[Objective]Zn(Zinc)deficiency triggers'hidden hunger'.Enhancing Zn concentration in wheat grains and Zn fertilizer use efficiency through biofortification can effectively increase dietary Zn intake,thereby improving human Zn nutritional status.[Method]The study subjects were two distinctive colored-grain wheat varieties:'Taihei 5'(purple-grained)and'Tailan 8'(blue-grained).A two-year field experiment was conducted from 2022-2024 in Taigu District,Jinzhong City,Shanxi Province.Foliar Zn application was performed at 3-5 days after the flowering of colored-grain wheat(Over 50%of spikes in the wheat field had lemma and palea separation at middle-upper florets while anthers were dehiscing).Five Zn concentration treatments were applied:Zn0(deionized water),Zn1(Zn concentration:440 mg·L-1),Zn2(Zn concentration:587 mg·L-1),Zn3(Zn concentration:733 mg·L-1),Zn4(Zn concentration:880 mg·L-1).Through analysis of grain yield and Zn concentrations in grains,leaves,and stems across multiple post-anthesis periods for both colored-grain wheat types,Zn concentration variation dynamics,Zn accumulation and partitioning characteristics,Zn utilization efficiency,grain Zn biofortification index and grain Zn harvest indices were quantitatively analyzed to evaluate their Zn biofortification efficacy.[Result]Foliar Zn application significantly increased Zn concentrations in all organs and grain yield of colored-grain wheat,The Zn3 treatment produced the highest grain Zn concentration(21.79-67.90 mg·kg-1)and peak grain yield(4 937.36-5 097.27 kg·hm-2).Grain Zn accumulation reached its optimum(251.30-301.54 g·hm-2)under the Zn3 treatment,while Zn concentrations and accumulation in leaves and stems increased linearly with rising application concentrations.With increasing Zn application concentrations,the grain Zn accumulation proportion showed a declining trend(10%-18%),while the leaf Zn accumulation proportion rose to 66%,and stem Zn accumulation remained at 23%-30%.Furthermore efficient synergy in Zn utilization efficiency across all organs of colored-grain wheat was achieved under Zn3 treatment(5.68%-7.70%).With increasing Zn application concentrations,the grain Zn biofortification index and Zn harvest index declined.Compared with Zn1,other Zn treatments reduced the grain Zn biofortification index by 12.50%-47.02%,while relative to the control(Zn0),all Zn treatments decreased the Zn harvest index by 23.66%-60.44%.'Taihei 5'outperformed'Tailan 8'in grain Zn concentration,accumulation,utilization efficiency,and biofortification performance.Possibly influenced by precipitation,both types of colored-grain wheat performed better in the second growing season[Conclusion]Post-anthesis foliar Zn application effectively regulated Zn accumulation and partitioning in colored-grain wheat.The combination of purple-grained wheat varieties and foliar Zn application at 733 mg·L-1 achieved the optimal balance between grain Zn concentration and Zn utilization efficiency in colored-grain wheat systems.

Introduction:In the water-limited Loess Plateau of China, wheat productivity faces severe constraints. This study investigates the physiological and quality determinants of yield and protein content across multiple winter wheat cultivars to identify key breeding targets for dryland systems. Methods:Eleven cultivars were analyzed for soil water storage dynamics, dry matter accumulation and translocation, nitrogen use efficiency, and grain quality parameters, including volatile flavor compounds. Results:High yield potential was driven by superior pre-anthesis nitrogen assimilation and substantial post-anthesis dry matter remobilization. The highest-yielding cultivar (YH-805) achieved this through a greater number of grains per spike. Conversely, higher grain protein content (e.g., in YH-618) was linked to enhanced post-flowering nitrogen translocation. A fundamental yield-protein trade-off was confirmed. The medium-yield, high-protein cultivar YH-115 exhibited the most favorable flavor profile, associated with key volatile compounds like octanal and hexanal. Discussion:The results demonstrate that yield and quality are governed by distinct pre- and post-anthesis resource allocation strategies. Targeted breeding for specific traits-such as pre-anthesis nitrogen uptake for yield or post-anthesis nitrogen translocation for protein-can help optimize for either enhanced productivity or superior end-use quality in dryland wheat systems.

