Next Article in Journal
Flower Thinning Strategy of Flat Peach Inflorescence Based on RBCN-YOLO
Previous Article in Journal
Comparative Study on Photosynthetic Characteristics and Leaf Structure of Paphiopedilum parishii in Different Growth Periods
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Agronomy
Volume 15
Issue 12
10.3390/agronomy15122716
agronomy-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Partial Replacement of Chemical Fertilizer by Biochar-Based Fertilizer Increases Rice Yield and Soil Quality

by
Chao Ding
1,
Xikun Luo
2,
Yuhui Wang
3,
Weihua Long
1,
Yongxiang Guan
4,
Qiong Hou
1,
Cansheng Yuan
1 and
Lin Wang
1,*
1
Rural Revitalization College, Jiangsu Open University, Nanjing 210036, China
2
Rice Research Institute, Guizhou Academy of Agricultural Sciences, Guiyang 550006, China
3
Key Laboratory of Crop Physiology Ecology and Production Management, Nanjing Agricultural University, Nanjing 211800, China
4
Jiangsu Provincial Agricultural Technology Extension Station, Nanjing 210013, China
*
Author to whom correspondence should be addressed.
Agronomy 2025, 15(12), 2716; https://doi.org/10.3390/agronomy15122716
Submission received: 25 October 2025 / Revised: 18 November 2025 / Accepted: 24 November 2025 / Published: 25 November 2025
(This article belongs to the Section Soil and Plant Nutrition)
Browse Figures
Versions Notes

Abstract

Substituting chemical fertilizers with organic fertilizers is a significant agricultural practice that can enhance crop yield while influencing soil activity. To investigate the effects of biochar-based organic fertilizer on rice yield, quality, and soil physicochemical properties and activity, this study conducted a field experiment with three treatments: chemical fertilizer only (CK), 30% of chemical nitrogen substituted with conventional organic fertilizer (CF), and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF). Compared with chemical fertilizer alone (CK), both CF and BF treatments significantly increased rice yield by 8.9% and 14.2%, respectively, with BF showing a further increase over CF, primarily attributed to an 18.7% increase in panicle number. Both organic fertilizer treatments significantly improved grain quality, reducing amylose content by 4.6% and 13.1%, and increasing taste value by 3.3% and 3.6%, respectively. Dry matter accumulation throughout the growth period was significantly enhanced, with BF increasing total dry weight by 11.2% at maturity compared to CK. Root morphology was markedly improved, with BF increasing root volume by 146.1% at the grain-filling stage. Soil nutrient content was significantly elevated, showing maximum increases under BF of 118.9% for alkali-hydrolyzable nitrogen, 51.7% for ammonium nitrogen, 30.6% for available phosphorus, and 177.6% for available potassium. Soil enzyme activity analysis revealed significant enhancements in urease, acid phosphatase, and sucrase activities, with maximum increases of 91.5%, 105.6%, and 104.2%, respectively, under BF. These findings demonstrate that organic fertilizers, particularly biochar-based organic fertilizer, can synergistically enhance rice yield and quality by promoting root growth, strengthening soil microbial activity and enzymatic reactions, and optimizing nutrient supply. Biochar-based organic fertilizer exhibits significant advantages in improving soil biological fertility and maintaining stable nutrient supply during the late growth stages of rice.

1. Introduction

Rice is one of the most widely cultivated crops in China and even the world, and its stable and high yield is crucial to food security. Fertilizer input is a fundamental approach to ensuring high and stable crop yields. Numerous studies have shown that mineral or synthetic fertilizers contribute approximately 40% or even more to grain yield [1,2]. The application of mineral or synthetic fertilizers can effectively enhance soil fertility, promote plant growth, and increase crop production. However, the excessive use of mineral or synthetic fertilizers, especially nitrogen fertilizers, leads to a series of soil issues such as soil nutrient imbalance and acidification, which are detrimental to long-term crop cultivation [3,4].
Rational reduction of nitrogen fertilizer application is an effective way to promote the sustainable use of farmland soil. The application of organic fertilizers enhances soil organic matter and nutrient content while stimulating microbial activity. Furthermore, this improvement in soil properties promotes crop absorption of nutrients, leading to increased yield and quality. Ultimately, these practices contribute to soil physicochemical amelioration, achieving the dual goals of quality enhancement and efficiency improvement [5]. Therefore, substituting nitrogen fertilizers by organic fertilizers is an effective technique to increase rice yield, improve soil fertility, and achieve green rice production [6,7]. In current practical production, a common nitrogen substitution method is replacing part of the chemical nitrogen fertilizer with organic fertilizer, while the application rates of phosphorus and potassium fertilizers remain unchanged [8,9].
Biochar-based organic fertilizer is a novel type of organic fertilizer that uses biochar as a carrier. It combines the advantages of biochar, such as a large surface area, high porosity, improved soil aeration, and enhanced soil environment, with strong adsorption capacity, which prevents nutrient loss and enables slow release of fertilizer nutrients, thereby promoting crop growth [10]. Combining biochar-based organic fertilizer with reduced chemical fertilizer application can improve fertilizer utilization efficiency, stabilize yields, and even increase production [11,12]. Previous studies have extensively explored the substitution of conventional chemical fertilizers with biochar-based fertilizers [13,14,15], which indicates that long-term application of biochar does not enhance rice yield, while short-term application can significantly increase it, but there is limited research on biochar-based fertilizer substitution in soils with low basal fertility. Therefore, this experiment uses the rice variety Nanjing 9108 as the test material to study the effects of substituting conventional urea in base fertilizer with biochar-based fertilizer on rice yield formation, quality, and soil physicochemical characteristics under conditions of low-fertility sandy loam soil, aiming to provide a basis for the application and promotion of biochar-based fertilizer in production.

