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Optimising the management of water and fertilizer, and fully exploiting the positive effects of the coupling of water and fertilizer, are important ways of achieving high crop yields and promoting the sustainable development of water-efficient agriculture. The objective of this study was to investigate the coupling effects of different irrigation levels and different mixing ratios of slow-release nitrogen fertilizers on the physiological growth characteristics and yield of winter wheat in Guanzhong region under drip irrigation. In this study, field experiments were conducted in two winter wheat growing seasons, 2018–2019 and 2019–2020. The study included three irrigation levels: W1 (60% ETc, where ETc is the evapotranspiration of the crop), W2 (80% ETc), and W3 (100% ETc); and four N fertilizer treatments: U (100% urea), UNS1 (urea: slow-release N fertilizer = 1:1), UNS2 (urea: slow-release N fertilizer = 1:3) and SRF (100% slow-release N fertilizer). Compared to W1 and W2, W3 prolonged the winter wheat leaf functional period, increased leaf area index and net photosynthetic rate (P n), and promoted dry matter accumulation. The total N content of winter wheat decreased by 22.67% and 9.93% under W1 and W2 conditions, respectively. The nitrogen use efficiency (NUE) decreased by 5.87% and 1.97%, respectively, leading to a decrease in yield. Slow-release nitrogen fertilizer (SRF) and its mixture treatments (UNS1, UNS2) increased post-flowering nitrogen uptake in winter wheat compared to U. At the same irrigation level, water use efficiency (WUE) was increased by 34.03%, 13.35%, and 20.86% in the UNS2 treatment compared to U, UNS1, and SRF, respectively. W3UNS2 obtained the highest grain yield: 8026.32 kg hm−2 (2018–2019) and 8993.25 (2019–2020) kg hm−2, with a 9.85–68.24% yield increase compared to other treatments. Und4er the treatments of this study, yield, WUE, and NUE of winter wheat reached 90% of the maximum at irrigation levels of 82.04–91.83% ETc and 59.18–83.67% of slow-release N fertilizer in blended fertilizer. Under water stress conditions, UNS1 and UNS2 can mitigate the effects of water deficit on plant growth and stabilize grain yield. This study provides useful information for optimising water and nitrogen management decisions for winter wheat in semi-arid climatic regions, and contributes to the promotion of sustainable development of wheat production and water-efficient agriculture. • The two-year drip trial was conducted in a sheltered canopy in GuanZhong. • Field trial address in the coupling impacts of irrigation&fertilizer on winter wheat. • Recommended irrigation volumes and mixing ratios were obtained using modelling. • Blended slow-release nitrogen fertilizer can effectively mitigate the drought effects. • 100% ETc with U:SRF = 1:3 is the most recommended irrigation and fertilization option. [ABSTRACT FROM AUTHOR]

• Mulching method and nitrogen type effects on maize yield and gaseous emissions were explored. • No differences in yield and NUE existed between ridge-furrow mulching and straw mulching. • GWP and GHGI increased under ridge-furrow mulching, but decreased under straw mulching. • Urea + NBPT minimized NH 3 volatilization, while Urea + DMPP mitigated N 2 O emission. • Straw mulching with Urea + DMPP was recommended for sustainable dryland maize production. Understanding the comprehensive impact of soil mulching and nitrogen (N) fertilization on agronomy, economy and environment is important for developing sustainable dryland agriculture. A two-year experiment was conducted on dryland maize (Zea mays L.) in a sub-humid but drought-prone climate zone to explore the responses of grain yield, N use efficiency (NUE), economic benefit, ammonia (NH 3) volatilization and greenhouse gas emissions to various mulching methods (NM: non-mulching, SM: wheat (Triticum aestivum L.) straw mulching and RF: ridge-furrow cultivation with plastic film mulching on the ridge) and N types (U: urea, U + CRU: mixture of urea and controlled-release urea at a ratio of 3:7, U + DMPP: urea with 2 % 3, 4-dimethylpyrazole phosphate and U + NBPT: urea with 2 % N -(n -butyl) thiophosphoric triamide). The results showed that RF and SM significantly increased grain yield and NUE, and decreased residual soil mineral N in the 0−200 cm soil layer relative to NM, but the differences in these indices were not significant between RF and SM. The net benefit under SM was comparable to that under RF (1558.5 and 1613.6 USD ha−1). The RF treatment significantly increased global warming potential (GWP) and greenhouse gas intensity (GHGI) by 33.7 % and 20.4 % compared with NM, and by 71.9 % and 67.5 % compared with SM. Compared with urea, U + CRU, U + DMPP and U + NBPT exhibited promoting effect on grain yield and NUE, but decreased residual soil mineral N. Compared with U, U + NBPT and U + DMPP produced much lower NH 3 volatilization and nitrous oxide (N 2 O) emission, respectively. Compared with U, U + CRU also reduced NH 3 volatilization and N 2 O emission, but its economic benefit was 4.9 % lower. Both U + DMPP and U + NBPT exhibited inhibitory effect on methane (CH 4) oxidation, but the CH 4 pattern under U + CRU was inconsistent in the two years. The smallest GWP and GHGI were generally observed under U + DMPP among various N types. The interaction of mulching method and N type had significant influence on grain yield in 2019, CO 2 emission in 2018, N 2 O emission, GWP and GHGI in both years. In conclusion, wheat straw mulching with nitrification inhibitor application achieved better balance among agronomic, economic and environmental benefits for dryland maize in northwest China. [ABSTRACT FROM AUTHOR]

• Irrigation and fertilization effects on grain macronutrient concentrations were explored. • Grain N concentration increased and then decreased with increasing fertilization or decreasing irrigation. • Grain P concentration decreased with the increase in irrigation and fertilization rates. • Grain yield and grain N concentration exhibited a positive relationship. • Mild water deficit and appropriate fertilization improved grain NPK uptake and productivity. Understanding the grain macronutrient uptake requirements with increased grain yield is essential to optimize the irrigation and fertilizer management for high-yield and high-quality wheat production to meet the increasing future food demand. A three-season control experiment was conducted on drip-fertigated winter wheat to investigate the dynamic changes in concentrations of nitrogen (N), phosphorus (P) and potassium (K) under varying water and fertilizer supply regimes. The results showed that the grain N concentration firstly decreased and then increased during grain filling. Specifically, it firstly increased and then decreased with the increase in fertilization rate, while it firstly decreased and then increased with increasing irrigation rate. The average of grain P concentration decreased with the increase in irrigation and fertilization rates. The grain K concentration showed a slow decline trend at the initial grain-filling stage until reaching a stable value at the mid-filling stage, and it increased with the increase in fertilization rate. Grain NPK uptake at maturity increased with increasing fertilization rate under normal irrigation, while the mild water deficit was found to promote grain NPK uptake. Grain yield and grain N concentration exhibited a positive relationship, and both irrigation and fertilization had significant effects on grain yield and NPK uptake. The grain protein content and N:P ratio were mainly affected by fertilization. The mild water deficit and appropriate fertilization rate improved the grain NPK uptake and production of winter wheat with higher grain protein content, which was conducive to the development of water- and fertilizer-saving agriculture. [ABSTRACT FROM AUTHOR]