广元市植烟土壤的养分含量及综合评价

Nutrient Content of Tobacco-planting Soil and Comprehensive Evaluation of Tobacco-planting Soil Fertility in Guanyuan City

为广元市植烟土壤的选择、改良及平衡施肥提供科学依据,对广元市剑阁县、昭化区和旺苍县3个植烟地区600个土壤样品的养分指标进行测定,并运用偏相关分析计算土壤养分指标的权重,采用土壤肥力综合指标值(IFI)对植烟区土壤肥力进行综合评价。结果表明:土壤样品的pH、交换性钙、交换性镁和有效硫含量偏高,而有效钾、有效锌、有效硼和有效铜含量偏低。剑阁县75.95%土壤的IFI低或较低,昭化区和旺苍县的IFI较高和高的土壤比例分别为70.71%和62.5%,IFI从西南向东北呈递增趋势。pH、交换性钙含量与其他养分含量大多呈显著或极显著负相关,有机质、碱解氮、速效磷、速效钾、有效硼、有效锌、有效铁和有效铜含量两两间大多呈显著或极显著正相关。有效铁、有效锰和速效钾含量的权重较高,分别为0.119、0.115和0.11,对IFI影响较大;有机质、有效硫、有效硼含量的权重较低,分别为0.043、0.045和0.046,对IFI影响相对较小。

The nutrient indexes of 600 soil samples from three tobacco-planting regions of Jiange County,Zhaohua District and Wangcang County in Guangyuan City were determined,then the weight of soil nutrient indexes was calculated by partial correlation analysis,and finally the soil fertility of tested tobacco-planting areas was comprehensively evaluated by the integrated fertility index（IFI）to provide the scientific basis for selection of tobacco-planting soil,soil improvement and balanced fertilization in Guangyuan City.Results：The pH,exchangeable Ca,exchangeable Mg and available S of tested soil samples is high but the content of available K,available Zn,Available B and available Cu is low.The IFI value of 75.95%soil samples from Jiange County is low or lower but the IFI value of 70.71%soil samples from Zhaohua District and 62.5% soil samples from Wangcang County is high or higher.The IFI value presents a gradual rising trend from Southwest to Northeast.The pH value and exchangeable Ca content of soil samples are negatively related to other soil nutrients significantly or very significantly.There are significant or very significant positive correlations between two soil nutrients in organic matter,available nitrogen,rapidly available P,rapidly available K,available B,available Zn,available Fe and Available Cu.The weight of available Fe,available Mn and rapidly available K is 0.119,0.115 and 0.11 respectively,which has great influence on IFI.The weight of organic matter,available S,available B is0.043,0.045 and 0.046 separately,which has relatively little influence on IFI.