Rice is a crucial staple food for over half the world’s population, playing a vital role in global food security [38]. Global rice production has increased significantly, from 215.6 million tonnes in 1961 to 650.1 million tonnes in 2007, with productivity rising from 1.86 to 4.18 tonnes/ha [6]. This growth has been attributed to the adoption of modern varieties, improved nutrient management, and pest control [6]. Rice is particularly important in Asia, where it accounts for 90% of global consumption [3]. Despite its importance, rice is a poor source of vitamins and minerals, putting rice-dependent populations at risk of deficiencies [38]. Sustainable rice production practices are crucial for food security in changing climates, focusing on increasing productivity, improving soil health, enhancing water efficiency, and diversifying income for growers [3].

The System of Rice Intensification (SRI) is an innovative approach to rice cultivation that offers potential benefits for food security and sustainable production. SRI practices involve using younger seedlings, wider spacing, reduced water usage, and improved soil management [14, 38]. This method has been shown to increase rice yields while reducing input costs, making it accessible to resource-limited farmers [38]. SRI has demonstrated resilience to adverse climate conditions, with studies showing smaller yield reductions during drought years compared to conventional methods [30]. Additional benefits include improved soil conditions, reduced greenhouse gas emissions, and lower arsenic levels in rice [30]. Despite its potential, SRI faces some limitations and criticisms that hinder wider adoption [5]. To promote SRI, extensive research, extension programs, and supportive government policies are needed to establish this system more broadly [5].

SRI enhances productivity while reducing input requirements [61], with principles including early plant establishment, reducedplant density, and controlled water application [17]. This method increases yields by 25–50% while decreasing water usage, chemical fertilizers, and methane emissions (Roy & Bisht, 2012). SRI promotes soil health, improves crop resistance to stresses, and lowers greenhouse gas emissions [17, 62]. The spread of SRI has been supported by farmer-to-farmer extension and innovative alliances among diverse stakeholders [62]. As climate change and resource constraints challenge agriculture, SRI offers a sustainable approach to food production by increasing output while reducing inputs, making it a promising strategy for enhancing food security and farmer incomes [62],Berkhout & Glover, 2011).

Conventional rice farming faces numerous challenges, including water scarcity, soil degradation, and low yields [34, 58]. Climate change exacerbates these issues, threatening food security [12]. To address these challenges, researchers propose sustainable practices such as SRI, which can increase yields while reducing water use and input costs [12, 34]. Other recommended strategies include precision agriculture, improved water management techniques, and the development of climate-resilient rice varieties [58]. Additionally, integrated nutrient and pest management can minimize environmental impacts and increase efficiency [12]. Despite these innovations, obstacles remain, including labor shortages, shrinking arable land, and the need for stronger extension systems [58]. Overcoming these challenges requires a multifaceted approach combining technological advancements, policy support, and farmer education [34], [58].

Conventional rice farming also faces significant challenges, including nutrient leaching and environmental contamination [12, 34]. Studies have shown that inorganic nitrogen leaching occurs in both organic and conventional systems, with conventional paddies leaching a higher percentage of applied nitrogen [37]. Water scarcity and excessive agrochemical use further exacerbate these issues [12]. To address these challenges, precision farming technologies offer promising solutions, including site-specific nutrient management, remote sensing, and variable rate applicators, which can optimize fertilizer and water use efficiency [60]. Sustainable practices such as SRI, integrated nutrient management, and water-saving techniques like alternate wetting and drying can significantly reduce environmental impacts while maintaining productivity [12, 34]. Implementing these eco-friendly approaches requires farmer education, policy support, and collaborative partnerships [34].

SRI is an innovative agricultural practice that enhances rice productivity while reducing inputs [17]. SRI principles include early plant establishment, reduced plant density, and controlled water application [10, 17]. Benefits of SRI include increased yields, reduced water usage, lower cultivation costs, improved soil conditions, and decreased greenhouse gas emissions [17, 18]. SRI has spread to over 40 countries, demonstrating its adaptability and scalability [56]. In Mali, SRI implementation evolved over three years, with farmer participation increasing from 1 to 450 [56]. Despite its advantages, SRI faces challenges in wider adoption due to some limitations and criticisms [17]. However, SRI has sparked a transnational innovation system, with farmers actively participating in its dissemination and adaptation [18]. This farmer-driven approach has contributed to SRI’s global spread and continuous improvement [66].

