科尔沁沙地油松人工林的土壤养分含量变化特征

Variation Characteristics of Soil Nutrient Content of Pinus tabuliformis Plantation in Horqin Sandy Land

以科尔沁沙地18 a、34 a、43 a和56 a林龄的油松人工林为研究对象,探讨油松人工林土壤养分含量随林龄的变化特征。结果表明:随着林龄的增加,土壤有机质、全氮、全磷含量显著增大,有机质含量由对照样地的2.75 g·kg^(-1)增至43 a林地的11.95 g·kg^(-1);全氮含量由对照样地的0.23 g·kg^(-1)增至56 a林地的0.62 g·kg^(-1);全磷含量由对照样地的0.08 g·kg^(-1)增至56 a林地的0.16 g·kg^(-1);全钾含量和速效养分在各林龄中无明显规律性变化。在0~2 cm土层中有机质和速效钾含量显著大于2~10 cm和10~20 cm土层,0~2 cm土层有机质在各林龄阶段平均为19.73±8.16 g·kg^(-1),2~10 cm和10~20 cm土层分别为7.17±0.74 g·kg^(-1)和5.08±1.21 g·kg^(-1);土壤全氮、全磷、全钾、速效氮和速效磷含量随土层变化无显著变化。双因素方差分析表明,林龄和土层均能显著影响土壤有机质、全氮、全磷、速效氮、速效磷和速效钾含量。综上所述,随着林龄的增加,油松人工林的土壤养分含量得到了明显改善,而且表层土壤较下层土壤的养分含量提高程度更为明显。

Taking 18-year,34-year,43-year and 56-year Pinus tabuliformis plantation in Horqin Sandy Land as research object,the variation characteristics of soil nutrient content with forest age were discussed.The results showed that soil organic matter,total nitrogen and total phosphorus increased significantly with the increase of the forest age of Pinus tabuliformis,the organic matter content increased from 2.75 g·kg^(-1) of the control to 11.95 g·kg^(-1) of 43 years,the total nitrogen content increased from 0.23 g·kg^(-1) of the control to 0.62 g·kg^(-1) of 56 years,the total phosphorus content increased from 0.08 g·kg^(-1) of CK to 0.16 g·kg^(-1) of 56 years,there was no obvious regular change in total potassium content and available nutrients in different forest ages.The organic matter and available potassium in 0-2 cm soil layer was significantly higher than that in 2-10 cm and 10-20 cm soil layer.The average organic matter content in 0-2 cm soil layer was 19.73±8.16 g·kg^(-1),with 7.17±0.74 g·kg^(-1) and 5.08±1.21 g·kg^(-1) for 2-10 cm and 10-20 cm soil layer respectively.The contents of total nitrogen,total phosphorus,total potassium,available nitrogen and available phosphorus had no significant changes with the change of soil layer.Two-factor variance analysis showed that both forest age and soil layer could significantly affect the contents of soil organic matter,total nitrogen,total phosphorus,available nitrogen,available phosphorus and available potassium.The results showed that with the increasing of forest age,the soil nutrient content of Pinus tabuliformis plantation was obviously improved,with the nutrient of surface soil higher than the one of lower soil.