摘要
pH和CaCO_3含量是土壤常规分析的两个测定指标,但其室内测定均需借助相应的仪器设备完成,耗时费力。以山西省土系调查采集的110个典型土壤剖面的426个发生层土样的野外测定的石灰反应强度和实验室测定的土壤pH、CaCO_3含量、交换性钠饱和度(Exchangeable Sodium Percentage,ESP)数据为基础,尝试建立石灰反应强度与pH、CaCO_3含量之间的定量关系模型。结果表明:北方黄土性母质土壤,当pH<9.0时,CaCO_3含量是影响土壤pH的重要因素,二者的回归拟合最优关系符合幂函数曲线;当pH>9.0时,CaCO_3与pH之间无明显关系。石灰反应强度在一定程度上可以半定量地反映pH或CaCO_3含量,但其确定的pH或CaCO_3含量尚是一个范围,并非精确值。同时,从发生学意义角度,土壤中CaCO_3含量高低对形态学研究具有重要意义,在这种情况下,如果需要用pH或CaCO_3含量来确定准确的土壤系统分类类型(如确定土体是否为酸性、具有钙积层/钙积现象等),为慎重起见建议还是以实验室的准确测定数据为准;对于非碱化(pH<9.0)、野外有泡沫反应的北方黄土性母质土壤,无论泡沫反应强弱和CaCO_3含量高低,土壤pH基本稳定在8.51±0.49,这一pH范围对作物生长基本没有制约,如果仅从pH或CaCO_3含量是否影响作物生长角度考虑,无需实验室测定pH或CaCO_3含量。
【Objective】Soil CaCO3 content and pH are two common indices in routine soil analysis,while lime reaction,pH and content of carbonate equivalents are the three important diagnostic indices in the Chinese Soil Taxonomy. However,generally,the determination of soil pH and CaCO3 content needs to be done with the help of experimental instruments in lab,which is rather costly and time consuming;Actually,intensity of lime reaction can be measured in field with titration of 1∶3 dilute hydrochloric acid,which is simple,quick and cheap. Moreover,content of CaCO3,pH and intensity of lime reaction are somewhat interrelated. Therefore,if a model of quantitative relationships between soil CaCO3 content,pH and lime reaction intensity can be built up for a specific area,it will no doubt save or spare the time and money needed for determination of soil pH and CaCO3 content in lab,and it will help make tentative determination in the field of what type of calcareous soil in the Chinese Soil Taxonomy. The purpose of this paper is to try to establish such a model.【Method】Correlation analysis and regression analysis were performed of the data of the 110 typical soil profiles investigated during the provincial soil survey of Shanxi Province,including lime reaction intensities determined in the field,and soil pHs,calcium carbonate contents and ESPs（Exchangeable Sodium Percentage）measured in lab of the soil samples from their 426 genetic horizons,for relationship between calcium carbonate content and soil pH,and statistical analysis was for relationships of lime reaction intensity with soil pH and calcium carbonate content.【Result】Results show that in the soil developed from loess parent material in North China with pH 〈9,content of calcium carbonate is an important factor affecting soil pH,and the optimal relationship between the two fitted with regression accords with an exponential curve,while pH〉 9,no significant relationship was observed between the two,but lime reaction intensity could be used as indicator,refl
出处
《土壤学报》
CAS
CSCD
北大核心
2017年第6期1369-1376,共8页
Acta Pedologica Sinica
基金
国家自然科学基金项目(41671216)
国家科技基础性工作专项(2014FY110200)资助~~
