1 Introduction

Tea (Camellia sinensis) is one of the most widely consumed beverages globally, cherished for its cultural, economic, and health significance. Cultivated across diverse agro-climatic regions, tea production supports the livelihoods of millions of farmers and contributes significantly to the economies of many countries, particularly in Asia, Africa, and South America (Hajiboland, 2017; Xu et al., 2021). As one of the most consumed beverages globally, tea not only serves as a staple in many cultures but also as a critical agricultural product with a high economic value (Qiu et al., 2020; Rokhmah et al., 2022). With an estimated annual global production of over 6 million tons, tea contributes to food security and international trade. Beyond its economic impact, tea is recognized for its health benefits, attributed to bioactive compounds such as polyphenols, catechins, and flavonoids (Samanta, 2022; Sang, 2022). The increasing global demand for tea, driven by its health-promoting properties, underscores the need for optimizing cultivation techniques to enhance yield and quality (Hajiboland, 2017).

However, optimizing tea plant yield presents several challenges. Environmental factors, such as climate change, pose significant threats to tea production by altering rainfall patterns and increasing temperatures, which can lead to drought stress and reduced yields (Ahmed et al., 2019; Rigden et al., 2020; Rokhmah et al., 2022). The heavy reliance on chemical fertilizers to boost production has led to soil degradation and environmental concerns, necessitating a shift towards more sustainable agricultural practices (Jiang et al., 2019; Xu et al., 2021). The susceptibility of tea plants to pests and diseases further complicates yield optimization, as the use of pesticides can adversely affect tea quality and pose health risks (Hajiboland, 2017). Additionally, the genetic diversity of tea plants and the variability in their response to agronomic practices complicate efforts to standardize cultivation techniques (Tong et al., 2024). Smallholder farmers, who constitute the majority of tea producers, often lack access to modern agricultural technologies and resources, limiting their ability to adopt advanced practices.

This study systematically evaluates various cultivation techniques aimed at optimizing tea yield and quality, integrating findings from multiple studies to identify effective strategies that address environmental and agricultural challenges. Specifically, it includes an assessment of the impact of climate change on tea yield, an analysis of sustainable fertilization practices, and an exploration of innovative technologies, such as machine learning, in yield prediction. This study seeks to provide actionable insights for improving tea cultivation practices, ensuring economic viability and environmental sustainability.

2 Key Factors Affecting Tea Plant Yield and Quality

2.1 Soil quality and fertility

Soil quality and fertility are critical determinants of tea plant yield. The degradation of soil, often exacerbated by high leaching and strong soil acidity, poses significant challenges to tea cultivation, particularly in tropical and subtropical regions like southern China. Studies have shown that different tea plant varieties can influence soil nutrient profiles, with high-nutrient-efficiency varieties like Longjing43 (LJ43) demonstrating better soil nutrient retention and reduced acidification compared to low-nutrient-efficiency varieties such as Liyou002 (LY002) (Ruan et al., 2023). Intercropping strategies, such as incorporating legumes, have been found to improve soil fertility by increasing soil organic matter and total nitrogen, which in turn enhances tea quality and yield (Huang et al., 2022).

Moreover, the management of soil nutrients through fertilization practices significantly impacts tea yield. Long-term nitrogen fertilization, for instance, has been shown to increase tea yield and amino acid content, although it may also lead to soil acidification and reduced microbial diversity (Ma et al., 2021). The balance of nutrient inputs is crucial, as excessive use of chemical fertilizers can lead to environmental pollution without proportionate increases in yield. Therefore, optimizing fertilization strategies, such as integrating organic fertilizers, can mitigate soil degradation and enhance tea production (Xie et al., 2018).

