Thesis of the Doctor of agricultural science academic degree by specialty 06.01.02 – agricultural melioration (agricultural sciences) – Institute of Water Problems and Land Reclamation of the National Academy of Agrarian Sciences of Ukraine, Kyiv, 2021.
The dissertation work provides a theoretical generalization and the results of experimental studies that solve an important scientific and applied problem on the preservation and reproduction of soil fertility with drip irrigation with water of different quality and the use of various fertilization systems for perennial plantations.
The experimental part of the research was carried out during 2009-2015. In Kherson («Kamyanskyi» LLC, «Bilozerskyi» Agrofirm-state farm, «Solodukhin» DAF State Enterprise, «Brylivske» State Enterprise», IWPLR NAAS), Mykolaiv region («Radsad» PJSC) and the Autonomous Republic of Crimea (2009-2013, State enterprise state farm-plant «Plodove»).
The regularities of the development of soil processes and regimes, changes in the physical, agrophysical and physicochemical properties of soils, as well as the productivity of fruit crops under drip irrigation were established depending on the quality of irrigation water and various fertilization systems.
It was found that under drip irrigation with water of different quality, the physical indicators of soils underwent the greatest changes – the density of the structure, the structural and aggregate composition. The most significant changes in the vertical distribution of the parameters of the density of the structure of soils subject to drip irrigation occurred in sandy and medium loamy rocks in the 0-40 cm layer, and in heavy loamy rocks in the 0-50 cm layer. The positive effect of local moisture on the formation of quantitative and qualitative indicators structural and aggregate state of soils.
The regularities of changes in the ion-salt composition of the water extract were established, which consisted in an increase in the amount of salts and their redistribution in the soil profile. In particular, drip irrigation contributed to the washing out of water-soluble salts from the soils of the moistened zone downward, however, when irrigated with water with a salinity of 1,0-2,26 g/dm3, salts accumulated within 20-120 cm.
The highest productivity of peach plantations was obtained with the introduction of mineral nutrition (+50,0 % compared to the control), and apple plantations – with the organic-mineral nutrition system (+23,7 % to the control).
Predictive models of changes in irrigation alkalization and soil salinity have been developed, which include the capacitive characteristics of soils (the sum of absorbed cations, the content of absorbed calcium, physical clay and humus), the attraction of which ensures an increase in the accuracy of the models (R2 = 0,67-0,86), which is permissible for predicting changes in soils in moisture zones in the seasonal and annual cycles and allows you to determine the degree of their possible negative manifestation during the growing season.
In order to control and manage soil processes, an «Analytical and Information System for Managing Soil Modes with Drip Irrigation» (AIS) was created, and «Methodological Recommendations for the Fertilization of Perennial Plantations with Drip Irrigation» were prepared.
A methodology for managing the ecological-reclamation state of soils under drip irrigation has been developed, which is based on new approaches and requirements for organizing and conducting a system of routine observations of the parameters of the ecological-reclamation state of soils for conditions of local moisture.
Measures have been scientifically substantiated to reduce the level of secondary salinization and alkalinization, to provide conditions for the formation of a water-resistant structure using measures of chemical reclamation of soil and irrigation water, phytobiological and biological soil reclamation.
Based on some calculations it was substantiated economic efficiency of the implementation of intensive drip irrigation technology for fruit crops under the conditions of the Steppe of Ukraine.
Key words: soil processes and regimes, soil fertility, drip irrigation, fertilization systems, fruit crops, productivity, fruit quality.