2. Materials and Methods

2.1. Study Site and Experimental Design

A field experiment was conducted from May to October 2023 and 2024 at the Baima Teaching and Research Base of Nanjing Agricultural University, Baima Town, LiShui District, Jiangsu Province (119°10′48.482″ E, 31°36′51.559″ N). The experimental soil was classified as sandy clay loam, with the following basic nutrient properties: organic matter content 1.87%, total nitrogen 0.75 g/kg, available potassium 99.87 mg/kg, available phosphorus 18.48 mg/kg, ammonium nitrogen 18.55 mg/kg, alkali-hydrolyzable nitrogen 48.92 mg/kg, and pH 6.93. The tested rice variety was Nanjing 9108, a late-maturing medium japonica cultivar widely cultivated in Jiangsu Province, developed by the Institute of Food Crops, Jiangsu Academy of Agricultural Sciences. The organic fertilizers used included a biochar-based organic fertilizer (Biochar content ≥ 20%, organic matter content ≥ 50%, pH 7.9, nitrogen content 2%, and CEC 154.5 cmol/kg) provided by Shanghai SEK Bio-Technology Co., Ltd. (Shanghai, China) and a conventional organic fertilizer (Organic matter content ≥ 48.3%, pH 7.6, nitrogen content 2%, and CEC 71.5 cmol/kg.) supplied by Nanjing Ningliang Bio-Fertilizer Co., Ltd. (Nanjing, China). The conventional organic fertilizer was prepared by composting a mixture of livestock manure and edible mushroom residue in a 4:1 volumetric ratio. The biochar-based organic fertilizer was produced by further composting the initial compost mixture of the conventional organic fertilizer with biochar in a specific dry mass ratio. The biochar was produced using rice and wheat straw as raw materials through anaerobic pyrolysis at 500 °C for 10 h, followed by natural cooling and sieving through a 40-mesh sieve.
The field experiment comprised three treatments arranged in a randomized complete block design with three replications, totaling nine plots, each covering an area of 25 m2. The fertilization treatments included: synthetic fertilizer (CK); 30% of chemical nitrogen substituted with conventional organic fertilizer (CF); and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF). the total nitrogen application rate was maintained consistently at 300 kg ha−1 across all three treatments. The specific nutrient input amounts for each treatment are detailed in Table 1.
The seedlings were cultivated using the hard-ground micro-sprinkler seedling raising system. Sowing was conducted on 24 May, and transplanting followed on 17 June. The planting density was set at a hill spacing of 12 cm and row spacing of 30 cm, with multiple seedlings per hill. In the CK treatment, nitrogen (N) was applied as urea (N content: 46%), following a split application ratio of base fertilizer:tillering fertilizer:panicle grain fertilizer = 3:3:4. Phosphorus fertilizer (P2O5)was applied at a rate of 90 kg ha−1 using single superphosphate (P2O5 content: 12%), all of which was applied as base fertilizer. Potassium fertilizer (K2O) was applied at a rate of 120 kg ha−1, split equally between the base fertilizer and panicle grain fertilizer applications, using potassium chloride (K2O content: 60%). Organic fertilizer was applied in a single dose as base fertilizer. Prior to land preparation for rice, plastic film was used to cover the bunds (ridges) of each plot and pressed down to the plow pan layer to prevent nutrient leakage between plots. Each plot was equipped with independent inlet and outlet channels for water management. Irrigation followed the alternate wetting and drying (AWD) method. All other field management practices adhered to local high-yielding cultivation practices.

2.2. Sampling and Measurements

2.2.1. Yield Measurement

At maturity, the number of panicles per hill was surveyed for 100 hills across each plot to calculate the panicle number per unit area. Five representative rice plants were selected to examine the grains per panicle, seed-setting rate, and 1000-grain weight. Each plot was harvested for actual yield measurement, and the grain yield was converted to a standard moisture content of 14.5%.

2.2.2. Measurement of Major Rice Quality Indicators

Rice was harvested at the appropriate maturity stage, threshed using a threshing machine, air-dried to standard moisture levels, and stored for three months to allow physicochemical properties to stabilize. For each treatment, three 150 g samples were taken, and measurements were conducted with reference to the Chinese National Standard GB/T 17891-2017 (High-Quality Paddy) [16]. The parameters measured included brown rice rate, milled rice rate, head rice yield, chalky grain rate, chalkiness degree, protein content, and amylose content. A 30 g sample of milled rice was randomly weighed, and its total protein content was determined using an Infratec 1241 Grain Analyzer near-infrared rapid quality analyzer (FOSS Tecator, Höganäs, Sweden). Rice taste quality, including appearance, hardness, viscosity, balance score, and overall taste value, was measured using a rice taste analyzer (STSRFN1A, Satake Corporation, Tokyo, Japan).
The iodine colorimetric method was employed to determine the amylose content. The absorbance of standard samples with known amylose content was measured at a wavelength of 720 nm using a 722N visible spectrophotometer (Shanghai Yidian Analytical Instrument Co., Ltd., Shanghai, China). A standard curve was plotted with absorbance as the x-axis and amylose content as the y-axis. The amylose content of the test samples was then derived from their absorbance values based on this standard curve.
The Rapid Visco Analyzer (RVA) profile characteristics of rice flour were rapidly determined using a Super 3 RVA (Rapid Viscosity Analyzer, Newport Scientific Instruments, Warriewood, NSW, Australia).

