张家川县耕地土壤肥力评价及空间分布特征

Soil Fertility Evaluation and Spatial Distribution Characteristics of Cultivated Land in Zhangjiachuan County

本研究通过对张家川县闫家乡、张家川镇、恭门镇3个乡镇的耕地土壤肥力指标进行测定,采用主成分分析法评价了土壤肥力质量,并结合GIS分析了各肥力指标及土壤综合肥力的空间变异性。结果表明:研究区耕地土壤呈碱性,其中恭门镇南部地区耕地土壤碱性较强;有机质含量中等,闫家乡有机质含量最丰富,达到16.75 mg/kg;全氮含量较丰富而速效氮缺乏,空间分布均呈现从西到东逐渐升高的特征;速效钾、有效磷的含量丰富,分别呈现东高西低、南低北高的分布趋势。主成分分析结果表明,张家川镇、恭门镇土壤速效养分供应能力强,但保肥能力较差;闫家乡土壤养分蓄积能力强。土壤综合肥力质量从高到低依次为闫家乡、张家川镇、恭门镇,呈现出东高西低的空间分布趋势。综上,研究区内土壤养分及综合肥力分布不均,需协调氮、磷、钾肥施用比例,做到“因地、因苗、因水、因时”分期精准施肥。

Through the determination of soil fertility indicators of cultivated land in three townships(Yanjia Township,Zhangjiachuan Town and Gongmen Town)of Zhangjiachuan County,the quality of soil fertility was evaluated by principal component analysis,and the spatial variability of each soil fertility indicator and comprehensive soil fertility were analyzed by combining GIS analysis.The results showed that,the soil in the study area was alkaline,with strong alkaline soil in the southern area of Gongmen Town;organic matter content was medium,the organic matter content of Yanjia Township was the richest,reaching 16.75 mg/kg;total nitrogen content was rich while available nitrogen content was lacking,and the spatial distribution showed a gradual increase from west to east;the available potassium content and available phosphorus content were rich,and showed the distribution trend of high in east and low in west,low in south and high in north respectively.Principal component analysis results showed that the supply capacity of soil available nutrients in Zhangjiachuan Town and Gongmen Town was strong,but the fertilizer retention capacity was poor;Yanjia Township soil nutrient accumulation capacity was strong.The soil comprehensive fertility quality from high to low was in the order of Yanjia Township,Zhangjiachuan Town,Gongmen Town,showing a spatial distribution trend of high in the east and low in the west.In summary,soil nutrients and comprehensive fertility distribution in the study area is uneven,so it is necessary to coordinate the application ratio of nitrogen,phosphorus and potassium fertilizer,to achieve precise fertilization in stages through"due to the land,due to seedlings,due to water,due to the time".