1 Introduction

Integrated rice-fish farming is an agricultural method that combines rice cultivation with aquaculture. This method is more environmentally friendly and can also bring good economic benefits. Fish, ducks, or crayfish and other aquatic animals are raised in rice fields, and they can cooperate with rice. On the one hand, this can make the nutrient cycle in the field smoother, reduce pests, and improve the soil; on the other hand, it can also help increase food production (Jin et al., 2020). Farming aquatic animals can also bring additional income, while using less fertilizers and pesticides and reducing environmental pollution. Now, many places have already had similar traditional farming practices, and people are paying more and more attention to the role of this method in food security and sustainable agricultural development (Prakash et al., 2022; Anwar et al., 2023).

Traditional rice farming methods rely heavily on fertilizers and pesticides. If they are used too much, it is easy to make the soil and water quality deteriorate, and the number of plant and animal species will decrease. These problems will make this farming method more and more difficult to sustain. As the input increases, the effect is declining, such as the soil fertility decreases, pests become more difficult to control, and the final yield does not increase much. Moreover, traditional methods often fail to make good use of existing natural resources, resulting in low efficiency and waste (Syed et al., 2023; Wang et al., 2023).

Given the many limitations of traditional rice cultivation, there is an urgent need to optimize rice production management in the rice-fish integrated system. This study takes the rice-fish symbiotic system as the core, systematically analyzes its application mechanism and advantages in rice production management, combines typical breeding models in different regions, and optimizes and analyzes key links such as rice planting density, fertilization management, water regulation, and pest and disease control through field empirical surveys and production practice data, in order to improve the productivity and sustainability of the system by screening effective symbiotic breeding models. This is of great significance for expanding the application scope of rice-fish integrated breeding, meeting the needs of sustainable food production, and ensuring the long-term stability of agricultural ecosystems.

2 Structural Components of Rice-Fish Co-Culture Management

2.1 Field layout and land shaping adaptations

In the rice-fish co-cultivation system, how the fields are arranged and how the terrain is shaped are very important. These are directly related to whether rice and aquaculture can produce high yields together. Traditional paddy fields are generally transformed, such as digging ditches or opening ditches on the ridges of the fields, so that fish have places to hide and swim, so that they are easier to survive and grow faster (Jin et al., 2020). This is not only beneficial for fish farming, but also makes the water flow in the fields smoother and the nutrients more evenly distributed, which helps rice grow better. When designing fields, we should not only consider rice, but also take into account the needs of fish. For example, the water should not be too deep or too shallow, and the location of rice planting and fish activities should be arranged reasonably so that both can grow well.

2.2 Hydrological connectivity between paddy and aquaculture areas

Effective hydrological connectivity is the basis for the success of rice-fish co-cultivation. This connectivity facilitates the effective exchange of water, nutrients and organisms between rice fields and aquaculture areas, thereby maintaining ecological balance and optimizing output benefits (Jiao et al., 2020). Scientific water management measures, such as precision irrigation and reasonable drainage, are the key to maintaining suitable water levels and water quality, providing a good living environment for fish and ensuring the absorption of water and nutrients by rice (Ohira et al., 2015; Du et al., 2022).

2.3 Framework for coordinated crop-aquaculture management

Building a coordinated management framework is the key to achieving a benign interaction between rice cultivation and aquaculture. For example, when rice is planted and harvested should be in sync with when fish are released and caught, so that resources can be better utilized and conflicts between the two operations can be avoided (Li et al., 2025). Another benefit of putting fish in the fields is that fish can eat insects and weeds, which can help reduce pests and diseases. This method does not require too much pesticide, makes the entire system more stable, and increases yields. By establishing a systematic and integrated collaborative management mechanism, the rice-fish farming system can achieve higher economic and environmental benefits (Cazenave et al., 2024).

3 Agronomic Practices for Optimized Rice-Fish Integration

3.1 Adjusted transplanting methods and planting density

Planting too densely or inappropriate transplanting methods will affect the effect of the rice-fish system. Adjusting the transplanting method and planting density is the key to increasing the yield of rice and fish. For example, planting rice with dry direct seeding (DSR) not only saves labor and water, but is also more suitable for the current climate than the traditional paddy field transplanting method (PTR). Planting too densely will leave fish no place to move; too sparsely, the rice will not grow well (Duan et al., 2019; Dou et al., 2021). Therefore, the density must be arranged reasonably so that both rice and fish can grow well and the ecology in the field will be more balanced.