The main objective of this manuscript is to comprehensively review the System of Rice Intensification, evaluating its principles, practices, agronomic outcomes, environmental benefits, challenges, and future prospects for enhancing rice productivity and sustainability in major rice-producing countries. Specific research questions include: (1) What are the core mechanisms by which SRI improves rice plant performance and yield? (2) How does SRI impact resource efficiency, particularly water use and greenhouse gas emissions? (3) What are the key barriers to SRI adoption, and how can they be addressed through mechanization and policy? (4) What projections can be made for rice production increases if SRI is scaled in major producing countries?

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to ensure rigor and transparency. Literature was sourced from databases including Web of Science, Scopus, Google Scholar, and ResearchGate, using keywords such as “System of Rice Intensification,” “SRI rice yield,” “SRI water efficiency,” “SRI environmental impact,” and “SRI adoption challenges.” Inclusion criteria were peer-reviewed articles, reports, and theses published from 2000 to 2025, focusing on SRI practices, outcomes, and comparisons with conventional methods in rice-producing regions. Exclusion criteria included non-English publications and studies lacking empirical data.

A total of 1,200 records were identified, with 850 screened after duplicates removal. Full-text assessment led to 150 studies included in the qualitative synthesis. Bibliometric analysis was incorporated to identify research trends and gaps, using VOS viewer for keyword co-occurrence and publication trends. Data from bibliometric studies indicate an exponential increase in SRI-related publications from 1990 to 2020, with peaks at 291 documents in 2020. Top contributing countries include India (313 articles on rice/irrigation, many SRI-related), China (218), and the US (163). Key authors like Norman Uphoff (at least 8 documents) dominate, with keywords linking SRI to “food security,” “water scarcity,” and “climate change.” This analysis highlights SRI’s growing relevance in agroecological research, with gaps in long-term soil health studies and mechanization in diverse contexts.

3.1 Principles and practices of SRI

SRI is an innovative rice cultivation method with four core components: transplanting young seedlings, wider spacing, alternate wetting and drying irrigation (AWD), and mechanical weeding [31, 44]. SRI practices can significantly increase rice yields by 50–100% while reducing water usage by 30–50% [4]. The method promotes better root development, increased resistance to pests and diseases, and improved adaptability to climate change [4]. Studies across 13 Indian states showed that SRI fields had higher yields and gross margins compared to conventional practices, with full adopters experiencing the highest yield increase of 31% [44]. However, challenges remain, including labor requirements and the need for organic fertilizers [2]. Despite these constraints, SRI has been introduced in many countries with local adaptations [4].

3.1.1 Young seedlings

Transplanting young rice seedlings, typically 8–12 days old, preserves growth potential [50]. This method, along with wide spacing, intermittent wetting and drying, and mechanical weeding, can lead to increased grain yields, reduced water usage, and improved resistance to pests and diseases [4]. Studies have shown that transplanting younger seedlings results in higher yields compared to older seedlings [50]. However, the effectiveness of SRI practices may vary depending on rice varieties and environmental conditions [11]. While some research supports the benefits of young seedling transplantation, others suggest that it may not always lead to significant yield improvements, particularly for certain upland varieties (Katambara et al., 2013). Overall, SRI practices have been adopted in many countries with local adaptations [33].

3.1.2 Wide spacing

Wide spacing is a core component of SRI, with studies suggesting optimal spacing of 20 × 20 cm or 25 × 25 cm, depending on theseason and location (Fig. 1) [58]. Wider spacing improves individual hill performance, including root growth, tiller production, and grain yield, but must be balanced with optimal plant population for maximum area yield [9, 58]. SRI has shown significant yield increases compared to conventional methods, with reports of 50–100% yield improvements in India [63]. The method has been successfully adapted and scaled up in various countries, demonstrating its potential as a sustainable agricultural innovation [9].

Comparative effects of SRI practices on root development, water use, and nutrient uptake, based on studies from India and Tanzania, showing 50–100% yield increases

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3.1.3 Water management

SRI incorporates AWD irrigation (Fig. 1), which significantly reduces water usage by 25–70% compared to conventional flooded rice cultivation [27]. AWD and SRI practices substantially decrease methane emissions, although this is partially offset by increases in nitrous oxide and carbon dioxide emissions [16]. SRI has been associated with higher grain yields of 6.4 t/ha compared to 3.4 t/ha from traditional methods [63]. AWD can maintain or improve rice yields by 10–20% while reducing arsenic and mercury content in grains [27]. When combined with leaf color chart-based nitrogen management, AWD in SRI can increase nitrogen use efficiency by 73% and yield by 47% compared to conventional methods [1]. These practices offer promising solutions for sustainable rice production.

