贵州省仁怀市耕地土壤养分地球化学特征及其影响因素研究

【研究目的】为仁怀市农业生产中土壤养分的合理利用、农业结构调整及土地利用价值的提升等提供科学依据。【研究方法】本文利用电感耦合等离子体发射光谱法、容量法及电位法获取了5486件表层土壤样品氮磷钾（全量和有效态）及有机质的含量,系统研究了其地球化学特征及含量影响因素。【研究结果】仁怀市耕地土壤氮、磷、钾、有机质、碱解氮、速效磷及速效钾的平均值分别为1.74 g/kg、0.75 g/kg、19.90 g/kg、30.90 g/kg、100.28 mg/kg、10.40 mg/kg和101.03 mg/kg。其中,氮、碱解氮、磷、钾及有机质的含量及分布与地层关系密切;速效磷及速效钾的含量及分布与地层关系较差。仁怀市耕地土壤肥力较好,以较丰富等级为主,较丰富及丰富等级占比为57.6%。其中,氮、磷及钾皆处于丰富水平;碱解氮及有机质处于中等水平;速效磷及速效钾处于缺乏水平。【结论】仁怀市耕地土壤养分的含量及分布不仅受地质背景、土壤类型、海拔高度、酸碱度及土壤深度等自然因素影响,还与土地利用方式等人为活动有关。创新点：系统统计了仁怀市耕地土壤氮磷钾（全量和有效态）及有机质的含量,对其地球化学等级开展了评价,并系统分析了它们的含量影响因素。耕地土壤养分的含量及分布不仅受地质背景、土壤类型等自然因素影响,还与土地利用方式等人为活动有关。

Geochemical characteristics and influencing factors of soil nutrients in cultivated land in Renhuai, Guizhou Province

This paper is the result of agricultural geochemical survey engineering.Objective]The research aimed to provide a scientific basis for the rational use of soil nutrients in agricultural production, adjustment of agricultural structure and improvement of land use value in Renhuai.Methods]Total and available nitrogen (phosphorus and potassium) content and organic matter content of 5,486 topsoil samples were obtained using inductively coupled plasma emission spectrometry, volumetric method, and potentiometric method. Their geochemical characteristics and influencing factors were systematically studied.Results]The average values of nitrogen, phosphorus, potassium, organic matter, available nitrogen, rapidly available phosphorus, and rapidly available potassium were 1.74 g/kg, 0.75 g/kg, 19.90 g/kg, 30.90 g/kg, 100.28 mg/kg, 10.40 mg/kg, and 101.03 mg/kg, respectively. The contents and distributions of nitrogen, available nitrogen, phosphorus, potassium, and organic matter were closely related to the stratum, whereas those of rapidly available phosphorus and rapidly available potassium were not. Cultivated land in Renhuai had a relatively high soil fertility rating, which was mainly dominated by relatively rich soil grades, with the share of relatively rich and rich grades reaching 57.6%. Rich nitrogen, phosphorus, and potassium levels were found, along with medium available nitrogen and organic matter levels. However, rapidly available phosphorus and rapidly available potassium were at deficient levels.Conclusions]The content and distribution of soil nutrients in cultivated land are not only affected by natural factors such as geological background, soil type, altitude, pH, and soil depth, but also related to human activities, such as land use patterns.Highlights: Total and available nitrogen (phosphorus and potassium) content and organic matter content in cultivated soil in Renhuai were systematically calculated, their geochemical grades were evaluated, and the influencing factors of their contents were systematically analyzed. The content and distribution of soil nutrients in cultivated land were not only affected by natural factors, such as geological background and soil type, but also related to human activities, such as land use patterns.