The effects of N fertilization on growing root was most obvious, and growing root of 100 and 200 mg kg-1 N fertilizer increased 1.67 and 2.56 times in May, and 1.08, 1.31 times in Oct respectively.

• 三类根中，氮肥对生长根的效果最为明显，在5月份100mg kg~(-1)和200mg kg~(-1)氮肥的处理分别比CK增加了1.；67、2