BACKGROUND:In winter wheat, low nitrogen (N) and zinc efficiency limits production. Although combined application boosts yield and grain zinc, the underlying mechanisms and optimal rates remain unclear. This study aims to uncover these mechanisms and identify the best management strategy. RESULTS:Applying N at 240 kg ha-1 significantly enhanced post-anthesis glutamine synthetase (GS) and glutamate synthase (GOGAT) activities in flag leaves compared to 180 kg ha-1, promoting pre-anthesis N translocation and post-anthesis N accumulation. This extended the grain-filling period by 0.8-1.44 days, increased the maximum grain-filling rate by 3.11-12.30% and boosted yield by 6-8% through improvements in spike number, grains per spike and thousand-kernel weight. Grain Zn concentration and Zn use efficiency increased by 12-21% and 35%, respectively, but N uptake and utilization efficiency declined. Foliar Zn application at anthesis (2.4 kg ha-1) further enhanced GS and GOGAT activities during grain filling, increased post-anthesis N accumulation and improved the grain-filling rate by 0.63-9.96%. This raised thousand-kernel weight by 0.70-10.97% and yield by 0.71-5.78%. Grain Zn concentration reached 40.59-41.12 mg kg-1, whereas N uptake efficiency and partial factor productivity of N increased by 1.94-11.61% and 0.71-5.78%. Correlation analysis indicated strong associations of yield with grain N accumulation, post-anthesis GS/GOGAT activities and N partial factor productivity, whereas grain Zn concentration correlated with Zn use efficiency and post-anthesis N metabolism. CONCLUSION:The combination of N at 240 kg ha-1 and foliar Zn at 2.4 kg ha-1 during anthesis optimized post-anthesis N metabolism, prolonged grain filling and synergistically improved yield, grain Zn content and NZn efficiency. © 2026 Society of Chemical Industry.

Phosphorus fixation represents a primary constraint limiting the agronomic efficiency of phosphate fertilizers in calcareous soil. Rapeseed roots secrete amounts of organic matter, which can mobilize and decompose insoluble phosphorus in the soil. However, the activation mechanism of sparingly insoluble phosphorus in calcareous soils by rapeseed rhizosphere microorganisms remains unclear. This study aimed to screen and identify phosphate-solubilizing microorganisms from the rapeseed rhizosphere of calcareous soil, and to elucidate their key metabolic pathways for activating insoluble phosphorus. The results demonstrated that (i) fourteen dominant phosphate-solubilizing strains were isolated from rapeseed rhizosphere soil. Among these, Advenella alkanexedens was verified to significantly promote wheat growth and increase soil available phosphorus content. (ii) The culture condition optimization and functional characterization for Advenella alkanexedens revealed that its optimal growth temperature was 30°C, with an initial pH of 7. Its phosphate-solubilizing ability was regulated by Mg2+, K2+, and Ca2+ ions, and the strain exhibited considerable salt tolerance and the ability to produce siderophores. (iii) Advenella alkanexedens increased soil available phosphorus content by 11.49%-81.91% and elevated phytase activity by 36.87%-82.49%. Correlation analysis indicated that soil available phosphorus and phytase activity were significantly positively correlated with Ca2-P, Ca8-P, and Al-P fractions. (iv) Amino acids and organic acids were identified as the key metabolites influencing the phosphate-solubilizing function of Advenella alkanexedens. The KEGG pathway analysis showed these metabolites were primarily enriched in β-alanine metabolism and arginine and proline metabolism pathways. Our findings confirm that Advenella alkanexedens not only promotes crop growth but also significantly increases labile P fractions (Ca2-P, Ca8-P, Al-P) while reducing more stable forms (Ca10-P), thereby enhancing soil phosphorus use efficiency. This study holds important implications for planting rapeseed to activate insoluble phosphorus in soil, to reduce phosphate fertilizer application, and to promote sustainable utilization of soil phosphorus resources. Furthermore, it provides a theoretical foundation for developing agricultural microbial inoculants.IMPORTANCEOur results confirm that Advenella alkanexedens not only benefits crop growth but also converts insoluble phosphates (O-P, Ca10-P) into highly active inorganic phosphorus components, thereby enhancing the utilization efficiency of soil phosphorus. This study was of great significance in activating the insoluble phosphorus in the soil, reducing the input of phosphate fertilizers, achieving the sustainable utilization of phosphorus resources, and protecting the environment. Additionally, it provided a basis for developing agricultural microbial agents.

