桂西北秃杉人工林土壤理化性质

Physical and chemical edaphic properties of Taiwania flousiana plantation in Northwest Guangxi

为了了解禿杉人工林对林边土壤的影响,采用野外调查结合室内分析的方法,对广西西北部的南丹县、凤山县和天峨县的秃杉人工林土壤物理、化学性质进行了研究。结果表明：不同秃杉引种区具有相似的土壤理化性质,土壤（0-40 cm）密度为0.89-1.16 g/cm3,土壤总孔隙度为43.68%-53.65%,土壤最大持水量为46.36%-74.61%;土壤p H为4.30-4.88,土壤有机质含量为17.78-68.30 g/kg;土壤全氮和水解氮含量分别为0.82-3.37 g/kg和81.5-347.6 mg/kg;土壤全磷和速效磷含量为0.24-0.41 g/kg和0.40-2.87 mg/kg;土壤速效钾含量为28.3-136.2 mg/kg。表明桂西北秃杉引种栽培区林地土壤较疏松、通气、透水性能良好,土壤有机质及氮素养分含量高。随着林龄增加,林地土壤总孔隙度和最大持水量均呈增大趋势,土壤有机质、全氮和水解氮也有相同的变化规律,但土壤密度呈下降趋势。表明秃杉人工林能改善土壤结构和水分状况,提高土壤有机质和养分含量。

With the aim of understanding the influences of Taiwaniaflousiana plantation on the physically and chemically e- daphic properties, we analyzed the soil physical and chemical properties of T. flomiana plantation in Nandan, Fengshan and Tian＇ e County of Northwest Guangxi by using the methods of field investigation and laboratory analysis. The results showed as follows： similarly edaphic properties existed among different introduction regions. The density of soil（0-40 cm） ranged from O. 89 to 1.16 g/cm3 , soil total porosity from 43.68% to 53.65% , soil maximum moisture capacity from 46.36% to 74.61% ,organicmatter content from 17.78 to 68.30 g/kg, contents of total nitrogen and hydrolyzed nitrogen from 0.82 to 3.37 g/kg and 81.5 to 347.6 mg/kg, contents of total phosphorus and available phosphorus from 0.24 to 0.41 g/kg and 0.40 to 2.87 mg,/kg, and contents of available kalium from 28.3 to 136.2 g/kg, respectively. The results indicated that the soil was looser with good ventilation , and soil main nutrients as organic matter and nitrogen were rich in the introduction regions in Northwest Guangxi. With the stand age increasing, the soil total porosity and maximum moisture capacity increased, similarly change tendency existed on the content of soil organic matter, total N and hydrolyzable N, but the density of soil was in reverse trend. Therefore, the T.flousiana plantation could improve soil structure and moisture con-dition, the content of soil organic matter and nutrients, prevent soil degradation and protect eco-environment.