不同林地清理方式下生物炭和氮添加对桉树红锥混交林土壤养分的影响

【目的】阐明不同林地清理方式下(火烧清理和人工清理)生物炭和氮添加对桉树红锥混交林土壤养分的影响,为人工林的经营管理提供参考。【方法】在火烧清理和人工清理林地的桉树红锥混交林中,设置生物炭和氮添加的控制实验,研究生物炭和氮添加对土壤有机碳(SOC)、全氮(TN)、全磷(TP)、全钾(TK)、有效磷(AP)和有效钾(AK)含量的影响。【结果】不同林地清理方式下,生物炭和氮添加对林地土壤养分的影响存在差异:与对照相比,人工清理林地时,添加生物炭显著增加了20～40cm土层的AP含量;氮添加极显著增加了0～10cm土层的SOC、TP、AP含量和C∶N;10～20cm土层的SOC、AK含量,20～40cm土层的AP和AK含量也显著增加;而0～10cm土层的N∶P则极显著降低。林地清理方式为火烧清理时,生物炭添加极显著增加0～10cm土层的TP含量,而0～10cm、10～20cm土层的SOC和AK含量,0～10cm土层的C∶N,10～20cm的AP∶TP、C∶P以及0～10cm、10～20cm、20～40cm土层的AK∶TK显著降低,0～10cm土层的AP含量、AP∶TP、C∶P和N∶P更是极显著降低。氮添加显著降低10～20cm土层的N∶P以及0～10cm土层的AP∶TP,0～10cm土层的AP含量以及10～20cm的TN含量下降达到极显著水平。【结论】人工清理林地条件下,实施生物炭和氮添加有利于提高桉树红锥混交林的土壤养分。

Effects of Biochar and Nitrogen Addition on Soil Nutrients under Different Ground Clearance method in Mixed Eucalyptus and Castanopsis hystrix Plantations

[Objective] The purpose of this study was to clarify the effects of biochar and nitrogen addition on soil nutrients under different ground clearance method (fire clearance and manual clearance) in mixed Eucalyptus and Castanopsis hystrix plantations and provide reference for the management of plantations.[Methods] In the mixed Eucalyptus and Castanopsis hystrix plantations that had been cleaned by fire and cleaned manually, control experiments of biochar and nitrogen addition were set up to study the effects of biochar and nitrogen addition on the content of soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available phosphorus (AP), and available potassium (AK) content.[Results] Under different ground clearance methods, there were differences in the effects of biochar and nitrogen addition on soil nutrients.Compared with the control, the addition of biochar significantly increased the AP content in the 20-40 cm soil layer when manually cleaning the woodland.Nitrogen addition significantly increased SOC, TP, AP content and C:N in 0-10 cm soil layer.SOC and AK content in 10-20 cm soil layer, and AP and AK content in 20-40 cm soil layer also increased significantly.And N:P in 0-10 cm soil layer was extremely significantly reduced.When the ground clearance method was fire clearance, the addition of biochar significantly increased the TP content in 0-10 cm soil layer.While the SOC and AK content in 0-10 cm, 10-20 cm soil layers, C:N in 0-10 cm soil layer, AP:TP and C:P in 10-20 cm soil layer, AK:CK in 0-10 cm, 10-20 cm, 20-40 cm soil layers decreased significantly.AP content, AP:TP, C:P, and N:P in 0-10 cm soil layer extremely significantly reduced.Nitrogen addition obviously reduced the N:P in 0-10 cm soil and AP:TP in 10-20 cm soil layer, AP content in 0-10 cm soil layer, and TN content in 10-20 cm soil layer decreased significantly.[Conclusion] Under the condition of manually clearance woodland, the implementation of biochar and nitrogen addition will help improve soil nutrients in the mixed Eucalyptus and Castanopsis hystrix plantations.