采用ArcGIS9.3、克吕格空间插值技术对山丹县1986 — 2007年土壤养分变化情况进行时空比较分析。结果表明，与第二次土壤普查相比，耕地土壤有机质、全氮和碱解氮总体呈现下降趋势，土壤有效磷、速效钾含量呈现增长趋势。

Using ArcGIS9.3 and Krueger spatial interpolation techniques， and by spatial-variation data comparative analysis of soil nutrients changes in the period of 1986 to 2007. The result shows that the soil organic matter， total nitrogen and available nitrogen in soil has been a decreasing trend compared with the second soil survey， and the contents of available phosphorus and available potassium has been going up all the time.

S159.2

甘肃省科技支撑计划“旱作农田精确施肥技术研究”(1104NKCA093)