摘要
为明确不同土地利用方式的土壤钾素固定规律,通过现场调查采样、室内分析、模拟试验和方程拟合的方法研究土壤钾素固定过程、影响因素及动力学特征.结果表明:风沙土固钾量随施钾量的提高而不断增加,固钾率则表现为急剧下降后渐趋平缓.随施钾量的增加,未采取任何治理措施的流动、半流动沙地的固钾能力逐渐高于其他土地利用方式.Freundlich模型优于Langmuir模型和Temkin模型,是最适合研究区的吸附等温曲线.影响研究区土壤固钾能力的因素为速效钾、非交换性钾、阳离子交换量、土壤水溶性盐和有机质.因此,风沙土可遵照"少量多次"原则补充钾,以保证固钾能力稳定和植物的生长.
Abstract
In order to clarify the soil potassium fixation characteristics of different land use types,a comprehensive in-vestigation involving field sampling,laboratory analysis,simulation tests,and equation fitting was conducted to study the soil potassium fixation process,influencing factors,and kinetic characteristics.The results showed that the amount of potassium fixation in aeolian sandy soil increased with increasing potassium application;however,the rate of potas-sium fixation exhibited an initial sharp decline followed by a gradual flattening.Moreover,in comparison to other land use types,mobile and semi-mobile sandy land without any control measures displayed a progressively higher increase in their potassium fixation capacity with increasing potassium application.Freundlich model was found to be superior to Langmuir model and Temkin model,and was the most suitable for the adsorption isothermal curve in the study area.The factors affecting soil potassium fixation capacity were available potassium content,non-exchangeable potassium content,cationexchange content,soil water-soluble salts concentration,and organic matter content.Therefore,the potassium should be applicated by small amount but frequently to ensure both stable levels of potassium fixation capacity and optimal plant growth.
基金项目
民生科技计划联合计划(2021JH2/102000)
维普
万方数据