不同轮作措施对黔西南州烟区土壤碳/氮养分的空间变异特征

Effect of Different Rotation Patterns on Spatial Variation Characteristics of Soil Organic Carbon/Nitrogen in Tobacco-growing Areas of Qianxinan Prefecture

为黔西南州烟区土壤质量维护及烤烟生产的合理施肥提供依据,采用野外布点采样,利用GIS技术分析方法定量研究烟区土壤有机碳/氮素的空间异质性及分布特征。结果表明:黔西南州烟区表层土壤有机碳平均含量为20.84～23.88g/kg,平均为22.36g/kg,变异系数为32.70%。全氮与速效氮分别为1.65～20.3g/kg和120.97～160.45mg/kg,平均为1.89g/kg和139.02mg/kg,变异系数为31.06%和46.26%,属中等强度的空间变异性;土壤有机碳、碳氮比指数的空间分布规律类似,空间分布总体呈较均匀趋势。全氮和pH的空间分布规律类似,表现为北低南高;速效氮的空间分布规律不明显。在生产过程中,应针对不同烟区的土壤养分状况因地制宜、分类指导,采用不同的烤烟专用复合肥配方,提高烟区土壤的养分均衡供应能力。

The spatial heterogeneity and distribution characteristics of soil organic carbon/nitrogen in tobacco-growing areas were quantitatively determined by field stationing sampling and GIS technology to provide the scientific basis for soil quality maintenance in tobacco-growing areas and rational fertilization in tobacco production in Qianxinan Prefecture. Result： The organic carbon content in topsoil is 20.84-23.88 g/kgand the average value and variable coefficient are 22.36g/kg and 32.70% respectively. Total nitrogen content in topsoil is 1.65--20.3 g/kg and the average value and variable coefficient are 1.89 g/kg and 31.06% separately. The available nitrogen content in topsoil is 120. 97--160. 45 mg/kg and the average value and variable coefficient are 139. 02 mg/kg and 46.26% respectively. Total nitrogen and available nitrogen content in topsoil has a moderate strength spatial variability. The spatial distribution pattern of soil organic carbon content and C/N ratio index is alike and the spatial distribution presents a more uniform trend overall. The spatial distribution pattern of soil total nitrogen content and pH is alike and the soil total content and pH value in Northern Qianxinan Prefecture are lower than in Southern Qianxinan Prefecture. The spatial distribution pattern of available nitrogen content is not obvious. The balanced supply capacity of soil nutrients can be improved by adopting different special complex fertilizer formula according to soil nutrient situation of different tobacco-growing areas in tobacco production in Qianxinan Prefecture.