Influence of edaphic conditions on the productivity of eastern persimmon

The dependence degree of the eastern persimmon productivity on the edaphic conditions of the southern coast of the Crimea has been studied. Experimental areas were laid on the territory of the Nikita Botanical Gardens and Koreiz. The study of the architectonics of the root system of persimmon plants performed by the “cut” method according to V.A. Kolesnikov, showed that the roots have mastered almost the entire soil profile to the depth of the dense rock. At the same time, up to 80% of the root cuts, both conducting and absorbing, were localized in the meter layer of the soil profile. The analysis of the research results showed that in the experimental areas where normally developed persimmon trees grow, characterized by high fruit yields, the degree of density of the fine earth ranged from 1.21 to 1.67 g cm^‑3, and under a group of oppressed trees – from 1.35 to 1.70 g cm^‑3. An increase in the density of fine soil and a decrease in soil porosity leads to oppression of trees and a decrease in the productivity of persimmon plantations. It was revealed that the reserves of fine earth in a meter layer of soil in the studied areas under normally developed persimmon trees averaged 15,000 t ha^‑1, humus reserves – 279 t ha^‑1; under trees in a depressed state – 6,000 and 178 t ha^‑1, respectively. The granulometric composition of the fine-loamy part of the analyzed soils ranged from heavy loamy to light-loamy with a predominance of silty fractions (up to 31.7%). The reaction of the aqueous soil suspension is alkaline, pH is in the range of 7.80-8.50. The average CaCO₃ content in a meter layer of soil in areas with normally developed trees is low – from 0.3 to 5.0%, under oppressed plants – the soil is highly carbonate (up to 55%). The soils in all experimental plots, regardless of the state of the persimmon trees, are low-humus, the humus content is not more than 3.3%. The study of the reaction of persimmon plants to the properties of brown planted soils on the southern coast of Crimea made it possible to identify the main factors influencing the productivity of plantations: heavy granulometric composition, high density of fine earth, low humus reserves and high carbonate content.