黄土丘陵区撂荒对土壤酶活性的影响

Effect of Farmland Abandonment on Soil Enzyme Activities in Loess Hilly Region

为了解侵蚀环境下植被恢复对土壤酶活性的影响,以典型侵蚀环境黄土丘陵区纸坊沟流域生态恢复1至50年撂荒地长期定位试验点为研究对象,选取坡耕地为对照,分析了植被恢复过程中土壤脲酶、磷酸酶、蔗糖酶、淀粉酶、纤维素酶、过氧化氢酶、多酚氧化酶及理化性质的演变特征。结果表明,土壤酶活性前期变化波动较大,后期(20-30a)年变化趋于稳定;尿酶、碱性磷酸酶、蔗糖酶、过氧化氢酶和多酚氧化酶与其他因子相关性相对较强,可以作为评价土壤质量的生物学指标;尿酶、淀粉酶、碱性磷酸酶、蔗糖酶、过氧化氢酶和纤维素酶活性随恢复年限而增加,多酚氧化酶则减少;土壤酶指数可以作为评价土壤质量的方法。

In order to determine the effect of vegetation restoration on soil enzyme activities of abandoned farmland under erosion environment, seven kinds of soil enzyme （urease, amylase, alkaline phosphatase, catalase, sucrase, polyphenol oxidase, and cellulase） activities of farmland with an abandoned age sequence of 0, 1, 5, 7, 10, 15, 20, 25, 30, 40, and50 years in Zhifanggou watershed （8.73 km^2）, Shaanxi province were studied and 0-year abandoned slope farmland as CK. The results show that soil enzyme activities showed a fluctuant variation in the beginning, and then showed a stable increase or decrease tendency later （〉25 a）. Urease, alkaline phosphatase, catalase, sucrase, and polyphenol oxidase could be used as biological indicator to evaluate soil quality because of a significant correlation between those en- zyme activities and soil physicochemical and microbiological properties. The activities of urease, amylase, alkaline phosphatase, sucrase, catalase, and cellulose increased along with increasing restoration age, while polyphenol oxidase decreased. Soil enzyme index could be used as a way to assess soil quality.