Тупроқшунослик ва агрокимё илмий-тадқИҚот институти ҳузуридаги илмий даражалар берувчи dsс

SCIENTIFIC COUNCIL AWARDING SCIENTIFIC DEGREES 
DSс.25/30.12.2019.Qx/B.43.01 AT THE RESEARCH 
INSTITUTE OF SOIL SCIENCE AND AGROCHEMISTRY 
RESEARCH INSTITUTE OF SOIL SCIENCE AND AGROCHEMISTRY 
PARPIEV GAFURJON TOKHIROVICH 
REGIONAL FEATURES OF SEROZEM-OASIS SOILS AND THEIR 
ROLE IN THE FORMATION OF SOIL FERTILITY 
03.00.13-Soil science 
DISSERTATION ABSTRACT OF DOCTOR
OF BIOLOGICAL SCIENCE (DSc) 
 
 
 
 
 
Тashkent-2021 

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INTRODUCTION (abstract of doctoral (DSc) dissertation thesis) 
The aim of the study
is to determine the role, activity and regularities of the 
directions of regional properties of oasis soils, developed under the influence
of various natural and anthropogenic factors of the serozem belt in the formation
of soil fertility, to develop scientific and practical recommendations for preserving, 
increasing soil fertility and their effective use. 
The object of the research
is serozem-oasis, serozem-meadow-oasis and 
meadow-oasis soils developed in the northeastern (Tashkent oasis), central 
(Mirzachul oasis and Zaravshan valley) and southern (Surkhan-Sherabad valley) 
regions of the Republic of Uzbekistan. 
The scientific novelty of the research
is as follows: 
correlation between humus and such soil properties as silt and dust particles, 
absorbed bases, bulk density in the process of fertility formation of oasis soils
of the serozem zone has been substantiated; 
it was proved that the relative age of oasis soils increased due to the formation 
of agro-irrigation layers towards the northeastern region > to the central > southern 
region under the current suspended sediment of the inflow rivers flowing from 
different regions; 
«critical limits» of general physical properties (bulk density, porosity and 
specific gravity) of oasis soils, their micro-, macro-aggregate state, and the degree 
of carbonate content have been evaluated; 
it was proved the carrying capacity of soils from «very low» (5-10 mEq.) 
groups to «low» (5-10 mEq.) and «medium» (15-25 mEq.) groups depending
on the humus content in the soil, as well as a change in absorption capacity
to positive side in the process of formation of oasis soils; 
it was determined that a decrease in percent of toxic salts relative to the total 
amount of salts from serozem-oasis soils of the northeastern and central regions> 
to serozem-meadow-oasis>meadow-oasis soils and, on the contrary, an increase
in their content in the southern region, directly from the content of difficult soluble 
sulfate salts.