3.1.4 Soil fertility

SRI combined with organic fertilizers has shown promising results in improving soil health and rice productivity. Studies have demonstrated that SRI cultivation with organic fertilizers, such as market waste compost, can enhance soil biological properties and increase rice yield [48, 57]. The use of local microorganisms in compost production for SRI has been found to improve soil microbial populations and maintain soil fertility [21]. Research has also shown that bio-organic fertilizers can partially substitute inorganic fertilizers in SRI, leading to improved biomass, plant weight, and nutrient uptake (Fig. 1) [69]. Furthermore, the combination of farmyard manure and inorganic fertilizers in SRI has demonstrated significant yield benefits, with optimal row spacing dependent on soil fertility levels (Elita, 2021, [19]. These findings suggest that integrating organic matter into SRI practices can effectively enhance soil health and rice productivity while reducing reliance on chemical inputs.

3.1.5 Weed and pest management

Mechanical weeding and wider plant spacing are key components. Mechanical weeding, often using rotary weeders, can increase yields by 1–3 t/ha without additional soil amendments by improving soil health and nutrient cycling [54]. It also reduces labor input by 28.3% compared to hand weeding. Mechanical cultivation effectively reduces weed biomass, density, and species diversity across different weed classes [7]. The use of competitive rice cultivars can further suppress weed growth, particularly for sedges and grasses [7]. SRI practices lead to significant phenotypical changes in plant structure and function, resulting in higher yields [15]. However, challenges remain in adopting SRI, including labor requirements and the need for organic fertilizers [15].

3.2 Mechanisms emprovement under SRI ecosystem

3.2.1 Tillering, roots development and respiration

SRI enhances rice productivity through modified practices including wider spacing, intermittent flooding, and single seedling transplantation. Wider spacing (25–30 cm) promotes root development, tillering, and individual hill performance [28, 58]. Intermittent flooding during the vegetative stage improves root length density, physiological activity, and chlorophyll content, leading to higher yields compared to continuous flooding [25]. Single seedling transplantation reduces intra-hill competition and, when combined with intermittent flooding, produces synergistic effects on grain yield [25]. SRI practices can result in water savings of up to 64% compared to conventional methods [28]. However, optimal spacing and water management should be determined based on local conditions [26]. In China, SRI adaptations include young seedling transplantation, wide spacing, and organic nutrient addition [45].

3.2.2 Role of soil microbiology and nutrient cycling

SRI has shown positive effects on soil microbial populations and activities compared to conventional rice cultivation methods. SRI practices, combined with organic amendments, enhance rhizospheric microbial diversity, phytohormone production, and enzyme activities (Fig. 1) [67]. The use of local microorganisms in compost production for SRI improves soil microbial populations and maintains soil fertility [21]. In saline soils, SRI cultivation with organic fertilizers, particularly market waste, increases soil biological properties and rice yield [57]. Bio-organic fertilizers containing indigenous Azotobacter and Pseudomonas fluorescens bacteria play crucial roles in nutrient cycling and plant growth promotion in SRI systems. These microbes enhance rice metabolism, leading to increased vegetative and generative growth, with production reaching up to 9.21 t/ha while reducing the need for inorganic fertilizers [22].

3.2.3 Role of planting density, water use, and input requirements

Plant density plays a crucial role, with spacing of 25 × 25 cm generally found optimal, though this may vary by season and location (Fig. 2) [13]. SRI has shown greater yield enhancements for hybrids and long/medium-duration cultivars, particularly in constrained soil conditions [46]. Water savings of 40–47% have been observed with SRI [5]. Integrated nutrient management, combining organic and inorganic sources, has proven effective in SRI (Fig. 2) [46]. However, weed management remains a challenge in SRI systems, necessitating integrated approaches [51].

