Response of maize hybrids to irrigation methods and primary tillage in the Ukrainian Steppe

The aim of the study was to determine the response of maize hybrids to drip irrigation compared to traditional sprinkler irrigation under conventional plowing (30-32 cm) and deep tillage (35-37 cm) as the primary soil cultivation methods. The article presents the results of evaluating the effectiveness of drip irrigation and sprinkler irrigation, as well as the impact of deep non-inversion tillage versus classical plowing on maize yield across different FAO maturity groups in the Ukrainian Steppe. The research was conducted in an irrigated crop rotation on southern solonetsic chernozem soils with a humus content of 2.9-3.2% and a pH of 6.2. The preceding crop was sunflower. The total water application rate during the growing season was 4,000 m³/ha. The study included 11 hybrids with FAO numbers ranging from 210 to 370. A low yield variation (CV = 12.7-13.4%) indicates a uniform response of the studied hybrids to changes in growing conditions. Maize yield significantly increased under drip irrigation by +0.75 to +2.13 t/ha (+7.5 to +18.3%). Deep tillage provided a notable yield increase of +0.46 t/ha under sprinkler irrigation and +0.70 t/ha under drip irrigation. The hybrids VN 63 (FAO 280) showed a strong positive response to deep tillage (+1.0 to +1.35 t/ha), as did Gran 6 (FAO 300) with +0.87 to +1.23 t/ha, Tesla (FAO 350) with +0.66 to +0.99 t/ha, and Gran 1 (FAO 370) with +0.89 to +1.12 t/ha under both irrigation methods. The study established that hybrids with FAO less than 280 are not suitable for cultivation in the Southern Steppe due to lower grain yield. Among the FAO 200-300 group, VN 63 and Gran 6 achieved significant yield increases of +0.5 to +2.5 t/ha, with yields of 10.93 and 11.99 t/ha, respectively. In the FAO 320-400 group, Tesla and Gran 1 demonstrated substantial yield gains of +0.61 to +2.08 t/ha, with average yields of 14.06 and 13.92 t/ha, respectively. The highest grain yields of 15.57 and 15.49 t/ha were achieved by the Tesla (FAO 350) and Gran 1 (FAO 370) hybrids under deep tillage combined with drip irrigation, significantly (>CI0.99) outperforming the standard. The analysis indicates the high effectiveness of drip irrigation and deep tillage in enhancing maize yields in the Southern Ukrainian Steppe