西部干旱区农林复合模式下土壤养分空间变异研究——以新疆泽普县为例

Spatial Variability of Soil Nutrients under the Agroforestry Mode of Western Arid Areas——Take Zepu County in Xinjiang as example

【目的】摸清农林复合模式下土壤养分空间变异情况。【方法】以泽普县为例,采用GIS与地统计学相结合的方法对农林复合模式下耕层土壤(0～20 cm)的有机质、全氮、速效氮、速效磷和速效钾等5种养分要素的空间变异特征进行分析;并与二次土壤普查结果对比分析研究土壤养分变化。【结果】研究区耕层土壤各养分含量呈正态分布,变异性表现为:速效磷>速效钾>碱解氮>全氮>有机质;全氮、有机质变异函数曲线符合指数模型,碱解氮、速效磷、速效钾的变异函数曲线符合线性无基台模型。从地理位置上看,5种土壤养分含量总体分布呈现西高东低、南北低、中间高的趋势。与1982年相比,除速效钾外,其他4种养分土壤含量都有不同程度的增加,其中速效磷的增加幅度最大。【结论】研究区内土壤养分含量属于中等偏低水平,应增加有机肥的投入,在重视施用氮磷化肥的基础上,也必须重视钾肥施用,培肥土壤,从而保障耕地的可持续利用和发展。

[Objective]The purpose of this program was conducted to understand the spatial variability of soil nutrients under the Agroforestry mode.[Method]Traditional statistics combined with geostatistics was applied to analyze the spatial variation of soil nutrients by taking Zepu Country as an example.The spatial variability of the 5 nutrients;total available nitrogen,alkali - hydrolyzable nitrogen,organic matter,available phosphorus and available potassium under the topsoil（0 - 20 cm） was analyzed by using GIS combined with geo - statistics method on the Agroforestry mode,and then the results were compared with those of general detailed soil survey conducted in 1982 to study the soil nutrients change.[Result]The contents of the topsoil nutrients in our study area showed a normal distribution,the five kinds of soil nutrients varied differently,and the specific variability was displayed as follows：available phosphorus〉available potassium〉alkali -hydrolyzable nitrogen〉total nitrogen〉organic Matter.The theory model of variation function curves of total nitrogen and organic matter was consistent with the exponential model,and the variation function curves of alkali - hydrolyzable nitrogen,available phosphorus and available potassium conformed to linear stepless model.The geographical distribution patterns of the five soil nutrients were revealed as high in the west and middle,low in the east,south and north.Compared with the results of 1982,the average soil nutrients of our study suggested that the contents of other four soil nutrients（except available potassium） all displayed the different increasing trends.And the available phosphorus increased most.[Conclusion]This research revealed that the contents of soil nutrients throughout the study area were modest or relatively low.Hence,we should increase the use of organic fertilizer,and pay more attention to the employment of nitrogen phosphorus fertilizer,and also emphasize expanding the input of potash fertilizer.Only in this way can we make sure the general improving of soil fertility,and the sustainable utilization and development of the cultivated land.