Mineral composition of alfalfa, alfalfa-cereal, and cereal feed agrophytocenoses biomass

The relevance of the results of these studies lies in the fact that until recently, changes in the mineral composition of different types of meadow agrophytocenoses under the influence of symbiotic alfalfa and mineral nitrogen in the content of macro- and microelements, heavy metals, and nitrates in feed biomass have not yet been sufficiently investigated, which hinders the development and implementation of feed production findings in agricultural production. The purpose of the study is to establish changes in the accumulation of various meadow agrophytocenoses in dry feed biomass on various agricultural zones of mineral elements during cultivation on dark grey soils of the Right-Bank Forest-Steppe. During this study, field and laboratory methods were used, and an analytical method was used to determine the mineral composition of dry feed biomass. The results of studies on the accumulation of alfalfa, alfalfa-cereals, and cereal stands in in dry feed mass on various backgrounds of fertilisation and liming of raw ash, macro- and microelements, heavy metals, and nitrate nitrogen are presented. It is shown that under the action of symbiotic nitrogen in alfalfa and alfalfa cereal stands, compared with cereals in the dry mass of feed, raw ash accumulates more macroelements, trace elements, and heavy metals by 0.6-0.8%, the ratio of calcium to phosphorus increases by 0.11-0.26, and potassium to the sum of calcium and magnesium decreases by 0.11-0.26. Under the action of mineral nitrogen in the case of the introduction of N90 in the cereal stand, the content of nitrates increases from 0.02 to 0.04%, zinc – from 9.1-9.2 to 12.4-12.6 or by 3.2-3.5 mg/kg, copper – from 3.4-3.7 to 5.3-5.5 mg/kg, as well as manganese, lead, nickel, cadmium in the dry mass of the feed of the cereal stand. It is proved that the content of macro- and microelements in the dry mass of feed corresponds to zootechnical standards for feeding cattle, and nitrates and heavy metals do not exceed the maximum permissible concentrations. The results of these studies can be used in the development of recommendations on technologies for growing perennial cereals for feed purposes and in the educational process