YIELD AND QUALITY INDICATORS OF NAPA CABBAGE (BRASSICA PEKINENSIS SKEELS) AT VARIOUS APPLICATION RATES OF MINERAL FERTILIZERS
In the conditions of sod-podzolic heavy loamy highly-cultivated soil with high content of easily hydrolyzed nitrogen and very high content of mobile forms of phosphorus and potassium, the application of N120 mineral fertilizers for Napa cabbage of the F1 hybrid Kudesnitsa allowed to receive cabbage yield amounting to 17-41 t/hectare, while the Nika F1 hybrid has demonstrated the highest yield of 24-43 t/hectare after the introduction of N120P90K120. The authors have analyzed main product types according to the following quality indicators: the content of solid substances (4.6-5.6%), ascorbic acid (8-20 mg of %), reducing sugars (0.6-3.3 %), nitrates (1100-4100 mg/kg of wet weight), nitrogen (3.4-6.9% for absolutely dry weight), phosphorus (1.6-2.8% for absolutely dry weight), and potassium (4.7-8.6% for absolutely dry weight). The output of by-products contained: 5.4-9.2% of solid substances, 3.3-5.7% for absolutely dry nitrogen weight, 1.5-2.0% of phosphorus and 4.1-8.6% of potassium. The dynamics of nitrogen accumulation (ammonium and nitrate forms), phosphorus, potassium, dry and wet weight of Napa cabbage has also been studied to determine: the yield of N (1.8-4.2 kg), P2O5 (0.9-1.5 kg), K2O (2.4-5.6 kg) of 1 t of wet weight, utilization coefficients of easily hydrolyzed nitrogen from soil (22-29 %), mobile forms of phosphorus (2-3 %) and potassium (12-21 %), utilization coefficients of nitrogen (31-70 %) and potassium (to 20 %) from mineral fertilizers.