[Objective]To clarify the precise management of water and fertilizer based on spring growth stages,and to reveal the mechanism of optimizing yield components through efficient light energy utilization,thereby contributing to the increase in grain yield of winter wheat.[Method]The field experiment was conducted at the TaiGu Winter Wheat Experimental Station in Jinzhong,Shanxi Province,from 2021 to 2023.A split-plot design was adopted,with two spring nitrogen top-dressing rates(90 kg·hm-2,N90;120 kg·hm-2,N120)as main plots,and four top-dressing times after regreening(10 d,20 d,30 d,and 40 d)as sub-plots.Through systematic surveys of tillering dynamics and measurements of canopy photosynthetic active radiation interception,combined with the fitting of the grain-filling process using the Richards model,we systematically analyzed the effects of different nitrogen topdressing treatments on the winter wheat population structure,canopy light distribution,and grain-filling characteristics.Correlation analysis was conducted to clarify the intrinsic relationships among population photosynthetic performance,tillering dynamics,and yield components.[Result]Compared with other treatments,applying 120 kg·hm-2 of nitrogen at 30 days after regreening reduced the peak tiller number,delayed the occurrence of the tillering peak,and decreased the tiller senescence rate by 28%-43%.It also decreased the number of ineffective tillers(50-70 days after regreening)by 15%-30%,thereby significantly increasing the tiller-to-spike ratio by 10%-23%.Significantly increased the canopy PAR interception rate and extinction coefficient during the anthesis and mid-grain-filling stages,while significantly reducing the decline rate of lower-layer PAR interception during the anthesis-to-grain-filling period.Significantly increased the theoretical maximum 1000-grain weight,initial filling potential,average and maximum grain-filling rates,the time to reach maximum grain-filling rate,the duration of the gradual-increasing phase,and the grain-filling rates during the rapid-increasing and slow-increasing phases;significantly increased spike length by 3%-10%,spike weight by 8%-14%,and seed setting rate by 2%-12%.Significantly increased the number of spikes by 4%-10%,the number of grains per spike by 3%-10%,and the 1000-grain weight by 5%-10%,resulting in an increase in grain yield of 7%-20%.The Population Photosynthetic Potential during the booting-anthesis period showed a significant positive correlation with the tiller number at 45-70 days after regreening;meanwhile,the tiller number at 45-70 days after regreening was significantly and positively correlated with the spike number at maturity.The radiation interception rate in the lower layer of the canopy at the mid-grain-filling stage showed a significant positive correlation with the tiller number at 50-55 days after regreening;meanwhile,the tiller number at 50-55 days after regreening was significantly and positively correlated with the number of grains per spike.The PAR interception rate in the canopy at anthesis and mid-grain-filling stages showed a positive correlation with the tiller number at 50-55 days after regreening;meanwhile,the population photosynthetic potential during the booting-anthesis period was significantly and positively correlated with the tiller number at 50-55 days after regreening,and the tiller number at 50-55 days after regreening was significantly and positively correlated with the 1000-grain weight.[Conclusion]Application of 120 kg·hm-2 nitrogen topdressing 30 days after regreening achieved a synergistic improvement in the number of effective spikes,grains per spike,and 1000-grain weight,thereby significantly increasing grain yield.This was realized by suppressing and delaying the tillering peak,optimizing the post-anthesis canopy light distribution,and enhancing the grain-filling process.Furthermore,correlation analysis further confirmed that the population photosynthetic potential before anthesis and the canopy photosynthetic performance after anthesis,by influencing spikelet formation and grain filling,jointly determined the final grain yield.This study provides a critical nitrogen management strategy for achieving high-yield and efficient cultivation of winter wheat in the irrigation area of the Loess Plateau by improving the population photosynthetic efficiency through integrated water and fertilizer management.