2.2.3. Measurement of Plant Traits

Sampling was conducted at the jointing, heading, and maturity stages. Three representative hills, based on the average tiller number, were selected and separated into four parts: stems, leaves, panicles, and roots (from the 0–20 cm soil layer). The stems, leaves, and panicles were placed in an oven, deactivated at 105 °C for 30 min, and then dried at 80 °C until a constant weight was achieved. The dry matter mass of each part was measured using an electronic balance. Roots were carefully placed in a glass dish (with a thin layer of water) and scanned using a flatbed scanner. The resulting images were analyzed using the WinRHIZO root analysis system (Regent Instruments Inc., Quebec, Canada) to determine root length, root surface area, and root diameter.

2.2.4. Measurement of Soil Physicochemical Properties

At the jointing, heading, and maturity stages, three soil samples were collected from each plot at a depth of 15–20 cm. Each sample was a composite from multiple points within the plot. Plant residues and roots were removed. The collected samples were transported to the laboratory on ice packs. In the lab, further impurities were removed, and each sample was divided into three parts: one part was air-dried and sieved for detecting physicochemical properties like soil organic matter (requiring air-dried samples); another part was stored at 4 °C in a refrigerator for measuring pH and other physicochemical indicators (can use fresh samples).
For air-dried soil samples passed through a 1 mm sieve: Nitrate nitrogen (NO3−-N) was determined by KCl extraction-phenol disulfonic acid colorimetry, alkali-hydrolyzable nitrogen was measured by the alkaline hydrolysis diffusion method, available phosphorus was determined by NaHCO3 extraction-molybdenum blue colorimetry, and available potassium was measured by ammonium acetate extraction-flame photometry [17].
Soil enzyme activities were assessed as follows: Catalase activity was determined using the potassium permanganate titration method. Urease activity was measured by the indophenol blue colorimetric method. Acid phosphatase activity was determined using the disodium p-nitrophenyl phosphate colorimetric method. Sucrase (Invertase) activity was measured using the 3,5-dinitrosalicylic acid (DNS) colorimetric titration method [18].

2.3. Statistical Analysis

All data from this experiment were processed and statistically analyzed using Microsoft Excel 2021 and SPSS 27.0 software. Significance testing of means was performed using the Least Significant Difference (LSD) method at the 0.05 probability level (LSD0.05). Graphs were plotted using Origin 2021 and RStudio (Version 4.2.1).

3. Results

3.1. Rice Yield

Both CF and BF treatments significantly increased rice yield and its main yield components compared with CK (Table 2). Specifically, the CF treatment increased rice yield and panicle number by 8.89% and 10.3%, respectively, but decreased the seed-setting rate by 3.4%. The BF treatment resulted in even greater increases in these indicators, reaching 14.2%, 18.7%, and 4.9%, respectively, although the reduction in the seed-setting rate was also larger at 7.4%.
Further analysis revealed that the BF treatment showed a significant advantage of 4.8% in rice yield over the CF treatment. This yield advantage was mainly attributed to a significant 7.7% increase in panicle number, while no significant differences were observed in the seed-setting rate and 1000-grain weight between the two treatments.

3.2. Rice Quality

Both CF and BF treatments significantly improved rice quality compared with CK. The CF treatment reduced the amylose and protein contents by 4.6% and 19.8%, respectively, but increased the taste value by 3.3% (Table 3). The BF treatment had a more pronounced effect, reducing amylose and protein contents by 13.1% and 5.3%, respectively, and increasing the taste value by 3.6%.
Compared with CK, both CF and BF treatments significantly enhanced the cooking quality of rice. The CF treatment increased the peak viscosity, trough viscosity, breakdown value, and final viscosity by 6.4%, 3.8%, 10.7%, and 6.3%, respectively, while reducing the setback value by 6.8% (Table 4). In contrast, the BF treatment had a greater impact on these indicators, increasing peak viscosity, trough viscosity, breakdown value, and final viscosity by 10.7%, 4.6%, 21.0%, and 3.8%, respectively, but increasing the setback value by 52.7%.

3.3. Dry Matter

Both CF and BF treatments significantly promoted dry matter accumulation in various rice organs at different growth stages compared with CK (Figure 1). At the panicle initiation stage, the CF treatment significantly increased leaf, stem, and total dry weight by 8.6%, 11.0%, and 10.0%, respectively. The BF treatment showed even more significant promotion effects, with increases of 36.0%, 17.2%, and 25.1%, respectively. By the heading stage, the CF treatment increased leaf, stem, panicle, and total dry weight by 6.9%, 4.2%, 7.5%, and 6.0%, respectively, compared with CK. The BF treatment demonstrated stronger promotion effects, with increases of 26.2%, 18.0%, 15.5%, and 18.8%, respectively. At the maturity stage, the CF treatment increased stem and leaf dry weight, panicle dry weight, and total dry weight by 7.5%, 6.8%, and 7.1%, respectively. The increases under the BF treatment were even greater, reaching 10.9%, 11.4%, and 11.2%, respectively.

3.4. Root System

Both CF and BF treatments significantly improved root morphology at different growth stages compared with CK (Figure 2). At the panicle initiation stage, CF increased total root length, root surface area, average root diameter, and root volume by 28.6%, 4.1%, 12.1%, and 9.1%, respectively. BF increased these indicators by 100.6%, 40.6%, 7.6%, and 40.9%, respectively.
At the heading stage, CF increased total root length, root volume by 21.8% and 10.3%, respectively. BF increased these indicators by 24.3% and 20.6%, respectively.
At the grain filling stage, CF increased total root length, root surface area, average root diameter, and root volume by 23.2%, 32.1%, 13.2%, and 70.1%, respectively. BF increased these indicators by 41.9%, 76.8%, 23.8%, and 146.1%, respectively.

