Phosphorus sorption and desorption properties of soils developed on basic rocks under a subhumid Mediterranean climate
Author(s) -
Horta C.,
Monteiro F.,
Madeira M.,
Torrent J.
Publication year - 2013
Publication title -
soil use and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.709
H-Index - 81
eISSN - 1475-2743
pISSN - 0266-0032
DOI - 10.1111/j.1475-2743.2012.00405.x
Subject(s) - sorption , freundlich equation , soil water , topsoil , desorption , chemistry , environmental chemistry , soil horizon , adsorption , langmuir , phosphorus , precipitation , soil science , environmental science , physics , organic chemistry , meteorology
Representative samples of A, B and C horizons from 11 pedons (Luvisols, Solonetzs and Cambisols) developed on intermediate and basic rocks were studied regarding evaluation of phosphorus (P) behaviour, with the aim of delineating site‐specific management practices. For this purpose, (i) sorption properties were evaluated by Langmuir and Freundlich isotherms, (ii) soil samples were fertilized to a level of ca. 0.5 mg P/L, estimated by the Freundlich isotherm fitted to each horizon and (iii) the amount of phosphate‐P desorbed to a dilute electrolyte mimicking fresh water over periods of up to 60 days at soil:solution ratios of 1:100, 1:1000 and 1:10 000 was measured. The pedons had a slightly acidic or alkaline reaction and a limited capacity to sorb P, sorption seemingly occurring by both adsorption and precipitation. The nature of the sorption processes seemed to change with depth: precipitation dominated in C horizons, adsorption in A horizons and both types of processes being balanced in B horizons. The short‐term capacity of the soil to transfer P to water was related to the sorption curve parameters and the nature of the process seemingly controlling sorption. The ability of soil to desorb P increased with decreasing soil:solution ratio and when precipitation was the dominant process in sorption. After P fertilizer application, soils exhibited a high capacity to transfer P to water, thus making it advisable to use a replacement P strategy to prevent P accumulation in the topsoil and its downward movement.