Taking the rhizosphere soil of artificial seabuckthorn forest in loess hill and gully region of Eastern Gansu Province as experiment objects

the soil humus composition and combined form and optical properties of humic acid in different recovery stages of artificial seabuckthorn forest were investigated. The results showed that the organic carbon content in humin(HM) >humic acid(HA) >fulvic acid(FA) in different years

meanwhile

PQ(proportion of HA) of CK >the soil of artificial seabuckthorn forest of 7 years old >in 2001 soil of artificial seabuckthorn forest of 10 years >the soil of artificial seabuckthorn forest in 1995

and all the PQ were more than 52% at each layer of the artificial seabuckthorn forest soil of 15 years old. The value of E4/E6 and hue coefficient(ΔlgK) demonstrated that:15 years >10 years >CK >7 years; the humification degree of soil of 15 years was significantly higher than that of 10 years

CK and 7 years

which demonstrated that

along with recovery time

humification degree of soil trend to simple

and the oxidation stability of soil humic acid decreased. Meanwhile

it was adversed to the advancement of soil fertility. Therefore

artificial seabuckthorn forests should be regenerated when it was planted more than 15 years to prevent soil erosion and improve soil fertility.