3.5. Soil Properties

Both CF and BF treatments significantly increased soil nutrient content compared with CK (Figure 3). The alkali-hydrolyzable nitrogen content increased by 50.1–82.1% under CF and 61.5–118.9% under BF; NH4+-N content increased by 30.7–51.6% under CF and 20.09–51.66% under BF; available phosphorus content increased by 21.06–23.16% under CF and 22.2–30.6% under BF; and available potassium content showed more significant increases of 108.5–154.0% under CF and 135.1–177.6% under BF.
In terms of soil enzyme activities, CF and BF treatments exhibited different regulatory effects (Figure 4). H2O2 activity was inhibited under both treatments, decreasing by 9.3–23.5% under CF and 16.4–22.8% under BF compared with CK. In contrast, urease activity increased significantly by 0.3–49.9% under CF and 13.6–91.5% under BF. Acid phosphatase activity also increased markedly by 19.5–36.6% under CF and 27.4–105.6% under BF. Sucrase activity significantly increased by 6.7–51.6% under CF and 32.0–104.2% under BF.

4. Discussion

4.1. Key Mechanisms of Organic Fertilizer Substitution in Enhancing Rice Yield

Partial substitution of synthetic fertilizer with organic fertilizer enhances rice yield primarily by increasing the number of panicles per unit area. The core mechanism lies in how organic fertilizer application optimizes the nutrient supply pattern and significantly improves root system morphology and function. Compared to the exclusive use of synthetic fertilizer, the nitrogen in organic fertilizer must be released through microbial mineralization. This process creates a slow-release and stable nutrient supply reservoir, ensuring that during the critical growth stage of tillering—which determines the panicle number—the rice receives a continuous and effective nutrient supply. This lays the material foundation for the early emergence of numerous tillers and their healthy development into effective panicles [19].
Furthermore, the application of organic fertilizer improves soil physical structure. The active substances produced during its decomposition stimulate root growth, leading to a significant increase in indicators such as total root length, root surface area, and root volume, thereby forming a more developed root system [20]. This virtuous cycle of “fertilizer promoting roots, and roots nourishing shoots” enables the rice plant to absorb and utilize soil nutrients and water more efficiently, thereby robustly supporting the initiation and growth of above-ground tillers, ultimately manifesting as a significant increase in panicle number.
The reason biochar-based organic fertilizer outperforms regular organic fertilizer in increasing yield is primarily attributed to the unique properties of its biochar component. The immense specific surface area and abundant porous structure of biochar make it an excellent nutrient reservoir, more effectively reducing nitrogen loss through volatilization and leaching, thus further improving nutrient use efficiency. It also works synergistically with organic matter to create a more persistent and steady slow-release effect, providing stronger momentum throughout the entire rice growth cycle [21,22]. Additionally, biochar’s ability to ameliorate soil physico-chemical properties far exceeds that of regular organic fertilizer. It significantly enhances the porosity, water retention, and nutrient retention capacity of low-fertility sandy loam soils, creating an excellent environment for root growth [23]. Simultaneously, biochar provides a habitat for beneficial microorganisms, enriching functional microbial communities that further activate soil nutrients. Together, these effects promote a “super” improvement in root morphological metrics [24]. This dual enhancement of “increased efficiency” and “root promotion” means that rice treated with biochar-based organic fertilizer achieves further superiority over that treated with regular organic fertilizer in terms of panicle formation, dry matter accumulation, and final yield.

4.2. Key Mechanisms of Organic Fertilizer Substitution in Improving Rice Eating Quality

In this study, while the conventional chemical fertilizer treatment (CK) exhibited rapid nutrient release initially, its concentrated release pattern led to insufficient later-stage supply, causing a sharp decline in nutrition during the mid-to-late grain filling stage. This resulted in incomplete grain filling, increased chalkiness, and altered starch and protein composition, ultimately reducing eating quality. In contrast, partial substitution with organic fertilizers demonstrated distinct advantages. Due to their inherent slow-release properties, CF and BF maintained a steady supply of nitrogen and other nutrients during the critical reproductive stages. This stable and prolonged nutrient availability ensured efficient transformation and transport of photosynthetic products during grain filling, leading to more uniform, complete, and plump grains. These improvements were directly reflected in significantly reduced amylose content and enhanced taste value [25]. BF outperformed CF in quality improvement, primarily due to the unique properties of its biochar component. The high adsorption capacity of biochar effectively reduced nitrogen leaching and volatilization losses, maintaining higher soil available nitrogen levels during the mid-to-late filling stage, achieving a “slow and steady” nutrient supply. This optimized nutrient regime not only more significantly regulated the amylose synthesis pathway but also moderately maintained protein content, favoring flavor formation. Furthermore, the marked improvement in cooking quality, evidenced by RVA (Rapid Visco Analyzer) profiles—such as a substantial increase in breakdown value and a decrease in setback value—confirmed the enhanced grain filling quality from a rheological perspective. A high breakdown value indicates soft and sticky cooked rice, while a low setback value suggests less hardening upon cooling. These superior cooking and eating traits are intrinsically linked to the high-quality grain structure fostered by adequate and stable nutrient supply during the filling period [26].
In summary, partial substitution of chemical fertilizers with organic fertilizers optimizes nutrient supply during the late growth stages of rice through slow-release characteristics, ensuring a smooth and substantial grain filling process. This is the core mechanism for improving rice quality. Biochar-based organic fertilizer further strengthens this mechanism via its biochar carrier, achieving better synchrony between nutrient supply and crop demand, thereby demonstrating more pronounced effects in enhancing rice eating and cooking quality.

