THE INFLUENCE OF SOWING LOCAL APPLICATION OF ORGANIC AMELIORANTS ON THE PHOTOSYNTHETIC PRODUCTIVITY OF SPRING BARLEY

Abstract

Field research was conducted in the period 2023–2025 on the basis of the Kyiv Specialized Branch of the Ukrainian Institute for Plant Variety Examination, located in the Bila Tserkva district of Kyiv region. Spring barley (Hordeum vulgare L.) was grown using organic technology, where the predecessor in the crop rotation was meadow clover (Trifolium pratense). Organic ameliorants (biochar, sapropel and biohumus) were applied at a dose of 100 kg ha-1 using a seeder during barley sowing. During three years of research, local application of biochar at sowing contributed to positive changes in the growth and productivity of spring barley: leaf area increased by 6–11 %, plant mass increased by 3–9 %, photosynthetic potential of crops increased by 2–7 %, net productivity of photosynthesis by 3–6 %, and grain yield showed an increase of 2–5 % compared to the control variant, where organic ameliorants were not used. Local application of sapropel at sowing had a positive effect on the agrobiological indicators of spring barley. In particular, an increase in the leaf surface area of plants by 8–13 %, fresh mass by 8–12 %, photosynthetic potential of crops by 5–9 %, and yield by 7–11 %. However, its introduction did not cause significant changes in the net productivity of photosynthesis for the varieties of KWS Krissy and Absolut, although a tendency to improve was observed for the variety of Komandor – by 5 %. The use of biohumus during sowing showed the most pronounced effect (compared to biochar and sapropel) on the intensity of photosynthesis and yield of spring barley. The leaf surface area of spring barley increased by 13–21 %; biomass accumulation – by 12–21 %; photosynthetic potential of crops – by 9–14 %; grain yield – by 12–19 % compared to the control variant without organic ameliorants. Biohumus significantly increased the level of net productivity of photosynthesis for the variety of Komandor – by 21 %, while for the varieties of KWS Krissy and Absolut there was only a tendency to increase – by 3–5 %. Leaf area was strongly positively correlated (r = 0.89–0.95) with spring barley yield during all growing periods, except for earing and waxy maturity, when the correlation was insignificant and moderate (r = 0.05–0.35). Leaf area was also strongly positively correlated with spring barley plant fresh weight (r = 0.73–0.99). Plant biomass accumulation was strongly positively correlated with spring barley yield (r = 0.91–0.99) during all growing phases. Photosynthetic potential of the crop was strongly positively correlated with spring barley yield (r = 0.97) and weakly correlated with net photosynthetic productivity (r = - 0.17). Net photosynthetic productivity was weakly correlated with spring barley yield in this study (r = 0.28). The results of this study should serve to improve and accelerate the implementation of organic spring barley growing technology.