3.2 Dynamic water management and alternate wetting-drying

Dynamic water management, especially the "wet-dry" (AWD) irrigation technology, is a key strategy to improve water use efficiency and enhance crop resistance in rice-fish co-culture. "Wet-dry" (AWD) means sometimes letting the field dry for a period of time and then irrigating it. This can save water, reduce greenhouse gas emissions, and is good for the environment. At the same time, this method can also help adjust the temperature and quality of water, so fish can survive more easily and grow faster in such water (Figure 1) (Zhang et al., 2023).

Figure 1  Conceptual diagram of AWD influencing rice yield (Adopted from Zhang et al., 2023)

3.3 Integrated pest management with eco-friendly approaches

The rice-fish system also needs to prevent diseases and pests, but it cannot always rely on pesticides. Integrated pest management (IPM) is to use more environmentally friendly methods to deal with pests. For example, you can grow insect-resistant rice varieties, or you can rely on fish to eat some insects. In this way, less pesticides are used and the ecology of the field is healthier (Kabir and Rainis, 2015). Although this method is good, it is not used much now, mainly because farmers do not understand it and have not learned it. If there is more training and publicity, people will be more willing to use it, and the rice-fish system will become more stable and efficient.

4 Nutrient and Input Management in Integrated Systems

4.1 Nutrient cycling through organic and aquaculture inputs

In the rice-fish system, adding organic fertilizer and fish excrement can make the nutrient cycle smoother and more environmentally friendly. Fish feces are natural organic fertilizers that can increase the organic matter in the soil and make microorganisms active. In this way, the roots of rice can absorb more nutrients (Orellana et al., 2017; Jernigan et al., 2024). This method can use less chemical fertilizers, save money and reduce pollution, so that both rice and fish can grow better.

4.2 Efficient fertilizer use and application timing

If you want to use less chemical fertilizers but get better results, the method is also very important. For example, "micro-fertilization" is to apply a little fertilizer at the sowing point or near the roots of rice, which can make the fertilizer absorbed faster, especially suitable for soils with insufficient nutrients (Tsujimoto et al., 2021). In addition, when to apply fertilizers is also important. If the fertilization time can be matched with the key growth period of rice, fertilizer loss can be reduced, rice can grow better, and the environment can be safer.

4.3 Feed management and its impact on soil and water quality

In the rice-fish system, feeding fish also requires methods. The type and amount of feed will affect the nutrients in water and soil. If you feed too much, it is easy to make the water quality deteriorate and the soil will also have problems (Otero-Jiménez et al., 2021; Takele et al., 2023). Therefore, feeding should be reasonable. When to feed and how much to feed should be arranged according to the actual situation. In this way, the fish can eat well, the rice can grow normally, and the whole system can operate healthily and continuously.

5 Environmental and Economic Benefits

5.1 Improved water use efficiency and irrigation savings

The rice-fish system can reduce the number of irrigations, and there is no need to release water all the time, which saves a lot of water. With fish in the fields, the water level is more stable and the water quality is better, so there is no need to add water frequently. Because less water is used, pumping water does not use as much electricity, which naturally saves energy. Overall, this management method is beneficial to water conservation and sustainable agricultural development (Ahmed et al., 2025).

5.2 GHG mitigation and carbon sequestration potential

Compared with traditional rice cultivation methods, the rice-fish system can emit less greenhouse gases, especially methane (CH₄) and nitrous oxide (N₂O) (Shakoor et al., 2021; Yoo et al., 2024). Fish farming can also help improve the soil environment and allow the soil to absorb more carbon, which is also helpful in mitigating global warming (Hu et al., 2023). In addition, "dry-wet alternating irrigation" and the use of organic fertilizers can not only reduce gas emissions, but also make the soil healthier.

5.3 Diversified outputs and increased farmer income

The rice-fish model can not only grow rice, but also raise fish. With more output, farmers can make more money in more diversified ways. In this way, not only is food guaranteed, but income is also more stable. Whether it is market price fluctuations or bad weather, this combination of planting and breeding is more resistant to risks and is easier to be accepted and promoted by farmers (Liu and Chuang, 2023).