Comparison of SRI and convention system caused by mechanisms improvements on tillers per hill and overall plant growth

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3.3 Agronomic outcomes

3.3.1 Increased yields

SRI has demonstrated significant yield improvements compared to conventional rice cultivation methods across multiple studies [36]. In Bangladesh, SRI increased grain yield by 10.17% [39], while in India, a six-year study reported a 50% yield increase with SRI compared to conventional transplanting [32]. In Myanmar, SRI methods implemented through Farmer Field Schools resulted in average yields of 6.4 t/ha compared to previous yields of 2.1 t/ha (Thakur, 2023). Similarly, in Benin, farmer-conducted research showed a 54% increase in average yields using SRI [36] (Table 1). Besides yield improvements, SRI demonstrated additional benefits such as enhanced soil microbial populations, reduced greenhouse gas emissions,and improved water productivity [32]. However, SRI implementation may require increased labor inputs [36], although modified SRI methods can potentially reduce labor requirements while maintaining yield benefits [32].

3.3.2 Improved plant vigor and resistance to stress

SRI has shown promising results in improving rice productivity and resilience. Studies across India demonstrated that SRI methods led to lower incidence of pests like stem borers and planthoppers, while promoting natural predators [15]. In Myanmar, SRI practices implemented through Farmer Field Schools resulted in significantly higher yields compared to conventional methods [20]. Philippine trials reported yield increases of 114% over the national average, with substantial improvements in return on investment [20]. In India’s Dharwad district, SRI practices required 87% less seed while producing 40% higher yields and 76% greater economic returns per hectare, even during drought conditions [8]. These studies consistently demonstrate SRI’s potential to enhance rice plant vigor, increase yields, and improve resistance to various stresses, making it a promising approach for sustainable rice cultivation.

3.4 Environmental sustainability

3.4.1 Reduced water usage

SRI has demonstrated significant benefits in water conservation and yield improvement compared to traditional flooding methods. Multiple studies have reported water savings of 40–74% with SRI practices [46],Kumary et al., 2023). SRI has also shown increased grain yields, ranging from 21–26% higher than traditional methods [8, 35]. Water use efficiency was substantially improved under SRI, with increases of 91–195% reported [35]. Additionally, SRI practices enhanced soil microbial biomass, with higher microbial biomass carbon and nitrogen levels observed compared to traditional methods [35]. However, the effectiveness of SRI may vary depending on factors such as nitrogen application rates and rice varieties [46], [8]. Overall, these studies suggest that SRI offers a promising approach for sustainable rice cultivation, balancing water conservation with improved productivity.

3.4.2 Lower greenhouse gas emissions

SRI has been shown to significantly reduce greenhouse gas emissions, particularly methane, compared to conventional rice cultivation methods. Studies have found that SRI practices can decrease methane emissions by up to 70%[24]. This reduction is primarily attributed to the water management techniques employed in SRI, such as AWD [16]. While SRI may slightly increase nitrous oxide emissions, the overall global warming potential is still reduced [24]. Additionally, SRI has demonstrated improved yields and water productivity compared to conventional methods [24, 47]. However, maintaining groundwater levels close to the soil surface in SRI fields is crucial for optimal yield and water productivity while still reducing greenhouse gas emissions [47]. These findings suggest that SRI offers a promising approach to sustainable rice production with lower environmental impact.

3.4.3 Soil health through organic inputs

SRI has shown promising results in improving rice yields and soil health, particularly when combined with organic inputs. Studies have demonstrated that SRI cultivation with organic fertilizers can enhance soil biological properties and increase rice production, even in saline soils [57]. The application of SRI methods with organic manure has been found to significantly improve various growth parameters and yield components of rice [52]. SRI principles are being adapted to other crops, promoting better root growth and soil fertility through organic materials, leading to higher yields with reduced inputs and greater climate resilience (Adhikari et al., 2018). Notably, the effectiveness of SRI appears to be influenced by soil properties, with more substantial yield benefits observed in highly weathered, infertile soils compared to more fertile soils traditionally favored for rice production [55]. The labor-intensive nature of SRI, particularly in transplanting and weeding, remains a significant barrier to adoption. The primary constraints include the high labor requirements [40] and the need for assured irrigation. Despite these challenges, changing water management practices may be the most feasible SRI component for farmers to adopt.

3.5 Challenges and limitations

3.5.1 Labor intensity of SRI practices

Lack of knowledge, training, and awareness are significant obstacles to SRI adoption [53],Asheri & Katambara, 2020). Improper implementation of demonstrations and poor monitoring also contribute to low adoption rates [53]. However, farmers with higher education levels, extension contacts, and access to information sources tend to have better knowledge of SRI practices [42]. Factors influencing adoption include high grain yield and increased return to labor (Table 1). Multiple constraints such as access to information, extension services, labor availability, and irrigation facilities also affect SRI adoption (Asheri & Katambara, 2020). To overcome these barriers, relevant and effective training programs, proper selection and distribution of informative materials, and improved access to extension services are crucial for increasing SRI adoption among farmers [53], [42],Asheri & Katambara, 2020).

