Commercial organic fertilizer substitution increases wheat yield by improving soil quality

Stricter cadmium and lead standards needed for organic fertilizers in China

This study aims to evaluate the adequacy of China's national standards for heavy metals in organic fertilizers by predicting their concentrations in grains using machine leaning. A comprehensive dataset was collected from literature, including soil properties, organic fertilizer application rates, and heavy metal concentrations in soils, fertilizers, and grains. Ten key variables were used as inputs for machine learning models developed via H2O AutoML, to predict heavy metal concentrations in maize, wheat, and rice grains across China. The models demonstrated strong predictive performance, with R2 values ranging from 0.74 to 0.95. Predictions were generated using the national standard limits for heavy metals in organic fertilizers, along with geographical feature maps of China and the pre-trained machine learning models, to assess compliance with food safety standards. The results indicated that the current national standards for As, Cr, and Hg in organic fertilizers are adequate, as the heavy metal concentrations in grains remained within safe limits nationwide. However, for Cd and Pb, even when organic fertilizers met the national standard limits, the predicted concentrations in grains exceeded safety standards in 39.1-63.6 % and 81.2-95.5 % of agricultural areas, respectively. These findings suggest that the existing national standards for Cd and Pb in organic fertilizers are too lenient to ensure food safety in China. Stricter regulations are therefore necessary to reduce the risk of heavy metal contamination in staple crops and to safeguard public health.

Effect of biostimulants combined with fertilization on yield and nutritional value of wheat crops

BACKGROUND

Bread wheat (Triticum aestivum) is one of the most widely cultivated crops globally; it is nutritionally demanding and may be responsible for soil exhaustion, requiring adequate fertilization to maintain high yields and grain quality. Targeted supplementation of macro- and micronutrients can also be used for the agronomic biofortification of the grains. However, excessive chemical fertilizers can harm the environment and human health, and more sustainable options are therefore required. This work proposes alternative strategies to chemical fertilization, including applying organic fertilizers, biostimulants, and low-impact agronomical practices like foliar spraying, to achieve high yields and enrichment in cationic nutrients calcium, magnesium, and potassium.

EXPERIMENTAL PLAN

The study investigates the impact of different fertilization strategies on wheat yield and nutrient composition using two wheat genotypes characterized by different nitrogen (N) grain content. The plants were grown in pots and underwent differential root fertilization with 50 kg ha-1 N at the tillering stage, comparing mineral and organic products. At heading, foliar treatments (25 kg ha-1 N) were applied, comparing a traditional urea supplementation with a combination of biostimulants from organic wastes and calcium, magnesium and potassium nitrates. The plants were analyzed for their health and the expression of genes for nutrient homeostasis during growth, and for yield and grain quality at harvesting.

RESULTS

The two alternative fertilization approaches positively impacted plant health and yield in both cultivars. Root fertilization accounted for most of the total variance, affecting both early and late-stage yield components; the organic fertilizer produced results comparable to those of the mineral one. Furthermore, the foliar application of base cations and biostimulants led to beneficial changes in nutrient homeostasis and grain mineral content, although the increase in calcium, magnesium and potassium was moderate and genotype-specific.

CONCLUSIONS

This work identifies organic amendments, foliar spraying and biostimulants as alternative and sustainable strategies that can be as effective as chemical fertilization in improving wheat plant health, yield and grain composition. On the other hand, supplementing with cation nutrients at heading showed minimal biofortification benefits. The study emphasizes the importance of considering genotype-specific needs to optimize nutrient uptake and yield across different wheat cultivars.

The Prolonged Application of Organic Fertilizers Increases the Quality and Yield of Tea Crops

The substitution of chemical nitrogen (N) with organic fertilizers in tea plantations has been widely recognized as a strategy to maintain tea yield and improve soil quality, ensuring the sustainability of tea production systems. However, the effects of long-term organic-fertilizer substitution on tea yield and quality, soil properties, and bacterial communities have yet to be fully investigated, and the underlying mechanisms affecting tea yield and quality remain unclear. We conducted a six-year-long field experiment in a tea plantation to investigate the relationships among soil properties, bacterial communities, and the yield and quality of tea. Four treatments were compared: no fertilizer (NF), conventional fertilization (CF), 50% chemical N fertilizer substituted with a microbial organic fertilizer (MF), and 50% chemical N fertilizer substituted with a special organic fertilizer for tea (OF). The results showed that the substitution of organic fertilizers increased the spring tea yield by 6.4%~8.5% and the amino acid content of tea by up to 7.8%, while reducing tea polyphenol levels by 1.2-4.4% compared to CF. The soil quality improved significantly, with total phosphorus rising by 20.0% (MF) and 22.9% (OF), and soil organic matter increasing notably in the MF treatment group. The soil quality index (SQI) improved by 38.6% in the OF treatment group compared to the CF treatment group. Organic treatments reshaped bacterial communities, with the OF boosting Acidobacteriota (36.4%) and Planctomycetota (444.4%), and the MF enriching Actinobacteria and Gemmatimonadetes. Bacterial diversity (Shannon and Chao1 indices) correlated positively with the soil organic matter, total nitrogen, and pH. Changes in microbial communities were driven by pH, soil organic matter, and nitrogen levels. The partial least squares path model analysis confirmed that fertilization indirectly influenced tea yield (67% variance explained) and quality (79% variance explained) via soil properties and bacterial communities. These findings highlight the potential of organic-fertilizer substitution to promote sustainable tea production.

Spatial variation of soil quality limiting indicators in the North China

The identification of cultivated land obstacle indicators and their spatial distribution are preconditions to soil quality and productivity improvement. This study takes the North China as the objective, using principal component analysis (PCA), entropy TOPSIS and obstacle degree (OD) models to establish a systematic evaluation framework to identify the major limiting indicators. Results reveal that 17.0% of the cultivated land faces severe obstacles, 32.1% and 41.9% experience moderate and slight obstacles, respectively. Only 9.0% of the land shows no significant obstacles. Soil pH and the available potassium content (AK) emerged as the most critical limiting indicators, severely affecting 42.0% and 27.2% of the land, respectively. Other indicators like soil total nitrogen (TN), organic matter (OM) content and cultivated-layer thickness (CLT) exhibited slight obstacles, while AP and BD showed no significant limitations. Spatial analysis highlighted that the pH, AP and BD present notable obstacle incidences, followed by OM and TN. Furthermore, spatial overlap of multiple obstacle indicators was also revealed, 87.1% of the area were limited by more than 3 indicators in the North China. The systematic framework proposes an effective tool for guiding the accurate regional cultivated land quality improvement.

