EFFICIENCY OF WATER USE, UNDER THE CONDITIONS OF GLOBAL CLIMATE CHANGES IN ECOLOGICAL TOMATOES, GROWN IN SOLARIUM, USING DRIP IRRIGATION PUBLISHEDN.C. SABĂU, M. CĂRBUNARU, Anișoara IENCIU, Adelina VENIG None email@example.com
Abstract. The need for food production, for a growing population, in sufficient quantities and of high quality, in the conditions of today's global climate changes represents an important challenge related to the necessity of rational management for water irrigation. In the case of the production of certified organic tomatoes, grown in the solariums, it is necessary to establish the correct water requirement administered by drip irrigation, the scheduling and warning of the waterings and the correct management of the soil moisture, in order to maximize the production. This paper proposes a simple but effective method of determining the water requirement, the scheduling and warning of watering and management of soil moisture, for the ecological culture of tomatoes grown in the solarium, in Husasau de Tinca, Bihor county, starting from the average air temperature, measured inside or outside the solarium. Potential evapotranspiration (ETP) determined with the help of air temperature using the Thornthwaite (ETP Th) and Blaney Criddle (ETP BC) relationships, have significant and distinctly significant correlative links with those measured inside the solarium using the Piche evaporimeter (ETP P) between 1999-2001. Knowing the water consumption of tomatoes grown in the solarium, for the period 1999-2001, specific crop coefficients (Kc) were determined, starting from the ETP Th. For the two systems of culture and distribution of water: without mulching (WM) and the distribution of water at the plant with T type drips and respectively mulching with black foil (mbf) and the distribution of water with microtubes (capillary tubes), the Kc have close values, between 0.55 in September and 1.03 in the May and July months. The optimum real evapotranspiration (ETRO), which is similar to the water requirement of tomatoes, for the hottest vegetation period (April - September) recorded in 2018 (T med = 20.08 ˚C) is 7543.2 m3ha-1, for the WM variant and respectively of 7262.4 m3ha-1 in the MBF variant. The values of Water Utilisation Efficiency coefficient (WUE = 96.1 lkg-1) and the Efficiency of Consumed Water (ECW = 10.5 kg m-3) in the hottest growing season (2018) demonstrate the need to irrigate the organic tomatoes grown in the closed spaces and the superior utilization of water in MBF variant.
Keywords: potential evapotranspiration; water consumption; drip irrigation; specific crop coefficient; water use efficiency;