基于地统计学的土壤肥力空间变异分析——以天津市武清区为例

Spatial Variation Analysis of Soil Fertility Based on Geostatistics:A Case Study in Wuqing District of Tianjin

以天津市武清区为例,通过选取土壤pH值、有机质、全氮、速效磷、速效钾为土壤肥力指标,运用综合指数法对土壤肥力状况进行评价;并将地统计学与GIS相结合,进一步分析土壤各肥力因子及总体肥力质量的空间变异规律.结果表明:所选的5种肥力指标中,pH值具有弱空间相关性,有机质、全氮、速效磷、速效钾均表现中等强度的空间相关性;运用Kriging空间插值发现pH值较高的部分处于研究区中部,而较低的部分处于北部,有机质含量由北向南逐渐增大,全氮、速效钾均呈同心圆模式由内向外逐渐降低,其核心点为黄庄街道,速效磷含量由北向南逐渐降低;整个武清区土壤肥力质量呈现北高南低的趋势,以中等质量土壤为主.该评价结果能有效为规范农户种植、施肥行为和制定相关农业规划提供科学依据.

Wish the research object of Wuqing District of Tianjin and the indicators of pH value, organic matter, total N, available P and available K, the soil fertility was evaluated by comprehensive index method. Geostatistics combined with GIS was used to analyze the spatial variation characteristics of soil fertility factors and the general quality. The results indi- cated that pH value demonstrated weak spatial dependence and others demonstrated moderate spatial correlation. Through kriging interpolation, it was found that the highest ofpH value was in the middle of the study area and the lowest was in the north. Soil organic matter increased from north to south, but available P varied in the contrary way. Both total N and available K decreased from the inside to the outside in the concentric circle mode and the core was in Huangzhuang Street. The fertility quality of Wuqing District was higher in the north and lower in the south, which was at a middle level of fertility. The con- clusions could effectively provide scientific reference for regulating household behavior of planting and fertilization and making agricultural policies.