2.2 Climatic conditions and adaptability

Climatic conditions, including temperature and precipitation patterns, play a pivotal role in tea plant yield. Tea plants are highly sensitive to climatic variability, with studies indicating that increased temperatures and precipitation variability can negatively affect yield. For instance, in Assam, India, warmer monthly average temperatures above 26.6 °C have been associated with reduced tea yields, while precipitation variability also poses challenges (Duncan et al., 2016). Similarly, in Kenya, rising temperatures are projected to decrease tea yields by up to 10% by 2040-2070, although potential increases in soil moisture could partially offset these losses (Rigden et al., 2020).

Adaptation to climatic changes is essential for sustaining tea yields. Strategies such as planting drought-tolerant clones, implementing mulching, and optimizing irrigation systems can help mitigate the adverse effects of climate change (Rokhmah et al., 2022). Understanding the interaction between tea plants and environmental factors is also crucial for developing effective adaptation strategies. This includes assessing the impact of climate-driven abiotic stressors and exploring the potential benefits of elevated CO₂ levels on tea yield (Jayasinghe and Kumar, 2021).

2.3 Genetic potential and plant variety

The genetic potential and variety of tea plants are fundamental to optimizing yield. Different genotypes exhibit varying responses to environmental conditions, which can lead to significant differences in yield and quality. For example, high-altitude grown teas are known for their aromatic qualities, whereas low-altitude teas tend to have higher yields but less distinctive flavors (Owuor et al., 2011). The choice of tea plant variety can thus influence both the quantity and quality of the harvest, with some varieties being more adaptable to specific environmental conditions than others.

Breeding programs aimed at developing high-yield, high-quality tea varieties are essential for improving tea production. These programs focus on selecting genotypes that are resilient to environmental stresses and capable of maintaining desirable traits across different growing conditions (Ruan et al., 2023). Additionally, the integration of advanced agricultural management practices tailored to specific genotypes can further enhance tea yield and quality, ensuring that the genetic potential of the plants is fully realized (Owuor et al., 2011).

3 Analysis of Tea Cultivation Techniques

3.1 Traditional methods and practices

Traditional tea cultivation methods have long relied on the extensive use of chemical fertilizers and pesticides to enhance yield and quality. In regions like Shaoxing, Zhejiang Province, China, traditional practices involve high rates of chemical inputs, which, while initially boosting productivity, have led to environmental concerns such as soil acidification and nutrient runoff (Xie et al., 2018). Similarly, in Northern Vietnam, conventional tea cultivation has been associated with soil health degradation and environmental pollution due to the overuse of chemical fertilizers (Le et al., 2023). These traditional methods, although effective in maintaining high yields, often result in long-term soil fertility issues and increased environmental risks.

Despite the challenges, traditional practices have been foundational in establishing tea as a major cash crop in many regions. In West Bengal, India, for instance, traditional soil management practices have been documented, showing a significant portion of soil samples with optimal pH and organic carbon levels suitable for tea cultivation (Malakar et al., 2022). However, the reliance on chemical inputs remains a concern, necessitating a shift towards more sustainable practices to ensure long-term soil health and productivity.

3.2 Modern innovations and technologies

Modern innovations in tea cultivation focus on reducing the environmental impact of traditional practices while maintaining or improving yield and quality. One such innovation is the dual reduction of chemical fertilizers and pesticides, which has shown promising results in improving soil health and reducing nutrient runoff in tea gardens (Xie et al., 2018). The use of agroecological management practices in Northern Vietnam has demonstrated significant improvements in soil organic matter and pH, leading to better tea quality and increased economic returns for farmers (Le et al., 2023).

Technological advancements such as the Nutrient Expert (NE) system have also been developed to optimize fertilization practices. This system has been shown to increase tea yield and quality while reducing greenhouse gas emissions and fertilizer use, thus enhancing economic benefits and environmental sustainability (Tang et al., 2021). These modern approaches highlight the potential for integrating technology and sustainable practices to optimize tea cultivation.

3.3 Integration of traditional and modern approaches

Integrating traditional and modern approaches in tea cultivation can offer a balanced solution to enhance productivity while mitigating environmental impacts. For instance, combining organic and chemical fertilizers has been identified as an effective strategy to improve soil nutrients and tea yield, as seen in studies conducted in various tea-growing regions (Wang et al., 2020). This integrated approach not only maintains the benefits of traditional methods but also incorporates modern sustainability practices to reduce environmental risks.

