This study aims to understand the influence of chlorophyll fluorescence parameters on the yield of winter wheat in some areas of China. Nitrogen (N) application is believed to improve photosynthesis in flag leaves, ultimately increasing the final yield. The results from different parameters of research showed that the grain number per spike improved by 12.2% and the 1000-grain weight by 7.3%, respectively. At 20–30 days after anthesis, the activities of superoxide dismutase (SOD), peroxidase (POD), and soluble protein in flag leaves of N150 were found to be the most effective. The grain yield under N manure partial substitution for N fertilizer treatment increased by 23 and 15%, respectively. The important implications of photosynthetic characteristics of variable fluorescence yield of the light-adapted state are that the contents of clear, ball, alcohol soluble, gluten, protein, and flour quality showed an increasing trend, while the contents of amylose, amylopectin, total starch, and direct/branch ratio were decreased of wheat. The net photosynthetic rate, transpiration rate, and relative chlorophyll content of wheat. The outcome of the present investigation suggests that chlorophyll fluorescence parameters could be a valuable insight into understanding yield stability under stress conditions. Moreover, the investigated parameters could be useful criteria for the selection of photosynthetic energy under varying nitrogen application levels.

This study aims to understand the influence of chlorophyll fluorescence parameters on the yield of winter wheat in some areas of China. Nitrogen (N) application is believed to improve photosynthesis in flag leaf, which ultimately increases the final yield. The experiment was conducted in the wheat experimental base of Shanxi Agricultural University in Taigu, Shanxi Province, China; before sowing, four N application rates were set—N0, N120, N150, and N210 kg ha^–1 of the Yunhan-20410 variety from 2019 to 2022. The results from different parameters of research showed that the organic manure partial substitution for chemical fertilizer increased post-anthesis N uptake by 16.4 and 81.4%, thus increasing the post-anthesis photosynthetic capacity and delaying leaf senescence. N150 treatment can improve dry matter (DM) accumulation, thus promoting the increase of the yield. The maximum net photosynthesis P_N value of the booting stage and flowering stage indicated that nitrogen application could significantly improve the photosynthetic rate of wheat leaves, among which medium nitrogen treatment had the most significant promoting effect. The single-photon avalanche diode (SPAD) value of the leaf of wheat in each treatment increased rapidly in a small range from the jointing stage to the booting stage, respectively. The grain yield under N fertilizer partial substitution for N fertilizer treatment increased by 23%. According to the different significance test, the effects of nitrogen application rate on net photosynthesis P_N of winter wheat were extremely significant at all growth stages, indicating that changing the population distribution mode and nitrogen level could effectively improve leaf photosynthetic performance and that N150 level was the best.

The application of nitrogen (N) improves the winter wheat yield. Excessive N application affects winter wheat yields, leading to low net incomes and negative environmental impacts, therefore, optimizing N application is essential. In this study, the effects of N rates on crop growth yield, net income (NI), water use efficiency (WUE), and nitrogen use efficiency (NUE) in the irrigated districts of the eastern loess plateau, China, were investigated using seven N application rates (N0, N90, N180, N210, N240, N270, and N300 kg ha⁻¹) during the 2016–2017 and 2017–2018 seasons. N application significantly increased the total water consumption at 0–200 cm during the growth period, the aboveground dry matter at maturity, the grain nitrogen accumulation, yield, NI, and WUE. However, N exceeding 240 kg ha⁻¹ did not favor dry matter and nitrogen accumulation or translocation from the anthesis stage to the maturity stage, thus leading to reduced yield, NI, and WUE. The transpiration rate and stomatal conductance N240 was highest 21–28 day after anthesis, at 187–276 kg ha⁻¹, which can achieve a high yield and profitability with relatively low environmental costs.

The current study was designed to investigate the best sowing method that encourages dry matter accumulation to increase dryland wheat yield, grain quality, and protein content. Three different seeding methods were applied: (I) wide-space sowing (WSS), (II) furrow sowing, and (III) drill sowing. Two nitrogen levels, namely low nitrogen (N1) and high nitrogen (N2), were also applied, and the pure nitrogen was 150 kg ha⁻¹ and 210 kg ha⁻¹, respectively. Wide-space sowing significantly increased the ears and yield production, the maximum, and average grain-filling rate while furrow sowing delayed the disappearance of the population after anthesis, increased the duration of grain filling, and then significantly increased the number of spikes and the 1000-grain weight increased, respectively. Drill sowing compared to wide-space sowing significantly increased the content of nitrogen in the grain of the nitrogen harvest index, and it increased the content of protein and the yield of protein, respectively. In addition, the grain yield and protein yield of wide-precision sowing were significantly higher than that of trench sowing. Our findings suggest that wide-space sowing was beneficial for increasing water consumption during the growth period, increasing the tiller dynamics, improving the plant dry matter quality, and increasing the grain protein.

Wheat (Triticum aestivum L.) is a staple crop worldwide and yield improvement since the green revolution was attributed to chemical nitrogen (N) fertilizer application. The field experiment was performed from 2016 to 2020 in the eastern part of Loess Plateau, China, to study the effect of two sowing practices carried out before summer fallow, i.e., wide-space sowing (WS) and drill sowing (DS). The results indicated the soil water content, root length surface density (RLSD), at anthesis by drought was 44% under WS and 29% with DS, while the reduction in above-ground dry weight was 67% under WS and 56% under DS. More soil water was depleted from the deep soil layer (80–100 cm depth) than that in the shallow layer (20–60 cm depth). The average contribution rates of soil water content at sowing to grain yield under DS were 23–25%. Thus, drill sowing in summer fallow should be adopted for high water storage and yield stability.