6 Case Studies and Regional Model Adaptation

6.1 Low-input, efficient rice-turtle model in Jiangxi

"Turtle-rice symbiosis" means that both produce and grow at the same time, which is a win-win model. It is based on paddy fields (ponds), with the high-quality and safe production of rice and turtles as the core, giving full play to the advantages of turtle-rice symbiosis in weeding, pest control, insect repellent, and fertilizing fields, so as to achieve organic, pollution-free and high-quality agricultural product production (Thornavalli et al., 2024). The turtle and rice live together, as if returning to the wild environment. The turtle can hide in the rice bushes to play, and eat more "wild things", such as insects, frogs, snails, grass seeds, etc. in the rice fields and on the rice leaves. These are all natural feeds that could not be eaten in the simple turtle pond before. For rice, the feces of turtles and the amino acids in the pond are used as fertilizers for rice planting, without the need for weeding, fertilization and medication, which improves the quality of rice. The most serious harm to rice is the brown rice louse, and the larvae will eat a large number of rice leaves. Now putting turtles in rice fields has a significant insect-proof effect (Figure 2) (Shi et al., 2023).

Figure 2 Model of rice-brown planthopper interactions (Adopted from Shi et al., 2023)

As a demonstration base, Zhejiang Qingxi Turtle Industry Co., Ltd. has started continuous turtle-rice rotation experiments since 1999, and has been conducting turtle-rice symbiosis experiments since 2010. Through more than 50 different models of experiments and control experiments, it has explored a variety of successful turtle-rice rotation and symbiosis models, accumulated relatively mature experience, and has been fully affirmed by the Fisheries Bureau of the Ministry of Agriculture, the National Aquatic Technology Extension Center, the Provincial Ocean and Fisheries Bureau and other superior departments and leaders.

The modern and advanced agricultural production model of turtle-rice symbiosis and rotation has not only improved economic benefits, but also ensured the stability of grain planting area, solved the worries of "what to do with grain", played a role in stabilizing grain and increasing income, and effectively promoted social stability and security. At the same time, it also played a good demonstration role, driving other aquaculture farmers to try and innovate (Wang et al., 2023).

6.2 Ecological cycling in rice-fish systems of Guangxi

The rice-fish integrated farming model has improved the ecological environment of rice fields. Rice-fish intercropping, fish feed on pests and weeds in rice fields, and rice uses fish feces as fertilizer, creating good growth conditions for rice growth. After the ban on pesticides and chemical fertilizers, the quality of rice has been greatly improved (Jin et al., 2020). This model has the advantages of increasing grain, increasing fertilizer, saving land, and being green and environmentally friendly. It also has the advantages of "not competing with people for grain, not competing with grain for land", achieving multiple uses of one field and one water, which not only ensures food security but also promotes farmers' income.

In the early years, crayfish became a delicacy on the table, pond farming gradually became saturated, and the growth of farming scale was hindered, so people turned their attention to idle paddy fields. Unexpectedly, the water layer depth and water quality of the rice fields were just right for them, as if they had found a home suitable for their growth. After little by little experiments by farmers in Pengze County, Jiujiang City, Jiangxi Province, the integrated rice-fish farming model, which mainly focuses on rice-crabs, rice-fishes and rice-turtles, has gradually matured. Crayfish are raised in rice fields in spring, and crabs and Pengze crucian carp are raised in rice fields in summer. This has formed a benign co-cultivation model of "one rice, one shrimp, one crab and one fish", which has improved the comprehensive utilization efficiency of agricultural land and achieved the "three wins" goal of economic benefits, social benefits and ecological benefits. Pengze County has also actively innovated and practiced the combination of agriculture and tourism, agriculture and commerce, and agriculture and research, and promoted the integration of the industrial chain and the improvement of the value chain of the integrated rice-fish farming model.

