Short-Range-Order Minerals and Dominant Accessory Properties Controlling P Sorption in Tropical Tephra Soils of the Cameroon Volcanic Line

• 作者: Bernard Palmer Kfuban Yerima Eric van Ranst Georges Kogge Kome Roger Kogge Enang
• 来源期刊: 土壤科学期刊(英文)
• 学科: 医学
• 关键词: ALLOPHANE FERRIHYDRITE MOUNT Kupe MOUNT Manengouba Sorption Isotherms
• 年，卷（期）: 2019,（8）
• 页码范围: 113-139
• 页数: 27页
• 分类号: R73

摘要

Knowledge on soil properties likely to influence P sorption in tephra soils is very important for sustainable management of available P. Sorption studies on six tephra soils were conducted to relate P sorption to soil characteristics in order to identify those with potential influence on P sorption. Four equilibrium-based sorption models commonly encountered in soil studies (Langmuir, Freundlich, Temkin, and Van Huay) were used to describe P sorption in the soils. P sorption was determined by measuring the residual P content of a clarified equilibrating solution of 0.02 N KCl containing varying concentrations (0, 5, 10, 15, 30, 40, 50, 60, 80, and 100 mg/L) of P as KH2PO4 after mixing with 1 g of soil in duplicates for 16 hours at 25°C. Maximum amount of P sorbed for the varying P concentrations used ranged from 2080 to 5402 mg/kg with a potential for greater P sorption maxima at higher P solution concentrations. P sorption in these soils was best described by the Langmuir and Freundlich models. Allophane and ferrihydrite are the principal species controlling the high P sorption in these soils. pH-NaF proved to be a potentially reliable test for assessing the presence of allophanic materials and thus for estimating P sorbed. This work would guide both effective and efficient P fertilizer management with economic implications for both the study area and similar environments.