Total Water Consumption and Evaporation of Winter Wheat in the Irrigation Zone of Southern Ukraine

The most important element in the development of the irrigation

regime of agricultural crops is the total water consumption or/and the amount

of water that plants need during the growing season to obtain the planned crop in

specific natural conditions while optimising all technological processes. The

purpose of the study is to determine the features of total water consumption

and average daily evaporation of winter wheat plants depending on the natural

moisture supply of growing years, irrigation regimes, and groundwater level in

the irrigation zone of southern Ukraine. In the course of the study, generally

accepted methods were used: system approach and systems analysis,

monographic, analysis and synthesis, abstract-logical, historical, field research,

statistical and economic-mathematical, etc. The highest indicators of total water

consumption were observed in the average weather conditions and amounted

to 4,263 m3

/ha in the 2-metre layer of soil, in wet years characterised by

moderate temperatures, high humidity, and a considerable number of days

with precipitation, the average water consumption from this soil layer was

3,993 m3

/ha. In dry years, which were characterised by hot weather with low

humidity and low precipitation, the total water consumption was the lowest

and amounted to 3685 m3

/ha. The reduction of the growing season occurs

in late June – early July when high air temperatures and low humidity are

observed, which is the main reason for the decrease in the total water

consumption of irrigated winter wheat. Analysis of data on the use of moisture

from different soil layers indicates that during the autumn growing season

and during the wintering of plants water reserves in the deep layers are

replenished. In general, during the growing season of winter wheat, considering

the winter period, the field of this crop consumes an average of 5.2 thousand m³ of

water during irrigation over 12 years. Observation of the average daily evaporation

of winter wheat plants in conditions of natural and artificial irrigation indicates

that it has the form of a parabola, the maximum mark of which falls on the

interphase period of earing – the beginning of milky ripeness of grain