Digestate-based organic amendment substitution improves the red soil quality and pakchoi yield

This study investigated the effect of the partially substituting chemical fertilizers (CF) with digestate-based organic amendment (OA) on the amelioration of red soil and the growth of plant. OA with nitrogen substitution rates ranging from 10 % to 40 % were mixed with CF and applied to red soil in a pot experiment. The results indicated that plant growth was significantly enhanced in the treatment where 20 % of the CF was substituted with the OA (OA20) compared to other treatments (p < 0.05). Specifically, the OA20 treatment increased nutrient use efficiency by 54.76 %-100.42 % compared to the treatment using only CF. Furthermore, all OA treatments improved the quality of red soil, with the nutrient content significantly higher in the OA20 group than in the other treatments (p < 0.05). The parameters of total phosphorus (TP), available nitrogen (AN), available phosphorus (AP), and total potassium (TK) significantly affected the soil quality index and plant growth, serving as reliable indicators of soil quality and plant yield. Microbial analysis revealed that the bacterial Chao index and the abundance of microorganisms involved in C-N nutrient cycling, such as Chryseolinea and norank_f__norank_o__Actinomarinales, were highest in the OA20 group. Significant correlations were observed between soil nutrient content (AN, AP, and TK) and the abundance of norank_f__norank_o__Actinomarinales and Chryseolinea, indicating their close relationship with pakchoi growth. Consequently, digestate-based OA may positively affect plant growth in acidic ecosystems by enhancing soil properties, inducing shifts in microbial community composition, and promoting the enrichment of potentially beneficial bacteria. This study provides valuable insights for the enhancement of low-quality soils and the resource utilization of digestate.

Integrated enzyme activities and untargeted metabolome to reveal the mechanism that allow long-term biochar-based fertilizer substitution improves soil quality and maize yield

Biochar-based fertilizer has potential benefits in improving soil quality and crop yield, but the biological mechanisms of soil microbial enzymes interacting with related metabolisms still need to be further investigated. In this study, we combined enzymology and untargeted metabolomics to investigate how biochar-based fertilizer substitution affects soil quality and crop yield by regulating soil enzymes and metabolites in dry-crop farmland. Our findings showed that biochar-based fertilizer substitution enhanced the activities of enzymes related to carbon, nitrogen, and phosphorus cycling, as well as influenced metabolite composition. The identified differential metabolites were enriched into 10 metabolic pathways including linoleic acid metabolism, fatty acid biosynthesis, styrene degradation, ABC transporters, biosynthesis of unsaturated fatty acids, glutathione metabolism, glycine, serine and threonine metabolism, phenylalanine metabolism, pyrimidine metabolism, and arachidonic acid metabolism. Substantial soil quality index improvement was demonstrated, with at least 63.46% increased, under biochar-based fertilizer application, while maize yield was increased by at least 11.16%, compared to conventional fertilizer. Model analysis elucidated mechanisms underlying soil quality and maize yield enhancement, emphasizing the importance of intrinsic regulation through the release of carbon- and nitrogen-related enzymes (e.g., α-glucosidase (α-GC), N-acetyl-β-D-glucosidase (NAG), and leucine aminopeptidase (LAP)) and specific metabolites (e.g., stearic acid, arachidonic acid, and melibiose). Moreover, the key role of soil quality factors was highlighted, with soil organic carbon (SOC), microbial biomass, and available nutrients playing a fundamental role in contributing to the increase in maize yield. The above findings illustrated that biochar-based fertilizer is crucial in modulating soil microbial activity and their metabolites, and their interactions in the soil are essential for promoting improved soil quality and crop yield.

Synergistic effects of Ca-bentonite and in-situ layered double hydroxide formation in ameliorating saline-alkali soil

Improving saline-alkali soil requires cost-efficient and stable technologies. In this study, a novel technology combining in-situ super-stable mineralization with Ca-bentonite was successfully applied to ameliorate saline-alkali soil. A simulation experiment was conducted on Ca-bentonite in solution to validate its feasibility, and in-situ mineralization using humic acid, Fe(NO3)3·9H2O, and Ca-bentonite was performed to treat saline-alkali soil. Additionally, climate modeling and field experiments were employed to investigate the effects of this technology on soil physicochemical properties, crop growth, and crop yield. Under natural conditions, Ca-bentonite can transform into Na-bentonite via cation exchange with Na+. The results from the in-situ mineralization experiment showed that the soil pH, total content of CO32- and HCO3-, Na+ content, electrical conductivity, and bulk density decreased from approximately 10.30 to below 9.00, 7.81 to 1.53 g/kg, 7.20 to 1.51 g/kg, 2741 to 552 μS/cm, and 1.63 to 1.24 g/cm3, respectively. Furthermore, the germination rate of corn increased from 0 % to 83.3 % in climate simulation experiments. Field trials conducted in Inner Mongolia and Jilin, China, further demonstrated significant improvements in soil properties. The seedling emergence rates for corn and oats significantly increased, rising from 0 % to over 85 % and 95 %, respectively. Correspondingly, crop yields reached 323 kg/hm2 for corn and 182 kg/hm2 for oats. Together, our study introduces a novel, cost-effective, and efficient technology to enhance crop growth by mitigating soil salinity and alkalinity. This approach provides a new perspective for alleviating salt-alkali stress and contributes to the advancement of healthy and sustainable agricultural practices.

Migration and retention mechanisms of cadmium in coal gangue reclamation soils: Insights from isotopic fractionation

Heavy metals present in coal gangue can migrate to surrounding soils through atmospheric deposition and rainwater leaching, resulting in soil heavy metal contamination. This study measured the Cd content and isotopic composition (δ114/110Cd) of surface and profile soils in a coal gangue reclamation area in eastern China and examined the impact of coal gangue reclamation on soil physicochemical properties, Cd enrichment, and retention. The results indicate that coal gangue reclamation substantially influences Cd enrichment in the soil (mean: 0.47 mg·kg-1), with notable isotopic fractionation observed at different soil depths. The δ114/110Cd values display complex trends with increasing depth across various soil profiles, and the migration behavior of Cd within the soil profile is primarily governed by iron and manganese oxides. Furthermore, the significant correlation between soil pH and Cd speciation suggests that alkaline conditions markedly affect Cd mobility. Source analysis results reveal that coal gangue is the predominant source of Cd in the study area's soil. Cd pollution is not confined to the surface layers of the upper soil profiles but progressively migrates downward with depth, forming stable residual states with coal gangue oxides. These findings provide a scientific basis and theoretical support for the prevention and remediation of soil Cd pollution in coal gangue reclamation areas.

