DRIP-IRRIGATED SWEET CORN WATER USE DEPENDING ON THE DEPTH OF PLOWING, MINERAL FERTILIZATION RATES AND CROPS DENSITY

The effect of plowing depth (20-22; 28-30 cm), mineral fertilization rates (N-P: 0-0, 60-60, 120-120 kg ha-1), and crops density (35,000, 50,000, 65,000, 80,000 plants ha-1) on the yield, and water use efficiency (WUE) of drip-irrigated sweet corn were studied. The field experiment was conducted in the semi-arid climatic conditions of the South of Ukraine (Kherson oblast) at the dark-chestnut middle-loamy soil. The trials were conducted using split-plot design in four replications. Irrigation scheduling and rates were set by the field water balance method considering the amounts of available soil moisture and precipitation. Manual harvesting of the crop ears was conducted at R3 phenological stage. WUE was calculated as the ratio of the ears' yield to the gross water use of the crop. Statistical evaluation was performed by analysis of variance (ANOVA) and regression analysis at the probability level of 95%. The studied factors and their interaction had a significant effect on sweet corn productivity and WUE. The best crop productivity along with the best WUE was provided by plowing on 20-22 cm, fertilization rates of 120-120 kg ha-1, and crops density of 65,000 plants ha-1.