3.5.2 Knowledge and training requirement

The System of Rice Intensification (SRI) faces several adoption barriers among farmers. Lack of knowledge, training, and awareness are significant obstacles to SRI adoption [53],Asheri & Katambara, 2020). Improper implementation of demonstrations and poor monitoring also contribute to low adoption rates [53]. However, farmers with higher education levels, extension contacts, and access to information sources tend to have better knowledge of SRI practices [42]. Factors influencing adoption include high grain yield and increased return to labor (Asheri & Katambara, 2020) (Table 1). Multiple constraints such as access to information, extension services, labor availability, and irrigation facilities also affect SRI adoption [65]. To overcome these barriers, relevant and effective training programs, proper selection and distribution of informative materials, and improved access to extension services are crucial for increasing SRI adoption among farmers [53], [42],Asheri & Katambara, 2020).

3.5.3 Initial resistance to changing traditional practice

Farmers’ resistance to adopting sustainable agricultural practices is often rooted in rational concerns rather than mere recalcitrance [64]. Barriers to adoption include conflicting information, risk, costs, complexity, and incompatibility with existing practices [64]. Similarly, in healthcare, barriers to electronic health record adoption include costs, technical concerns, and resistance to change [49]. Overcoming resistance to innovation may require increasing attraction, reducing barriers, or shifting the social system [49]. Change agents working with farmers identify several barriers, including lack of accurate information, inadequate government support programs, and social factors [68]. Interestingly, adopters and non-adopters differ in their assessment of adoption triggers, with non-adopters emphasizing performance improvements and adopters highlighting knowledge acquisition and social pressure [49]. Understanding these barriers and triggers is crucial for developing effective strategies to promote the adoption of innovative practices across various sectors.

3.6 Future Research

To further enhance the adoption and impact of SRI in sustainable rice cultivation, future research should address key gaps and challenges while building on its established benefits. Optimization of SRI practices across diverse environments should focus on tailoring to specific soil types, climates, and rice varieties, such as investigating optimal spacing and water management in saline or nutrient-poor soils (Suarez et al., 2024). Mechanization and labor-saving innovations are needed to address labor intensity, prioritizing affordable tools like drum seeders and mechanical weeders, alongside precision technologies. Long-term impacts on soil health and ecosystem services require studies on nutrient cycling, carbon sequestration, and biodiversity. Climate resilience and adaptation should evaluate SRI under extreme weather, including variety selection for stress conditions. Socio-economic and policy support for adoption involves evaluating extension models, digital platforms, and incentives, with cost–benefit analyses. Nutritional outcomes and food security research should assess SRI’s effects on rice quality, heavy metal reduction, and household impacts (Katambara et al., 2013).

The System of Rice Intensification (SRI) represents a transformative approach to rice cultivation, offering a sustainable pathway to address global food security challenges amidst climate change and resource constraints. By integrating practices such as young seedling transplantation, wider spacing, alternate wetting and drying (AWD) irrigation, and organic nutrient management, SRI has consistently demonstrated significant benefits, including yield increases of 10–114%, water savings of 40–74%, and reductions in greenhouse gas emissions, particularly methane, by up to 70%. These outcomes are complemented by improved soil health, enhanced plant vigor, and greater resilience to biotic and abiotic stresses, making SRI a promising strategy for sustainable agriculture. The review addresses the research questions by highlighting SRI’s mechanisms for plant improvement (e.g., better root development and microbial activity), resource efficiency gains, and adoption barriers, with projections indicating potential global production increases of over 275 million tons if scaled in major countries assuming 50% yield gains.

Despite its advantages, SRI faces barriers to widespread adoption, including labor intensity, knowledge gaps, and resistance to transitioning from conventional practices. Addressing these challenges requires targeted interventions, such as mechanization to reduce labor demands, robust extension services, and supportive government policies to facilitate farmer training and resource access. Key recommendations include prioritizing bibliometric-identified gaps like long-term ecosystem studies, promoting affordable technologies, and integrating SRI into national agriculture policies for major producers like China and India.