The Bases of Peach Tree Irrigation in the Fruit-Growing Basin from Oradea, Romania, and the Use of the Microsprinkler System

The paper presents the results obtained on preluvo-soil in Sâniob, Oradea, during 2007-2015. In order to maintain the soil water content between easily available water content and field capacity, the irrigation rate used was between 60 mm/ha and 470 mm/ha. Irrigation determined an increase of the total water consumption by 53% (712 mm/ha vs. 466 mm/ha). For the non-irrigated variant (71%) and for the irrigated one (46%), the rainfalls registered between 15 March-1 October yearly represented the main source of supplying the total water consumption, while irrigation supplied 40% of the total water consumption (with a variation range 11%-61%). The microsprinkler irrigation system led to a 30.6% yield gain, with a variation range of 15.8%-58.7%. It also determined a higher size index in comparison with the non-irrigated variant and a smaller percentage of kernels. All differences were statistically very significant. Several correlations were quantified in the soil-water-plant-atmosphere system. The parameters of the system were: pedological drought, strong pedological drought and water consumption. All correlations were statistically very significant; the best mathematical expression was the polynomial function. Four methods (Penman Monteith, Pan, Piche and Thornthwaite evaporimeter methods) were studied to determine the reference evapotranspiration (ETo) in comparison with the optimal water consumption of the peach tree. As it was cheaper and easier to use, the Pan evaporation method was recommended in the irrigation scheduling, although the Penman Monteith method could have given more accurate results in assessing the optimal water consumption.