Dryland wheat production on the Loess Plateau is constrained by water scarcity and low nitrogen use efficiency. A three-season field experiment (2022–2025) evaluated the combined effects of fallow tillage (subsoiling, SS; no-tillage, NT) and nitrogen rates (0, 90, 135, 180, 225 kg ha⁻¹) in a split-plot design. SS significantly increased soil water storage change during fallow (ΔSWSf) in the 100–200 cm layer by 37.4 mm, leading to a 101.4% increase in post-anthesis deep soil water use. When combined with optimized N (135–180 kg ha−1), SS reduced 0–200 cm nitrate residue compared to NT, whereas excessive N (225 kg ha−1) increased deep leaching risk. SS with optimized N also enhanced post-anthesis flag leaf photosynthesis, nitrogen metabolism enzyme activities, and antioxidant capacity, thereby promoting dry matter and nitrogen accumulation, especially in dry seasons. SS with 180 kg N ha−1 in the wet and normal seasons and 135 kg N ha−1 in the dry season achieved the highest grain yield of 7114, 5699, and 5211 kg ha−1 and water productivity of 13.55, 13.39, and 13.04 kg ha−1 mm−1. SS increased agronomic efficiency, recovery efficiency, and partial factor productivity of N, but these efficiencies declined significantly when N rates exceeded the optimum across all season types. Partial least squares path model identified ΔSWSf as the primary yield driver and flag leaf traits as a key regulator reducing nitrate residue. In conclusion, SS with optimized N rates (135–180 kg ha−1) synergistically improves yield, resource efficiency, and environmental sustainability, but excessive N under wet conditions should be avoided to prevent deep nitrate accumulation.

Excessive basal nitrogen (N) inputs and improper water management limit both wheat yields and N use efficiency. Thus, a field experiment was conducted for two years to evaluate whether optimizing water and N management could reduce basal N inputs, improve N uptake and utilization efficiencies (NUpE and NUtE), and achieve high yields. A split-plot design was employed with water and N management as the main plots (conventional water and N management, CM; and drip fertigation, DF) and basal N rates as the sub-plots (150, 125, 100, 75, 50, 25, and 0 kg ha(-1), designated as B150, B125, B100, B75, B50, B25, and B0, respectively), while maintaining a fixed topdressing N rate of 150 kg ha(-1). The results showed that DF increased the average yield by 12.7-15.9% compared with CM due to improvements in N absorption, tillering ability, ear and grain numbers, leaf area index, and biomass production. More importantly, DF reduced the sensitivity of yield to the basal N rate. Halving the basal N rate from B150 to B75 reduced the yield by 4.1-4.3% under DF (P > 0.05), but the yield loss was 10.9-11.4% under CM (P < 0.05). Under DF, the increased grain weight compensated for the reduced grains m(-2), but under CM, the 17.3-17.8% reduction in grains m(-2) was not fully offset by the increase of 8.4-9.9% in the grain weight. In addition, the increased NUpE and NUtE also contributed to relatively high yield at B75 under DF. Furthermore, the NO3--N residue under DF was 7.9-9.8% lower at B75 than at B150. In conclusion, DF combined with a reduced basal N rate is effective for increasing wheat production, while decreasing soil nitrate residual levels to mitigate environmental impacts.

Contents: Straw and organic fertilizers are abundant organic resources in China. However, their impacts on crop productivity and environmental pollution are unclear, leading to underutilization. Methods and objectives: In 2020, a long-term experiment was conducted on the Loess Plateau to study the effects of organic resources on wheat (Longjian 301) productivity and environmental benefits to promote sustainable agricultural development. Four treatments were tested: (1) CK: unfertilized with complete straw removal; (2) FM: conventional inorganic fertilization with straw removal; (3) SI: straw incorporation combined with inorganic fertilization; and (4) SIOM: straw incorporation with 10 % organic substitution of inorganic fertilizer. Results: Organic resources regulated wheat productivity and environmental benefits by changing the soil properties, and SIOM was most effective. Straw decreased N2O emissions but increased NH3 emissions, and organic fertilizer decreased N2O and NH3 emissions. Compared with FM, SIOM increased the nitrogen use efficiency and wheat yield by 42.63 % and 28.31 %, respectively, reduced NH3 and N2O emissions by 24.18 % and 41.75 %, and decreased the partial carbon footprint (0.21 kg CO2-eq ha(-1) year(-1)) and nitrogen footprint (17.91 g N-eq kg(-1) grain) by 43.99 % and 26.40 % (all P < 0.05). SIOM obtained the highest net ecosystem economic benefit (NEEB, 6249.49 CNY ha(-1)), which was 37.89 % and 9.27 % higher compared with FM and SI (P < 0.05). Conclusion: Long-term organic resource incorporation enhanced the wheat productivity and mitigated environmental pollution, ultimately increasing NEEB, which was associated with the improvement of soil properties.

