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The preservation of edaphic quality and productivity is critical for the ecological sustainability of vine orchards. The heavy utilization of intensified tillage and singular chemical fertilizers can shift changes in edaphic physicochemical and biological features, thus exerting significant pressure on agroecosystems. In current research, we assessed the shifts in soil physicochemical features and soil microbiome composition over 11 years carrying out no tillage and organic fertilizer substitution in a typical Chinese Guanzhong kiwifruit production area, and explore the fundamental factors that contribute to alterations in the microbial community and the influence on kiwifruit performance. Results showed that long‐term no tillage and organic fertilizer improved the soil condition by significantly increasing the proportion of soil macroaggregates, bulk density, and nutrient content (e.g., organic matter, nitrogen, and ammonia), as compared to conventional tillage with chemical fertilization. Moreover, no tillage significantly increased soil bacterial α‐diversity but had no significant effects on fungal. No tillage also enhanced the abundance of potential beneficial soil bacteria (e.g., Acidobacteria, Actinobacteria, and Nitrospira), while decreasing the abundance of Proteobacteria, Pseudomonas, and Fusarium. In addition, no tillage and mixed fertilized soil microbial network exhibited higher complexity (i.e., node and edge numbers, and positive edge proportion) and connectivity (i.e., average number of neighbors) than conventional tillage and chemical fertilization group. Changes in nitrate, ammonia, available phosphorus, and pH values accounted for the variation in the structure of soil microbial community. Hence, the utilization of both no tillage and organic fertilization practices could serve as a suitable and sustainable approach for managing kiwifruit production in the fragile environmental conditions of the Chinese Guanzhong region, and lead to an improvement in soil nutrient levels and help regulate the soil microbial community. [ABSTRACT FROM AUTHOR]

Soil-based irrigation and the partial substitution of chemical fertilizers with manure are promising practices to improve water and nitrogen (N) use efficiency. We hypothesize that their combination would simultaneously benefit potato production, tuber quality and profitability. A two-year experiment was conducted in semiarid northern China to investigate the combined effects of three water treatments [rainfed (W0), soil-based irrigation (W1), conventional irrigation (W2)] and three N treatments [no N (N0), chemical N (N1), 25% manure substitution (N2)] on these indicators, and to perform a comprehensive evaluation and correlation analysis. The results showed that water and N treatments separately affected all indicators except vitamin C content. Compared to W2, W1 significantly increased water productivity by 12% and irrigation water use efficiency (IWUE) by 30% due to 10% lower evapotranspiration and 21% lower water use. However, W1 and W2 negatively affected crude protein content. Conversely, this was compensated by the combination with N1 and N2. There were slight differences between N1 and N2 for all indicators on average across water treatments, while under W1, N2 significantly increased leaf area index (LAI) and N recovery efficiency (REN) by 18% and 29.4%, respectively, over N1. Also, comprehensive evaluations showed that W1N2 performed best, with the highest tuber yield, profit and acceptable quality. This can be explained by the increase in LAI, IWUE and REN due to the positive correlations with tuber yield and net return. Consequently, soil-based irrigation combined with 25% manure substitution had complementary effects on tuber quality and synergistic effects on potato productivity and profitability. [ABSTRACT FROM AUTHOR]

Introduction: In contemporary agriculture, the substitution of manure for chemical fertilizer based on phosphorus (P) input in vegetable production has led to a significant reduction in P fertilizer application rates, while, the effect of manure substitution rates on soil P transformation and uptake by root remain unclear. Methods: This research conducts a pot experiment with varying manure substitution rates (0%, 10%, 20%, 30%, 40%, 50%, 75% and 100%) based on P nutrient content to elucidate the mechanisms through which manure substitution affects P uptake in pepper. Results and Discussion: The result showed that shoot and root biomass of pepper gradually increased as manure substitution rate from 10% to 40%, and then gradually decreased with further increases in the substitution rate. Soil alkaline phosphatase activity and arbuscular mycorrhizal (AM) colonization gradually increased with manure substitution rates improvement. Specifically, when the substitution rate reached 30%-40%, the alkaline phosphatase activity increased by 24.5%-33.8% compared to the fertilizer treatment. In contrast, phytase activity and the relative expression of phosphate transporter protein genes in the root system was declined after peaking at 30% manure substitution. Additionally, soil available P remained moderate under 30%-40% substitution rate, which was reduced by 8.6%-10.2% compared to that in chemical fertilizer treatment, while microbial biomass P was comparable. In the current study, soil labile P similar to or even higher than that in chemical fertilizer treatment when the substitution rate was =40%. Correlation heatmaps demonstrated a significant and positive relationship between soil available P and factors related to labile P and moderately labile P. Conclusion: This finding suggested that substituting 30%-40% of chemical P with manure can effectively enhance root length, AM colonization, soil enzyme activity, soil labile P, and consequently improve P uptake in pepper. These findings provide valuable insights for future organic agricultural practices that prioritize P supply, aiming to standardize organic P management in farmland and achieve high crop yields and maintain soil health. [ABSTRACT FROM AUTHOR]

