Adaptive potential of technologies for stabilization of nitrogen nutrition of corn in conditions of hydrothermal stresses

Abstract

Goal. To assess the adaptive potential of the combined use of N-Lock ™ Max nitrification inhibitor and Blue N ™ biostimulant nitrogen-fixator under different climatic conditions during the growing season (HTC range — 0.56–1.09) to ensure stable nitrogen status and corn productivity in the Forest-Steppe of Ukraine. Methods. To assess the nitrogen status of plants, the Yara N-Tester-metric method was used. Statistical processing was carried out by methods of 3-factor dispersion and correlation analyses to establish patterns between hydrothermal parameters and the effectiveness of the studied technological measures. Results. Field studies were conducted during 2023–2025 in 3 contrasting locations: vil. Cherkas (Bila Tserkva district, Kyiv oblast) (typical black soil), and the Shargorod and Tulchynskyi districts (Vinnytsa oblast) (gray forest soils). It was found that the studied seasons were characterized by significant hydrothermal contrast. In dry 2024 (Shargorod) they recorded 19 days with critical air temperatures and precipitation deficiency (HTC=0.56), which led to dehydration of the topsoil and blocking the root absorption of nitrogen. It was proved that under such conditions the leading adaptive role was played by the preparation Blue N ™ (based on Methylobacterium symbioticum), which acted as a physiological buffer, providing an autonomous flow of nitrogen into the leaves, which made it possible to maintain the Yara N-Tester index at the level of 539–552 units (5.7–8.2% higher than in the control), and save the yield — 8.7 t/ha. It was proved that in wet periods (Levkivtsi, 2025, HTC=1.09, the amount of precipitation — 266.3 mm), the chemical stabilization of nitrogen by the drug N-Lock™ Max became critical. The retention of nitrogen in ammonium form due to inhibition of the nitrification process eliminated the risks of nitrate washing, which provided 25% higher agronomic payback of fertilizers. It was statistically confirmed that the combination of drugs against the background of N90 provided a yield equivalent to the full background N120 without stabilizers. Conclusions. The combination of chemical stabilization technologies and endophytic nitrogen fixation made it possible to neutralize the risks of nitrogen deficiency, regardless of the variability of hydrothermal conditions. The results of the study are the scientific basis for the introduction of climate-oriented precision farming systems to ensure food security in the face of global warming.