6.3 Standardized and smart-controlled rice-shrimp systems in Sichuan

The rice-shrimp co-cultivation model does not destroy the field structure, which is conducive to the mechanization, large-scale planting and full planting of rice. At the same time, because crayfish are omnivores, they can eat grass and insects, effectively inhibiting the damage of weeds and pests during the rice planting season. Their feces, feed residues and shrimp shells can also fertilize the fields. When planting rice, basically no herbicides and insecticides are used, and the amount of pesticides is reduced by more than 90%, and the amount of chemical fertilizers is reduced by more than 50%. The quality of rice products is excellent. At the same time, the residual water after drainage from the cultivation of crayfish in the winter idle season can meet the water demand for rice planting. The rice planting process can also purify the rice fields, which has a significant protective effect on the ecology and water resources (Xu et al., 2023).

Xingwen County, Sichuan Province has developed a total area of ​​about 67,000 mu of rice and shrimp farming, with an annual output of about 4,500 tons, of which a large number of crayfish are sold by air. In order to solve the transportation problem, the Yibin Early Shrimp Industry Federation and others formally signed the "South Sichuan Early Shrimp Air Transport Service Agreement" with Yibin Airport Air Port Logistics Co., Ltd., and the South Sichuan Early Shrimp obtained nearly 10 air logistics transportation rights with preferential prices and priority services, and the highest comprehensive cost reduction was about 5 cents per catty.

The rice-shrimp farming system in Sichuan is a modern upgrade of the traditional co-cultivation model, integrating standardization and intelligent control technologies to optimize production efficiency. The system uses advanced environmental monitoring and automatic control technologies to manage water quality, water temperature and other key ecological factors in real time to ensure that both rice and crayfish are in optimal growth conditions. This intelligent management not only improves unit output efficiency, but also enhances the sustainability of the system by reducing resource waste and environmental pressure (Jin et al., 2020).

7 Concluding Remarks

Optimizing rice management through integrated rice-fish farming is an important way to develop green and efficient agriculture. There are several key points to optimize. For example, to improve water efficiency, water management methods such as "dry-wet alternation" should be used. At the same time, environmentally friendly pest and disease control methods should be used. These practices can make better use of resources on the one hand, and improve agricultural output and the ecological environment on the other. After aquatic products are brought in, the nutrient cycle is smoother and can be used. In this way, less fertilizer can be used and the soil is healthier. The system becomes more efficient, which is of great help to agricultural development.

However, the environmental conditions, farmers' habits and resource conditions in each place are different. Therefore, the rice-fish model cannot be a one-size-fits-all approach, but should be adjusted according to the actual local conditions. In this way, the effect is the best and more sustainable in the long run. In order to make farmers willing to use this method, there must be policy support, such as building infrastructure, providing technical training, and some subsidy measures. At the same time, the government should also encourage investment in scientific research and promote successful experiences, so that the rice-fish model can develop faster.

Now, digital agricultural technology is becoming more and more advanced. Many systems can be controlled automatically, such as intelligent water diversion, water quality and temperature monitoring. These technologies can help farmers manage resources and improve decision-making efficiency, resulting in higher yields and lower costs. As digital agriculture continues to develop, its integration with the rice-fish system will become increasingly close, and will also bring about a new agricultural model that is more efficient, more environmentally friendly and more profitable.

Acknowledgments

Thanks to the reviewers for their valuable feedback, which helped improve the manuscript.

Conflict of Interest Disclosure

The authors affirm that this research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest.

References

Ahmed S., Kumar V., Zaman A., Dewan M., Khatun A., Hossain K., Singh S., Timsina J., and Krupnik T., 2025, Dry direct-seeded and broadcast rice: A profitable and climate-smart alternative to puddled transplanted aus rice in Bangladesh, Field Crops Research, 322: 109739.

https://doi.org/10.1016/j.fcr.2025.109739

Anwar D., Bao Y., Zhou Y., Chen S., Zhou J., Li L., Cheng Z., Dong X., Shi X., Su X., Li L., Wang H., Wang Y., Li S., Li Q., Li X., Liu M., Sun J., Zhao N., Yang Y., Li Y., Wang Q., and Jia W., 2023, 778-P: efficacy and safety of supaglutide as add-on to metformin in patients with type 2 diabetes, Diabetes, 72(Suppl_1): 778-P.

https://doi.org/10.2337/db23-778-p

Cazenave J., Bacchetta C., Repetti M., and Rossi A., 2024, Biomarker responses in fish caged in a rice field during a bifenthrin application, Environmental Research, 263: 120240.