Synthetic nitrogen (N) fertilizer has made a great contribution to the improvement of soil fertility and productivity, but excessive application of synthetic N fertilizer may cause agroecosystem risks, such as soil acidification, groundwater contamination and biodiversity reduction. Meanwhile, organic substitution has received increasing attention for its ecologically and environmentally friendly and productivity benefits. However, the linkages between manure substitution, crop yield and the underlying microbial mechanisms remain uncertain. To bridge this gap, a three-year field experiment was conducted with five fertilization regimes: i) Control, non-fertilization; CF, conventional synthetic fertilizer application; CF1/2M1/2, 1/2 N input via synthetic fertilizer and 1/2 N input via manure; CF1/4M3/4, 1/4 N input synthetic fertilizer and 3/4 N input via manure; M, manure application. All fertilization treatments were designed to have equal N input. Our results showed that all manure substituted treatments achieved high soil fertility indexes (SFI) and productivities by increasing the soil organic carbon (SOC), total N (TN) and available phosphorus (AP) concentrations, and by altering the bacterial community diversity and composition compared with CF. SOC, AP, and the soil C:N ratio were mainly responsible for microbial community variations. The co-occurrence network revealed that SOC and AP had strong positive associations with Rhodospirillales and Burkholderiales, while TN and C:N ratio had positive and negative associations with Micromonosporaceae, respectively. These specific taxa are implicated in soil macroelement turnover. Random Forest analysis predicted that both biotic (bacterial composition and Micromonosporaceae) and abiotic (AP, SOC, SFI, and TN) factors had significant effects on crop yield. The present work strengthens our understanding of the effects of manure substitution on crop yield and provides theoretical support for optimizing fertilization strategies.

Soil-based irrigation and the partial substitution of chemical fertilizers with manure are promising practices to improve water and nitrogen (N) use efficiency. We hypothesize that their combination would simultaneously benefit potato production, tuber quality and profitability. A two-year experiment was conducted in semiarid northern China to investigate the combined effects of three water treatments [rainfed (W0), soil-based irrigation (W1), conventional irrigation (W2)] and three N treatments [no N (N0), chemical N (N1), 25% manure substitution (N2)] on these indicators, and to perform a comprehensive evaluation and correlation analysis. The results showed that water and N treatments separately affected all indicators except vitamin C content. Compared to W2, W1 significantly increased water productivity by 12% and irrigation water use efficiency (IWUE) by 30% due to 10% lower evapotranspiration and 21% lower water use. However, W1 and W2 negatively affected crude protein content. Conversely, this was compensated by the combination with N1 and N2. There were slight differences between N1 and N2 for all indicators on average across water treatments, while under W1, N2 significantly increased leaf area index (LAI) and N recovery efficiency (REN) by 18% and 29.4%, respectively, over N1. Also, comprehensive evaluations showed that W1N2 performed best, with the highest tuber yield, profit and acceptable quality. This can be explained by the increase in LAI, IWUE and REN due to the positive correlations with tuber yield and net return. Consequently, soil-based irrigation combined with 25% manure substitution had complementary effects on tuber quality and synergistic effects on potato productivity and profitability.