Moreover, the use of organic inputs such as compost tea and anaerobic digestate has been shown to produce yields comparable to conventional chemical fertilizers, offering a viable alternative for sustainable tea production (Curadelli et al., 2023). Blending traditional knowledge with modern innovations, tea growers can achieve a more sustainable and productive cultivation system that supports both environmental health and economic viability.

4 Agronomic Practices for Yield and Quality Optimization

4.1 Pruning techniques

Pruning is a vital agronomic practice that significantly influences tea yield. The study shows that pruning can significantly improve the growth indicators of tea plants, such as leaf area, hundred-bud weight, chlorophyll content, and yield, while enhancing key metabolic pathways, including fatty acid synthesis, carbohydrate metabolism, and plant hormone signal transduction, thereby increasing yield (Figure 1) (Zhang et al., 2023b). Pruning also alters the rhizosphere soil microbial community, increasing the abundance of beneficial bacteria and enhancing soil nutrient transformation, which further supports tea plant growth (Zhang et al., 2023c). However, while pruning increases yield, it may negatively impact tea quality by reducing the content of quality-related compounds like polyphenols and amino acids (Zhang et al., 2023a; 2023b).

Despite its benefits for yield, pruning can lead to a reduction in tea quality. The decrease in quality is attributed to changes in the soil's microbial community and nutrient cycle, which affect the synthesis and accumulation of quality-related compounds in tea leaves (Zhang et al., 2023a). Therefore, while pruning is beneficial for increasing yield, it requires careful management to balance yield and quality, ensuring that the benefits of increased production do not come at the expense of tea quality.

4.2 Fertilizer application and management

Fertilizer application, particularly nitrogen, is a critical factor in tea cultivation, directly affecting yield and quality. Long-term nitrogen fertilization has been shown to increase tea yield and amino acid content, although it can decrease total polyphenol content, which is crucial for tea quality (Ma et al., 2021). The optimal nitrogen application rates for maximizing yield and quality have been identified, but excessive nitrogen can lead to soil degradation and reduced microbial diversity (Ma et al., 2021; Hu et al., 2024).

Reducing chemical fertilizer use and adopting alternative fertilization strategies can maintain or even enhance tea yield while improving soil quality. For instance, using tea-specific formula fertilizers or organic substitutions has been shown to increase yield and improve nutrient use efficiency without significantly compromising tea quality (Hu et al., 2024). These strategies not only support sustainable tea production but also enhance the economic benefits for farmers by reducing input costs and improving net income.

4.3 Irrigation strategies and water management

Irrigation strategies and water management are essential components of tea cultivation, particularly in the context of climate change. Effective water management can mitigate the effects of water stress, which is known to impact tea yield and quality. Water stress can lead to changes in the concentration of secondary metabolites, which are crucial for tea quality (Ahmed et al., 2019). Therefore, implementing efficient irrigation strategies is vital for maintaining both yield and quality under changing environmental conditions.

Moreover, the choice of irrigation strategy can influence soil properties and plant health. For example, maintaining optimal soil moisture levels can enhance root activity and nutrient uptake, leading to improved yield and quality (Zhang et al., 2020). As climate change continues to affect water availability, developing adaptive irrigation strategies will be crucial for sustaining tea production and ensuring the resilience of tea plantations against environmental stressors.

5 Role of Sustainable Practices in Yield and Quality Optimization 

5.1 Organic farming and its yield implications

Organic farming practices in tea cultivation have shown promising results in terms of yield optimization and environmental sustainability. Studies indicate that organic substitution of chemical fertilizers can enhance soil quality and maintain tea yield levels. For instance, partial substitution with organic fertilizers like biogas slurry and green manure has been effective in improving soil organic matter and tea yield (Wang et al., 2024). Although organic farming may sometimes result in slightly lower yields compared to conventional methods, the economic benefits can be substantial due to higher market prices for organic tea and reduced input costs (Le et al., 2023).

