杉木米槠混交林土壤肥力研究

Study on Soil Fertility of Mixed Forest of Cunninghamia lanceolata and Castanopsis carlesii

[目的]探究6年生杉木米槠混交林与杉木纯林的土壤肥力差异。[方法]通过多点取样,测定与分析土壤容重、土壤>0.25 mm水稳性团聚体、孔隙状况、土壤水分性质及主要土壤养分含量。[结果]混交林0~20 cm容重下降2.8%,土壤水稳性团聚体增加5.6%,土壤结构体破坏率降低16.7%,非毛管孔隙度、总孔隙度分别增加11.9%和4.1%,自然含水量、最大持水量及田间持水量分别增加2.3%、20.2%和11.6%。土壤有机质、全氮、全磷、水解氮、速效磷、速效钾分别增加24.1%、17.4%、6.1%、13.3%、6.5%和13.7%。20~40 cm土层土壤理化性质也有不同程度的变化,尤其是土壤表层变化较为明显。[结论]杉木米槠混交林可以改善土壤肥力,起到遏制或减缓地力衰退的积极作用。

[Objective]To study the difference of soil fertility between 6-year-old mixed forest of Cunninghamia lanceolata and Castanopsis carlesii and pure forest of Cunninghamia lanceolata.[Method]Through multi-point sampling,soil bulk density,water stable aggregates>0.25 mm,pore status,soil water properties and main soil nutrient contents were determined and analyzed.[Result]The 0-20 cm bulk density of the mixed forest decreased by 2.8%,the soil water stable aggregates increased by 5.6%,the soil structure damage rate decreased by 16.7%,the non capillary pores and total pores increased by 10.2%and 4.1%respectively,and the natural water content,maximum water capacity and field water capacity increased by 2.3%,20.2%and 11.6%respectively.Soil organic matter,total nitrogen,total phosphorus,hydrolyzed nitrogen,available phosphorus and available potassium increased by 24.1%,17.4%,6.1%,13.3%,6.5%and 13.7%respectively.The physical and chemical properties of 20-40 cm main soil also changed in different degrees,especially in the surface layer of soil.[Conclusion]Mixed forest of Cunninghamia lanceolata can improve soil fertility and play a positive role in curbing or slowing down the decline of soil fertility.