Study of morphological and micromorphological properties of some salt affected soil in the middle of Iraq

Abstract EN

Six sites in four regions in central Iraq were selected represent two sites of Sabakh soils, two sites of Shura soils, and two sites of normal soils (non salt affected) to study the morphological and micromorphological properties of theses salt affected soils and compare them to the normal soils in central Iraqi soils.

The results indicated that there is some variation in particle size distribution and no pattern was detected for that variation which is considered as one of the characteristics of alluvial soils, silt was the major separate in most soil samples which related to the quality of river Tigris loads in that region.

Chemical properties showed that pH values were neutral to nearly alkaline where negatively correlated to the electrical conductivity of soil solution,.

Organic matter was low generally with values ranged between 2 g.kg-1 up to 23 g.kg-1 the decrease in organic matter was due to the high temperatures and draught.

Calcium carbonate ranged between 128 g.kg-1 to 343 g.kg-1 .

Carbonate minerals distribution was homogeneous in most soil horizons due to alluvial soils circumstances of formation in mid and south of Iraq and being rich in these minerals.

Gypsum was positively correlated to EC values.

The results of Micromorohological of scanning electron microscope and polarized light microscope showed that the shura soils was chloridic in the almaameer area, while it was extended to include chloridic sulfatic in swaira area, that was clearly shown as soluans on the inner walls of the soil pores.

Metavughs and chambers were dominant voids in most of the thin section examinations, followed by channel voids, while the microstructure was varied from subangular blocky to spongy and vughy microstructure.

Also there were some abvious pedological features shown in these sections as soluans and calcians, besides some slides showed a presence of salt and gypsum crystals.