湖南邵阳烟区耕层土壤碱解氮含量分布及变化趋势

为了解邵阳烟区耕层土壤碱解氮含量分布状况,采用传统统计学和地统计学方法于2012年分析了邵阳烟区耕层土壤碱解氮含量适宜样本、不同pH组、不同有机质组、空间分布及变化趋势。结果表明:①邵阳烟区耕层土壤碱解氮含量总体处于适宜水平,平均值为112.70mg/kg,变异系数为32.70%,处于适宜范围内的样本占40.50%。②邵阳县耕层土壤碱解氮含量极显著高于隆回县和新宁县。③土壤碱解氮含量总体上从中部分别向西南部和北部递减的分布趋势。④耕层土壤pH与土壤碱解氮含量相关关系不显著。⑤土壤碱解氮含量有随有机质提高而增加的趋势。⑥与2002年相比,耕层土壤碱解氮含量呈下降趋势。

Distribution of available nitrogen contents in the surface soil from Shaoyang tobacco-growing areas and their changes

In order to understand the distribution of available nitrogen contents in surface soils from Shangyang tobacco-growing areas,distribution of suitable samples ratio,pH groups,organic matter groups and spatial distribution and changes of available nitrogen contents were investigatedanalyzed by the methods of traditional statistics and geo-statistics.The results were as follows：（1） The available nitrogen contents in the surface soil were generally suitable for tobacco cultivation,with a mean of 112.70mg/kg and variation coefficient of 32.70％.About 40.50％ of the soil samples had available nitrogen contents for suitable tobacco cultivation.（2）The available nitrogen contents in surface soils from Shaoyang counties were extremely significant higher than those from Longhui county and Xinning county.（3）Kriging interpolation map indicated that the spatial distributions of available nitrogen were reduced from the middle to the northern and south-western.（4） The correlation was not significant between the contents of available nitrogen and pHs in surface soils from Shaoyang tobacco growing areas.（5） The contents of available nitrogen was increased with the rise of organic matter in surface soils of Shaoyang tobacco growing areas.（6）Compared with the soil survey in 2002,the available nitrogen supply of soil showed adecreased tendency.