喀斯特山区植烟土壤肥力综合评价及空间分布特征——以安顺西秀区为例

Comprehensive Evaluation of Tobacco-growing Soil Fertility in Karst Mountain Area—Take Xixiu District of Anshun As an Example

为了明确喀斯特山区植烟土壤速效养分分布特点和土壤综合肥力,以安顺市西秀区为研究区域,采集100个植烟土壤样本,运用主成分分析法确定各土壤养分指标的权重,通过土壤肥力综合指标(IFI)法进行综合评价,同时运用普通克里金法对土壤pH值、碱解氮、速效钾、有效磷、IFI值的空间分布进行拟合。结果表明:安顺市西秀区植烟土壤pH值、有效氮、碱解磷、速效钾的含量范围、均值和变异系数分别为4.13~7.64、4.97 mg/kg、10.39%,62.52~249.17 mg/kg、158.40 mg/kg、22.14%,4.44~56.08 mg/kg、19.17 mg/kg、54.93%,35.53~593.35 mg/kg、165.61 mg/kg、56.93%。适宜烤烟生长的土壤pH值面积占总面积的85.89%,呈连续分布;碱解氮高及较高区域占60.01%,适宜区域占15.92%,低及较低区域占24.07%,交替分布,多呈岛状零星分布;土壤有效磷西低东高,适宜区域占64.22%,低及较低区域占35.78%,分布较连续;速效钾含量也呈西低东高,适宜区域占20.01%,低及较低区域占79.99%,分布零星。评价显示土壤综合肥力西高东低,低肥力(IFI<0.2)区域分布占31.84%,限制因素是碱解氮含量过高、磷钾含量过低;较低肥力(0.2≤IFI<0.4)区域面积占26.54%,限制因素是钾含量低下;肥力中等及较高(0.4≤IFI<0.8)区域面积占36.56%,氮含量是主要限制因素,磷钾适宜;高肥力(IFI≥0.8)区域面积占5.06%,氮磷钾养分含量及比例协调。

In order to clarify the distribution characteristics of available nutrients and comprehensive soil fertility of tobacco-growing soil in karst mountainous areas,100 tobacco-growing soil samples were collected in Xixiu District of Anshun City,and the weight of each soil nutrient index was determined by principal component analysis.Comprehensive evaluation was carried out by IFI method,and the spatial distribution of soil pH value,alkali-hydrolyzable nitrogen,available potassium,available phosphorus and IFI value was fitted by ordinary Kriging method.The results showed that the range,mean value and coefficient of variation of pH value,available phosphorus,available nitrogen and available potassium in tobacco-growing soil in Xixiu District of Anshun City were 4.13~7.64 mg/kg,4.97 mg/kg,10.39%,62.52~249.17 mg/kg and 158.40 mg,4.44~56.08 mg/kg,19.17 mg/kg,54.93%,35.53~593.35 mg/kg,165.61 mg/kg,respectively.The soil pH value area suitable for flue-cured tobacco growth accounted for 85.89%of the total area,showing a continuous distribution;high and high alkali-hydrolyzable nitrogen accounted for 60.01%,suitable areas accounted for 15.92%,and low areas accounted for 24.07%,which were alternately distributed and mostly distributed sporadically like islands;Soil available phosphorus was low in the west and high in the east,with suitable area accounting for 64.22%,low and lower areas accounting for 35.78%,and the distribution was continuous;The content of available potassium was also low in the west and high in the east,with suitable areas accounting for 20.01%,low and lower areas accounting for 79.99%,with sporadic distribution.The evaluation showed that the comprehensive soil fertility was high in the west and low in the east,and the regional distribution of low fertility(IFI<0.2)accounted for 31.84%.The limiting factors were the high content of alkali-hydrolyzable nitrogen and the low content of phosphorus and potassium.The area with low fertility(0.2≤IFI<0.4)accounted for 26.54%,and the limiting factor was low potassium content.The area with medium and high fertility(0.4≤IFI<0.8)accounted for 36.56%,nitrogen content was the main limiting factor,and phosphorus and potassium were suitable;The area with high fertility(IFI≥0.8)accounted for 5.06%,and the nutrient contents and proportions of N,P and K were coordinated.