喀斯特高原顶坛花椒生长过程中土壤养分变化特征

【目的】掌握喀斯特高原峡谷区顶坛花椒生长过程中土壤养分变化规律及土壤综合肥力情况,为其施肥管理提供参考。【方法】以亚热带喀斯特高原乡土经济植物顶坛花椒作为研究对象,采取空间代替时间的方法,以不同生长径阶(2、4、6、8 cm)的顶坛花椒代表生长过程中的不同生长发育阶段,测定其生长的土壤的养分(有机质、全氮、全磷、全钾、碱解氮、有效磷、速效钾)含量,计算土壤中C、N、P、K元素的化学计量比,并采用内梅罗指数法对顶坛花椒生长过程中土壤养分状况进行综合评价。【结果】顶坛花椒生长过程中,土壤全氮含量0.79~3.73 g/kg,全磷含量0.64~1.65 g/kg,全钾含量1.01~4.61 g/kg,碱解氮含量65.8~204.4 mg/kg,有效磷含量46.51~81.97 mg/kg,速效钾含量53.14~217.5 mg/kg,有机质含量13.07~45.94 g/kg,土壤养分含量呈现动态变化特征。在水平方向上,顶坛花椒土壤养分含量呈现变异性特征;在垂直方向上,随着土层深度的增加顶坛花椒土壤养分含量呈逐渐减少的趋势。顶坛花椒土壤的C、N、P、K化学计量比呈现出随径阶增加先降低、后升高的趋势。顶坛花椒土壤综合肥力系数为1.30~1.50,土壤肥力等级为Ⅲ级,土壤肥力随着土层深度增加总体呈现逐渐降低的趋势。【结论】喀斯特高原顶坛花椒的土壤肥力一般,在顶坛花椒生长过程中土壤养分含量水平变化特征具有变异性,垂直方向土壤养分含量具有明显的"表聚"特征。

Change characteristics of soil nutrients during Zanthoxylum bungeanum var.dingtanensis grow process in karst plateau

【Objective】To master change characteristics of soil nutrients during Zanthoxylum planispinum var.dingtanensis growing process in gorge region of karst plateau,and to provide some references for its fertilization management.【Method】Using local economic plant Z.planispinum var.dingtanensis in subtropical karst platea as research object,Z.planispinum var.dingtanensis plants at different growth and development stages of growth process were represented with plants with different growth diameters(2,4,6,8 cm),taking space instead of time,nutrient contents in rhizosphere soil were determined,concluding organic matter,total nitrogen,total phosphorus,total potassium,alkalihydrolyzable nitrogen,available phosphorus and available potassium.Stoichiometric ratios of C,N,P and K elements in soil were calculated,and soil nutrient status during Z.planispinum var.dingtanensis growing was comprehensively evaluated by using Nemero index method.【Result】During Z.planispinum var.dingtanensis growing,total nitrogen content is 0.79-3.73 g/kg,total phosphorus content is 0.64-1.65 g/kg,total potassium content is 1.01-4.61 g/kg,alkalihydrolyzable nitrogen content is 65.8-204.4 mg/kg,available phosphorus content is 46.51-81.97 mg/kg,available potassium content is 53.14-217.5 mg/kg,organic matter content is 13.07-45.94 g/kg,and soil nutrient contents present dynamic changes.In the horizontal direction,nutrient contents in Z.planispinum var.dingtanensis rhizosphere soil show variability characteristics.In the vertical direction,soil nutrient contents in Z.planispinum var.dingtanensis rhizosphere soil are gradually decreased with increase of soil depth.Stoichiometric ratios of C,N,P and K in Z.planispinum var.dingtanensis rhizosphere soil show a trend of decreasing first and then increasing with increase of diameter class.Comprehensive fertility coefficient of Z.planispinum var.dingtanensis rhizosphere soil is 1.30-1.50,and soil fertility grade isⅢ,and soil fertility generally is gradually decreased with increase of soil depth.【Conclusion】Fertility level of Z.planispinum var.dingtanensis rhizosphere soil in karst plateau is normal,changes of soil nutrient contents have a variability characteristic in the horizontal direction,and show a“gathering in surface soil”characteristic in the vertical direction,during Z.planispinum var.dingtanensis growing.