【摘要】 以杨树纯林和杨农复合林2种生态系统为研究对象,通过对土壤有机碳、氮、磷、钾等营养元素含量的测定,初步探讨土壤养分的分布特征。结果表明,杨树纯林和杨农复合生态系统中有机碳、全氮和有效磷含量随着土壤深度增加均呈现递减的趋势;有效钾含量在杨树纯林中随土壤深度的增加而降低,在杨农复合系统中表现出先增大后减小的倒"U"型变化趋势。土壤有机碳、氮、有效磷、有效钾含量范围分别为（6.34±0.22）^16.88±1.07g/kg,（0.57±0.09）^1.35±0.17g/kg,（4.76±0.44）^13.88±1.01mg/kg和（52.8±3.99）^176.1±8.45mg/kg。由于间作植物的影响,N,P,K和有机碳的含量在杨树纯林和杨农复合生态系统土壤层中表现出了一定的差异。杨农复合生态系统会在一定程度上改良土壤,增加土壤有机碳和养分元素的含量。更多还原

【Abstract】 The organic carbon and nutrient elements（ N,P,K） of different soil depth in poplar and poplar-crop intercropping patterns were studied in the north of Jiangsu Province. The results showed that the contents of soil organic carbon,total nitrogen,available phosphorus were decreased with the depth of soil. The variation trend of available potassium featured with inverted U-shape. The variation range of soil organic carbon,total nitrogen,available phosphorus and available potassium were from（ 6. 34 ± 0. 22） ^{16. 88 ± 1. 07} g / kg,（ 0. 57 ± 0. 09） ^{1. 35 ± 0. 17} g / kg,（ 4. 76 ± 0. 44） ^{13. 88 ± 1. 01} mg/kg and（ 52. 8 ± 3. 99） ^{176. 1 ± 8. 45} mg/kg,respectively. There were differences between the poplar and poplar-crop intercropping patterns in soil organic carbon and nutrient elements under the effects of crops,suggesting the poplar-crop agroforestry ecosystem may improve soil organic carbon and nutrient elements.更多还原