[Objective] The effects of total replacement of chemical fertilizer with pig manure, cattle manure and chicken manure on nitrogen and organic matter contents in paddy soil and rice yield were investigated in paddy field. [ Method] The rice field experiment was conducted in Gusheng village, Dali city, Yunnan province, with the principle of equal nitrogen full substitution. A total of 5 treatments were set up for the experiment. CKl was the non-fertilizer control, CK2 was the chemical fertilizer control, Tl was pig manure total fertilizer substitution treatment, T2 was cow manure total fertilizer substitution treatment, and T3 was chicken manure total fertilizer substitution treatment. [ Result] Compared with CK2, Tl and T3 treatments significantly increased the soil total nitrogen content by 4. 89% and 3. 83%. Compared with single fertilizer application, the content of ammonium nitrogen in soil of total manure substitution treatment decreased by 19. 36% - 29. 18%, and the content of nitrate nitrogen in soil showed opposite results, and T3 > T2 > Tl > CK2, indicating that total manure substitution treatment increased the risk of soil nitrogen leaching. The three manure substitution treatments could significantly increase soil organic matter content compared with the single fertilizer treatment, and it increased with the increase of C/N ratio of manure, and the increase range was 37. 52 % to 85. 98 % . The order of rice yield was T3 ( 10 399. 92 kg/hm2 ) > CK2 ( 9690. 85 kg/hm2 ) > Tl ( 9512. 39 kg/hm2 ) > T2 (8241. 55 kg/hm2 ) > CK! (7985. 96 kg/hm2 ). Compared with CK2 treatment, T2 treatment significantly reduced rice yield by 14. 96%, and Tl and T3 treatment had no significant difference in rice yield compared with CK2 treatment. There was no significant difference in rice yield composition between the total manure substitution treatments and the CK2 treatment. Tl and T3 handling the amounts of accumulated nitrogen of rice plants and nitrogen absorption efficiency than CK2 treatment had no significant difference. [ Conclusion] Comprehensive fertilizer input cost, pig manure replacement treatment can increase the soil total nitrogen (TN) and organic matter ( SOM) content under the premise of stable yield, that is, stable yield can improve the soil fertilizer supply capacity. Compared with the total replacement treatment of chicken manure, pig manure reduces the risk of nitrogen leaching loss, and is a better alternative manure type for the total substitution of chemical fertilizer. [ABSTRACT FROM AUTHOR]

The substituting chemical nitrogen (N) fertilizer with organic forms such as livestock manure in agroecosystems improves crop yields while reducing nutrient losses. However, the effects of such management practices in China on different soil types and cropping systems are widely unknown. The present lysimeter study investigated the different chemical fertilizer replacement rates on crop yields and N leaching rates for two spring maize systems on a Luvisol (the typical soil type in the North China Plain) and the other on a Chernozem (the typical soil in the Northeast China Plain). The results achieved herein indicated that manure substitution gave higher crop yields in the Luvisol, except for the treatment with 100% manure N replacement, which showed a slight yield reduction in the short term. For the Chernozem, manure substitution showed a significantly negative effect on crop yield in the short term, but the yield gradually increased and, over longer periods, even surpassed the yields found under baseline conditions. Manure substitution significantly reduced total N (TN) leaching by 57–76% in the Luvisol, while it increased TN leaching by 15–21% in the Chernozem. Results showed that soil properties, including water-holding capacity and clay and organic carbon contents are the main factors that can explain the contrasting effects of manure substitution on N leaching and crop yields for the two selected regions. Such information will enable more bespoke nutrient management measures in these two regions achieving agronomic and environmental benefits. [ABSTRACT FROM AUTHOR]

Maintaining phosphorus (P) supply for plants or reducing P mobility is critical to sustainable agricultural production and the environment. However, substituting long-term chemical fertilizer with a fraction of (i.e. partial substitution) manure and its effect on soil P surplus and P fractionation have not been widely studied. An eight-year protected field study with no fertilization (NF), chemical fertilizer substituted with no manure (NS), partial manure (40%, PS), and total manure (100%, TS) combined with multiple P characterization methods were conducted to examine P pools and stability in alkaline soil. NS, PS, and TS have the same input amount of nutrients. It showed that PS treatment lowered the annual P surplus by 6.21% and 11.2% compared with NS and TS, respectively, maintaining optimal P input–output balance and vegetable yields. TS decreased total Po by 31.9% and stable Ca-associated P by 21.1%, while increased labile organic P, compared with NS. The labile P in PS was at a moderate level compared with NS and TS treatments, which not only maintained the soil labile P pools but also reduced P leaching risk. Therefore, partial substitution of chemical fertilizer with manure leads to an optimal level of nutrients for vegetable production. [ABSTRACT FROM AUTHOR]