To address the issue of inefficient soil water utilization in dryland wheat fields, caused by a mismatch between summer fallow precipitation and crop growth periods, implementing fallow-period tillage was crucial for conserving water and enhancing yield. However, there was a lack of comprehensive evaluations of the impact of different tillage practices on soil functional quality based on multidimensional indicators, and the relationship between yield and soil functional quality remained unclear. This study established three treatments during the summer fallow period: no tillage (FNT), subsoiling tillage (FST) and plowing tillage (FPT). We determined the soil water-stable aggregates particle size distribution and stability, aggregate organic carbon (AOC) content, soil organic carbon (SOC) content and storage (SOCs), as well as winter wheat yield. Using the Z-score method, we integrated the soil's physical and chemical indicators to perform a comprehensive evaluation of different tillage practices. The results showed that FNT significantly enhanced soil aggregate stability in the 0-30 cm soil depths compared to FST and FPT (p < 0.05), which was primarily attributed to a substantial increase in the content of >2 mm aggregates. Meanwhile, FNT resulted in significantly higher SOCs within the 0-50 cm profile, with increases of 8.1% and 5.8% compared to FST and FPT (p < 0.05), respectively. This was primarily due to elevated SOC content and higher AOC contents within the 2-0.25 mm and >2 mm aggregates in the topsoil layer. In contrast, FST significantly increased grain yield compared to FNT and FPT, by 16.7% and 15.0% (p < 0.05), respectively, which was associated with higher ear number and ear grains. A comprehensive evaluation using the Z-score method revealed that FNT achieved the highest soil functional quality score across the five layers. Therefore, no tillage during the summer fallow can enhance soil functional quality, primarily due to its positive impact on soil structure and carbon sequestration, but may not immediately increase crop yield.

Improving yield and nitrogen-use efficiency (NUE) is essential for dryland winter wheat. We hypothesized that cultivars classified as high-yield and high-efficiency (HH) achieve superior performance through coordinated root-canopy traits that enhance water and nitrogen acquisition, sustain post-anthesis photosynthesis, and maintain assimilate and nitrogen remobilization. A two-year field experiment was conducted using ten regionally representative cultivars, which were grouped into HH, high-yield and low-efficiency (HL), low-yield and high-efficiency (LH), and low-yield and low-efficiency (LL) types based strictly on grain yield and NUE. Measurements included yield components, grain-filling, dry matter accumulation and partitioning, soil water use, nitrogen uptake and remobilization, and root-canopy structural traits. HH increased yield by 41.5% and water-use efficiency by 24.1% relative to LH, supported by denser shallow roots, moderate deeper-root development, higher leaf area index, and more compact canopies. HH also exhibited stronger post-anthesis dry matter and nitrogen translocation, resulting in a larger grain number per unit area and improved sink capacity. Correlation analyses further demonstrated positive associations among root-canopy traits, water and nitrogen dynamics, and yield formation. These results support the hypothesis that a coordinated root-canopy structure underlies the superior yield and NUE performance of HH cultivars in dryland systems, providing a physiological basis for cultivar improvement.

Context: Green manure (GM) can potentially increase crop yields by enhancing the soil properties to solve the contradiction between soil degradation and food security. However, the effects of GM on the soil properties and crop yields in variable environments, and the relationships between them remain unclear, and the key factors need to be identified. Moreover, global prediction are lacking of the effects of GM on crop yields. Objectives and methods: Therefore, we conducted a meta-analysis using 5125 pairs of data observations to study the overall effects of GM and environmental variability on the soil properties and subsequent crop yields, and to establish their relationships by introducing the soil quality index (SQI). In addition, we used a machine learning model to predict the global changes in SQI and the yields of maize, wheat, and rice under GM. Results: GM significantly increased the soil C, N, P, and K contents, and enzyme activities by 5.34-40.02 %, 8.81-32.39 %, 4.54-10.02 %, 1.18-8.74 %, and 9.49-19.76 %, respectively, increasing SQI by 16.96 %. The fundamental physical and chemical features of soil, duration of GM application, and climatic conditions significantly affected the improvements in the soil properties under GM. The initial total nitrogen (TN) content of the soil and duration of GM application were the two main factors associated with the effect of GM on SQI. When the initial soil TN content was lower than 0.75 g kg-1 and the GM application duration exceeded 15 years, SQI increased by 26.60 % and 19.94 %, respectively. GM significantly increased SQI by enhancing the soil properties to eventually increase the crop yield by 3.48 %. GM duration was the most important factor associated with the crop yield, and GM significantly increased the crop yield by 18.72 % when the duration exceeded 15 years. However, when the application duration is less than 5 years, the increase is only 2.10 %. The global machine learning model predicted that GM can potentially increase the SQI and crop yield by 23.98 % and 6.35 %, respectively. Conclusion: Therefore, we conclude that applying GM as a green fertilization strategy can increase crop yields by enhancing SQI, and its effects on increasing yields are greater in areas with insufficient soil fertility and longterm planting. Implication: This study highlights the importance of GM for farmland production. SQI was used to establish the relationship between soil quality and crop productivity, and we predicted the potential of GM for improving the global SQI and crop yields.