Furthermore, organic farming practices contribute to improved tea quality by increasing the content of beneficial compounds such as amino acids and polyphenols. This is achieved through optimized nutrient management that balances the use of organic manures with reduced chemical inputs, thereby enhancing the nutritional status of tea plants (Zhu et al., 2024). Organic farming not only supports yield optimization but also promotes a healthier ecosystem and better economic outcomes for tea farmers.

5.2 Integrated pest management (IPM)

Integrated pest management (IPM) is a sustainable approach that combines various pest control methods to minimize the use of chemical pesticides and enhance tea yield. The adoption of IPM practices has been shown to significantly reduce pesticide usage while maintaining or improving crop yields. For example, the implementation of Inhana Rational Farming technology, which focuses on soil and plant health management, has led to a substantial decrease in pesticide use and improved crop performance in tea plantations (Bera et al., 2024a). This approach not only reduces the environmental impact of tea cultivation but also enhances the resilience of tea plants to pest attacks (Bera et al., 2024b).

IPM strategies also contribute to improved soil health and biodiversity, which are essential for sustainable tea production. By reducing reliance on chemical pesticides, IPM practices help maintain a balanced ecosystem that supports beneficial organisms and natural pest predators. This holistic approach not only optimizes tea yield but also ensures the long-term sustainability of tea plantations (Tang et al., 2021; Bera et al., 2024a).

5.3 Agroforestry systems and biodiversity

Agroforestry systems, which integrate trees and shrubs into tea plantations, play a significant role in enhancing biodiversity and optimizing tea yield. These systems provide multiple ecological benefits, including improved soil fertility, enhanced water retention, and increased habitat diversity for various species. The presence of diverse plant species in agroforestry systems supports a more resilient ecosystem that can better withstand environmental stresses and pest pressures (Le et al., 2023; Bera et al., 2024a).

In addition to ecological benefits, agroforestry systems can also improve tea yield and quality. The shade provided by trees in these systems can help regulate microclimatic conditions, reducing temperature extremes and conserving soil moisture, which are beneficial for tea plant growth. Moreover, the increased biodiversity in agroforestry systems can lead to improved pollination and pest control, further supporting yield optimization. Agroforestry systems offer a sustainable approach to tea cultivation that enhances both environmental and economic outcomes.

6 Case Studies 

6.1 Successful yield improvement in Chinese tea plantations

In China, several studies have demonstrated successful strategies for improving tea yield through optimized cultivation techniques. One such approach involves the partial substitution of chemical fertilizers with organic alternatives, which has been shown to enhance soil quality and increase tea yield. For example, a study conducted in Southwest China analyzed the effects of substituting chemical fertilizers with organic fertilizers on soil quality, tea yield, and tea quality in tea plantations in this region. The results showed that partial organic substitution (BFG treatment) significantly improved soil organic matter (SOM), total nitrogen (TN), and alkali-hydrolyzed nitrogen (AN), and increased tea yield by 11.97% and tea quality (e.g., amino acid content increased by 7.78%) (Wang et al., 2024). In contrast, the full substitution scheme (OG treatment) failed to significantly increase yield due to insufficient nitrogen supply. Partial substitution (OFF treatment) achieved a better balance between economic benefits and environmental improvement. The study highlighted that by reducing nitrogen fertilizer application, partial organic substitution could enhance nitrogen use efficiency (NUE) while promoting sustainable management of tea plantations (Figure 2). For future implementation of organic substitution, optimizing the balance between cost and benefit is essential, and long-term studies are recommended to verify its profound impact on tea plantation ecosystems.

