## 3 Results
### Impact of Irrigation (a), N Fertilizer Rate (b), and Maize Hybrid (c) on Yield and Grain Compounds  
According to the ANOVA, the maize GY varied significantly (_p_ < 0.01) across the irrigation, N fertilizer rate, and maize hybrid variables (Figure 6), regardless of the weather conditions. In the first year of the study, i.e., the extremely wet year, the maize GY across the irrigation treatments ranged from 8.59 (a3) to 9.24 t ha\({}^{-1}\) (a1). In the extremely dry year, the maize GY ranged from 7.47 (a1) to 9.35 t ha\({}^{-1}\) (a3), while in the average year, the maize GY ranged from 7.37 (a1) to 10.28 t ha\({}^{-1}\) (a3). The N fertilizer rate increased the maize GY in all three growing seasons (_p_ < 0.01); that is, in the extremely wet year: 5.99 (b1) to 12.11 t ha\({}^{-1}\) (b3), in the extremely dry year: 6.10 (b1) to 10.25 t ha\({}^{-1}\) (b3), and in the average year: 8.11 (b1) to 9.55 t ha\({}^{-1}\) (b3). As for maize hybrids, a significantly (_p_ < 0.01) higher GY was recorded for the c3 hybrid with 10.55 t ha\({}^{-1}\), regardless of the weather conditions. Figure 6: Averages and significances (ANOVA) of the GY, protein, starch, and oil content across the irrigation (a1 = rainfed, a2 = 60–100% field capacity (FC), and a3 = 80–100% FC), N fertilizer rate (b1 = 0 kg N ha\({}^{-1}\), b2 = 100 kg N ha\({}^{-1}\), b3 = 200 kg N ha\({}^{-1}\)), and maize hybrid (c1 = OSSK596, c2 = OSSK617, c3 = OSSK602, and c4 = OSSK552) variables. The significance of the study factors on the GPC was year dependent (Figure 7). A significant (\(p<0.01\)) impact due to irrigation was recorded in the extremely wet and average years: a1 = 7.39% to a3 = 7.74% (extremely wet) and a1 = 10.26% to a3 = 9.82% (average year). A significant (\(p<0.01\)) impact of the N fertilizer rate was recorded, regardless of the weather condition, whereby the GPC was higher as the N fertilizer rate increased. A significantly (\(p<0.01\)) higher GPC was recorded for c1 = 10.33% only in the average climatic year. The irrigation significantly (\(p<0.01\)) affected the GSC in the extremely wet and average years, whereby the maximum GSC was recorded for the a3 irrigation treatment: a1 = 72.8% to a3 = 73.8 (a3) in the extremely wet year and a1 = 75.7% to a3 = 77.1% (a3) in the average climatic year (Figure 6). The impact of the N fertilizer rate on the GSC was significant (\(p<0.01\)) only in the extremely dry year: b1 = 73.5% to b3 = 72.9%. The maize hybrid had a significant (\(p<0.01\)) effect on GSC in all three years, whereby the highest GSC was recorded for c4 hybrid regardless of the weather condition. As for the GOC, significance (\(p<0.05\)) of irrigation treatment was only recorded in the extremely dry year: a1 = 4.6% to a3 = 4.7% (Figure 7). The impact of the N fertilizer rate on the GOC was significant in the extremely wet and average years: b1 = 3.4% to b2 = 3.24% (extremely wet) and b1 = 4.61% to b3 = 4.74% (average). The GOC significantly (\(p<0.01\)) varied across the hybrids in all growing seasons with inconsistency between hybrids, i.e., in the extremely wet year, a significantly (\(p<0.01\)) higher GOC was recorded for c3 = 3.42%, c1 = 3.54% in the extremely dry year, and c1 = 4.81% in the average year. Significant correlations (Figure 8) were found between the oil and protein content in the extremely wet year (\(r=0.32\), \(p<0.01\), N = 107). Furthermore, significantly correlations between oil and starch content were found during the extremely wet (\(r=-0.31\), \(p<0.01\)) and average years (\(r=0.27\), \(p<0.01\), N = 107) and between protein and starch content in the extremely wet (\(r=-0.48\), \(p<0.01\), N = 107) and extremely dry growing seasons (\(r=-0.81\), \(p<0.01\), N = 107).