Badania nad zastosowaniem różnych form azotu w hydroponicznej uprawie pomidora [Effects of nutrition with varied forms of nitrogen on the growth of tomatoes in hydroponic cultures]

Ammonium saltpeter used in hydroponic nutrient solution instead of calcium saltpeter decreased the yield of tomatoes by 30%. A smaller (15,4%) decrease in yield was observed when ammonium saltpeter was used jointly with urea. The 50% reduction of light gave a considerable 60% drop in the yield. The levels of phosphorus and chlorophyll in leaves of tomatoes grown under the above conditions were considerably higher than in tomatoes cultivated in full light. All the tomato plant took up almost the same quantities of mineral salts.