https://doi.org/10.1016/j.envres.2024.120240

Dou Z., Li Y., Guo H., Chen L., Jiang J., Zhou Y., Xu Q., Xing Z., Gao H., and Zhang H., 2021, Effects of mechanically transplanting methods and planting densities on yield and quality of Nanjing 2728 under rice-crayfish continuous production system, Agronomy, 11(3): 488.

https://doi.org/10.3390/AGRONOMY11030488

Du F., Hua L., Zhai L., Zhang F., Fan X., Wang S., Liu Y., and Liu H., 2022, Rice-crayfish pattern in irrigation-drainage unit increased N runoff losses and facilitated N enrichment in ditches, Science of the Total Environment, 848: 157721.

https://doi.org/10.1016/j.scitotenv.2022.157721

Duan M., Luo H., Pan S., Mo Z., Yang X., Tian J., Nie J., Li L., and Tang X., 2019, High transplant density causes yield loss and quality decrement by affecting photosynthesis, dry matter accumulation and transportation in super rice, Applied Ecology and Environmental Research, 17(3): 6069-6079.

https://doi.org/10.15666/AEER/1703_60696079

Hu W., Bai Z., Hu R., Diao Y., Xu X., and Wang H., 2023, Effects of different management patterns on greenhouse gas emissions from single-season rice fields, International Agrophysics, 37(4): 365-376.

https://doi.org/10.31545/intagr/163343

Jernigan A., Kao-Kniffin J., Pethybridge S., and Wickings K., 2024, Microarthropods improve oat nutritional quality and mediate fertilizer effects on soil biological activity, Agronomy Journal, 116(4): 2007-2033.

https://doi.org/10.1002/agj2.21597

Jiao Y., Zhao D., Xu Q., Liu Z., Ding Z., Ding Y., Liu C., and Zha Z., 2020, Mapping lateral and longitudinal hydrological connectivity to identify conservation priority areas in the water-holding forest in Honghe Hani Rice Terraces World Heritage Site, Landscape Ecology, 35(3): 709-725.

https://doi.org/10.1007/s10980-020-00975-0

Jin T., Ge C., Gao H., Zhang H., and Sun X., 2020, Evaluation and screening of co-culture farming models in rice field based on food productivity, Sustainability, 12(6): 2173.

https://doi.org/10.3390/su12062173

Kabir M., and Rainis R., 2015, Do farmers not widely adopt environmentally friendly technologies? Lessons from integrated pest management (IPM), Modern Applied Science, 9(3): 208.

https://doi.org/10.5539/MAS.V9N3P208

Li S.X., Jiang J., Lv W.G., Siemann E., Woodcock B.A., Wang Y.Q., Cavalieri A., Bai N., Zhang J.Q., Zheng X.Q., Zhang H.L., Zhang H.Y., Zhang Y., and Wan N.F., 2025, Rice-fish co-culture promotes multiple ecosystem services supporting increased yields, Agriculture, Ecosystems & Environment, 381: 109417.

https://doi.org/10.1016/j.agee.2024.109417

Liu W., and Chuang Y., 2023, Assessing the incentives and financial compensation of agroforestry considering the uncertainty of price and yield, Ecological Indicators, 146: 109753.

https://doi.org/10.1016/j.ecolind.2022.109753

Orellana L., Chee-Sanford J., Sanford R., Löffler F., and Konstantinidis K., 2017, Year-round shotgun metagenomes reveal stable microbial communities in agricultural soils and novel ammonia oxidizers responding to fertilization, Applied and Environmental Microbiology, 84(2): e01646-17.

https://doi.org/10.1128/AEM.01646-17

Otero-Jiménez V., Del Pilar Carreño-Carreño J., Barreto-Hernández E., Van Elsas J., and Uribe-Vélez D., 2021, Impact of rice straw management strategies on rice rhizosphere microbiomes, Applied Soil Ecology, 167: 104036.

https://doi.org/10.1016/J.APSOIL.2021.104036

Prakash N., Lokeshkumar B., Rathor S., Warraich A., Yadav S., Vinaykumar N., Dushynthkumar B., Krishnamurthy S., and Sharma P., 2022, Meta-analysis and validation of genomic loci governing seedling and reproductive stage salinity tolerance in rice, Physiologia Plantarum, 174(1): e13629.

