Salt distribution in peat substrate grown with melon (Cucumis melo L.)

In order to determine horizontal and vertical salt distribution in peat as one of the most commonly used organic substrates, investigation has been conducted with four levels of electrical conductivity (EC) in the nutrient solution (2, 4, 6 and 8 dS m(-1)). After five-week fertigation of melon (Cucumis melo L.) with saline solutions, EC of substrate was measured on each experimental with a portable conductometer. The arrangement of measurements was performed according to ordinary grid with distance of 7 cm on two depths (3 and 6 cm). For each treatment were made 3-D maps of salt distribution in peat bags. An average EC in substrate for both depths, in all treatments was 17-55% higher than in delivered nutrient solution. The lowest EC values of substrate were detected under the droppers and around of bulk root zone. The analysis of horizontal salt distribution have shown that EC values have been reduced in the direction from the edge of the bags to the plants, while to the centre of the bags EC values again have been increased. The highest salt concentrations were determined on the edges of peat bags and in the centre between two plants.