THE EFFECT OF SUBSTRATE WITH WOOD FIBER AND DIFFERENT NITROGEN FERTILIZATION ON CUCUMBER DEVELOPMENT

Abstract

Peat is used for greenhouse crops, which has good mechanical and physical properties and mineralizes and releases nutrients during the growing process. However, peat is an integral part of ecosystems that has been forming for several thousand years and is obtained from naturally formed and layered bogs. Preservation of carbon reserves in peatlands is very important in order to mitigate climate change. In a 2-factor experiment conducted in 2021 at the Academy of Agriculture of Vytautas Magnus University, in the controlled climate greenhouse of the Joint Research Center for Land and Forest Research, an alternative to peat was chosen - wood processing waste, in which cucumbers are grown. Wood not used for production is crushed, ground and its consistency becomes similar to fiber. Variants selected in the experiment: Factor A - four different media: 1. Peat substrate control 100% peat - SB; 2. Wood processing waste 100% - MP; 3. Wood processing waste and peat in a ratio of 50:50; 4. Wood processing waste and peat in a ratio of 25:75. Factor B – to evaluate the compensation of nitrogen immobilization, three additional fertilizations were performed: 1. Background fertilization N₁₂P₁₁K₁₈ standard nutrient solution 1.6g l^-1; 2. N₁₃ + background fertilization N₁₂P₁₁K₁₈; 3. N₂₃ + background fertilization N₁₂P₁₁K₁₈; 4. N₃₀ + background fertilization N₁₂P₁₁K₁₈. It has been determined that for growing cucumbers in a greenhouse, peat substrate can be replaced with a medium made from wood processing waste by regulating the immobilization of nutrients in the medium.