Another effective strategy is the optimization of nutrient management, particularly for albino tea cultivars like Baiye-1. By adjusting the rates and ratios of essential nutrients and incorporating organic manures, researchers were able to improve both the yield and quality of albino tea while reducing environmental risks (Zhu et al., 2024). Additionally, the use of controlled-release fertilizers has been shown to increase tea yield by 31.3% while reducing N₂O emissions, demonstrating a sustainable approach to nutrient management in tea plantations (Wu et al., 2018). These case studies underscore the potential of integrating organic and optimized nutrient management practices to achieve higher yields in Chinese tea plantations.

6.2 Sustainable tea farming in India

In India, sustainable tea farming practices have been increasingly adopted to address environmental and economic challenges. In Assam, the impact of climate variability on tea yield has been a significant concern. Research indicates that warmer temperatures and precipitation variability negatively affect tea yield, emphasizing the need for adaptive strategies to mitigate these impacts (Duncan et al., 2016). To promote sustainability, small tea growers in Assam have been encouraged to adopt organic cultivation methods. This shift not only enhances environmental management but also fosters entrepreneurship and improves income stability for growers (Deka et al., 2021).

The economic sustainability of organic tea cultivation has been further supported by studies showing that small-scale organic growers in Assam can achieve higher incomes compared to conventional growers, provided they maintain stable yields (Deka and Goswami, 2021). This transition to organic farming is facilitated by policy interventions that focus on training, resource optimization, and the establishment of grower-owned processing facilities. These efforts highlight the potential for sustainable tea farming practices to improve both environmental outcomes and economic viability for smallholder farmers in India.

6.3 Agroecological management enhances soil health and tea quality in Vietnam

Vietnam is also a major global tea exporter, with its tea plantations primarily located in the northern mountainous regions. However, the long-term reliance on traditional farming methods, coupled with excessive use of chemical fertilizers and pesticides, has led to soil acidification, reduced organic matter, and a decline in biodiversity. This not only threatens the ecological environment but also affects tea quality and farmers' economic returns. With the promotion of sustainable agricultural practices, agroecological management and land conversion have emerged as potential solutions for improving soil health and enhancing economic benefits (Doanh et al., 2018; Le et al., 2023).

A study conducted from 2019 to 2022 in northern Vietnam systematically assessed the effects of agroecological management practices (Le et al., 2023). The results showed that agroecological management significantly improved soil organic matter (increased by 0.8% on average) and pH (increased by 0.5 units), and enhanced soil biodiversity, with soil macrofauna and mesofauna populations increasing by 110% and 60%, respectively (Figure 3). In contrast, while traditional methods resulted in higher tea yields, they had a more significant impact on increasing soil total nitrogen (by 0.15%-0.2%). Economic analysis revealed that although agroecological cultivation had slightly lower yields, farmers' net income per hectare increased by approximately $8,400 due to the higher price of quality tea. Furthermore, agroecological management reduced reliance on chemical fertilizers, improving tea quality and market competitiveness.

7 Future Perspectives and Research Directions

7.1 Innovations in genetic improvement of tea varieties

The future of tea cultivation heavily relies on advancements in genetic improvement to enhance yield, quality, and resilience against environmental stresses. Recent studies have highlighted the potential of multi-omics approaches, including genomics and transcriptomics, in tea breeding. These techniques have facilitated the development of molecular markers that can be used to breed tea plants with desirable traits such as high yield, quality, and resistance to pests and diseases (Li et al., 2023). Furthermore, the integration of single-cellomics, pangenomics, and plant-microbe interactions into breeding programs is expected to revolutionize the genetic improvement of tea varieties, providing a robust framework for developing resilient tea cultivars (Xia et al., 2020).

In addition to these molecular techniques, there is a growing interest in leveraging naturally evolved traits and transformative engineering to address the challenges posed by climate change. Genetic strategies that focus on enhancing the sustainability and resilience of tea plants are crucial for ensuring consistent crop production in the face of biotic and abiotic stresses (Bailey-Serres et al., 2019). These innovations not only promise to improve tea yield and quality but also contribute to the broader goal of sustainable agriculture by reducing the dependency on chemical inputs and enhancing the ecological balance of tea plantations.