Phosphorus deficiency in soil limits crop yields, especially in calcareous soil in arid and semi-arid areas of the Loess Plateau. Brassica napus L. can activate insoluble phosphorus in soil; however, the specific inorganic phosphorus components activated by rapeseed remain unclear. Field experiments were conducted in 2020, with rapeseed planted during the summer leisure period, to investigate the effect of rapeseed on phosphorus availability both before and after returning to the soil. Rapeseed was returned to the soil at two timings prior to winter wheat sowing: at flowering (F0) and 10 days after flowering (F10). The following treatments were applied: CK (no plants or fertiliser), N0P0 (no fertiliser), N150P0 (only N fertiliser), N150P60 (N + P2O5 [60 kg/ha]) and N150P120 (N + P2O5 [120 kg/ha]). Planting green manure during the summer fallow period after winter wheat harvest. Although rapeseed cultivation depletes the soil inorganic phosphorus pool, its incorporation increases soil total phosphorus and available phosphorus content by 14.3%-38.9%, respectively. The N150P60F0 treatment significantly enhances soil available phosphorus and alkaline phosphatase activity, thereby promoting phosphorus availability. After incorporation, the content of more active Ca2-P and Ca8-P in the soil increased, whereas the less soluble phosphorus fractions such as Al-P, Fe-P and O-P decreased. Early incorporation helps reduce the formation of poorly available Ca10-P, thereby enhancing soil phosphorus availability. N150P120F0 significantly increased soil bacterial and actinomycete counts, whereas fungal abundance was highest under the N150P60F0 treatment. Bacterial abundance showed a significantly positive correlation with soil available phosphorus and active phosphorus fractions (Ca2-P, Ca8-P), suggesting that bacteria play a key role in the phosphorus activation process driven by rapeseed straw return. Our results provide a theoretical basis for improving soil properties and enhancing soil phosphorus availability through rapeseed returning, thereby promoting efficient phosphorus utilisation by subsequent crops.

Under accelerating climate change, elevated atmospheric CO2 (e[CO2]) presents a substantial challenge to nitrogen (N) cycling in agricultural systems. This study elucidated the mechanistic role of biochar in regulating soil N transformations and plant N acquisition under e[CO2] conditions through a three-year pot experiment (2019-2022) with wheat. Using 15N isotope tracing combined with metagenomic sequencing, we examined the interactions between two CO2 concentrations (a[CO2] 400 μmol mol−1 vs. e[CO2] 600 μmol mol−1) and 2% (w/w) biochar amendment. Our results demonstrated that under e[CO2], biochar application reduced the incorporation of fertilizer-derived N into the recalcitrant heavy fraction organic N (HFON) by 39.4%, while enhancing the content of native soil-derived N in the light fraction N (LFON) by 34.0%. Concurrently, biochar promoted the formation of micro-aggregates (<0.25 mm) and particulate organic N (PON) by 37.3 and 13.2%, respectively. Metagenomic analysis revealed that biochar under e[CO2] suppressed the relative abundance of key N-cycling genes (involved in assimilation, nitrification, and nitrate reduction) that were upregulated under a[CO2] condition. These physicochemical processes, coupled with microbial modulation, resulted in a 52.6% reduction in soil NO3--N accumulation and a significant increase in aboveground N uptake. Structural equation modeling indicated that biochar counteracted the adverse effects of e[CO2] on micro-aggregate stability and N-cycling gene abundance. Synergistically, biochar enhanced the uptake of fertilizer-N and native soil-N by 30.8% and 111.4%, respectively, under e[CO2], leading to a 55.4% increase in grain N accumulation. Our findings demonstrate that biochar is an effective amendment for mitigating e[CO2]-induced N limitation by redistributing N from recalcitrant to labile pools, enhancing N bioavailability, and ultimately supporting crop productivity in future CO2-enriched agroecosystems.