4.3. Organic Fertilizer Substitution Activates Soil Nutrient Supply

In this study, the content of soil available nutrients was significantly improved under organic fertilizer treatments. CF and BF increased alkali-hydrolyzable nitrogen by 50.1–82.1% and 61.5–118.9%, ammonium nitrogen by 30.7–51.6% and 20.09–51.66%, available phosphorus by 21.1–23.2% and 22.2–30.6%, and available potassium by 108.5–154.0% and 135.1–177.6%, respectively. The enhancement of these nutrient indicators was significantly correlated with changes in soil enzyme activities [27]. The changes in key soil enzyme activities reflected increased microbial metabolic activity. Urease activity increased by 0.3–49.9% under CF and 13.6–91.5% under BF, indicating enhanced mineralization and transformation capacity of organic nitrogen. Acid phosphatase activity rose by 19.5–36.6% (CF) and 27.4–105.6% (BF), demonstrating significantly improved soil phosphorus activation capacity. Sucrase activity increased by 6.7–51.6% (CF) and 32.0–104.2% (BF), reflecting an accelerated soil carbon cycle process. The enhancement of these enzyme activities collectively promoted the transformation and supply of soil nutrients [28,29]. Notably, BF outperformed CF across all indicators, particularly in acid phosphatase and sucrase activities, where the improvement effect of BF was 2–3 times that of CF. This difference is likely attributable to the improved microbial habitat environment provided by the biochar carrier [30]. The porous structure and large specific surface area of biochar offer an excellent survival environment for microorganisms, facilitating the colonization and functional expression of microbial communities [18,31].
In conclusion, biochar-based organic fertilizer, significantly enhance the transformation efficiency and supply capacity of soil nutrients by activating the soil microbial community and enhancing key enzyme activities. This biological process is an important mechanism for improving soil fertility.

5. Conclusions

In summary, the findings of this study demonstrate that the partial substitution of synthetic fertilizer with organic fertilizer, particularly biochar-based organic fertilizer, is an effective strategy that synergistically enhances rice yield, improves grain quality, and promotes soil fertility. Owing to its unique biochar carrier, the biochar-based organic fertilizer exhibits significant advantages in enhancing the persistence of soil nutrient supply, promoting root development, and activating soil microbial function, outperforming conventional organic fertilizer. This technical model not only provides a feasible fertilization approach for green rice production but also offers important theoretical and practical foundations for the recycling of agricultural waste and the maintenance of soil health, indicating broad prospects for application and extension. Future research could further focus on its long-term effects and applicability across different soil types.

Author Contributions

Conceptualization, C.D.; methodology, C.D.; software, X.L.; validation, L.W., W.L. and Y.G.; formal analysis, C.D.; investigation, Y.W. and Q.H.; resources, L.W.; data curation, C.D. and X.L.; writing—original draft preparation, C.D.; writing—review and editing, C.D. and X.L.; visualization, C.D.; supervision, W.L., C.Y. and Y.G.; project administration, L.W. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by 2024 Jiangsu Province Higher Education Institutions Basic Sciences (Natural Sciences) General Research Project (24KJB2100038).

Data Availability Statement

The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.

Acknowledgments

We are appreciative of the students and farmers who assisted with the experiments for their institutional support, making this research possible.

Conflicts of Interest

The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.