Silkworm excrement organic fertilizer substitution compound fertilizer improves bamboo shoot yield by altering soil properties and bacterial communities of Moso bamboo (Phyllostachys edulis) forests in subtropical China

To achieve high economic benefits, reapplying fertilizers has been a common business measure taken for harvesting Moso bamboo shoots and timber in the past decades in subtropical China. Applying compound and organic fertilizers is an effective measure to enhance soil fertility and promote plant production. To demonstrate how compound fertilizer (CF) decrement and application of silkworm excrement organic fertilizer (SEOF) effect on soil quality, bamboo shoot yield and quality of Moso bamboo plantations, six CF decrement treatments (0 %, 25 %, 50 %, 75 %, and 100 % SEOF substitution, and no fertilization) were examined in our study. Soil nutrients, enzyme activities, bacterial community structures, bamboo shoot yield and quality were determined, and their relationships were analyzed. The results showed that adding SEOF improved soil quality and bamboo shoot yield. Compared with CF, the combined CF-SEOF treatments increased soil pH, soil organic carbon, N and P availability, and the activities of enzymes related to C, N, and P cycling. SEOF substitution significantly changed the soil bacterial community structure and increased the relative abundance of Proteobacteria and Actinobacteria. Higher proportions of organic fertilizer substitution (OF75, OF) enhanced the bamboo shoot yield (by 20.23 % and 16.55 %, respectively) and their total flavonoid and vitamin C content, compared to CF (p< 0.05). Moreover, the soil quality index of OF75 and OF50 was significantly higher than that of OF and OF25 in the 0-40 cm soil layer (p< 0.05). Pearson's correlation tests showed that bamboo shoot yield was positively related with soil nutrients (p< 0.05). In addition, SEM revealed that fertilization affected soil enzyme activities through soil microorganisms, thereby affecting soil nutrient availability and promoting SQI and bamboo shoot yield. In conclusion, our study revealed that SEOF production is advisable for improving soil quality and bamboo shoot yield, providing evidence that soil nutrients and bacteria contribute to shoot yield and promote the sustainable management of soil and Moso bamboo forests.

The impact of the combined application of biochar and organic fertilizer on the growth and nutrient distribution in wheat under reduced chemical fertilizer conditions

Organic fertilizer can help replenish fertility in cropland and reduce the use of chemical fertilizers, with biochar is an important soil conditioner. Under the premise of chemical fertilizer reduction, whether the application of biochar and organic fertilizer affect the yield and nutrient absorption and utilization of wheat? In this experiment, 7 treatments were set up in a randomized field trial with each treatment repeated three times: (1) CK1: no fertilizer; (2) CK2: 100% inorganic fertilizer; (3) T1: recommended amount of biochar with 100% inorganic fertilizer; (4) T2: recommended amount of organic fertilizer with 80% inorganic fertilizer; (5) T3: recommended amount of organic fertilizer and biochar with 80% inorganic fertilizer; (6) T4: recommended amount of organic fertilizer with 60% inorganic fertilizer; and (7) T5: recommended amount of organic fertilizer and biochar with 60% inorganic fertilizer. The results of this study showed that biochar combined with organic fertilizer can reduce the amount of chemical fertilizer by 40%~20% while ensuring wheat yield. Combining the input and output, 80% inorganic fertilizer with biochar and organic fertilizer (T3) was recommended. Under this fertilization scheme, the wheat yield was 37.32% higher than that of 100% chemical fertilizer (CK2), and the photosynthetic capacity was 54.97% higher at seedling stage. At the tillering stage, the root nitrogen content of T3 was significantly higher than that of T2, T4 and T5, which was 21.44%, 54.63% and 60.16%, respectively. The nitrogen content of T3 was significantly higher than that of other treatments at maturity, and the nitrogen content of T3 was 4.38% higher than that of CK2. At heading stage, the nitrogen allocated to T3 leaves was 4.71% higher than CK2. Overall, the results of this study showed that the combination of biochar and organic fertilizer could effectively reduce the application of chemical fertilizer. The recommended fertilizer regimen was 80% inorganic fertilizer with biochar and organic fertilizer, under this scheme, wheat had stronger photosynthetic capacity and better nutrient absorption and distribution mechanism.

Crop rotation increases Tibetan barley yield and soil quality on the Tibetan Plateau

Tibetan barley (Hordeum vulgare) accounts for over 70% of the total food production in the Tibetan Plateau. However, continuous cropping of Tibetan barley causes soil degradation, reduces soil quality and causes yield decline. Here we explore the benefits of crop rotation with wheat and rape to improve crop yield and soil quality. We conducted 39 field experiments on the Tibetan Plateau, comparing short-term (≤5 years), 5-10 years and long-term (≥10 years) continuous cropping with rotation of Tibetan barley with wheat or rape. Results showed that Tibetan barley-wheat and Tibetan barley-rape rotations increased yields by 17% and 12%, respectively, while improving the soil quality index by 11% and 21%, compared with long-term continuous cropping. Both Tibetan barley rotations with wheat and rape improved soil quality and consequently yield, mainly by increasing soil microbial biomass nitrogen and microbial biomass carbon and decreasing pH. By contrast, long-term continuous cropping led to decreased soil organic matter, lower microbial biomass nitrogen and increased pH, contributing to yield decline. The benefits of rotations on crop yield and soil quality increased over time. Implementing crop rotation with wheat or rape thus offers a sustainable agricultural strategy for improving food security on the Tibetan Plateau.

Heavy metals concentrations in commercial organic fertilizers and the potential risk of fertilization into soils

Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect heavy metals in 74 typical and representative commercial organic fertilizers (COFs) collected in major COF production areas in China. The potential risk of fertilization into soils was evaluated. The concentrations of heavy metals (mg kg- 1) in these COFs were 1.55-36.95 (As), 0.04-2.32 (Hg), 1.43-78.05 (Pb), 0.15-7.49 (Cd), 11.03-212.90 (Cr), 7.74-555.11 (Cu), 21.46-2705.68 (Zn), and 5.62-244.47 (Ni), respectively. Based on China's Organic Fertilizer Standard (2021), COFs with excessive heavy metals accounted for 45.95% (As), 1.35% (Hg), 2.70% (Pb), 8.11% (Cd), and 6.76% (Cr). According to the European Union standard (2019), the rate of COFs with excessive heavy metals was 32.43% for Cu, 75.68% for Zn, and 85.14% for Ni. Estimated by applying 3854 kg hectare- 1 (dry bass) of fertilizer per hectare per year, to guarantee the safe use of organic fertilizer, the risk monitoring of Cd in soil should be emphasized. China should formulate appropriate standards for the limits of Cu, Zn, and Ni in organic fertilizer as soon as possible and should pay great attention to heavy metal pollution of soils.

