Оценка на продуктивността на поливната вода при три сорта памук.

The aim of this paper was to study the effect of irrigation and the productivity of irrigation water in three varieties of cotton grown under conditions of natural moisture and irrigation. The field experiment was carried out in the region of Stara Zagora, Bulgaria on typical meadow-cinnamon soil with nitrogen fertilization rates for cotton-0, 80, 160 and 240 kg/ha for the period 2018- 2020, characterized by uneven distribution of precipitation during the growing season of the crop, in the conditions of optimal irrigation regime and natural moisture supply. It was found the productive possibilities of cotton with optimal irrigation and natural moisture supply have been established. The productivity of the irrigation water is calculated, which is from 6.72 to 48.72 kg.ha-1.mm, during the years with different precipitation provision. A strong positive linear relationship between the additional yield and the productivity of the irrigation rate has been established. The correlation coefficient was determined (r=0.88). The rate of development of irrigation water productivity is dynamic, but with smaller amplitudes than the rate of additional yield. [ABSTRACT FROM AUTHOR]