Determination of the Optimal Nitrogen Content in a Fertigation Medium for the Greenhouse Cucumber Grown on Slabs of Compressed Straw

In the years 2004-2008, research work was carried out whose aim was to determine the optimal nitrogen fertilization dose for greenhouse cucumbers grown on mats made of compressed, finely shredded straw. In the experiments, the short-fruited variety of the greenhouse cucumber, Milenium F₁, was used. The level of nitrogen in the nutrient solution was varied in the range of 200-350 mg·dm^-3. The nitrogen content in the solution in the amount of 200 mg·dm^-3 was not sufficient and caused the cucumber yield to fall. The increasing N concentrations in the medium were found to have a significant effect on the nitrogen content in the indicator parts of cucumber plants. The highest nitrogen content was found in the plants fertilized with a nutrient solution containing the highest concentration of N-NO₃, which was 350 mg·dm-3. Cucumber plants grown on straw need to be more intensely fertilized with nitrogen for about 1/3 of the growing season, and then to have its level in the fertigation medium reduced for the remaining part of the cultivation period.