磷素水平对不同大豆品种氮素营养的影响

选用近年来黑龙江省推广面积比较大并具有代表性的3个大豆品种作为试验材料,采用盆栽,在N、K肥 施用量一定的基础上,设4个P处理,利用凯氏定氮法测定了不同大豆品种各器官氮素含量。结果表明,施磷对大 豆植株及各器官氮素含量有较大影响, 3个品种不同处理全株氮素含量从分枝期逐渐增加,成熟期达到高峰;同一 品种不同处理表现为适宜的磷水平有利于氮素的积累, 3个品种花期后都是P5 (每千克土施P2O5 0. 033g)处理全 株氮素含量最高,说明适宜的施磷有利于促进氮素积累。同一处理不同品种间高蛋白品种的氮素含量多于中间型 品种和高油品种,说明高蛋白品种需氮量多于中间型品种和高油品种。植株氮素含量高表现为单株产量和蛋白质 含量高,而脂肪含量却不是最高,氮素对脂肪形成影响较小。

The effect of phosphorus level on nitrogen uptake of different soybean varieties

Three soybean varieties,which were widely planted in Heilongjiang province,were planted in pots with the same amount of N and K fertilizer,but four different levels of phosphorus.The nitrogen amounts in different organs were determined with the classical method of Kai's Fixed Nitrogen.The results suggested that there were relatively large effects of phosphorus on the nitrogen accumulation in total plants and each organ.In all three soybean varieties with different phosphorus treatments,the nitrogen amounts in total plants were gradually increased from branching stage and reached peak values at ripening stage.Suitable phosphorus level showed beneficial for the accumulation of nitrogen.The highest accumulation of nitrogen in total plants were obtained with P_5 treatment after flowering stage,indicating that suitable phosphorus application can help nitrogen reaching optimum balance,acquiring higher accumulation level.Nitrogen accumulation was higher in the variety with high protein than that in the variety with medium level of protein and high level of oil content,suggesting the nitrogen requirements was higher in high protein content variety.The higher nitrogen amounts in plants was followed by higher yield of single plant and higher content of protein,whereas fat content was lower.The nitrogen had little effect on fat formation.