亚热带山地草甸土壤速效养分分布特征研究——以江西武功山为例

摘要

[Objective]The alpine meadow soil of different elevations and human disturbance levels in Wugong Mountain was taken as the objecr of study,it will provide theoretical reference and scientific basis for restoration and management of degraded mountain meadow.[Method] Based on the soil nutrient system (ASI) method,the contents of soil available nutrients in different treatment areas were determined,the distribution characteristics of soil pH,organic matter,available nitrogen,available phosphorus and available potassium were analyzed.Multivariate statistical analysis and mapping were conducted by using SPSS 21.0 and SigmaPlot 12.5.[Result]The results showed that:(i) The pH value of soil was strongly acidic,the mean was 4.56,the soil organic matter content was rich,the mean was 3.11％,the soil available nitrogen content was medium,the mean was 38.96 mg/L,the means of available phosphorus was 5.01mg/L and available potassium was 46.79mg/L.(ii) The contents of soil organic matter,available nitrogen,available phosphorus and available potassium in the upper soil were higher than those in the lower layers at different elevations.The soil organic matter content was extremely significandy different (P ＜ 0.01),the content of available nitrogen showed a "W" distribution pattern with the changed of elevations,and was significant difference (P ＜ 0.05),along with the increase of elevations,the content of the available potassium showed a gradual increase and then decrease trend,there were significant differences at different elevations(P ＜0.05).(iii) The soil pH values in the SD region were significantly different from those in other areas (P ＜ 0.01).The soil organic matter content in SD region was significantly different from that in SLD region (P ＜0.05).There was no significant difference in soil available nitrogen content between different human disturbance levels (P ＞ 0.05).In the CK and MD regions,the available nitrogen content in different soil depths was significantly different (P ＜ 0.05).The content of available phosphorus in the upper soil of SD region was significantly different from that in other areas (P ＜ 0.05).There was significant difference in available potassium content between CK and SLD (P ＜ 0.05),and no significant difference between the upper and lower soil layers (P ＞ 0.05).The elevations and soil pH were correlated with extremely significantly positively (P ＜ 0.01),and negatively correlated with organic matter and available phosphorus (P ＜ 0.05),the human disturbance levels were extremely significantly negatively correlated with pH and available potassium (P ＜ 0.01).[Conclusion] The elevations and human disturbance are the important factors that affect the change of available nutrients in meadow soil of Wugong Mountain.The soil pH value had little variation in different areas of meadow,but organic matter,available nitrogen,available phosphorus and available potassium content showed medium variation.The soil available nutrients were rich,the combination of biological and engineering measures can be used to repair vegetation human disturbance areas in a timely manner so as to prevent further destruction of the regional environment.%[目的]以武功山不同海拔和干扰程度的山地草甸土壤为研究对象,为退化山地草甸恢复治理提供理论参考和科学依据.[方法]基于土壤养分系统研究法(AS1法)测定各处理区域土壤速效养分含量,运用SPSS21.0及SigmaPlot12.5进行多元统计及绘图,分析土壤pH、有机质、速效氮、速效钾的分布特征.[结果]土壤pH值呈强酸性,均值为4.56,有机质含量丰富,平均含量为3.11％;土壤速效氮(AN)含量中等,平均含量为38.96 mg/L;速效磷(AP)平均含量为5.01 mg/L;速效钾(AK)平均含量为46.79mg/L.不同海拔高度的上层土壤OM及AN、AP、AK含量高于下层;土壤OM含量有极显著差异(P＜0.01),不同海拔之间上层土壤AN具有显著差异(P＜0.05),土壤AN含量随海拔变化呈现“W”型波动状分布,AK的含量依旧随海拔升高呈现先增高然后减低的趋势,不同海拔含量具有极显著差异(P＜0.05).SD区域内土壤pH值与其他区域内具有极显著差异(P＜0.01),SD区域上层土壤OM含量与SLD区域具有显著差异(P＜0.05),不同干扰程度上、下层土壤AN含量无显著差异(P＞0.05),在CK和MD区域,不同土层深度的AN含量差异显著(P＜0.05).SD区域内上层土壤的AP含量与其他区域差异显著(P＜0.05),不同干扰程度上、下层AK含量均无显著差异(P＞0.05),在CK及SLD不同土层深度土壤AK含量有显著差异(P＜0.05).海拔高度与土壤pH值呈极显著正相关(P＜0.01),与OM、AP呈极显著负相关(P＜0.05).退化程度与pH、AK呈极显著负相关(P＜0.01).[结论]海拔和人为干扰是影响武功山草甸土壤速效养分含量变化的重要原因.不同区域草甸土壤pH值呈弱变异,OM、AN、AP、AK等含量呈中度变异.武功山土壤速效性养分含量丰富,可运用生物和工程措施相结合的方法,及时对植被退化区域进行修复,以防止区域环境的进一步破坏.