ABSTRACT

Different planting ages of forests will have a certain impact on the physical and chemical properties of the soil. This study investigated whether different growth years of hazelnut have an influence on soil organic carbon (SOC) content and humic acid (HA) structure. To do this, four treatments were implemented: no hazelnut planting (CK), hazelnut planting 2 years (A2), hazelnut planting 4 years (A4), hazelnut planting 5 years (A5), hazelnut planting 8 years (A8) were considered. With the extension of the hazelnut cultivation years, the SOC content of 0～20 cm and 20～40 cm gradually decreased, reaching 18.84 and 24.53 g kg⁻¹ in the fifth year, but increased by 10.36 and 3.50 g kg⁻¹ in the eighth year. The H/C ratio in the HA structure of 0～20 cm and 20～40 cm soil of A8 increased by 0.010 and 0.057. The Fourier transform infrared spectroscopy (FTIR) spectra and thermogravimetric analysis (TG) results revealed that at 2, 4, and 5 years after planting hazelnut, the structural condensation of HA increased and the degree of aliphatic group decreased. In 8 years after planting, the HA structure had the weakest degree of condensation and more aliphatic structure, while the HA structure was younger and unstable. In conclusion, this study is helpful for hazelnut cultivation and effective management of sustainable utilization of garden soil .

摘要

不同种植年限的森林会对土壤的理化性质产生一定的影响。本研究调查了不同生长年限的榛子是否对土壤有机碳（SOC）含量和腐植酸（HA）结构产生影响。为此，实施了四个处理：考虑不种植榛子（CK）、种植榛子 2 年（A2）、种植榛子 4 年（A4）、种植榛子 5 年（A5）、种植榛子 8 年（A8）。随着榛子栽培年限的延长，0～20 cm和20～40 cm的SOC含量逐渐降低，第5年分别达到18.84和24.53 g kg ^-1，增加了10.36和3.50 g kg ^-1在第八年。A8 0～20 cm和20～40 cm土壤HA结构中H/C比分别增加0.010和0.057。傅里叶变换红外光谱（FTIR）光谱和热重分析（TG）结果表明，在种植榛子后2、4和5年，HA的结构缩合增加，脂肪族基团程度降低。种植后8年，HA结构凝结度最弱，脂肪族结构较多，而HA结构较年轻且不稳定。综上所述，本研究有助于榛子栽培和园林土壤可持续利用的有效管理。