Effect of gypsum placement on the physical chemical properties of a saline sandy loam soil

Abstract

Reclamation of salt affected soils using gypsum (Ca2SO4.2H2O) as a low cost material is one of the means to reverse a degraded land while improving its fertility for agricultural use and generate income to the farmers living in such lands. A study was therefore undertaken outside the glasshouse of the International Centre for Eremology, University of Ghent, at the end of July 1994. The main objective was to evaluate the effect of gypsum and placement methods on the physical chemical properties of a saline soil during reclamation process by leaching under natural rainfall. Soil samples were collected from a provisionally stored dredged material in a big well near the Peak- shaving plant of Distrigaz in the southern part of inner harbour of Zeebrugge located at 51º18′18″N and 3º14′47″E. The experiment involved six treatments with four replications in a randomised complete block design. Results showed that incorporating gypsum full depth (20 cm) without weekly mixing was superior compared with the other placement methods for the improvement of most of the studied parameters. Furthermore, these results also showed that Naexch, ECe, SAR, ESP and AWC were significantly (P≤0.05) improved. Although gypsum application caused gradual decline in Ks, it however did not reverse it completely, probably due to heavy storm leading to compaction, and/or inequilibrium between Ca2+ and Mg2+ ions in the soil material.