Ecological-genetically peculiarities and diagnostics of the cultivated urban soils in the Central Botanical Garden of NAS of Azerbaijan

The soil forming process leaks under the conditions of semidesert, dry and hot climate as a result of what is formed weak developed saline - salty grey-brown soils in the research object. In the virgin land the humic - accumulative horizons of the grey-brown soils are weakly developed and capacity doesn't rise 15-20 sm. The humus content on the upper horizons is little and forms 0,9-1,1%, but nitrogen - 0,07-0,09%. The high calcareous soils, CaCO3 content over the whole profile is 19-26%. A quantity of the absorbing capacity is also little and forms 16-18 m-ekv per 100 g of soil on the upper horizons. The long (more than 70 years) intensive use of the garden territory under various green grove and performance of the scientific - research works and lines of the agrotechnical measures (deep tillage, regular irrigation, application of manure and mineral fertilizers) have been strongly represented in formation of the morphological profile from urban soils and their diagnostic indices. Enough powerful cultivated layer (AUa = 40-50 sm) is formed with the granular - cloddy structure where humus content is 2,4-2,7%, nitrogen - 0,20-0,22%, which aren't characteristic with grey-brown soils in Absheron. Maximal content of carbonates (CaCO3 = 18-20%) and clayey fractions (<0.01 mm = 40-50%) are noted in the mean part of the soil profile, as a result of leaching from upper layer. The cultivated urban soils are distinguished with enough increased capacity of absorption (23-25 mg-ekv) and profile weight is leached from light soluble salts (dense residue 0.088-0,230%)