普洱市不同退耕还林模式改良土壤效应研究

Improving Soil Effects after Different Returning Farmland to Forest in Pu'er City of Yunnan

退耕还林是退化生态系统重建的重要途径。为了探讨不同退耕还林模式下土壤理化性质的演变规律,以云南普洱市退耕还林地为研究对象,对6种不同退耕还林模式样地的土壤理化性质进行了对比分析。结果表明:退耕还林后,土壤理化性质有很大改善,土壤团聚体含量、孔隙度、持水量、有机质含量、氮素含量、磷素含量和阳离子交换量均表现为退耕地>坡耕地,钾含量表现为坡耕地>退耕地;不同模式退耕林地土壤质量的恢复具有明显差异,按改良土壤的效果排序为:思茅松+西南桦>西南桦>思茅松>核桃>桉树>茶;以思茅松+西南桦、西南桦、思茅松或核桃为主要树种的乔灌草模式是当地退耕还林的理想模式。

Converting cultivated land into forestland is an important way for the rebuilding of degraded ecosystem.In order to investigate the evolution law of the physiochemical properties of soil under the different models of returning farmland to forest,the paper conducted comparative analysis on the physiochemical properties of soil under 6 different models of returning farmland to forest.The outcomes show that a) after retuning farmland to forest,the physiochemical properties of soil have been greatly improved.The soil aggregates,porosity,water holding capacity,organic matter content,nitrogen content,phosphorus content and CEC of returned farmland are all greater than that of the slope farmland and the potassium content of slope farmland is greater than that of the returned farmland;b) the soil quality of recovering of returning farmland to forest under the different modes is remarkably different.According to the effect of soil improvement,Pinus kesiya+Betula alnoides>Betula alnoides>Pinus kesiya>Juglans regia>Eucalyptus>Tea;c) the arbor-shrub-grass pattern of Pinus kesiya+Betula alnoides,Betula alnoides,Pinus kesiya or Juglans regia as the main species is an ideal model for the local returning farmland to forest.