This study aimed to determine the effects of different irrigation levels (50%, 75%, and 100% of ETo values calculated using evaporation from Class-A pan) and nitrogen doses (0, 90, 180, and 270 kg ha ⁻ ¹) on yield, yield components, and the nutritional properties of sorghum grains. According to the research results, increasing irrigation and nitrogen fertilization levels enhanced plant height, thousand-grain weight, grain number per panicle, grain weight per panicle, and grain yield. The highest grain yield (7120 kg ha ⁻ ¹) was obtained with 100% irrigation and 180 kg ha ⁻ ¹ N application. While increasing irrigation levels increased oil content, higher nitrogen doses caused a decrease for it. The highest oil content (6.64%) was recorded with 100% irrigation and 0 kg ha ⁻ ¹ N application. Protein content increased with irrigation and nitrogen applications, reaching the highest level (11.85%) with 100% irrigation and 270 kg ha ⁻ ¹ N application. Higher irrigation levels also increased total starch and phytic acid content. Among nitrogen applications, the dose of 270 kg ha ⁻ ¹ resulted in the maximum total starch (77.29%) and phytic acid content (1.83%). The ratio of resistant starch (RS) was found to be high at 50% irrigation with low nitrogen doses, indicating an inverse relationship with the total starch content. Both irrigation and nitrogen applications significantly affected the ratios of oleic and linoleic acids. Specifically, increased irrigation raised the linoleic acid content, while nitrogen applications enhanced the oleic acid content. Additionally, as irrigation levels increased, the contents of potassium (K), magnesium (Mg), iron (Fe), phosphorus (P), and zinc (Zn) also increased. Conversely, the levels of calcium (Ca) and manganese (Mn) decreased. Generally, higher nitrogen doses resulted in increased mineral content, with the highest levels of magnesium, iron, and zinc observed at nitrogen doses between 180 and 270 kg ha ⁻ ¹. According to the research results, the most suitable irrigation level for optimizing high yield and grain nutritional properties was determined to be 100%, with a nitrogen dose of 180–270 kg ha ⁻ ¹. These findings will contribute to future studies on different sorghum varieties under varying climate and soil conditions.

Understanding the impact of irrigation levels on maize (Zea mays L.) nutritional properties is crucial for optimizing water use in sustainable agriculture. This study investigates the effects of three irrigation levels (I75: 75%, I100: 100%, and I125: 125% of depleted water from field capacity) on the biochemical composition, mineral content, and fatty acid profile of five maize cultivars’ grain. Biplot analysis was employed to identify superior irrigation levels and cultivars regarding nutritional traits and to visually interpret their interrelationships. The findings indicate that increased irrigation enhances oil, protein, ash, total starch, amylopectin, resistant starch, and non-resistant starch while reducing dietary fiber, phytic acid, and amylose levels. Mineral contents generally increased with irrigation, except for sulfur, which declined, and potassium, which peaked at I100 before decreasing. The fatty acid composition was largely cultivar-dependent, with no significant effect from irrigation. Among the tested irrigation levels, I100 was the most optimal, providing the best nutritional quality and mineral composition balance across the maize cultivars. Pioneer PR31Y43 and Syngenta Dracma cultivars stood out under limited irrigation conditions (I75), Pioneer PR31G98 and Tareks OSSK644 cultivars under optimum irrigation conditions (I100), and Syngenta Inove and Tareks OSSK644 cultivars under over-irrigation conditions (I125). These results highlight the necessity of cultivar-specific irrigation strategies to maximize maize nutritional quality and resource efficiency.

In this study, the effects of different irrigation levels (0 (rainfed), 25, 50, 75 and 100%) and nitrogen doses (100, 150 and 200 kg ha^− 1) on water use, morphological characteristics, herbage yield and herbage quality of annual ryegrass were investigated. Experiments were carried out in randomized blocks–split plots experimental design with 3 replications in 2021–2022 and 2022–2023 for 2 years. Applied irrigation water quantities varied between 190 and 762 mm in 2021–2022 and between 204 and 816 mm in 2022–2023. Crop water consumptions (ETc values) were calculated as between 179 and 872 mm in the first year and 170–916 mm in the second year. The highest green-dry herbage yields, plant height, plant diameter and number of tillers were obtained from IT100xN200 treatments, and the highest protein yield was obtained from IT50xN200 treatments. While ADF, NDF, ADL, crude fiber and crude ash contents increased, crude protein content decreased with increasing irrigation water levels. Crude protein and crude ash contents increased, and cell fiber content decreased with increasing nitrogen doses. Mineral contents of ryegrass increased with increasing irrigation water levels and nitrogen doses. It was concluded based on present findings that IT100xN200 treatments could be applied for herbage yield and mineral contents and IT50xN200 treatments could be applied for protein yield and quality herbage production in ryegrass production.