تأثير الاستغلال الزراعي في بعض الصفات المورفولوجية و المايكرومورفولوجية لبعض الترب الجبسية في جامعة تكريت

الملخص EN

This study was conduct to study the effect of cultivation on the development of some gypsiferous soils.

four pedons between width equator - 43 43 north and length equator 34 32-east in the farm of agriculture college/ university of tikrit were selected on the bases of their past management.

Two pedons represent cultivation for at lest 15 year under different irrigation springulare system fixed system and the other moving the second part of the farm had never been cultivated.four pedons at each site were excavated, morphologically described and sampled for some physical and chemical analysis.undisturbed soil samples were also for micromorphological studies.The study showed the following results, Appearance of different pedogenic features through soil horizons particulary cultivation as results of a clear role for soil management for changing soil properties.

Micromorphological studies of thin sections indicated the occurance of dissected clay skins either around soil particales or on the internal surfaces of pores calcitans and gypsans for uncultivated pedons.

The dominance of vughs pore for cultivated pedons, while channels and chamber types for un cultivated soil.

Occurance single lenticuler crystals or spindle shope spreaded in soil matrix or in from of cutans paralel for pore walls or in from of nests filling soil pores.

However the dominat structurs in most horizons of the soil pedons studied were the granular and the spongy and the sub angular blocky.

Proe of vughs, chamber and planer type were abundant, Depending on clay accumulation index(Ci) and value of clay contact in B horizon to contect of clay in A horizon observed presence of case pedogenic development in particularly cultivation on version particularly un cultivation which was object weak development.

Soil pedons have been classified according to (soil survey staff,(05)to great group level and to the series level according to Al-Agidi (1).