不同浓度陪补离子对棕壤钙吸附的影响

Effect of Different Concentration of Complementary Ions on Calcium Adsorbed by Brown Soil

本论文以棕壤为研究对象,采用模拟培养的方法系统研究了不同浓度比例的NH 4+、K+、Mg2+的离子以及不同温度条件对土壤钙吸附的影响。结果表明:在25℃条件下添加NH 4+离子在钙铵浓度比例较低时NH 4+离子抑制钙的吸附,随着钙铵浓度比例的增加,NH 4+离子对钙吸附的抑制作用减弱,且在钙铵浓度比例为2∶1,Ca2+离子浓度为40和80 mg.kg-1时促进了钙的吸附;K+离子对钙吸附的影响与Ca2+离子浓度有关:当溶液中Ca2+离子浓度较低(40 mg.L-1)时,K+离子均促进了钙吸附,当Ca2+离子浓度较高时,则抑制钙吸附。当土壤溶液中钙钾浓度比例较高(2∶1)时,K+离子更多的表现为促进钙的吸附;Mg2+离子在溶液中钙镁浓度比例较低时抑制了钙的吸附,随着溶液中钙镁浓度比例的增加,Mg2+离子对钙吸附的抑制作用减弱,在钙镁浓度比例较高(2∶1)溶液中Ca2+离子较低时表现为促进作用。未添加陪补离子条件下,随温度增加,土壤对钙的吸附量增加。而添加陪补离子后,随着温度增加,土壤对钙的吸附量也增加,但是增加幅度降低,因此随温度的增加,添加陪补离子对钙吸附的影响表现为抑制作用。

In this paper,using brown soil as samples,the calcium absorption of the soil was studied with ions of NH＋4,K＋,and Mg2＋ under different concentration proportions and different temperature conditions through simulated cultivation.The results showed that when temperature was at 25 ℃,NH＋4 inhibited calcium absorption with low calcium-ammonium proportion,and along with the increase of calcium-ammonium proportion the inhibition decreased. When calcium-ammonium proportion was 2∶1,NH＋4 promoted the calcium absorption when Ca2＋ ion concentrations were 40 and 80 mg·kg-1.Influence of K＋ on calcium absorption was relevant with Ca2＋ concentration： K＋ promotes calcium absorption while Ca2＋ concentration was or lower than 40 mg·L-1,otherwise,inhibited calcium absorption; when calcium-potassium proportion was higher than that of 2∶1,K＋ was more likely to stimulate calcium absorption.Mg2＋ inhibited calcium absorption when calcium-magnesium proportion was low,while the inhibition weakens with the proportion＇s increase.When the proportion went up to 2∶1 or more and Ca2＋ concentration was low,Mg2＋ had stimulating effect.When temperature rose,the soil＇s calcium absorption quantity increased without complementary ion,while with complementary ion,the increase tended to reduce.Thus,with the rise of temperature, complementary ion would inhibit the calcium absorption.