Comammox Nitrospira represents a groundbreaking discovery in nitrogen cycle research, showcasing its remarking ability for complete ammonia oxidation, which challenges prior conceptions of nitrification. In this study, we examined the response of comammox Nitrospira gene abundance, diversity, and community structure to different rates of pig manure substitution (0 %, 25 %, 50 %, 75 %, and 100 %) in subtropical agroforestry soils. The abundance of ammonia-oxidizing microorganisms was assessed by qPCR, whereas the diversity and structure of comammox Nitrospira were determined by high-throughput sequencing. Our findings revealed that pig manure substitution led to an increase in soil pH, available phosphorus (AP), comammox Nitrospira abundance, and diversity within soils under Cinnamomum camphora coppice planting. Soil pH and AP were the primary factors influencing the diversity and community structure of comammox Nitrospira. Moreover, pig manure substitution significantly influenced the composition of comammox Nitrospira , notably by increasing the relative abundance of clade A.2.1 while reducing that of clade A.2.2. However, pig manure substitution did not exert a significant impact on net nitrification rates, suggesting bacterial relative abundances were more sensitive to manure substitution compared to the underlying biogeochemical processes. Overall, our results offer new insights into the response of comammox Nitrospira to different rates of pig manure substitution in Cinnamomum camphora coppice planting soils, highlighting the pivotal role of soil AP and pH as the key determinants shaping comammox Nitrospira diversity and community structure. [ABSTRACT FROM AUTHOR]

Smart cropland management practices can mitigate greenhouse gas (GHG) emissions while safeguarding food security. However, the integrated effects on net greenhouse gas budget (NGHGB) and grain yield from different management practices remain poorly defined and vary with environmental and application conditions. Here, we conducted a global meta‐analysis on 347 observation sets of non‐CO2 GHG (CH4 and N2O) emissions and grain yield, and 412 observations of soil organic carbon sequestration rate (SOCSR). Our results show that for paddy rice, replacing synthetic nitrogen at the rate of 30%–59% with organic fertilizer significantly decreased net GHG emissions (NGHGB: −15.3 ± 3.4 [standard error], SOCSR: −15.8 ± 3.8, non‐CO2 GHGs: 0.6 ± 0.1 in Mg CO2 eq ha−1 year−1) and improved rice yield (0.4 ± 0.1 in Mg ha−1 year−1). In contrast, intermittent irrigation significantly increased net GHG emissions by 11.2 ± 3.1 and decreased rice yield by 0.4 ± 0.1. The reduction in SOC sequestration by intermittent irrigation (15.5 ± 3.3), which was most severe (>20) in alkaline soils (pH > 7.5), completely offset the mitigation in CH4 emissions. Straw return for paddy rice also led to a net increase in GHG emissions (NGHGB: 4.8 ± 1.4) in silt‐loam soils, where CH4 emissions (6.3 ± 1.3) were greatly stimulated. For upland cropping systems, mostly by enhancing SOC sequestration, straw return (NGHGB: −3.4 ± 0.8, yield: −0.5 ± 0.6) and no‐tillage (NGHGB: −2.9 ± 0.7, yield: −0.1 ± 0.3) were more effective in warm climates. This study highlights the importance of carefully managing croplands to sequester SOC without sacrifice in yield while limiting CH4 emissions from rice paddies. [ABSTRACT FROM AUTHOR]

Manure application is a global approach for enhancing soil organic carbon (SOC) sequestration. However, the response of SOC decomposition in manure-applied soil to abrupt warming, often occurring during diurnal temperature fluctuations, remains poorly understood. We examined the effects of long-term (23 years) continuous application of manure on SOC chemical composition, soil respiration, and microbial communities under temperature shifts (15 vs 25 °C) in the presence of plant residues. Compared to soil without fertilizer, manure application reduced SOC recalcitrance indexes (i.e., aliphaticity and aromaticity) by 17.45 and 21.77%, and also reduced temperature sensitivity ( Q 10 ) of native SOC decomposition, plant residue decomposition, and priming effect by 12.98, 15.98, and 52.83%, respectively. The relative abundances of warm-stimulated chemoheterotrophic bacteria and fungi were lower in the manure-applied soil, whereas those of chemoautotrophic Thaumarchaeota were higher. In addition, the microbial network of the manure-applied soil was more interconnected, with more negative connections with the warm-stimulated taxa than soils without fertilizer or with chemical fertilizer applied. In conclusion, our study demonstrated that the reduced loss of SOC to abrupt warming by manure application arises from C chemistry modification, less warm-stimulated microorganisms, a more complex microbial community, and the higher CO 2 intercepting capability by Thaumarchaeota.

