N could be translocated efficiently from pod wall to seeds after R5 stage.However, only 9% of total seed N was estimated to be provided by the pod wall.

• 荚果壁内所含N素在种子充实期间可大量转移，亦即具有较高的利用效率，唯种子含N量由荚果壁转移者，估计最高不超过9%25。