Analysis of the impact of soil pollution with heavy metals on the ontogenesis of oil crops in arid conditions (using Helianthus annuus L. as an example)

Orenburg State University, Orenburg, Russia

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

This paper presents the results of a study examining the combined effects of drought and increasing concentrations of the most common agricultural soil pollutants - cadmium (Cd) and lead (Pb) - on the vegetation of Helianthus annuus L. Phenological observations were conducted regularly in a field experiment throughout the entire vegetative development period and focused on recording the main phenophases, from seedling emergence to head maturation. A delay in seedling emergence was observed in soils contaminated with heavy metals and with a soil moisture deficit, as well as an increase in the sunflower vegetation period under the influence of Cd and a reduction under the influence of Pb, primarily due to an extension/shortening of the flowering and seed filling periods, respectively. It was established that the biological minimum temperatures required to initiate a certain phenophase under Pb soil contamination do not differ from the control, while under the influence of Cd, the opposite trend was revealed: the heat requirement of plants increases dose-dependently. Increased dose-dependent accumulation of Cd in sunflower seeds was established.