## 4 Discussion
The result of this analysis was compared with [PERSON] et al. [71], who noted that irrigation has more of an influence than N fertilization on leaching water quality and that the optimal irrigation, combined with optimal fertilization, was efficient at reducing the potential environmental risk caused by excessive fertilization. These differences could be explained by the fact that, in the mentioned research, a considerably higher net irrigation (6525 m\({}^{3}\) ha\({}^{-1}\)) was added compared to our research (1050 m\({}^{3}\) ha\({}^{-1}\) in the extremely wet year and 2450 m\({}^{3}\) ha\({}^{-1}\) in the average year). The GY vs. irrigation and N fertilizer rate (Figure 6)provides evidence for this statement since a strong positive correlation was found between GY and N fertilizer rate, regardless of the weather conditions, while for the irrigation rate, only a strong positive correlation was found during the average year. The importance of N fertilizer was also confirmed during the extremely wet year, where the GYs in the irrigated plots were reduced less with increasing N fertilizer rate. It seems that this is not only valid for growing conditions with excessive amounts of rainfall but also drought, as [PERSON] and [PERSON] [72] made the important claim that a higher N fertilizer rate can be used to compensate for a shortage of water under limited water resources. Nevertheless, when the GY is considered, then both the IWUE and FUE should be analyzed considering both factors, i.e., the IWUE in relation to N fertilizer rate and vice versa. Here, again, the specificity of extreme weather conditions was noted. The IWUE decreased with an increasing N rate in the extremely wet growing season (Table 5). During the extremely dry growing season, the IWUE increased with an increasing N rate, whereby the maximum IWUE was found for the a2b3 treatment (18.19 kg ha\({}^{-1}\)/mm). Moreover, [PERSON] and [PERSON] [73] found that N fertilizer positively affected IWUE. In the average year, for both the a2 and a3 irrigation treatments, the highest IWUE was noted on control plots (0 kg N ha\({}^{-1}\)). Similar results were obtained for the FUE (Table 5). In the extremely wet and average growing seasons, the highest FUE of b2 and b3 was obtained for rainfed plots (a1), while in the extremely dry year, the FUE was higher when the irrigation rate was higher. Furthermore, the highest FUE was found for the a2b3 treatment (38.3 kg ha\({}^{-1}\) kg\({}^{-1}\)). The present study confirmed the findings regarding the importance of maize hybrids (genotypes) that are adaptable to different growing conditions, i.e., those that produce high yields under diverse and marginal conditions (weather extremes). From our results, it is clear that hybrid c3 showed the best adaptability to environmental conditions (Figure 6) since the highest yields were recorded for this hybrid, regardless of the weather conditions. We emphasize that all hybrids used in the study belong to a similar maturity group (sown and harvested at the same time); therefore, the result of the higher yield potential was a response to a genetic trait. This is in line with previous studies from different parts of the world [74, 75, 76, 77], where authors agreed that future research should involve modifying the maize selection criteria to combine tolerances to both drought and wet condition stresses. As previously stated, grain quality in maize is a result of the interaction of genetic, environmental, and agronomic management factors [79], and the effect of these factors on grain quality is more complex than on yield [80]. In our study, the highest values of GPC, GOC, and GSC were recorded in the average year (Figure 6). Among the tested factors, a similar pattern was found across the study period, i.e., a higher irrigation rate reduced the GPC and increased the GSC, while a higher N rate increased the GPC and reduced the GSC. This was also explored in a prior study by [PERSON] et al. [80].