References

  1. Zhang, W.F.; Ma, L.; Huang, G.Q.; Wu, L.; Chen, X.P.; Zhang, F.S. The Development and Contribution of Nitrogenous Fertilizer in China and Challenges Faced by the Country. Sci. Agric. Sin. 2013, 46, 3161–3171. [Google Scholar] [CrossRef]
  2. Zhou, W.; Ding, W.C. Strategic researches of reducing fertilizer use and increasing use efficiency in China in the new era. J. Plant Nutr. Fertil. 2023, 29, 1–7. [Google Scholar] [CrossRef]
  3. Ren, K.; Xu, M.; Li, R.; Zheng, L.; Liu, S.; Reis, S.; Wang, H.; Lu, C.; Zhang, W.; Gao, H. Optimizing nitrogen fertilizer use for more grain and less pollution. J. Clean. Prod. 2022, 360, 132180. [Google Scholar] [CrossRef]
  4. Li, N.; Tian, Y.L.; Zhang, L.; Wang, S.T.; Zhu, C.X.; Li, H.N. Research on action and technology for reducing fertilizer usage and enhancing efficiency in China. J. Agric. Resour. Environ. 2025, 42, 1–10. [Google Scholar] [CrossRef]
  5. Zhang, R.F.; Chen, Y.; Sun, X.L.; Xu, Z.H.; Miao, Y.Z.; Zhang, N.; Liu, D.Y.; Shen, Q.R. Biofertilizer and organic fertilizer research over thirty years in China: Retrospect and prospect. J. Plant Nutr. Fertil. 2024, 30, 1262–1273. [Google Scholar] [CrossRef]
  6. Zhu, Y.H.; Yin, J.; Ma, Z.H.; Yang, Y.P. Effect of Organic Fertilizer Replacing Nitrogen Fertilizer on Major Grain Yield in China. Environ. Sci. 2025, 46, 478–488. [Google Scholar] [CrossRef]
  7. Zhao, T.C.; He, A.B.; Khan, M.N.; Yin, Q.; Song, S.K.; Nie, L.X. Coupling of reduced inorganic fertilizer with plant-based organic fertilizer as a promising fertilizer management strategy for colored rice in tropical regions. J. Integr. Agric. 2024, 23, 93–107. [Google Scholar] [CrossRef]
  8. Hou, Q.; Ni, Y.M.; Huang, S.; Zuo, T.; Wang, J.; NI, W. Effects of substituting chemical fertilizers with manure on rice yield and soil labile nitrogen in paddy fields of China: A meta-analysis. Pedosphere 2023, 33, 172–184. [Google Scholar] [CrossRef]
  9. Hayatu, N.G.; Liu, Y.R.; Han, T.F.; Daba, N.; Zhang, L.; Shen, Z.; Li, J.-W.; Muazu, H.; Lamlom, S.F.; Zhang, H.M. Carbon sequestration rate, nitrogen use efficiency and rice yield responses to long-term substitution of chemical fertilizer by organic manure in a rice-rice cropping system. J. Integr. Agric. 2023, 22, 2848–2864. [Google Scholar] [CrossRef]
  10. Rasse, D.P.; Weldon, S.; Joner, E.J.; Joseph, S.; Kammann, C.I.; Liu, X.; O’Toole, A.; Pan, G.; Kocaturk-Schumacher, N.P. Enhancing plant N uptake with biochar-based fertilizers: Limitation of sorption and prospects. Plant Soil 2022, 475, 213–236. [Google Scholar] [CrossRef]
  11. Shi, W.; Bian, R.; Li, L.; Lian, W.; Liu, X.; Zheng, J.; Cheng, K.; Zhang, X.; Drosos, M.; Joseph, S. Assessing the impacts of biochar-blended urea on nitrogen use efficiency and soil retention in wheat production. Glob. Change Biol. Bioenergy 2022, 14, 65–83. [Google Scholar] [CrossRef]
  12. Yang, Z.; Liu, P.; Wang, S.; Zhang, B.; Li, H.; Wang, X.; Lv, S.; Li, J.; Abdo, A.I.; Wang, L. Optimum nitrogen rate combined with biochar increased wheat yield whileimproving lodging resistance. Eur. J. Agron. 2026, 172, 127849. [Google Scholar] [CrossRef]
  13. He, H.; Peng, M.; Lu, W.; Hou, Z.; Li, J. Commercial organic fertilizer substitution increases wheat yield by improving soil quality. Sci. Total Environ. 2022, 851, 158132. [Google Scholar] [CrossRef]
  14. Zhang, X.T.; Feng, X.Y.; Chai, N.; Kuzyakov, Y.; Zhang, F.; Li, F.M. Biochar effects on crop yield variability. Field Crops Res. 2024, 316, 109518. [Google Scholar] [CrossRef]
  15. Jin, P.; Chen, Z.; Wang, H.; Lv, R.; Hu, T.; Zhou, R.; Zhang, J.; Lin, X.; Liu, Q.; Xie, Z. 12-year continuous biochar application: Mitigating reactive nitrogen loss in paddy fields but without rice yield enhancement. Agric. Ecosyst. Environ. 2024, 375, 109223. [Google Scholar] [CrossRef]
  16. GB/T 17891-2017; High Quality Paddy. Standardization Administration of China: Beijing, China, 2017.
  17. Liu, S.B.; Wang, J.Y.; Pu, S.Y.; Blagodatskaya, E.; Kuzyakov, Y.; Razavi, B.S. Impact of manure on soil biochemical properties: A global synthesis. Sci. Total Environ. 2020, 745, 141003. [Google Scholar] [CrossRef]
  18. Wang, J.; Sun, L.J.; Sun, Y.F.; Yang, S.; Qin, Q.; Xue, Y. Integrated enzyme activities and untargeted metabolome to reveal themechanism that allow long-term biochar-based fertilizer substitution improves soil quality and maize yield. Environ. Res. 2025, 270, 120935. [Google Scholar] [CrossRef] [PubMed]
  19. Pan, Y.; Guo, J.; Fan, L.; Ji, Y.; Liu, Z.; Wang, F.; Pu, Z.; Ling, N.; Shen, Q.; Guo, S. The source-sink balance during the grain filling period facilitates rice production under organic fertilizer substitution. Eur. J. Agron. 2022, 134, 126468. [Google Scholar] [CrossRef]
  20. Xiang, Y.Z.; Deng, Q.; Duan, H.L.; Guo, Y. Effects of biochar application on root traits: A meta-analysis. Glob. Change Biol. Bioenergy 2017, 9, 1563–1572. [Google Scholar] [CrossRef]
  21. Shi, W.; Ju, Y.Y.; Bian, R.J.; Li, L.; Pan, G. Biochar bound urea boosts plant growth and reduces nitrogen leaching. Sci. Total Environ. 2020, 701, 134424. [Google Scholar] [CrossRef] [PubMed]
  22. Omokaro, G.O.; Kornev, K.P.; Nafula, Z.S.; Chikukula, A.A.; Osayogie, O.G.; Efeni, O.S. Biochar for sustainable soil management: Enhancing soil fertility, plant growth and climate resilience. Farming Syst. 2025, 3, 100167. [Google Scholar] [CrossRef]
