天全河流域土壤氮素的空间分布特征及其影响因素分析

【目的】研究天全河流域土壤氮素的空间分布特征及其影响因素。【方法】采用常规统计、地统计学和地理信息系统相结合的方法分析780个表层土壤(0～30cm)样点数据。【结果】该流域土壤全氮含量达(1.40±0.52)g/kg,碱解氮含量达(125.79±56.24)mg/kg。土壤全氮含量由高到低为水稻土>潮土>黄壤>紫色土,土壤有效氮含量则为水稻土>黄壤>潮土>紫色土。全氮和有效氮块金值/基台值分别为0.78～0.90和0.96～0.97,两种氮素空间变异均以指数模型最好。【结论】全氮和有效氮的空间分布均呈由西向东逐渐减少的趋势。成土母质、地形部位、土地利用和耕地种植制度都极显著地影响土壤全氮和有效氮的含量。

Spatial Distribution of Soil Nitrogen and Iis Influencing factors in the Tianquan Rever Basin

【Objective】 The aim of this study was to study spatial distribution of soil nitrogen and influencing factors of in the Tianquan River Basin.【Method】 Traditional statistics,geostatistics and software ArcGIS 9.0 were used to analysis data of soil nitrogen content from the 780 soil samples(0-30 cm).【Results】 The contents of soil total nitrogen(TN) and available nitrogen(AN) were(1.40±0.52) g/kg and(125.79±56.24) mg/kg,respectively.Soil TN contents in paddy soil and fluvo-aquic soil were more than those in yellow soil and purple soil.While soil AN contents showed an order of paddy soil > yellow soil > fluvo-aquic soils > purple soil.The ratios of nugget to sill were 0.78-0.90 in soil TN and 0.96-0.97 in soil AN.Exponential model was the best to explain the spatial variation in both soil TN and AN.【Conclusion】 The spatial distribution of soil TN and AN showed a decrease tendency from the west to the east in the basin.Moreover,parent material,landform,landuse and cropping system in plowland had significant effects on soil TN and AN.