中文摘要：

研究旨在揭示黄土高原沟壑区耕地土壤速效养分的空间变异特征和分布状况,为土壤培肥和农业生产提供理论基础。采用富县2009年测土配方施肥项目实测的0~20 cm耕层土壤速效氮、钾、磷数据,运用地统计学结合GIS技术方法,建立养分最佳半方差函数,进行插值分析和丰缺分析。在平均间距为1214 m的采样尺度下,速效养分最优理论模型均为指数模型且具有各向异性特征,速效磷、钾表现为中等空间相关性,速效氮表现为弱空间相关性。养分含量高低区域分布明显,大致成西高东北低的态势,施肥、田间耕作、地形地貌和降水等是影响其空间变异的主要因素。总体上该地区富钾,氮和磷缺乏,农业耕作中针对不同作物应积极制定＂增氮补磷＂措施,并关注土壤钾的消耗。

英文摘要：

The study aimed to explore the spatial variability and distribution pattern of soil available nutrients in Gully loess plateau farmland,in order to provide guidance for soil fertilization management and agricultural production.Shanxi Fuxian was chosen as the research site.Geostatistics combined with geographical information system（GIS） was applied to study the best semi-variance theory models and to analyze Oridinary Kriging interpolation of soil available nitrogen（AN）,available phosphorus（AP） and available potassium（AK） based on the data of 666 soil samples taken by ＂S＂ shape methods in the 0 ~ 20 cm topsoil supported by soil testing and formulated fertilization project.The best theoretical models all were Exponential models,with anisotropy.Soil available P and K demonstrated moderate spatial dependence;available N demonstrated weak spatial dependence under the 1214 m average distance sampling scale.During the past 20 years,soil available N,K and P content increased by12.18%,25.46% and 44.20%,respectively.Soil available nutrients content decreased from west to northeast in generally,which was affected not only by complex topography and precipitation,but also by fertilization and artificial cultivation management.The soil fertility of study area was rich in AK content,lack of AP and AN content.Measures could be taken in time to increase AN and AP content according to different crops and areas.