Fertigation: content of mineral nutrients in the soil and in the leaves of sweet cherry trees between two applications

This paper presents the results of an investigation focused on tuning the microsprinkling- and drip-fertigation of sweet cherry (Prunus avium L.) trees on both vigorous and dwarfing rootstocks. The investigation was carried out in two experimental plots over the course of two consecutive years. During the first year, cherry trees from the first plot ('Lapins' on 'Gisela 5' rootstock, 4×2 m) were ten years old, while those from the second plot ('Bigareaux Burlat' on Prunus avium L. rootstock, 6×4 m) were eight years old. In each plot the trees were supplied with water and fertilizers through either microsprinkling or drip irrigation systems, the application rates of fertilizers being equal. Mineral nutrient concentrations in the soil solution and in the leaves were measured on samples collected on a daily basis in the 15-day period between two fertilizer applications. Extractors (tensionics) were used for solution sampling from depths of 10, 30, 50 and 70 cm, as well as from 90 cm in the second plot. Immediately after the fertilization and before the next application, soil samples were taken from the same depths and analyzed nitrogen, phosphorus and potassium content, as well as EC and pH. The mineral nutrient distribution downwards through the soil profile was similar under drip and microsprinkler irrigation. Generally P2O5, K2O, EC and pH of the soil solution remained unchanged between applications. Nitrate concentrations increased significantly after fertigation but through dilution and intensive root extraction decreased gradually, reaching their natural concentrations in five-six days. Two or three applications of ammonium nitrate in the period between the basic fertigation applications maintained a more constant nitrate concentration in the soil solution. Either application method provided proper mineral nutrition to the cherry trees.