Drip irrigation is a water-saving and fertilizer-saving application technology used in recent years, with which the frequency of drip irrigation nitrogen application has not yet been determined. In order to investigate the effects of different drip irrigation nitrogen application frequencies on the processing quality of medium-gluten wheat (Jimai22) and strong-gluten wheat (Jimai20 and Shiluan02-1), a two-year field experiment was carried out. Two frequencies of water and N application were set under the same conditions of total N application (210 kg·ha⁻¹) and total irrigation (120 mm): DIF4, consisting of four equal applications of water and N (each of 30 kg·ha⁻¹ of N application and 30 mm of irrigation) and DIF2, consisting of two equal applications of water and N (each of 60 kg·ha⁻¹ of N application and 60 mm of irrigation). The results showed that IF4 significantly increased protein content by 2–8.6%, wet gluten content by 4.5–22.1%, and hardness value (p > 0.05), and PC2 was considered as a protein factor; the sedimentation value was highly significantly correlated with most of the parameters of the flour stretch (p < 0.01). DIF4 improved the stretching quality, and the flour quality of Jima22 was decreased, the flour quality of strong-gluten wheats Jimai20 and Shiluan02-1 was improved, and PC1 was considered to be the dough factor. In conclusion, although the frequency of nitrogen application by drip irrigation increased the protein factor and improved the tensile quality, the flour quality was not necessarily enhanced.

This study was designed to determine the optimal nitrogen application rate for strong-gluten wheat cultivation in the North China Plain. Employing Zhongmai 578, a strong-gluten wheat variety, a field experiment was conducted with the following four nitrogen levels: 0 kg/ha (N0), 150 kg/ha (N1), 210 kg/ha (N2), and 270 kg/ha (N3). The research focused on examining the impact of nitrogen application on the photosynthesis, yield, and quality of strong-gluten wheat. The findings revealed that the N2 treatment (210 kg/ha) yielded the highest results compared to the N0 treatment. Photosynthetic parameters, including chlorophyll content in wheat flag leaves, generally exhibited an increase followed by a decrease, peaking at 7 days after anthesis (except for the transpiration rate, which peaked at 14 days post-anthesis). In the first year, quality indices such as water absorption, capacity, sedimentation value, ductility, protein, and wet gluten initially increased and then decreased with rising nitrogen levels. Conversely, in the second year, these quality indices, including hardness, showed a progressive increase with elevated nitrogen application. These results indicate that enhanced nitrogen application can significantly improve the photosynthetic characteristics of strong-gluten wheat, thereby augmenting both yield and quality. Within the parameters of this experiment, an application of 210 kg/ha of nitrogen emerged as the optimal rate, promoting the superior yield and quality of strong-gluten wheat in the North China Plain.

The North China Plain is one of the major wheat cultivation regions. As a cornerstone of global food security, wheat makes the enhancement of its yield critically important. Sulfur critically regulates photosynthesis, antioxidant defense, and grain filling dynamics. To elucidate the physiological mechanisms of S in wheat grain filling and guide field practices, a two-year field experiment (2022–2023 and 2023–2024) was conducted in the North China Plain using two dominant cultivars, Jimai 20 (JM20) and Yannong 999 (YN999). Four sulfur (ammonium sulfate) gradients (S1: 15 kg ha⁻¹; S2: 30 kg ha⁻¹; S3: 45 kg ha⁻¹; S4: 60 kg ha⁻¹) and a control (S0) were applied at the jointing stage via a drip fertigation system. The key findings reveal that optimal S application (YN999: 45 kg ha⁻¹; JM20: 30–45 kg ha⁻¹) enhanced post-anthesis photosynthetic capacity by increasing flag leaf SPAD values and superoxide dismutase (SOD) activity while reducing malondialdehyde (MDA) accumulation, thereby delaying leaf senescence. These improvements translated into optimized grain filling parameters: YN999 and JM20 exhibited 2.27–5.62% and 13.20–13.86% increases in mean grain filling rate, 3.92–4.73% and 2.11–4.36% extensions in grain filling duration, and 7.62–7.83% and 9.55–10.23% boosts in thousand grain weight, respectively. Consequently, yield increased by 0.58–1.54 t ha⁻¹ for YN999 and 1.36–1.49 t ha⁻¹ for JM20. Under drip fertigation conditions in the North China Plain, sulfur application at 30–45 kg ha⁻¹ effectively enhances wheat yield. These findings provide fertilization guidance for the development of precision agriculture and can help alleviate the local soil sulfur deficiency trend.

