Effects of Land Use Patterns on Soil Enzyme Activity and Fertility in Rocky Desertification Area of Peak-cluster Depression

Three enzyme indexes of soil sucrase, urease and phosphatase and 5 fertility indexes of organic matter, total nitrogen, total phosphorus, alkali-hydrolyzable nitrogen and available phosphorus in different land use patterns in typical peak-cluster depression area were selected. Soil enzyme index method(SEI) and soil fertility index method(IFI) were used to study soil enzyme activity and fertility in rocky desertification area. The findings indicated that there were significant differences in enzyme activities of different land use modes, and the range of soil sucrase, urease and phosphatase activities in different land use modes was 20.15–40.05 mg/(g·24 h), 32.05–109.59 mg/(g·24 h), 0.81–1.06 mg/(g·24 h), the changes of soil enzyme index were as follows: shrub grassland(0.581) > arbor shrub grassland(0.517) > maize field(0.479) > kiwifruit land(0.381) > walnut land(0.369) > wasteland(0.348); there were significant differences in soil fertility between different land use methods, and the contents of organic matter, alkaline hydrolyzable nitrogen, total nitrogen, total nitrogen, total phosphorus and available phosphorus in different land use methods were 27.96–76.25 g/kg, 99.40–263.45 mg/kg, 1.002–2.35 g/kg, 0.41–1.19 g/kg, 4.67–21.73 mg/kg, the changes of soil comprehensive fertility index were as follows: barren land(0.978) > shrub grassland(0.868) > maize field(0.733) > walnut field(0.665) > arbor shrub grassland(0.476) > kiwi land(0.421); in addition to kiwifruit field, there was a significant correlation between soil enzyme activity and fertility in other land use modes in the rocky desertification area of the peak-cluster depression(P < 0.05). In order to restore and rationally use the land in the rocky desertification area of the peak-cluster depression, human interference should be minimized for abandoned land. For shrub grassland, arbor-shrub grassland, corn land, walnut land, and kiwifruit land with human intervention, reasonable artificial measures can be applied to improve soil quality. Shrub grassland can be used as a priority land use type in the ecological restoration process of the rocky desertification area of the peak-cluster depression.