Scientific Journal of KubSAU

Description of nitrogen stock for black soils of southern and eastern European facies is given in the article. It is ascertained, that the black soil subtypes in the South of Russia have low content of mineral nitrogen (0,4-4,2%) and easily hydrolysable one (6,0-8,3), two times more than that of hard-to- hydrolyze nitrogen (13,4-16,4%), while the main part of nitrogen stock (74,4-78,9%) is found in unhydrolyzable fraction which practically does not participate in farm crop nutrition

Based on many years balance studies, the possibility of humus stock maintenance in common black soils for crop rotations of different structures is given in the article. Fertilizer omitted crop rotations with bare fallow and without it, with perennial legumes and small variations in parts of other crop are considered

The role of root and aftermath residues of basic field farm crops for retention and increase in organic matter content of the soil with fertilizing and fertilizer omitted is substantiated in the article. It is ascertained that the quantity of aftermath residues coming into the soil is 2,6-3,5 times less than that of natural vegetation while dry matter is removed with the main production and by-products 2,0-2,2 times more than is remained in the soil

The article gives the overview of the non-invasive method of NMR relaxation and assess the efficiency of using this method in the study of cultured under in vitro plant objects on the example of Rosa hybrida plants