Determining the water productivity of maize is of great significance for ensuring food security and coping with climate change. In 2018 and 2019, we conducted field trials in arid areas (Changji), semi-arid areas (Qitai) and semi-humid areas (Xinyuan). The hybrid XY335 was selected for the experiment, the planting density was 12.0 × 10⁴ plants ha⁻¹, and five irrigation amounts were set. The results showed that yield, biomass, and transpiration varied substantially and significantly between experimental sites, irrigation and years. Likewise, water use efficiency (WUE) for both biomass (WUE_B) and yield (WUE_Y) were affected by these factors, including a significant interaction. Normalized water productivity (WP*) of maize increased significantly with an increase in irrigation. The WP* for film mulched drip irrigation maize was 37.81 g m⁻² d⁻¹; it was varied significantly between sites and irrigation or their interaction. We conclude that WP* differs from the conventional parameter for water productivity but is a useful parameter for assessing the attainable rate of film-mulched drip irrigation maize growth and yield in arid areas, semi-arid areas and semi-humid areas. The parametric AquaCrop model was not accurate in simulating soil water under film mulching. However, it was suitable for the prediction of canopy coverage (CC) for most irrigation treatments.

Sustainable agricultural intensification requires innovative approaches to simultaneously enhance productivity and mitigate environmental impacts—a challenge critical to global food security and climate change mitigation. The traditional fertilization system, with a single application of nitrogen fertilizer, while effective for crop yields, often leads to soil organic carbon (SOC) depletion, whereas green manure systems offer a dual benefit of nitrogen supply and SOC sequestration potential. However, the mechanisms by which green manure substitution enhances soil carbon sequestration (SCS) remain systematically underexplored in comparison to chemical fertilization. This review systematically examines (1) the mechanisms underlying SOC sequestration, (2) SOC losses associated with traditional fertilization practices, and (3) the theoretical foundation and practical applications of green manure as a nitrogen fertilizer substitute. We provide an in-depth analysis of the mechanisms through which green manure substitution drives SCS. Furthermore, we identify three critical areas for future investigation: (i) optimization of green manure management strategies to enhance SCS efficiency; (ii) comprehensive assessment of green manure’s ecological benefits through long-term, multi-scale studies; and (iii) evaluation of green manure’s climate change adaptation capacity and carbon sequestration potential across diverse climatic scenarios. These findings fundamentally advance our understanding of green manure’s role in sustainable agriculture by establishing its dual function as both a nitrogen source and carbon sequestration driver. In addition, these insights have immediate relevance for agricultural policy and practice, particularly in regions where soil health and carbon storage are prioritized alongside crop yield.

Legume green manure incorporation offers a potential pathway for sustainable cropping in arid irrigated areas. This study aimed to determine whether water and nitrogen inputs could be concurrently reduced without compromising maize productivity under this practice. A two-year field experiment (2024–2025) was conducted using a split-plot design with three irrigation levels (I1: 4045, I2: 3240, I3: 2430 m³·ha⁻¹) and three nitrogen rates (N1: 360, N2: 288, N3: 216 kg·ha⁻¹). Compared with conventional management (I1N1), 20% co-reduction in water and nitrogen (I2N2) maintained stable leaf area index (LAI), net photosynthetic rate (P_n), transpiration rate (T_r), DM, and GY, while significantly increasing water use efficiency (WUE) by 7.6% and nitrogen use efficiency for grain yield (NUtEg) by 11.7%. Excessive water reduction (I3) or nitrogen reduction (N3) significantly inhibited growth and reduced yield (p < 0.05). Soil water content under I2N2 did not differ significantly from I1N1 in the 0–110 cm profile, and soil total nitrogen remained higher at silking.) Structural equation model (SEM) revealed SWC and STN indirectly affected P_n and T_r via regulating LAI and SPAD (path coefficients: 0.48–0.62), which drove DM accumulation and determined GY (R² = 0.81). These short-term results suggest that moderate water-nitrogen reduction with green manure can sustain yield while improving resource efficiency, offering a promising practice for arid irrigated maize systems, though longer-term validation is needed.

Excessive chemical fertilizer and low N use efficiency constrain mulched drip irrigated maize production in China’s Hexi Oasis, while livestock manure is underutilized. Recycling biogas residue and slurry offers a solution, but optimal substitution ratios under reduced N remain unknown. We conducted a two year field experiment with two reduced N rates (15% and 30% relative to the conventional local rate of 360 kg N ha⁻¹) combined with biogas residue replacing basal N at rates of 25%, 50%, or 75% and biogas slurry replacing 50% of topdressed N. The best performing treatment (N₁25: 15% N reduction + 25% residue substitution) significantly increased LAI (11.77%), SPAD value (10.98%), dry matter (2.51%), leaf and stem N translocation (13.81% and 10.00%, respectively), leading to a 2.14% yield gain. NUE, ANUE, and PFPN improved by 27.4%, 19.5%, and 18.5%. Path analysis revealed that N₁25 enhanced canopy photosynthesis and dry matter translocation, increasing grain weight. These findings demonstrate that integrated N reduction with biogas substitutes enhances productivity and N efficiency while recycling organic waste. Therefore, under the present experimental conditions, N₁25 represents a promising strategy for simultaneously improving grain yield and nitrogen use efficiency; however, multisite and long term validation is warranted to substantiate its broader applicability.

Enhancing both grain yield and water productivity (WP) under water scarcity is a critical challenge for sustainable maize production. Conventional farmer practices—characterized by low planting density (D₁: 9.0 × 10⁴ plants·ha⁻¹) and excessive irrigation (I₅)—often limit the potential for both. To advance the high-density production system enabled by precision stage-specific regulation (HD-PSR), we conducted a multi-region field experiment across arid to sub-humid climates in Xinjiang, China. Treatments included region-specific full irrigation (I₅) and four deficit levels (I₁–I₄, each reduced by 90 mm relative to I₅). Compared with the conventional model (D₁ + I₅), the HD-PSR-based optimized model (D₂, 12.0 × 10⁴ plants·ha⁻¹ plus regulated deficit irrigation, I_opt) synergistically increased grain yield by 18.8–25.0% and WP by 8.7–20.0% across sites, while saving 11.1–50.0% of irrigation water. This synergy was driven by improved canopy coverage and sustained dry matter accumulation under precision-regulated irrigation that maintained soil water storage at ~70% of field capacity, thereby reducing non-productive water losses (soil evaporation in arid/semi-arid areas and excessive transpiration in the semi-humid area). Our study provides a quantitative irrigation module for the HD-PSR and identifies a translatable soil water threshold (~70% FC) for sustainable intensification of maize in water-limited regions.