The combined application of organic and inorganic fertilizers improved the quality of colored wheat by physicochemical properties and rheological characteristics of starch

Excessive use of nitrogen fertilizer can degrade the quality of wheat grain, while appropriate use of organic fertilizer can enhance starch quality. To clarify the effects of chemical fertilizer and organic fertilizer on wheat quality. We measured indicators such as amylose content, starch granules, starch structure, gelatinization characteristics, and rheological properties of wheat under different proportions of combined application of organic fertilizer and chemical fertilizer, revealing the effects of combined application of organic fertilizer and chemical fertilizer on the physicochemical properties and structure of starch. The results showed that compared with single application of chemical fertilizer (T1), organic fertilizer instead of 30 % fertilizer (T2) significantly increased amylose content (10.13 %), starch solubility (35.54 %, 90 °C), swelling power (7.40 %, 90 °C) and wheat yield (18.78 %), but decreased relative crystallinity (37.40 %) and order degree of starch, resulted in a decrease in gelatinization temperature (3.27 %). Meanwhile, rheological analysis also proved that the starch under T2 showed strong elasticity and hardness. This research highlights the importance of organic fertilizer for grain quality and propose that replacing 30 % of chemical fertilizer with organic fertilizer could significantly enhance the starch structure of colored wheat, providing theoretical support for the improvement of wheat quality.

Co-application of sheep manure and commercial organic fertilizer enhances plant productivity and soil quality in alpine mining areas

Background and aims

The addition of organic fertilizers and sheep slat manure have important effects on soil quality in alpine mining areas, but how they affect soil physicochemical properties and microorganisms is not yet known.

Methods

The current study employed field-controlled experiments and high-throughput sequencing technology to investigate differences in soil physicochemical properties, microbial community structures, and diversity under four treatments: no fertilization (CK), 100% sheep manure (SM), a combination of 50% sheep manure and 50% commercial organic fertilizer (MF), and 100% commercial organic fertilizer (OF).

Results

Aboveground biomass increased by 191.93, 253.22, and 133.32% under SM, MF and OF treatments, respectively, when compared to CK treatment. The MF treatment resulted in significantly higher soil total nitrogen, total phosphorus, organic matter, and available nitrogen content compared to other treatments. Soil total nitrogen content, total phosphorus content, organic matter, available nitrogen content and available phosphorus content were 211, 120, 380, 557, and 271% higher, respectively, under the MF treatment than the CK treatment. Different nutrient additions significantly influenced soil microbial community composition. The SM and MF treatments notably increased soil bacterial and fungal community Operational Taxonomic Units (OTUs) indices and Chao 1 indices, while nutrient addition had no meaningful effect on the Simpson indices for microbial communities. There was a highly significant positive correlation between aboveground biomass and observed soil nutrient content.

Conclusion

The combined application of sheep manure and commercial organic fertilizer is more conducive to improving soil quality and enhancing plant productivity in alpine mining areas.

Insect frass from upcycling vegetable by-products with cereals: Effects on the soil properties, plant development and soil invertebrate fitness

The use of insects in organic management systems is expanding due to their ability to recycle waste into valuable co-products for agriculture, notably frass, constituted by the insect's excrements, larval exuviae, and remaining undigested feedstock. This study aimed to assess the effects of different application rates of frass (0.16, 0.32, 0.64, 1.28, 2.56 and 5.12%) produced by black soldier fly Hermetia illucens larvae (BSFL) on the survival and reproduction of two non-target invertebrate species, the enchytraeid Enchytraeus crypticus and the collembolan Folsomia candida, and early development of three representative species of crops as onion Allium cepa, turnip Brassica rapa and tomato Solanum lycopersicum. Chemical analyses were conducted to evaluate changes in the soil properties. Results showed that BSFL frass did not impact the invertebrates' survival while significantly enhancing the production of E. crypticus juveniles (after 21 days). F. candida juveniles remained similar (after 28 days). Seed germination decreased at the highest frass rate (5.12%), while the development was promoted at intermediate rates (0.64%-1.28%). The different outcomes may be linked to changes in certain soil parameters, such as the soil pH and electrical conductivity, the soil organic matter, and the availability of nutrients. In summary, frass posed no risk to the tested invertebrate species but may hinder seed germination at high rates, representing a risk for agricultural production. Nevertheless, intermediate rates of BSFL frass promoted plant development, showing potential as a sustainable alternative to conventional fertilizers. Further research is needed to ensure its safe and efficient application in agriculture.

Substituting partial chemical nitrogen fertilizers with organic fertilizers maintains grain yield and increases nitrogen use efficiency in maize

Introduction

Long-term application of excessive nitrogen (N) not only leads to low N use efficiency (NUE) but also exacerbates the risk of environmental pollution due to N losses. Substituting partial chemical N with organic fertilizer (SP) is an environmentally friendly and sustainable fertilization practice. However, the appropriate rate of SP in rainfed maize cropping systems in semi-arid regions of China is unknown.

Methods

Therefore, we conducted a field experiment between 2021 and 2022 in a semi-arid region of Northern China to investigate the effects of SP on maize growth, carbon and N metabolism (C/NM), and NUE. The following treatments were used in the experiment: no N application (CK), 100% chemical N (SP0, 210 kg N ha-1), and SP substituting 15% (SP1), 30% (SP2), 45% (SP3), and 60% (SP4) of the chemical N. The relationship between these indicators and grain yield (GY) was explored using the Mantel test and structural equation modeling (SEM).

Results and discussion

The results found that the SP1 and SP2 treatments improved the assimilates production capacity of the canopy by increasing the leaf area index, total chlorophyll content, and net photosynthetic rate, improving dry matter accumulation (DMA) by 6.2%-10.6%, compared to the SP0 treatment. SP1 and SP2 treatments increased total soluble sugars, starch, free amino acids, and soluble protein contents in ear leaves via increasing the enzymatic reactions related to C/NM in ear leaves during the reproductive growth stage compared with SP0 treatment. The highest plant nitrogen uptake (PNU) and nitrogen recovery efficiency were obtained under the SP2 treatment, and the GY and nitrogen agronomic efficiency were higher than the SP0 treatment by 9.2% and 27.8%. However, SP3 and SP4 treatments reduced DMA and GY by inhibiting C/NM in ear leaves compared to SP0 treatment. Mantel test and SEM results revealed that SP treatments indirectly increased GY and PNU by directly positively regulating C/NM in maize ear leaves. Therefore, in the semi-arid regions, substituting 30% of the chemical N with SP could be considered. This fertilizer regime may avoid GY reduction and improve NUE. This study provides new insights into sustainable cultivation pathways for maize in semi-arid regions.