Contents: Deep fertilization (DF) can enhance crop productivity while decreasing nitrous oxide (N2O) and ammonia (NH3) emissions. However, global evaluations are lacking of the effects of DF on crop productivity, and N2O and NH3 emissions. In addition, the key factors involved are unclear and the global adoption potential of DF remains uncertain. Objectives and methods: Thus, we conducted a meta-analysis to quantify the responses in term of crop productivity and gaseous nitrogen losses to DF using 1336 observations from 107 peer-reviewed articles, and determined the key factors involved and global potential of DF using random forest and machine learning models. Results: Meta-analysis showed that DF increased the crop yield and nitrogen utilization efficiency (NUE) by 13.88 % and 36.27 %, respectively, and reduced nitrous oxide (N2O) and ammonia (NH3) emissions by 34.18 % and 69.68 %. The increased crop yield and decreased N2O and NH3 emissions reduced the yield-scaled N2O and NH3 emissions by 44.96 % and 72.49 %, respectively. Random forest modeling identified climate as the most important factor, and DF has a greater potential for enhancing crop productivity with lower environmental costs in lower latitude areas. Machine learning modeling predicted that DF could increase the global crop yield and NUE by 33.93 % and 24.70 %, respectively, and decrease N2O and NH3 emissions by 29.50 % and 72.48 %. Conclusion: DF can achieve the win-win goal of economic and environmental benefits by producing more grain with lower environmental costs, and thus the DF strategy should be applied in lower latitude areas globally. Implication: This study focused on the trade-off between crop productivity and environmental pollution, and showed that higher grain yields can be obtained with lower gaseous nitrogen losses under DF.

Drought stress inhibits quinoa (Chenopodium quinoa Willd.) seed germination and seedlings growth, significantly affecting yield and quality. Nevertheless, the molecular mechanisms underlying quinoa’s drought stress response are not yet fully elucidated. Therefore, a multi-omics analysis of the response to drought stress was conducted using two drought-resistant quinoa varieties (LL1 and LQ18) subjected to normal (CK) and severe (DS2, 20

Understanding how tillage-residue practices regulate water balance is essential for sustaining rain-fed agriculture winter wheat production on the Loess Plateau. This study integrated a three-year field experiment (2020−2023) with a 38-year (1978–2016) WHCNS simulation to compare the effects of no-tillage with surface straw mulching (NT) and rotary tillage with straw incorporation (RT) on soil water dynamics and winter wheat yield. The WHCNS model achieved acceptable performance for soil moisture, leaf area index, and biomass, but failed to accurately capture yield losses triggered by extreme pre-sowing-to-early-seedling-stage waterlogging. Compared with RT, NT suppressed soil evaporation, promoted transpiration and infiltration, and improved water use efficiency, grain yield and inter-annual yield stability. Correlation and covariance-based structural equation modelling (CB-SEM) revealed divergent fallow-rainfall utilization mechanisms between the two systems. Under RT, high bare-soil evaporation during hot July–August largely dissipated early fallow rainfall, so pre-sowing initial soil-water storage (ISW) and yield strongly relied on late-fallow September precipitation. By contrast, surface straw mulching under NT reduced non-productive evaporation, enabling early-season July–August fallow rainfall to effectively recharge soil water; September rainfall still exerted positive effects, yet August rainfall made meaningful contributions to ISW. For both treatments, fallow rainfall regulated grain yield mainly via the mediation chain: fallow rainfall → pre-sowing ISW → water stress → wheat yield. This study provides theoretical insights for adopting NT as a sustainable water-saving management practice for semi-arid rain-fed wheat regions, though simulation-derived findings require further field validation.

