渭北生草果园土壤有机碳矿化及其与土壤酶活性的关系

通过短期(31 d)室内培养法测定苹果园清耕、苹果∕白三叶间作、苹果∕小冠花间作这3种管理模式下土壤有机碳矿化动态和4种土壤酶活性,探讨了渭北果园不同生草条件下土壤有机碳矿化规律及其与土壤酶活性的关系.结果表明,在培养过程中,3种管理模式下土壤有机碳日矿化率均表现出先升高后降低,后期保持低且比较稳定的趋势.培养31 d后,与对照处理土壤有机碳矿化累积量为367 mg·kg-1相比较,白三叶处理最大为590 mg·kg-1、小冠花处理为541 mg·kg-1,并且3个处理在垂直方向上有机碳累积矿化量均随土层深度增加而减小.由一级动力学方程拟合发现,生草果园土壤有机碳矿化碳潜力(Cp)和矿化速率常数(k)值分别为0.252~2.74 g·kg-1和0.019~0.051 d-1,果园生草处理Cp值与对照处理Cp值差异显著,并且土壤蔗糖酶和纤维素酶与土壤有机碳矿化有较高的相关性.

Mineralization of Soil Organic Carbon and Its Relationship with Soil Enzyme Activities in Apple Orchard in Weibei

A total of 36 kinds of soil samples were collected from apple orchards under three kinds of management model, including clear tillage model, intercropping white clover model and intercropping small crown flower model, the mineralization of soil organic carbon and four kinds of soil enzymes activities were determined, and the relationship between the two parameters was also analyzed. The results showed that the soil organic carbon mineralization of all the three treatments was almost the same. The daily SOC mineralization rate first increased and then decreased, and finally tended to be stable. After 31 days incubation experiment, the maximum accumulative amount of SOC mineralization occurred in white clover treatment with 590 mg·kg^-1, followed by small crown flower treatment with 541 mg·kg^-1, and the minimum value was 367 mg·kg^-1 in the control treatment, and the accumulative amount of SOC mineralization decreased with increasing soil depth. Discovered by the first-order kinetics, the fitting parameter Cp value ranged from 0.252 to 2.74 g·kg^-1 and k value ranged from 0.019 to 0.051 d^-1, and the two grass treatments both showed significant difference in Cp value from the control treatment, and the soil invertase and cellulose activities showed obvious relationship with soil organic carbon mineralization.