Mechanisms and influential factors of soil chromium long-term stability by an accelerated aging system after chemical stabilization

Chemical stabilization is one of the most widely used remediation strategies for chromium (Cr)-contaminated soils by reducing Cr(VI) to Cr(III), and its performance is affected by human and natural processes in a prolonged period, challenging long-term Cr stability. In this work, we established a method for evaluating the long-term effectiveness of remediation of Cr-contaminated soils, and developed an accelerated aging system to simultaneously simulate acid rain leaching and freeze-thaw cycles. The mechanisms and influencing factors of long-term (50-year) change in soil Cr speciation were unravelled after stabilization with Metafix®. Chemical stabilization remarkably decreased the contents of Cr(VI)soil, Crtotal-leach and Cr(VI)leach, among which the removal rate of Cr(VI) in soil was up to 89.70 %, but it also aggravated soil Cr instability. During the accelerated aging process, Crtotal-leach change rates in chemically stabilized soil samples were 0.0462-0.0587 mg/(L·a), and soil Cr became instable after 20-year accelerated aging. The proportion of Cr bound to organic matter and residual Cr increased in soil, and exchangeable Cr decreased. Linear combination fitting results of XANES also showed that Cr(VI) and Cr3+ were transformed into OM-Cr(III), Fh-Cr(III) and CrFeO3 after restoration. During the accelerated aging process, acid rain leaching activated Cr(III) and dissolved Cr(VI), whereas freeze-thaw cycle mainly affected OM-Cr. Chemical stabilization, acid rain leaching and aging time were the major factors influencing the stability of soil Cr, and the freeze-thaw cycle promoted the influence of acid rain leaching. This study provided a new way to explore the long-term effectiveness and instability mechanisms at Cr-contaminated site after chemical stabilization.

Bio-manure substitution declines soil N2O and NO emissions and improves nitrogen use efficiency and vegetable quality index

Substituting mineral fertilizer with manure or a combination of organic amendments plus beneficial soil microorganisms (bio-manure) in agriculture is a standard practice to mitigate N2O and NO emissions while enhancing crop performance and nitrogen use efficiency (NUE). Here, we conducted a greenhouse trial for three consecutive vegetable growth seasons for Spinach, Coriander herb, and Baby bok choy to reveal the response of N2O and NO emissions, NUE, and vegetable quality index (VQI) to fertilization strategies. Strategies included solely chemical nitrogen fertilizer (CN), 20 (M1N4) and 50% (M1N1) substitution with manure, 20 (BM1N4) and 50% (BM1N1) substitution with bio-manure, and no fertilization as a control and were organized in a completely randomized design (n = 3). Manure decreased N2O emissions by 24-45% and bio-manure by 44-53% compared to CN. Manure reduced NO emissions by 28-41% and bio-manure by 55-63%. Bio-manure increased NUE by 0.04-31% and yields by 0.05-61% while improving VQI, attributed to yield growth and reduced vegetable NO3- contents. Improvement of root growth was the main factor that explained the rise of NUE; NUE declined with the increase of N2O emissions, showing the loss of vegetable performance under conditions when denitrification processes prevailed. Under the BM1N1, the highest VQI and the lowest yield-scaled N-oxide emissions were observed, suggesting that substitution with bio-manure can improve vegetable quality and mitigate N-oxide emissions. These findings indicate that substituting 50% of mineral fertilizer with bio-manure can effectively improve NUE and VQI and mitigate N-oxides in intensive vegetable production.

The mechanism of using magnetized-ionized water in combination with organic fertilizer to enhance soil health and cotton yield

Addressing critical challenges in sustainable agriculture, notably water scarcity and soil degradation, necessitates innovative irrigation and fertilization methods. This investigation thoroughly assessed the effects of combining inorganic and organic fertilizers under brackish water irrigation, particularly focusing on magnetized-ionized brackish water-a promising solution for these challenges. The study shows that the integration of inorganic and organic fertilizers notably enhances soil water retention and salt leaching when applied with magnetized-ionized brackish water irrigation (MIBIO treatment), with water storage rate and salt accumulation rate observed at -0.454 and -0.075, respectively. Additionally, soil microbial diversity and uniformity witnessed significant improvement, positively influencing cotton growth rates, particularly noting a dry matter accumulation rate of 9.3262 kg·(ha·°C)-1. Transcriptomic analysis revealed that the MIBIO treatment elevated gene expression during the boll period, with notable enrichment in pathways such as the MAPK signaling pathway-plant and amino sugar and nucleotide sugar metabolism. Furthermore, the partial least squares path modeling indicated that soil alkali-hydrolyzed nitrogen (AN) and available potassium (AK) positively impact cotton leaf transcription and yield, with path coefficients of 0.613 and 0.428, respectively. Specifically, AN and AK contribute to enhancing cotton growth and affect the expression of metabolism genes in cotton leaves, thereby increasing cotton yield. Our study highlights the crucial role of irrigation and fertilization in influencing the soil environment and cotton growth. We recommend the use of magnetized-ionized water irrigation in combination with organic fertilizers as a strategy to boost agricultural productivity. Through the development of these strategies, our goal is to offer farmers practical guidance that can be readily implemented to enhance crop production efficiency, reduce environmental impact, and adhere to the principles of sustainable agriculture.

Effect of Organic Manure on Crop Yield, Soil Properties, and Economic Benefit in Wheat-Maize-Sunflower Rotation System, Hetao Irrigation District

The combined application of manure and mineral fertilizer represents an effective strategy for enhancing crop yield. However, the relationship between soil fertility and crop yield remains unclear in saline-alkaline soil. Here, a 9-year field experiment (2015-2023) was conducted to investigate the effects of manure application and crop rotations on crop yield and economic efficiency as well as potential associated mechanisms in the Hetao Irrigation District. The results showed that in the third cropping rotation cycle, combined application of manure and mineral fertilizers (NPKO) caused a 6.2%, 38.9%, 65.3%, and 132.2% increase in wheat, sunflower, wheat equivalent yield, and the economic income of sunflower, respectively. The average grain yield had a positive correlation with soil organic matter and nutrient supply. This suggested that the soil organic matter had a positive effect on the crop yield due to its impact on nutrient supply. Simultaneously, the sunflower seed setting rate increased by 65.2% under NPKO. The linear regression model revealed that each additional input of 20 Mg ha-1 of manure resulted in an increase of 3.56 kg ha-1 in crop phosphorus harvest and a 0.05 Kg ha-1 increase in wheat equivalent yield compared to NPK. In conclusion, our results highlighted that manure application promotes soil properties and improves crop yield.