At present, the use of hybrids is becoming more and more widespread, and the study of its traditional cultivation methods also needs to pay attention to the combination of good seed and good methods to achieve maximum economic benefits. “Good seed” is selected from varieties with high production potential and strong resistance to stress. To investigate the effects of sowing dates on biomass accumulation and photosynthetic characteristics of hybrid winter wheat, this study was conducted over two growing seasons (2021–2023) using a hybrid variety, Jingmai 17, and a conventional variety, Jimai 22. Three sowing dates were tested: October 13 (D1), October 23 (D2), and November 2 (D3). Results indicated that Jingmai 17 had a larger leaf area per culm (LAC) post-anthesis, and a lesser variation in SPAD values throughout the middle and late irrigation phases, leading to enhanced photosynthetic performance and higher biomass accumulation at maturity. It outperformed Jimai 22 by approximately 10% in yield. The optimal sowing date (D2) allowed both varieties to maintain a favorable LAC, which supported higher SPAD values, net photosynthetic rates (Pn), and stomatal conductance (Gs) during late grain filling. Correlation analysis revealed a positive relationship between post-anthesis biomass accumulation and yield, suggesting that increased accumulation at this stage underpins yield formation. Under D2 conditions, Jingmai 17 and Jimai 22 achieved yields of 9603.70 kg·ha⁻¹, 9058.68 kg·ha⁻¹ and 8785.44 kg·ha⁻¹, 8294.89 kg·ha⁻¹, respectively, which are 3.4%, 4.6% and 3.4%, 12.4% higher than under D1 conditions, respectively, and 10.7%, 12.4% and 12.8%, 14.5% higher than under D3 conditions, respectively. D1 had higher thousand-grain weight (TGW) but lower number of grains per unit area (GN); D3 had lower TGW, while the GN was not significantly higher, and D2 was effective in improving seed yield. Overall, Jingmai 17 demonstrated significant photosynthetic and yield advantages, maximizing yield potential through optimal interactions among spike number (SN), grain number per spike, and TGW at the October 23 sowing date.

Colored wheat is rich in nutrients such as minerals, amino acids, and anthocyanins, offering significant health benefits. However, its typically low yield limits cultivation and production efficiency. This study, conducted during the 2021–2023 winter wheat seasons, compared the yield and quality of four purple wheat varieties (Qingyan Purple Wheat No.1 (QYZ-1), QYZ-2, Shannong Purple Wheat No.1 (SNZM1), Nongda 3753 (ND3753)), two blue wheat lines (20064 and 20072), and the modern white-grain wheat Jimai 22 (JM22). Results showed that QYZ-1 had the highest yield due to its higher thousand-grain weight and grain number per unit area. Colored wheat varieties, especially SNZM1 and 20072, had significantly higher Se, Zn, Fe, and Mn contents compared to JM22. Additionally, colored wheat is rich in Ca, K, Mg, and anthocyanins. QYZ-2 and ND3753 had a diverse range of anthocyanins, while 20072 had the highest total anthocyanin content. High wet gluten content and gluten index in colored wheat, particularly QYZ-1 and ND3753, indicated excellent processing characteristics. QYZ-1 also had the highest crude protein content. The total and non-essential amino acid contents in colored wheat were significantly higher than in JM22. The study concluded that colored wheat, particularly QYZ-1, shows superior nutritional content and quality. Moreover, the spike number is significantly positively correlated with yield; therefore, we believe that its yield can be further improved by increasing thousand-grain weight while maintaining stable grain numbers per unit area.