干物质量、氮素含量、氮素积累量均不再显著增加。子粒干物重在4个施氮量(N1、N2、N3、N4)条件下分别比无氮处理增加2.51%,5.01%,9.55%和0.51%,在4.5kg·hm-2(N3)条件下最高,为21.8g/株。同一施氮量条件下,大豆不同器官15N积累量为子粒>茎>叶>荚皮>叶柄>根;在不同施氮量条件下,15N在各器官积累量随施氮量增加而增加,在4.5kg·hm-2(N3)条件下达到最高值,子粒15N积累量为8.17mg/株。从N1到N3处理增加施氮量降低了15N在子粒中的分配比例,但提高了15N在叶片中的分配比例,同时提高了15N在子粒中的积累量。本研究从理论上证明了在大豆R5期进行叶面施氮时,氮素主要积累于子粒中,从而有利于子粒干物质积累,最终获得增产。

For research the effects of nitrogen uptake and distribution in soybean,Using soybean cultivar‘He Feng50＇in Sanjiang Plain in Heilongjiang as test materials and taking15 N tracer method for leaves nitrogen application in R5 to study the nitrogen uptake and distribution of different soybean organs. The results show that there were no signification increments in dry weight, nitrogen content and nitrogen accumulation if the nitrgen application rates were over4. 5kg·hm- 2（ N3） and the percentages of soybean seeds dry weight increase over contral were 2. 51%,5. 01%,9. 55%and 0. 51%. The seeds weight had the highest value of 21. 8 g·plant- 1in 4. 5kg·hm- 2（ N3） treatment. The different organs ^15 N accumulation were seed〉 leaf 〉pod〉 petiole 〉root under the same nitrgen application rate. The ^15 N accumulation of different organs were increased with the nitrgen application rates increased and the seed15 N nitrogen accumulation had the highest value of 8. 17 mg·plant- 1under the different nitrgen application rate. The15 N distribution in seeds reduce with nitrogen application rates from N1 to N3 treatment,but there was a reverse trend in leavse and the seed15 N nitrogen accumulation was increased at the same time. This research theoretically proved that the nitrogen main accumulated to the seeds when leaf nitrogen application in R5 period and in favour of the seeds dry weight accumulation and got high yield at last.