STRUCTURE OF TOTAL WATER CONSUMPTION BY CORN

Abstract

The article presents the results of studying the total and average daily water consumption of corn for grain in interphase periods with different moisture supply of the growing season.The main source of moisture supply for maize plants for grain is the precipitation in the vegetation period, so the weather conditions for the period from 2010 to 2016 were analyzed.The moisture supply of the growing season had a significant impact on the structure of total water consumption of corn for grain. The total water consumption of maize for grain varied in wet growing periods from 3164 to 4192 m3/ha, average periods of vegetation with average water supply – from 3277 to 4174, in medium wet growing seasons – from 2508 to 3507, arid vegetation periods from 2708 to 2917 m3/ha. The share of atmospheric precipitation in the total consumption of maize water for grain ranged from 48.7 to 95.2 %, and the share of soil moisture ranged from 51.3 to 4.8 %, respectively, and depending on the water supply in the growing season.During the period from sowing to flowering plants spent on average from 48.0 to 57.5 % of water from the total amount on the formation of biomass. The highest amount of moisture is consumed by corn from the flowering period to the stage of milky ripeness. During this period the plants consumed from 594 to 777 m3/ha of moisture. In the structure of water consumption from the flowering period to the milky ripeness stage precipitation accounted for 21.7-37.7 %, and the use of soil moisture made up 62.3-78.3 %.The average daily water consumption of corn plants for grain from soil layer 0-100 cm changes in interphase periods. From the stage from sprouting to flowering, the average daily water consumption increased depending on the availability of easily accessible moisture and precipitation. On average, maize crops evaporated per day from 19.1–22.9 m3/ha in the period of germination the 5th leaf stage to 34.6–39.0 m3/ ha at the 15th leaf stage in the milky ripeness of grain. The maximum daily average water consumption reached its maximum values in the interphase period from flowering to milky ripeness of grain and depended on the conditions of water supply of the crop. During this period, the indexes of average daily water consumption varied from 39.8 to 43.5 m3/ha.