7.2 Emerging trends in sustainable agriculture

Sustainable agriculture is becoming increasingly important in tea cultivation, with a focus on practices that enhance soil health, reduce environmental impact, and improve economic efficiency. Agroecological management practices have been shown to significantly improve soil health indicators and increase the net income of tea farmers, despite lower yields compared to conventional methods (Li et al., 2023). These practices include the use of organic fertilizers and the optimization of nutrient management, which have been demonstrated to improve both the yield and quality of tea while reducing greenhouse gas emissions (Zhu et al., 2024).

The role of soil microorganisms in sustainable tea production is gaining attention as well. The diversity and functions of soil microbial communities are crucial for nutrient cycling, pest control, and bioremediation, all of which contribute to improved tea yield and quality (Jibola-Shittu et al., 2024). By harnessing these natural processes, tea producers can reduce their reliance on chemical fertilizers and pesticides, thereby promoting a more sustainable and environmentally friendly approach to tea cultivation.

7.3 Collaboration and knowledge sharing in the global tea industry

Collaboration and knowledge sharing are essential for advancing the global tea industry, particularly in the context of sustainable practices and innovation. The integration of tea cultivation with tourism, for instance, has been identified as a strategy to enhance community livelihood sustainability and promote cultural exchange (Su et al., 2019). By fostering partnerships between tea producers and the tourism sector, there is potential to create diversified income streams and increase local participation in the tea economy.

Global collaboration in research and development can accelerate the adoption of sustainable practices and technologies. Initiatives such as the Inhana Rational Farming Technology demonstrate the benefits of collaborative efforts in improving soil health, reducing pesticide usage, and enhancing crop sustainability. By sharing knowledge and best practices across borders, the tea industry can collectively address the challenges of climate change, economic pressures, and environmental degradation, ensuring a sustainable future for tea production worldwide.

8 Concluding Remarks

The research on optimizing tea yield through various cultivation techniques and sustainable strategies has highlighted several critical insights. Agroecological management practices have been shown to enhance soil health and increase the economic returns for tea farmers, despite slightly lower yields compared to conventional methods. Optimized nutrient management, particularly for albino tea cultivars, has improved yield, quality, and reduced environmental risks by decreasing fertilizer use. Reducing chemical fertilizers and incorporating organic alternatives have been effective in maintaining or even boosting tea yield and quality while improving soil conditions. Furthermore, interventions such as reducing nitrogen fertilizer usage and adopting regenerative farming practices have demonstrated potential in mitigating greenhouse gas emissions and enhancing soil quality.

Stakeholders in the tea industry, including farmers, policymakers, and agricultural researchers, should consider adopting agroecological and optimized nutrient management practices to improve both economic and environmental outcomes. Encouraging the use of organic fertilizers and reducing reliance on chemical fertilizers can lead to sustainable tea production with minimal environmental impact. Policymakers should support initiatives that promote regenerative farming techniques, which have shown promise in reducing pesticide use and improving soil health. Additionally, leveraging machine learning for land suitability assessments can guide strategic decisions in tea cultivation, ensuring optimal use of resources.

Achieving optimized and sustainable tea yield requires a multifaceted approach that integrates advanced cultivation techniques, sustainable nutrient management, and innovative technologies. The transition towards more sustainable practices not only enhances tea yield and quality but also contributes to environmental conservation and economic resilience. By adopting these strategies, the tea industry can ensure long-term sustainability and profitability, benefiting both producers and consumers. The collective efforts of stakeholders in embracing these practices will be crucial in addressing the challenges posed by climate change and resource limitations, ultimately leading to a more sustainable future for tea cultivation.

Acknowledgments

The authors sincerely thank Dr. Zhang for reviewing the manuscript and providing valuable suggestions, which contributed to its improvement. Additionally, heartfelt gratitude is extended to the two anonymous peer reviewers for their comprehensive evaluation of 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.

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