  23. Tahery, S.; Munroe, P.; Marjo, C.E.; Rawal, A.; Horvat, J.; Mohammed, M.; Webber, J.B.W.; Arns, J.-Y.; Arns, C.H.; Pan, G.; et al. A comparison between the characteristics of a biochar-NPK granule and a commercial NPK granule for application in the soil. Sci. Total Environ. 2022, 832, 155021. [Google Scholar] [CrossRef]
  24. Xu, Z.C.; Zhou, R.; Xu, G.R. Global analysis on potential effects of biochar on crop yields and soil quality. Soil Ecol. Lett. 2025, 7, 240267. [Google Scholar] [CrossRef]
  25. Kakar, K.; Xuan, T.D.; Noori, Z.; Aryan, S.; Gulab, G. Effects of Organic and Inorganic Fertilizer Application on Growth, Yield, and Grain Quality of Rice. Agriculture 2020, 10, 544. [Google Scholar] [CrossRef]
  26. Ali, I.; Iqbal, A.; Ullah, S.; Muhammad, I.; Yuan, P.L.; Zhao, Q.; Yang, M.; Zhang, H.; Huang, M.; Liang, H.; et al. Effects of Biochar Amendment and Nitrogen Fertilizer on RVA Profile and Rice Grain Quality Attributes. Foods 2022, 11, 625. [Google Scholar] [CrossRef]
  27. Iqbal, A.; Liang, H.; McBride, S.G.; Yuan, P.L.; Ali, I.; Zaman, M.; Zeeshan, M.; Khan, R.; Akhtar, K.; Wei, S.Q.; et al. Manure applications combined with chemical fertilizer improves soil functionality, microbial biomass and rice production in a paddy field. Agron. J. 2022, 114, 1431–1446. [Google Scholar] [CrossRef]
  28. Liu, J.; Shu, A.P.; Song, W.F.; Shi, W.C.; Li, M.C.; Zhang, W.X.; Li, Z.Z.; Liu, G.R.; Yuan, F.S.; Zhang, S.X.; et al. Long-term organic fertilizer substitution increases rice yield by improving soil properties and regulating soil bacteria. Geoderma 2021, 404, 115287. [Google Scholar] [CrossRef]
  29. Li, X.; Li, B.; Chen, L.; Liang, J.Y.; Huang, R.; Tang, X.Y.; Zhang, X.; Wang, C.Q. Partial substitution of chemical fertilizer with organic fertilizer over seven years increases yields and restores soil bacterial community diversity in wheat-rice rotation. Eur. J. Agron. 2022, 133, 126445. [Google Scholar] [CrossRef]
  30. Feng, W.H.; Sánchez-Rodríguez, A.R.; Bilyera, N.; Wang, J.Q.; Wang, X.Q.; Han, Y.H.; Ma, B.X.; Zhang, H.Y.; Li, F.; Zhou, J.; et al. Mechanisms of biochar-based organic fertilizers enhancing maize yield on a Chinese Chernozem: Root traits, soil quality and soil microorganisms. Environ. Technol. Innov. 2024, 36, 103756. [Google Scholar] [CrossRef]
  31. Zhang, K.; Khan, Z.; Khan, M.N.; Luo, T.; Luo, L.J.; Bi, J.G.; Hu, L.Y. The application of biochar improves the nutrient supply efficiency of organic fertilizer, sustains soil quality and promotes sustainable crop production. Food Energy Secur. 2024, 13, e520. [Google Scholar] [CrossRef]
Agronomy 15 02716 g001
Figure 1. Aboveground dry matter accumulation of the plants under synthetic fertilizer treatment (CK), 30% of chemical nitrogen substituted with conventional organic fertilizer (CF), and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF). Notes: PI, HS and MS means panicle initiation stage, heading stage and maturity stage. Different lowercase letters above bars of the same color indicate significant differences at the 0.05 level.
Figure 1. Aboveground dry matter accumulation of the plants under synthetic fertilizer treatment (CK), 30% of chemical nitrogen substituted with conventional organic fertilizer (CF), and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF). Notes: PI, HS and MS means panicle initiation stage, heading stage and maturity stage. Different lowercase letters above bars of the same color indicate significant differences at the 0.05 level.
Agronomy 15 02716 g001
Agronomy 15 02716 g002
Figure 2. Root morphological characteristics of the plants under chemical fertilizer alone treatment (CK), conventional organic fertilizer substitution treatment (CF) and biochar-based fertilizer substitution treatment (BF). Each data in (A–D) represents the value of total root length, root surface area, mean root diameter and root volume for each treatment, respectively. Notes: PI, HS and FS means panicle initiation stage, heading stage and filling stage. Different lowercase letters above bars of different colors indicate significant differences at the 0.05 level.
Figure 2. Root morphological characteristics of the plants under chemical fertilizer alone treatment (CK), conventional organic fertilizer substitution treatment (CF) and biochar-based fertilizer substitution treatment (BF). Each data in (A–D) represents the value of total root length, root surface area, mean root diameter and root volume for each treatment, respectively. Notes: PI, HS and FS means panicle initiation stage, heading stage and filling stage. Different lowercase letters above bars of different colors indicate significant differences at the 0.05 level.
Agronomy 15 02716 g002
Agronomy 15 02716 g003
Figure 3. Soil physicochemical properties under chemical fertilizer alone treatment (CK), conventional organic fertilizer substitution treatment (CF) and biochar-based fertilizer substitution treatment (BF). Each data in (A–D) represents the value of alkali-hydrolyzable N, NH4+-N, available phosphorus and available potassium for each treatment, respectively. Notes: PI, HS and FS mean panicle initiation stage, heading stage and filling stage. Different lowercase letters above bars of different colors indicate significant differences at the 0.05 level.
Figure 3. Soil physicochemical properties under chemical fertilizer alone treatment (CK), conventional organic fertilizer substitution treatment (CF) and biochar-based fertilizer substitution treatment (BF). Each data in (A–D) represents the value of alkali-hydrolyzable N, NH4+-N, available phosphorus and available potassium for each treatment, respectively. Notes: PI, HS and FS mean panicle initiation stage, heading stage and filling stage. Different lowercase letters above bars of different colors indicate significant differences at the 0.05 level.