Carbon footprint of maize-wheat cropping system after 40-year fertilization

Two main challenges which human society faces for sustainable development goals are the maintenance of food security and mitigation of greenhouse gas (GHG) emissions. Here, we examined the impacts of six fertilization treatments including unfertilized control (CK), mineral nitrogen (N, 90 kg N ha-1), mineral N plus 30 kg P ha-1 phosphorus (NP), NP combined with 3.75 Mg ha-1 straw (NP + Str), farmyard manure (Man, 75 Mg ha-1), and NP combined with manure (NP + Man) on crop productivity and carbon emissions (soil GHG emission; GHGI, yield-based GHG intensity; NGHGB, net GHG balance; carbon footprint, CF) in a maize-wheat cropping system during two years (April 2018-June 2020) in a semi-arid continental climate after 40 years of fertilization in the Northwest China. Manure and straw increased total GHG by 38-60 % compared to the mineral fertilizers alone, which was mainly due to the 49-80 % higher direct emissions of carbon dioxide (CO2) rather than nitrous oxide (N2O). Compared to the N fertilizer alone, organic amendments and NP increased cumulative energy yield by 134-202 % but decreased GHGI by 38-55 %, indicating that organic fertilizers increased crop productivity at the cost of higher GHG emissions. When the soil organic carbon changes (ΔSOC) were accounted for in the C emission balance, manure application acted as a net C sink due to the NGHGB recorded with -123 kg CO2-eq ha-1 year-1. When producing the same yield and economic benefits, the manure and straw addition decreased the CF by 59-85 % compared to N fertilization alone. Overall, the transition from mineral to organic fertilization in the semi-arid regions is a two-way independent solution to increase agricultural productivity along with the reduction of C emissions.

Continuous straw returning enhances the carbon sequestration potential of soil aggregates by altering the quality and stability of organic carbon

Soil structure plays an important role in organic carbon (OC) sequestration, thereby influencing soil fertility and changes in global climate. However, aggregate OC chemical structure changes due to long-term return of straw in oasis farmland of arid northwest China remains unclear. This study conducted 0-, 5-, 10-, 15-, and 20-year straw returning experiments during which three soil components where measured: (1) the functional carbon (C) pool and macroaggregates; (2) microaggregates and silt + clay; (3) the chemical structure of soil OC (SOC). The results demonstrated that in comparison with the control, straw return increased SOC, particulate OC (POC), and mineral-associated OC (MAOC) by 21.90%-63.51%, 5.00%-31.00%, and 46.00%-226.00%, respectively. With increasing duration of straw return, microaggregates transitioned to macroaggregates, and percentages of soil macroaggregates under 10-year straw return increased by 20.26%, 3.39%, 4.40%, and 11.12% compared with that under 0-, 5-, 15- and 20-year straw return, respectively. Soil geometric mean diameter (GMD) and mean weight diameter (MWD) first increased and then decreased, with maximum values after 10-year straw return at 1.20 mm and 1.63 mm, respectively. Solid state 13C NMR (Nuclear Magnetic Resonance) indicated O-alkyl C to be the dominant chemical component of soil OC over different years of straw return. There were increases in aromatic C, aromaticity, and hydrophobicity up to 10-year straw return, after which they decreased. A mantel test confirmed positive correlations of the distributions of macroaggregates, microaggregates, OC of macroaggregates, and silt + clay with MWD and GMD, whereas the OC content of aggregates was positively correlated with O-OA and hydrophobicity. Long-term straw returns improved soil structure and stabilized soil OC, thereby facilitating soil sequestration of OC.

Manure replacing synthetic fertilizer improves crop yield sustainability and reduces carbon footprint under winter wheat-summer maize cropping system

Manure replacing synthetic fertilizer is a viable practice to ensure crop yield and increase soil organic carbon (SOC), but its impact on greenhouse gas (GHG) emissions is inconsistent, thus remains its effect on CF unclear. In this study, a 7-year field experiment was conducted to assess the impact of replacing synthetic fertilizer with manure on crop productivity, SOC sequestration, GHG emissions and crop CF under winter wheat-summer maize cropping system. Five treatments were involved: synthetic nitrogen, phosphorus, and potassium fertilizer (NPK) and 25%, 50%, 75%, and 100% of manure replacing synthetic N (25%M, 50%M, 75%M, and 100%M). Compared with NPK treatment, 25%M and 50%M treatments maintained annual yield (winter wheat plus summer maize) and sustainable yield index (SYI), but 75%M and 100%M treatments significantly decreased annual yield, and 100%M treatment also significantly reduced annual SYI. The SOC content exhibited a significant increasing trend over years in all treatments. After 7 years, SOC storage in manure treatments increased by 3.06-11.82 Mg ha-1 relative to NPK treatment. Manure treatments reduced annual GHG emissions by 14%-60% over NPK treatment. The CF of the cropping system ranged from 0.16 to 0.39 kg CO2 eq kg-1 of grain without considering SOC sequestration, in which the CF of manure treatments lowered by 18%-58% relative to NPK treatment. When SOC sequestration was involved in, the CF varied from -0.39 to 0.37 kg CO2 eq kg-1 of grain, manure treatments significantly reduced the CF by 22%-208% over NPK treatment. It was concluded that replacing 50% of synthetic fertilizer with manure was a sound option for achieving high crop yield and SYI but low CF under the tested cropping system.

Unlike chemical fertilizer reduction, organic fertilizer substitution increases soil organic carbon stock and soil fertility in wheat fields

BACKGROUND

Improvements in farmland soil organic carbon (SOC) stock enhance crop yield and soil fertility while mitigating climate change. Rational fertilization in agricultural production is crucial for safeguarding SOC stock. In this study, field experiments were conducted with different ratios of chemical fertilizer reduction and organic fertilizer substitution for three consecutive years (2018-2020) to explore their effects and interlinkages on SOC fractions, soil properties and SOC stock.