Manure and chemical fertilizers have different effects on soil properties, the nitrogen cycle, and crop yield. This study aimed to investigate the effects of different fertilizer applications under the same N input on soil physicochemical properties and soil bacterial communities and to explain the contributions of soil properties to grain yield. Manure substitution of chemical fertilizer was conducted in leaching monitoring systems. The study began in 2009 and sampling was carried out in 2014 and 2016. Three fertilizer treatments with the same total N, P, and K application rates and one control treatment were designed as follows: (1) CK, without nitrogen fertilizer; (2) 100%U, whole nitrogen coming from urea; (3) 100%M, whole nitrogen coming from composted cattle manure; and (4) 50%U + 50%M, half nitrogen from composted cattle manure and half nitrogen from urea. Soil organic carbon (SOC) content was positively correlated with total N (TN), NO3−–N, and NH4+–N contents, the mean weight diameter of soil aggregates, and the Shannon diversity index of bacteria, whereas SOC content was not significantly correlated with grain yield. NO3−–N content was positively correlated with grain yield. Substituting half the amount of chemical fertilizer with manure as a nitrogen source improved soil stability, increased bacterial diversity, and enhanced nitrogen supply, while reducing nitrogen loss from ammonia volatilization and nitrogen leaching. Substituting half the amount of chemical fertilizer with manure as a nitrogen source was a more sustainable way to increase grain yield through a sustainable nitrate supply and to reduce N loss. [ABSTRACT FROM AUTHOR]

Partial substitution of organic fertilizer is adopted to increase production and alleviate farmland greenhouse gas (GHG) emissions. However, there is a lack of integrated assessment of soil quality, crop productivity, and environmental benefits through organic fertilizer substitution. Therefore, an in-situ experiment was conducted with the single nitrogen (N) treatments (120, 180, 240 kg N ha−1, expressed with N120, N180, N240, respectively) and partial substitution with manure fertilizer (each N treatment decreased by 30 kg N ha−1 and plus 2 t ha−1 pig manure, expressed with NM120, NM180, NM240, respectively) for rainfed wheat production on the Loess Plateau. A comparison between N and NM treatments showed that manure substitution treatments: 1) increased soil quality index by 50.9 − 57.4%, grain yield by 9.0 − 42.9%, total N accumulation by 8.6 − 31.1% and nitrogen recovery efficiency by 10.7 − 76.9%; 2) decreased N 2 O emission by 10.6 − 15.3% and CH 4 uptake by 2.9 − 3.6%, whereas increased CO 2 emission by 5.1 − 6.7%; 3) reduced the carbon footprint by 1.7 − 2.3 time mainly by the soil organic carbon sequestration. The global warming potential (GWP), Greenhouse gas emission intensity (GHGI), grain yield and net ecosystem economic benefit (NEEB) increased as the fertilizer rates increasing. NM180 had higher yield (average 6022 kg ha−1) and lower GWP (16489 kg CO 2 -eq ha−1) than N180, which obtained the smaller GHGI (2.67 kg CO 2 -eq kg−1) and maximum NEEB (4150 RMB ha−1). Overall, manure partial substitution with appropriate N rate enhances soil quality, crop productivity and environment benefit, which is a sustainable rainfed wheat practice. • Both single N and manure substitution treatments improves soil quality index. • The GWP ascended but the GHGI declines markedly in manure partial substitution. • Manure substitution meets wheat productivity with farmland environmental benefit. [ABSTRACT FROM AUTHOR]

Conventional fertilization of agricultural soils results in increased N 2 O emissions. As an alternative, the partial substitution of organic fertilizer may help to regulate N 2 O emissions. However, studies assessing the effects of partial substitution of organic fertilizer on both N 2 O 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 N 2 O emissions and yield stability. The tested fertilizer regimes, were CK (no fertilizer), CF (chemical fertilizer alone, N 300 kg ha−1, P 2 O 5 150 kg ha−1, K 2 O 90 kg ha−1), CF + M (chemical fertilizer + organic manure), CFR (chemical fertilizer reduction, N 225 kg ha−1, P 2 O 5 135 kg ha−1, K 2 O 75 kg ha−1), CFR + M (chemical fertilizer reduction + organic manure), and organic manure alone (M). Our results indicate that soil N 2 O emissions are primarily regulated by soil mineral N content in arid and semi-arid regions. Compared with CF, N 2 O 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 N 2 O 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 N 2 O 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 N 2 O emissions and contributing to food security in arid and semi-arid regions. [Display omitted] • Soil N 2 O emissions were mainly regulated by soil mineral N content in arid and semi-arid regions. • Chemical fertilizer results in higher N 2 O emissions than does the application of organic fertilizer containing the same amount of N. • Partial substitution of organic fertilizer allowed for mitigating N 2 O emissions while simultaneously maintaining crop outputs. • Partial substitution of organic fertilizer has the greatest yield stability. [ABSTRACT FROM AUTHOR]

