湘西植烟土壤交换性镁含量及空间分布研究

为了解湘西州植烟土壤交换性镁含量分布状况,测试湘西州主要烟区488个土壤样本的交换性镁含量,采用传统统计学和地统计学方法分析了湘西州植烟土壤交换性镁含量适宜样本分布、县域差异、土壤类型差异、海拔差异及空间分布。结果表明:(1)湘西州植烟土壤交换性镁含量总体上适宜,平均值为177.76 mg/kg,变异系数为54.24%,处于适宜范围内的样本占32.38%。(2)不同县之间的植烟土壤交换性镁含量差异达极显著水平,保靖县、龙山县和凤凰县植烟土壤交换性镁含量属丰富水平,古丈县植烟土壤交换性镁含量属缺乏水平。(3)不同植烟土壤类型的交换性镁含量差异达显著水平,灰黄棕土的交换性镁含量显著高于水稻土。(4)不同海拔高度的植烟土壤交换性镁含量差异达极显著水平,湘西州植烟土壤交换性镁含量有随海拔升高而升高的趋势。(5)植烟土壤交换性镁含量Kriging插值图显示,湘西州植烟土壤交换性镁含量呈有规律地分布,在龙山县的北部、永顺县的东部、保靖县的东部、花垣县的西部各有一个高值区,在永顺县的北部、古丈县的东部、芦溪县西部和凤凰县的东部各有一个低值区。

Spatial Distribution and Exchangeable Magnesium Contents of Tobacco-growing Soil in Xiangxi Autonomous Prefecture

In order to understand the distribution of exchangeable magnesium content in the tobacco growing soil in Xiangxi,the distribution frequencies of exchangeable magnesium contents,differences in different counties,differences in different soil types,differences in different altitudes and the spatial distribution of exchangeable magnesium contents were analyzed based on 488 soil samples.The results were as follows:(1) The exchangeable magnesium contents in the tobacco soil were generally suitable for tobacco cultivation,with a mean of 177.76 mg/kg and variation coefficient of 54.24%.About 32.38% of the soil samples had exchangeable magnesium contents for suitable tobacco cultivation.(2) There existed extremely significant differences among different counties in the contents of exchangeable magnesium.The average content of exchangeable magnesium was at an abundant level in Baojing,Longshan and Fenghuang counties.The average content of exchangeable magnesium was at a level of shortage in Guzhang County.(3) There existed extremely significant differences among different soil types in the contents of exchangeable magnesium.The average content of exchangeable calcium in yellow-brown ash soils was significantly higher than that in paddy field.(4) There existed extremely significant differences among different altitude soils in the contents of exchangeable magnesium.The exchangeable magnesium contents increased with the rise of altitude in the tobacco growing soils in Xiangxi.(5) Kriging interpolation map indicated that the spatial distribution of exchangeable magnesium was of regular distribution.The area of high value exchangeable magnesium was in the northern Longshan County,the eastern Yongshun and Baojing,western Huayuan Counties,respectively.The area of low value exchangeable magnesium was in the northern Yongshun,the eastern Guzhang,the western Luxi,the eastern Fenghuang Counties,respectively.