不同立地类型土壤有机质含量对板栗初生长的影响

以广西东兰县退耕还林地栽种板栗的5种立地类型为研究对象,采用典型抽样的方法,每个立地类型分别在3个乡镇设置土壤剖面,分A、B层采集土壤样品,再利用重铬酸钾法测定土壤有机质含量;采用样点调查的方法,调查相应的退耕板栗纯林的地径、树高、冠幅生长量,还调查同一立地条件下已生长成林的荒山林地板栗。研究结果表明,5种立地类型的土壤有机质含量存在差异,相应的年平均生长量也存在差异;有机质含量在中等及以上的第8、9、10立地类型,A层土壤有机质含量与各项的年平均生长量基本呈正相关,而有机质含量在中等及以下的则这种关联不明显。这一结果可为该县退耕林地施肥管理提供理论依据。

Effect of Soil Organic Matter Content at Different Site Types on Early Growth of Castanea mollissima

The experiment was conducted in 5 site types of returning farmland to forests in Donglan County,Guangxi.A typical sampling method was adopted.Soil profile was set up in each site type in the three towns.Points A,B of the soil samples were collected.Soil organic matter content was determined with potassium dichromate.At the same time,the diameter,height and crown growth of Castanea mollissima in the pure forest were investigated with samples survey method.And the growth in the forest under the same site was investigated.The results show that,there were differences among organic matter contents in 5 site types.There were also significant differences among the corresponding average annual growth.Soil organic matter content in A layer in the middle section 8,9,10 and above and the annual average growth showed basic positive correlation.But the correlation in the middle and the following wasn't obvious.The research could provide a theoretical basis for the management of fertilizer in the county's forest.