Conversion from synthetic nitrogen (N) fertilizer to organic manure has been well documented to effectively mitigate nitric oxide (NO) emissions in the current year or growing season. However, a clear understanding of NO emissions following long-term manure substitution is lacking. We hypothesize that soil conditions (particularly the accumulation of organic matter) following long-term manure substitution may stimulate NO emissions by providing more N substrates under favorable conditions. The primary aims of this study were to (1) quantify the long-term effects of manure substitution on NO emissions, and (2) identify the major regulating factors that contribute to the variations. Field measurements were conducted under summer maize-winter wheat rotations in a long-term fertilization experiment (since 1990) over three experimental years (from June 2016 to May 2019). The three treatments included an unfertilized control (CK), full synthetic urea in both crop seasons (NPK), and full synthetic urea in the maize season with 70% urea substituted by dairy manure in the winter wheat season (NPKM). Annual NO emissions varied from 0.10 to 0.22 kg N ha−1 and from 0.32 to 1.53 kg N ha−1 in CK and the fertilized treatments, respectively. We attributed the variations in annual NO emissions from the fertilized treatments to mean soil temperature by fitting a significant linear regression between the two variables (r2 = 0.681, p = 0.008). Seasonal NO emissions from NPKM treatment were lower (range, 2–66%, not always significant) and larger (range, 115–294%, not always significant) than those from NPK during the winter wheat and maize seasons, respectively. Annual NO emissions from NPKM treatment were 78% larger (range, 44–112%, not always significant) than those from NPK across the experimental years. Overall, this three-year field measurement revealed that cumulative NO emissions from NPKM treatment were significantly (p = 0.038) larger than those from NPK (2.73 versus 1.53 kg N ha−1). We concluded that long-term manure substitution for synthetic fertilizer in the winter wheat seasons did not mitigate, but rather stimulated cumulative NO emissions. • Manure substitution reduces NO emissions only in the current winter wheat season. • Long-term manure substitution enhances cumulative NO emissions in three years. • Annual NO emissions linearly relate to mean soil temperature in fertilized treatments. • Low NO emissions are probably owing to optimized N input rate in this study. [ABSTRACT FROM AUTHOR]

Long-term fertilization regimes can substantially change soil organic carbon (SOC) dynamics within different soil fractions. However, the underlying mechanisms of these effects, particularly under manure substitution regimes, remain elusive. Soils from different fertilization regimes [i.e., control, mineral NPK fertilization, and NPK with three manure substitution rates (30%, 50%, and 70%)] in a 33-year red paddy field experiment in southern China were sampled. The mean weight diameter (MWD) of soil aggregates and soil microbial properties (PLFAs), SOC content, and chemical composition of particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) under different treatments were determined to investigate the effects of manure substitution regimes on SOC quantity and quality. The results showed mineral NPK fertilization alone significantly (p < 0.05) decreased the MWD of soil aggregates by 14.4%, whereas 30%, 50%, and 70% manure replacement significantly (p < 0.05) increased the MWD by 12.0%, 19.9% and 27.2%, respectively. Compared to the mineral NPK fertilization regime, manure substitution practices continuously and significantly (p < 0.05) increased SOC along with its content in microbial biomass C and POC when the substitution rate of manure increased from 30% to 70%. Regardless of the substitution rates, manure substitution regimes decreased the O-alkyl C and aryl C proportions of POC, but increased the recalcitrant alkyl C resulting in higher alkyl C to O-alkyl C ratios compared with mineral NPK fertilization. Pearson analysis further showed that the O-alkyl C of POC were more associated with the soil microbial biomass C and N and total PLFAs. Partial least squares path modeling analysis indicated that microbial biomass C, POC, and MAOC were positive factors impacting SOC, whereas the promotion of manure substitution on SOC stabilization progressed mainly through increasing POC content. Our results suggested that substitution of 70% mineral N with manure N is the most effective fertilizer practice for improving POC-related SOC sequestration in rice paddy soil of subtropical regions. • Manure substitution significantly increased SOC relative to NPK fertilization. • The functional groups from POC were more associated with the soil microbial traits. • Manure promoted SOC stabilization mainly by increasing POC formation. • Manure substitution was more beneficial to form POC with abundant recalcitrant C levels. [ABSTRACT FROM AUTHOR]