The Loess Plateau is a principal dryland winter wheat production region in China, where unreasonable sowing rate and fertilization management limit yield and quality. A two-factor split-plot experiment was conducted during 2019-2021 with three sowing rates (150 kg ha-1, 180 kg ha-1, 210 kg ha-1) and three fertilization type (CK, OPT, OPT-N). Increasing sowing rate to 210 kg ha-1 significantly improved population tiller, secondary root number, and canopy structure. OPT reduced N input by > 50% but maintained plant growth and delayed leaf senescence. The 180 kg ha-1 rate enhanced canopy light interception at anthesis, while 210 kg ha-1 better sustained post-anthesis chlorophyll content, net photosynthetic rate, and stomatal conductance. Compared with OPT, OPT-N markedly restricted root growth, photosynthesis, and matter accumulation. 210 kg ha-1 + OPT significantly increased 1000-grain weight by 5-11%, grain yield by 1.7-3.7%, total starch by 1.91-5.22%, and flour processing quality. The interaction significantly regulated growth, photosynthesis, yield, and quality. This study demonstrates that 210 kg ha-1 + OPT realizes synchronous improvements in yield, quality, and resource efficiency under reduced N input, providing a green cultivation model for dryland wheat.

Plastic film mulching increases crop yields but elevates greenhouse gas (GHG) emissions. Deep nitrogen fertilization may alleviate this trade-off but direct evidence remains elusive. Thus, we conducted a two-year field experiment (2023–2024) by testing traditional fertilization without mulching (F), deep nitrogen application without mulching (DF), traditional fertilization with mulching (PF), and deep nitrogen application with mulching (DPF) to examine whether deep nitrogen fertilization mitigates GHG emissions under plastic film mulching. The DNDC model was further employed to evaluate the long-term yield improvement and potential for reducing GHG emissions. The results showed that DPF significantly increased the maize yield and reduced GHG emissions by improving the shallow soil water contents and lowering the inorganic nitrogen content. Compared with F, DPF reduced the N2O emissions and global warming potential (GWP) by 36.47% and 43.93%, respectively, while obtaining the highest yield (12,148.22 kg ha–1) and economic benefit (8199.60 CNY ha–1), thereby increasing the net ecological and economic benefits by 78.47%. Compared with PF, DPF increased the maize yield by 8.65% while reducing GWP by 61.81%. DNDC model simulations indicated that DPF increased the yield and maintained GHG emission reductions from 2025 to 2040 under different climate scenarios. However, the mitigation effect weakened during 2041–2100 under DPF, where GWP and GHGI increased by 74.64–105.80% and 35.13–62.50%, respectively, compared with F. Scenario analysis further showed that film mulching partly mitigated the N2O emission risks from long-term deep fertilization as the N2O increases were 25.95–36.23% higher under DF than DPF. Overall, DPF obtained short-term emissions reduction benefits and maintained its relative mitigation advantages under the near-future climate scenario (2025–2040), although its long-term GHG mitigation potential may decline during 2041–2100 according to DNDC simulations.

Delayed sowing of winter wheat is increasingly common in the winter wheat-summer maize rotation system of northern China, yet whether its yield penalty can be mitigated without increasing seasonal water and nitrogen (N) inputs remains unclear. A three-year field experiment was conducted to test whether stage-specific drip fertigation could mitigate yield loss in winter wheat sown 20 d late without increasing total seasonal water and N inputs. Delaying sowing by 20 d under conventional management reduced grain yield by 21.0% relative to wheat sown at the conventional date (CK). The optimized regime (DF4) achieved a yield recovery rate of 100.7%. Grain number per unit area in DF4 was partly restored but remained 5.6% lower than in CK, indicating incomplete sink recovery. Yield recovery was therefore supported by post-anthesis source compensation, evidenced by a 17.0% increase in post-anthesis dry matter accumulation relative to CK and associated with higher post-anthesis N uptake and radiation use efficiency. Although root penetration depth under DF4 remained lower than in CK, root length in the 0-40 cm soil layer was restored to the CK level. DF4 also improved water use efficiency by 11.1% relative to CK while soil water consumption was only 56.4% of that in CK. These findings indicate that stagespecific timing and placement of water-N supply through drip fertigation can mitigate yield loss in winter wheat sown 20 d late by coordinating partial sink recovery with stronger post-anthesis source compensation, without increasing seasonal water or N inputs.