. Influence of critical excess of microelements on development of barley culture (Hordeum)

Abstract

Aspects of ecological danger of microelements imbalance in the soil-plant system are stated. The supercritical supply of nutrients to crops can be accompanied by various emergencies and man-made disasters, including military, chemical and pyrogenic. The main signs of toxic effects of micronutrients excess on cereals are presented. There is a positive linear correlation between soil contamination and reduced grain yields. The purpose, tasks and basic conditions of vegetative laboratory experiment on cultivation of barley of Virazh variety on the substrate of soil mix «Green Line» are presented. The peculiarity of the research is to study the influence of monoelement supercritical concentrations of Zn, Cu, Mo in the conditions of root and foliar feeding in barley cultivation. 7 experimental vegetation schemes of soil-plant with the use of sub-root and foliar receipt were studied. Based on the results of a 57-day experiment, quantitative parameters of culture, leaf morphology and root system were determined. Peculiarities of plant development at supercritical levels of microelements receipt and their deviation from the conditions of control plants within significant biogeochemical excess of Zn, Cu, Mo in soils are described. The inflow of zinc on the soil surface inhibits the relative development of the root system by 1.2 times and increases the height of shoots and leaves. The inflow of zinc on the plant surface inhibits the development of the leaf apparatus of barley 1.4 times and promotes the development of the root system. The influx of copper on the soil surface slightly inhibits the relative development of the root system and the height of the shoots. The influx of copper on the surface of the plant slightly inhibits the development of the leaf apparatus and does not change the root system of barley. The inflow of molybdenum to the soil surface inhibits the relative development of the root system by 1.4 times, and the growth of stem and leaf apparatus by 1.1–1.2 times. The entry of molybdenum on the surface of barley crops is less harmful than in the soil. It has been established that the greatest danger for the root system of barley and the location of its sprouts is the supercritical supply of molybdenum, which increased the position of the sprouts by 4–5 times and reduced the development and length of the root system to 2 times. The greatest danger for the leaf plate of barley sprouts is the supercritical foliar inflow of zinc, which reduced the height of the sprouts by 1.2 times and the length of the leaf blade by 1.4 times. It is concluded that differences in cultures in need of Mo, Zn, Cu affect the peculiarities of their response to toxic concentrations of nutrients in the food system. It is proposed to apply estimates of levels of man-made contaminated areas with heavy metals and trace elements in the preparation of areas for agricultural activities in modern anthropogenic conditions.