https://doi.org/10.1111/ppl.13629

Shakoor A., Dar A., Arif M., Farooq T., Yasmeen T., Shahzad S., Tufail M., Ahmed W., Albasher G., and Ashraf M., 2021, Do soil conservation practices exceed their relevance as a countermeasure to greenhouse gases emissions and increase crop productivity in agriculture? Science of the Total Environment, 805: 150337.

https://doi.org/10.1016/j.scitotenv.2021.150337

Shi S., Wang H., Zha W., Wu Y., Liu K., Xu D., He G., Zhou L., and You A., 2023, Recent advances in the genetic and biochemical mechanisms of rice resistance to brown planthoppers (Nilaparvata lugens Stål), International Journal of Molecular Sciences, 24(23): 16959.

https://doi.org/10.3390/ijms242316959

Syed F., Ballew O., Lee C., Rana J., Castela Â., Weaver S., Thomaidou S., Demine S., De Brachène A., Alvelos M., Chang G., Orr K., Yamada K., Liu J., Zaldumbide A., Scheuner D., Eizirik D., and Evans-Molina C., 2023, 25-OR: ADA presidents' select abstract: preclinical evaluation of TYK2 inhibitors in type 1 diabetes, Diabetes, 72(Suppl_1): 25-OR.

https://doi.org/10.2337/db23-25-or

Takele W., Ukke G., Josefson J., Vesco K., Redman L., Grieger J., Habibi N., Quinteros A., Leung G., Zhou S., Taylor R., Pathirana M., Liu K., Bonham M., Chen M., Fawcett A., Chivers S., and Lim S., 2023, 659-P: the effectiveness of lifestyle, metformin, or dietary supplements for the prevention of gestational diabetes mellitus (GDM) by intervention characteristics—a systematic review and meta-analysis, Diabetes, 72(Suppl_1): 659-P.

https://doi.org/10.2337/db23-659-p

Thornavalli B., Venugopal S., Soundararajan R., Mohankumar S., Suresh R., Baskaran V., Alagar M., Geetha B., Vignesh S., and Manonmani S., 2024, Phenotypic and genotypic insights into rice germplasm resistance against a biotype of the brown planthopper Nilaparvata lugens (stal), Plant Science Today, 11: 5677.

https://doi.org/10.14719/pst.5677

Tsujimoto Y., Tanaka A., and Rakotoson T., 2021, Sequential micro-dose fertilization strategies for rice production: Improved fertilizer use efficiencies and yields on P-deficient lowlands in the tropical highlands, European Journal of Agronomy, 131: 126381.

https://doi.org/10.1016/j.eja.2021.126381

Wang Q., Zhou Y., Wang W., Tong G., Jia W., Li L., Cheng Z., Lu Y., Shi B., Bian F., Wang Y., Shi X., Li Q., Su X., Wang K., Yuan G., Li L., Ling H., Hu X., Wang Y., Zhao N., Yang Y., Li Y., and Zhu D., 2023, 757-P: efficacy and safety of supaglutide monotherapy in patients with type 2 diabetes, Diabetes, 72(Suppl_1): 757-P.

https://doi.org/10.2337/db23-757-p

Xu Q., Dai L., Shang Z., Zhou Y., Li J., Dou Z., Yuan X.C., and Gao H., 2023, Application of controlled-release urea to maintain rice yield and mitigate greenhouse gas emissions of rice-crayfish coculture field, Agriculture, Ecosystems & Environment, 344: 108312.

https://doi.org/10.1016/j.agee.2022.108312

Yoo S., Son J., Jun K., and Ku H., 2024, Effects of GroMore^® program on rice yield and GHG emissions in a Korean paddy rice, Agronomy, 14(10): 2448.

https://doi.org/10.3390/agronomy14102448

Zhang Y., Wang W., Li S., Zhu K., Hua X., Harrison M., Liu K., Yang J., Liu L., and Chen Y., 2023, Integrated management approaches enabling sustainable rice production under alternate wetting and drying irrigation, Agricultural Water Management, 281: 108265.

https://doi.org/10.1016/j.agwat.2023.108265