Agronomy 15 02716 g003
Agronomy 15 02716 g004
Figure 4. Activities of relevant soil enzymes under chemical fertilizer alone treatment (CK), conventional organic fertilizer substitution treatment (CF) and biochar-based fertilizer substitution treatment (BF). Each data in (A–D) represents the value of H2O2 activity, urease activity, acid phosphatase activity and sucrase activity for each treatment, respectively. Notes: PI, HS and FS means panicle initiation stage, heading stage and filling stage. Different lowercase letters above bars of different colors indicate significant differences at the 0.05 level.
Figure 4. Activities of relevant soil enzymes under chemical fertilizer alone treatment (CK), conventional organic fertilizer substitution treatment (CF) and biochar-based fertilizer substitution treatment (BF). Each data in (A–D) represents the value of H2O2 activity, urease activity, acid phosphatase activity and sucrase activity for each treatment, respectively. Notes: PI, HS and FS means panicle initiation stage, heading stage and filling stage. Different lowercase letters above bars of different colors indicate significant differences at the 0.05 level.
Agronomy 15 02716 g004
Table 1. Nutrient Input Amounts for synthetic fertilizer treatment (CK), 30% of chemical nitrogen substituted with conventional organic fertilizer (CF), and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF).
Table 1. Nutrient Input Amounts for synthetic fertilizer treatment (CK), 30% of chemical nitrogen substituted with conventional organic fertilizer (CF), and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF).
TreatmentsBase Fertilizer (kg ha−1)Tillering Fertilizer
(kg ha−1)		Panicle Fertilizer
(kg ha−1)
Organic FertilizerUreaUreaUrea
CK0195.6195.6260.8
CF45000195.6260.8
BF45000195.6260.8
Table 2. Rice yield and its component factors under synthetic fertilizer treatment (CK), 30% of chemical nitrogen substituted with conventional organic fertilizer (CF), and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF).
Table 2. Rice yield and its component factors under synthetic fertilizer treatment (CK), 30% of chemical nitrogen substituted with conventional organic fertilizer (CF), and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF).
TreatmentPanicle Number (m−2)Spikelets Per PanicleSeed Setting Rate (%)Grain Weight (mg)Yield (t ha−1)
CK268.5 C149.2 A94.0 A26.6 B10.0 C
CF296.1 B148.5 A90.8 B27.3 AB10.9 B
BF318.8 A147.6 A87.0 C27.9 A11.4 A
Notes: Means in the same column followed by different uppercase letters are significantly different at the 0.05 level.
Table 3. Rice taste values and nutritional qualities under synthetic fertilizer treatment (CK), 30% of chemical nitrogen substituted with conventional organic fertilizer (CF), and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF).
Table 3. Rice taste values and nutritional qualities under synthetic fertilizer treatment (CK), 30% of chemical nitrogen substituted with conventional organic fertilizer (CF), and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF).
TreatmentAmylose Content (%)Protein Content (%)Taste Value
CK11.0 A11.8 A79.7 C
CF10.5 B9.5 B82.3 B
BF9.1 C9.0 B85.3 A
Notes: Means in the same column followed by different uppercase letters are significantly different at the 0.05 level.
Table 4. Rapid visco-analyzer (RVA) profile characteristics of rice under synthetic fertilizer treatment (CK), 30% of chemical nitrogen substituted with conventional organic fertilizer (CF), and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF).
Table 4. Rapid visco-analyzer (RVA) profile characteristics of rice under synthetic fertilizer treatment (CK), 30% of chemical nitrogen substituted with conventional organic fertilizer (CF), and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF).
TreatmentPeak ViscosityTrough ViscosityBreakdownFinal ViscositySetback
CK2720.3 C1710.7 B1009.7 C2336.7 B−383.7 A
CF2894.0 B1776.0 A1118.0 B2484.3 A−409.7 B
BF3011.0 A1789.0 A1222.0 A2425.3 A−585.7 C
Notes: Means in the same column followed by different uppercase letters are significantly different at the 0.05 level.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Ding, C.; Luo, X.; Wang, Y.; Long, W.; Guan, Y.; Hou, Q.; Yuan, C.; Wang, L. Partial Replacement of Chemical Fertilizer by Biochar-Based Fertilizer Increases Rice Yield and Soil Quality. Agronomy 2025, 15, 2716. https://doi.org/10.3390/agronomy15122716

AMA Style

Ding C, Luo X, Wang Y, Long W, Guan Y, Hou Q, Yuan C, Wang L. Partial Replacement of Chemical Fertilizer by Biochar-Based Fertilizer Increases Rice Yield and Soil Quality. Agronomy. 2025; 15(12):2716. https://doi.org/10.3390/agronomy15122716

Chicago/Turabian Style

Ding, Chao, Xikun Luo, Yuhui Wang, Weihua Long, Yongxiang Guan, Qiong Hou, Cansheng Yuan, and Lin Wang. 2025. "Partial Replacement of Chemical Fertilizer by Biochar-Based Fertilizer Increases Rice Yield and Soil Quality" Agronomy 15, no. 12: 2716. https://doi.org/10.3390/agronomy15122716

APA Style

Ding, C., Luo, X., Wang, Y., Long, W., Guan, Y., Hou, Q., Yuan, C., & Wang, L. (2025). Partial Replacement of Chemical Fertilizer by Biochar-Based Fertilizer Increases Rice Yield and Soil Quality. Agronomy, 15(12), 2716. https://doi.org/10.3390/agronomy15122716

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop