Research on Sandy Soils from Oltenia Plain and Their Cultivation

Abstract

Sandy soils from Oltenia Plain occupies the largest area in the country, about 209.400 ha and are situated on terraces of the Danube, the Jiu and Olt River and west Oltenia Plain. The primary material of the origin of the sand in the south Oltenia is the Carpathians South of Olt and Jiu, the differences consisting of the amount somewhat less coarse sand by the Danube, rich in calcium carbonate thereof as compared to the sand and sandy soils from Left Jiu. The territory between Olt, Jiu, and Danube consists of two distinct areas: one field Leu-Rotunda, located in southeastern Oltenia. This field is a continuation of the surface of the plateau levatinului Piedmont. The second area is formed by terraces Olt, Jiu and Danube. This area has the absolute altitude between 110-140 m with slopes to the east and south. As such relief formations have shown sandy dunes and interdune form. Dunes had heights of 5-15 m and 100-500 m width were interdune. Area with sandy soils in southern Oltenia is crossed by a river system, represented by the Danube River to the south, Olt River to the east and west Jiu River. Plant growth and development of the sandy, is related to the presence of water, which has a decisive role. Low rainfall, high temperatures and Austru wind, warm and dry, make sands of Oltenia sometimes take the form of semi-desert. From an textural, in most cases, the percentage of coarse sand is higher and the lower sand on the dune and the interdune increase both the proportion of sand and the clay. In Oltenia Plain appear dominant cernisols represented by typical chernozems, calcic chernozems, cambic chernozems, gleyic chernozems and argic chernozems, which are added some luvisols of type reddish preluvosols and typical luvosols and some typical eutricambosols. Not missing hidrisols nor salsodisols, and in floodplains and terraces predominate protisols with distric psamosols and eutric aluviosols. Lately, as a result of pedoameliorative measures, such as shaping and leveling, were essential changes in both the forms of relief, and the main physical and chemical properties, disappearing dunes due to mobilization on higher ground sand and depositing the material in interdune. Excavated and deposited quantities of sand are varied both in terms of origin and physic and chemical properties. Production potential is medium. Requires to stem deflation, the increase in organic matter in the soil and especially in the areas set (level model), the fertilization and maintaining forest cover.