锰离子对引黄灌区不同质地土壤铵态氮吸附影响

Effects of manganese ions on ammonium nitrogen adsorption in different textured soils in Yellow River irrigation area

为了研究锰离子对不同质地土壤铵态氮吸附的影响,选取河南省新乡市境内引黄灌区中的粉土、粉壤土和砂壤土作为研究对象.通过给土壤样品中添加锰离子和去除锰氧化物两种试验方式研究锰离子对不同质地土壤铵态氮吸附的影响.结果表明,不同质地土壤对铵态氮的吸附量不同,吸附能力从大到小依次为粉土,粉壤土,砂壤土.原土的铵态氮吸附量高于去锰土的铵态氮吸附量.吸附平衡时,去锰粉土、去锰粉壤土和去锰砂壤土较原土的吸附量变化率分别为-61.12%、-75.08%和-20.15%.土壤中添加的锰离子质量浓度不同,铵态氮的吸附量不同.粉土和粉壤土中添加锰离子质量浓度为0~0.8mg/L时,随着锰离子质量浓度增大,土壤对铵态氮吸附量增加,最大吸附量变化率分别为5.00%和11.43%.砂壤土中高质量浓度(10.0mg/L)锰离子抑制铵态氮吸附效果最显著,吸附量变化率为-66.00%.研究结果可为提高土壤固氮能力、合理灌溉及防治地下水铵态氮污染提供理论依据.

In order to study the effect of manganese ions on the adsorption of ammonium nitrogen in different textured soils,the silt,silty loam and sandy loam soils were collected from Yellow River irrigation area in Xinxiang city,Henan Province.The effects of Mn^(2+)on the ammonium nitrogen adsorption of different textured soils were studied by adding Mn^(2+)solution into the soil samples and removing manganese oxide.The results showed that the ammonium nitrogen adsorption capacity varied with soil textures.The adsorption capacity decreased in the order of silt,silty loam,sandy loam.The adsorption amount of ammonium nitrogen in the whole soil was higher than in the manganese oxide removed soil.For the manganese oxide removed soils,at adsorption equilibrium,the change rate of ammonium nitrogen adsorption capacity in silt,silty loam and sandy loam soils were-61.12%,-75.08%and-20.15%,respectively.The adsorption capacity of ammonium nitrogen changes with Mn 2+concentration of the adding solution.For silt and silty loam,when the Mn^(2+)concentration range was 0-0.8 mg/L,the adsorption capacity of ammonium nitrogen increased with the increase of Mn^(2+)concentration,and the maximum change rate was 5.00%and 11.43%,respectively.For sandy loam,high concentration of Mn^(2+)(10.0 mg/L)significantly inhibited adsorption of ammonium nitrogen,with the change rate of-66.00%.These results can provide theoretical basis for improving the N retention capacity of soil,rational irrigation and prevention of groundwater ammonium nitrogen pollution.