RESULTS

The results showed that organic fertilizer substitution increased SOC and its fractions content, SOC stock (by 3.98-12.98% and 7.15-18.13%) and soil fertility index (by 11.76-49.26% and 33.33-91.47%) compared to conventional fertilization in 2019 and 2020, while chemical fertilizer reduction had the opposite effect. Moreover, soil properties (except total nitrogen to total phosphorus ratio, N/P) and SOC fractions significantly affected SOC stock, with SOC fractions contributing more than soil properties. The high sensitivity of microbial biomass carbon (MBC) and dissolved organic carbon (DOC) can indicate changes in soil carbon pool. Structural equation modeling (SEM) revealed that organic fertilizer substitution increased SOC content and stock by increasing SOC fractions [recalcitrant organic carbon (ROC) and labile organic carbon (LOC) fractions] content and soil fertility.

CONCLUSIONS

Our study revealed the corresponding mechanisms of the two fertilization modes affecting SOC stock changes. The use of organic fertilizer substitution is recommended to increase SOC stocks and soil fertility in wheat fields. © 2023 Society of Chemical Industry.

The responses of CO2 emission to nitrogen application and earthworm addition in the soybean cropland

The effects of nitrogen application or earthworms on soil respiration in the Huang-Huai-Hai Plain of China have received increasing attention. However, the response of soil carbon dioxide (CO2) emission to nitrogen application and earthworm addition is still unclear. A field experiment with nitrogen application frequency and earthworm addition was conducted in the Huang-Huai-Hai Plain. Results showed nitrogen application frequency had a significant effect on soil respiration, but neither earthworms nor their interaction with nitrogen application frequency were significant. Low-frequency nitrogen application (NL) significantly increased soil respiration by 25%, while high-frequency nitrogen application (NH), earthworm addition (E), earthworm and high-frequency nitrogen application (E*NH), and earthworm and low-frequency nitrogen application (E*NL) also increased soil respiration by 21%, 21%, 12%, and 11%, respectively. The main reason for the rise in soil respiration was alterations in the bacterial richness and keystone taxa (Myxococcales). The NH resulted in higher soil nitrogen levels compared to NL, but NL had the highest bacterial richness. The abundance of Corynebacteriales and Gammaproteobacteria were positively connected with the CO2 emissions, while Myxococcales, Thermoleophilia, and Verrucomicrobia were negatively correlated. Our findings indicate the ecological importance of bacterial communities in regulating the carbon cycle in the Huang-Huai-Hai Plain.

Short term effects of digestate and composted digestate on soil health and crop yield: Implications for sustainable biowaste management in the bioenergy sector

Composting mitigates environmental risks associated with using solid digestate as fertilizer. However, evidence is lacking on benefits of using composted digestate as fertilizer in enhancing soil health and increasing agronomic yield compared to non-composted digestate (hereafter, digestate). A field study was conducted consisting of digestate, composted digestate, co-composted digestate with biogas feedstocks (corn [Zea mays L.] silage, poultry litter, corn silage + poultry litter or food processing by-product), inorganic nitrogen fertilizer, and control (no treatment applied) on soil microbial biomass, enzyme activities (EA), soil organic carbon (SOC), bioavailable P (P), total nitrogen (TN), soil health index (SHI), and sunflower (Helianthus annuus L.) yield. The Partial Least Square Path Model (PLS-PM) was used to predict: 1) nutrient cycling in response to changes in microbial growth and EA and 2) agronomic yield in response to SHI and soil nutrients dynamics. Composted digestate had equivalent soil health benefits with most of co-composted materials and digestate, albeit agronomic yield was greatest with composted digestate, which was 40 % and 100 % greater than with inorganic nitrogen fertilizer and digestate, respectively, indicating composted digestate's potential to replace the synthetic N fertilizer. Moreover, composts from a sole digestate, rather than the ones from co-composted with fresh feedsstocks, can be promising organic amendments and fertilizers for growing sunflower. The PLS-PM model identified that triggered microbial biomass growth and EA, following digestate and composted digestate applications, catalyzed organic matter decomposition, resulting in enhanced nutrients contents and soil health. However, the model revealed that improved SHI did not predict agronomic yield, as opposed to P and TN, suggesting agronomic performance may have been more sensitive to changes in specific soil nutrients status than the overall soil health condition. We conclude that the benefits of composted digestate as fertilizer hint the significance of digestate valorization via post-digestate composting and compost utilization for sustainability of the bioenergy sector.

Quantifying synergies and trade-offs in the food-energy-soil-environment nexus under organic fertilization

Recycling livestock manure in agroecosystems can maintain crop production, improve soil fertility, and reduce environmental losses. However, there has been no comprehensive assessment of synergies and trade-offs in the food-energy-soil-environment nexus under manure application. Here, we evaluate the sustainability of maize production under four fertilization regimes (mineral, mineral and manure mixed, manure, and no fertilization) from the aspect of food security, energy output, soil quality, and environmental impact based on a five-year field experiment. Manure and mineral mixed fertilization maintained grain and straw quantity and quality compared with mineral fertilization. Manure and mineral mixed fertilization increased stem/leaf ratio and field residue index by 9.1-28.9% and 4.5-17.9%, respectively. Manure also maintained the theoretical ethanol yield but reduced the straw biomass quality index by increasing ash. Further, manure application increased the soil quality index by 40.5% and reduced N2O emissions by 55.0% compared with mineral fertilization. Manure application showed the highest sustainability performance index of 19, followed by mineral (15), mixed (13), and without fertilization (8). In conclusion, manure application maintains food production and energy output, enhances soil quality, and reduces environmental impact, thereby improving the sustainability of maize production.

Microplastic pollution in organic farming development cannot be ignored in China: Perspective of commercial organic fertilizer

Commercial organic fertilizer, an essential fertilizer for developing organic farming in China, has been identified as a potentially important source of microplastics (MPs) on farmland. However, little is known about the occurrence of MPs in commercial organic fertilizers and their potential ecological risks nationwide. Here, stereoscopy and laser-infrared imaging spectrometry were used to comprehensively investigate the abundance, size, type and morphology of MPs in commercial organic fertilizers collected from mainland China, assess the ecological risks, and predict MP contamination. Commercial organic fertilizers contained many MPs (8.88 ×103 to 2.88 ×105 items/kg), especially rich in small-size MPs (<100 µm), accounting for 76.53%. The highest MP pollution load value was observed in fertilizers collected from East China. Chlorinated polyethylene, polyurethane, polyethylene and polypropylene were the dominant MPs with the shape of film and fragment, concentrated in small sizes (<100 µm). The risk index (H-index) of the MPs was used to quantify the ecological risk of the MPs in the different samples, and most of the fertilizers were at level Ⅲ with high risk. Predictably, 2.32 × 1013 - 2.81 × 1016 MPs will accumulate in orchard soils after five years of fertilization, especially in South, Southwest and East China. This study provides primary scientific data on MP pollution in commercial fertilizer and the health development of organic farming.

