Comparison of theoretical and applied water consumption in advanced technology greenhouses of soilless tomato growing

This study was conducted in a tomato greenhouse equipped with high-tech systems under Adana climate conditions. Each tunnel of the greenhouse is 9,60 m wide, 5,00 m bottom gutter height, and its side walls are covered with a double layer of polycarbonate (PC) with 8 mm spacing, and its roof is covered with a single layer of polyethylene (PE) plastic with a thickness of 180 µm. Thermal curtains were used in the greenhouse for energy conservation and shading purposes. While the temperature in the greenhouse was regulated by ventilation during hot periods, solar radiation reaching the greenhouse was partially blocked by shading in the April-June period, and the air temperature was tried to be regulated by fogging on some days. Irrigation in the greenhouse was carried out by drip irrigation. Fertilized water was given to each plant through capillary tubes (Spaghetti) with a capacity of 2 L/h. Irrigation was managed according to solar radiation intensity. Depending on the global coincidence measured by the climate computer, 100-120 ml of irrigation water was given per plant every 80 J/cm2. In order to control the irrigation, the drainage water collected from the control units installed in four different places in the greenhouse was measured every day and it was decided whether the irrigation was sufficient. In the experiment, while the external temperature values varied between -3 oC and 22 oC in January, the temperatures in the greenhouse were kept at 15 oC at night. During the day, it rose up to 27 oC depending on the outside temperature. While the outside temperature varied between 32 oC and 33 oC in May, the temperature values in the greenhouse increased to 32,8 oC in early May and 34-35 oC towards the end of May, due to the increase in external temperature values. While the number of irrigation calculated in the study was calculated as 6 days-1 for the first half of January, this value was calculated as 7 days-1 for the second half of January. While the number of irrigation calculated based on global radiation in the first half of May was 19 day-1, the number of irrigation for the second half was calculated as 22 day-1. In addition, in the calculations made in the research, assuming that 100 ml of water would be given to each plant during each irrigation during the production period, the daily water consumption applied during the production period was determined to be higher than the calculated daily water consumption.