Gypsum applications to aggregated saline sodic clay topsoils


Armstrong, A.S.B. and Tanton, T.W. (1992) Gypsum applications to aggregated saline sodic clay topsoils. European Journal of Soil Science, 43, (2), 249-260. (doi:10.1111/j.1365-2389.1992.tb00133.x).

Download

Full text not available from this repository.

Description/Abstract

Gypsum application was highly efficient as a treatment for reducing amounts of exchangeable sodium and inhibiting clay dispersion in highly structured saline-sodic clay topsoils.

Phosphogypsum, applied to the surfaces of aggregates in soil columns treated with simulated rainfall, was dissolved efficiently by frequent intermittent 'rainfall'. The calcium released by dissolution displaced sodium on the exchange complex within soil aggregates ranging from 7.5 mm to 45 mm in diameter. Of the applied calcium, 64–74% was transferred to ion exchange sites; however, almost one-third of this adsorbed calcium displaced exchangeable magnesium.

Comparison of three gypsum treatments, phosphogypsum, rock gypsum, and a saturated gypsum solution (representing a top dressing of highly soluble gypsum), showed that the effectiveness of calcium uptake on the exchange complex followed the order: rock gypsum < saturated solution < phosphogypsum, but differences were small.

Application of phosphogypsum caused a 90% reduction in the total amount of dispersed clay released in column leachates, and decreased the maximum clay concentration in the effluents by at least 80%, when compared to soils leached without gypsum treatment.

Item Type: Article
ISSNs: 1351-0754 (print)
1365-2389 (electronic)
Subjects: Q Science > QE Geology
H Social Sciences > HD Industries. Land use. Labor
T Technology > TA Engineering (General). Civil engineering (General)
Divisions: University Structure - Pre August 2011 > School of Civil Engineering and the Environment
ePrint ID: 75600
Date Deposited: 11 Mar 2010
Last Modified: 27 Mar 2014 18:54
URI: http://eprints.soton.ac.uk/id/eprint/75600

Actions (login required)

View Item View Item