Investigation of the incidence of heavy metals contamination in commonly used fertilizers applied to vegetables, fish ponds, and human health risk assessments

Overuse of fertilizers on agricultural lands and fish ponds may result in serious pollution problems, such as heavy metals that can enter the food chain and pose serious health problems. Due to this, the present study investigates the incidence of heavy metals in commonly used fertilizers and its association with heavy metals in vegetables, soil, fish species, and pond water. Samples were collected from different sites (fields and ponds) in district Kohat, where the application of fertilizers was common and control groups (no fertilizers used). Heavy metal analysis was carried out through a spectrophotometer. Results showed higher Cd and Cr concentrations in triple superphosphate (TSP), Cu and Pb in nitrogen, phosphorus, and potassium (NPK), while lower concentrations were found in gypsum. In vegetables (onion, tomato, brinjal, and potato) and associated soil, most of the heavy metals concentrations were significantly higher (P < 0.05) in fertilizer-applied sites than in the control. Also, the Cd concentration in potatoes and Pb level in all vegetables obtained from sites were greater than the WHO/FAO standard limit. In the case of fish species (Hypophthalmichthys molitrix and Cyprinus carpio) muscles and their habitat (water), all the understudy heavy metals were notably higher (P < 0.05) in fertilizer-applied sites (ponds) than the control group. Collectively, in all vegetables and muscles of fish species, the bioaccumulation factor was higher in sites compared to the control. The estimated daily intake (EDI) and target hazard quotient (THQ) values were also higher in fertilizer-applied sites (fields and ponds) than control. The health index (HI) value was > 1 in vegetables (onion, tomato, and potato) and fish muscles collected from different sites compared to the control. Thus, there is the possibility of severe health risks. The use of fertilizers must be carefully monitored in order to ensure that humans and animals are safe from exposure to heavy metals.

Moderate organic fertilizer substitution for partial chemical fertilizer improved soil microbial carbon source utilization and bacterial community composition in rain-fed wheat fields: current year

Organic fertilizers can partially replace chemical fertilizers to improve agricultural production and reduce negative environmental impacts. To study the effect of organic fertilizer on soil microbial carbon source utilization and bacterial community composition in the field of rain-fed wheat, we conducted a field experiment from 2016 to 2017 in a completely randomized block design with four treatments: the control with 100% NPK compound fertilizer (N: P2O5: K2O = 20:10:10) of 750 kg/ha (CK), a combination of 60% NPK compound fertilizer with organic fertilizer of 150 kg/ha (FO1), 300 kg/ha (FO2), and 450 kg/ha (FO3), respectively. We investigated the yield, soil property, the utilization of 31 carbon sources by soil microbes, soil bacterial community composition, and function prediction at the maturation stage. The results showed that (1) compared with CK, organic fertilizer substitution treatments improved ear number per hectare (13%-26%), grain numbers per spike (8%-14%), 1000-grain weight (7%-9%), and yield (3%-7%). Organic fertilizer substitution treatments increased the total nitrogen, available nitrogen, available phosphorus, and soil organic matter contents by 26%, 102%, 12%, and 26%, respectively, compared with CK treatments. Organic fertilizer substitution treatments significantly advanced the partial productivity of fertilizers. (2) Carbohydrates and amino acids were found to be the most sensitive carbon sources for soil microorganisms in different treatments. Particularly for FO3 treatment, the utilization of β-Methyl D-Glucoside, L-Asparagine acid, and glycogen by soil microorganisms was higher than other treatments and positively correlated with soil nutrients and wheat yield. (3) Compared with CK, organic fertilizer substitution treatments increased the relative abundance of Proteobacteria, Acidobacteria, and Gemmatimonadetes and decreased the relative abundance of Actinobacteria and Firmicutes. Interestingly, FO3 treatment improved the relative abundance of Nitrosovibrio, Kaistobacter, Balneimonas, Skermanella, Pseudomonas, and Burkholderia belonging to Proteobacteria and significantly boosted the relative abundance of function gene K02433 [the aspartyl-tRNA (Asn)/glutamyl-tRNA (Gln)]. Based on the abovementioned findings, we suggest FO3 as the most appropriate organic substitution method in rain-fed wheat fields.

Partial substitution of manure reduces nitrous oxide emission with maintained yield in a winter wheat crop

Conventional fertilization of agricultural soils results in increased N₂O emissions. As an alternative, the partial substitution of organic fertilizer may help to regulate N₂O emissions. However, studies assessing the effects of partial substitution of organic fertilizer on both N₂O emissions and yield stability are currently limited. We conducted a field experiment from 2017 to 2021 with six fertilizer regimes to examine the effects of partial substitution of manure on N₂O emissions and yield stability. The tested fertilizer regimes, were CK (no fertilizer), CF (chemical fertilizer alone, N 300 kg ha^-1, P₂O₅ 150 kg ha^-1, K₂O 90 kg ha^-1), CF + M (chemical fertilizer + organic manure), CFR (chemical fertilizer reduction, N 225 kg ha^-1, P₂O₅ 135 kg ha^-1, K₂O 75 kg ha^-1), CFR + M (chemical fertilizer reduction + organic manure), and organic manure alone (M). Our results indicate that soil N₂O emissions are primarily regulated by soil mineral N content in arid and semi-arid regions. Compared with CF, N₂O emissions in the CF + M, CFR, CFR + M, and M treatments decreased by 16.8%, 23.9%, 42.0%, and 39.4%, respectively. The highest winter wheat yields were observed in CF, followed by CF + M, CFR, and CFR + M. However, the CFR + M treatment exhibited lower N₂O emissions while maintaining high yield, compared with CF. Four consecutive years of yield data from 2017 to 2021 illustrated that a single application of organic fertilizer resulted in poor yield stability and that partial substitution of organic fertilizer resulted in the greatest yield stability. Overall, partial substitution of manure reduced N₂O emissions while maintaining yield stability compared with the synthetic fertilizer treatment during the wheat growing season. Therefore, partial substitution of manure can be recommended as an optimal N fertilization regime for alleviating N₂O emissions and contributing to food security in arid and semi-arid regions.