2025 Volume 13 Issue 3 Pages 57-75
Contemporary agriculture faces a crisis of eco-friendliness and sustainability caused by the false dichotomy between organic (OA) and conventional agriculture (CA). While some forms of OA, such as non-certified Japanese natural farming, prioritize ecological balance, others, such as profit-driven certified OA, often harm the environment due to monocultures and excessive organic inputs. On the other hand, modern CA has adopted eco-conscious techniques, such as conservation tillage, integrated nutrient and pest management, as well as precision fertilization and irrigation, but remains stigmatized as inherently unsustainable and not eco-friendly. This review critiques the binary OA-CA approach and proposes permaculture (PC) as a more flexible, context-based alternative for evaluating agricultural eco-friendliness and sustainability. Rooted in the ethics of Earth Care, People Care, and Fair Share, permaculture transcends rigid classifications by focusing on context and outcomes, rather than inputs and standards. For instance, Japan’s special cultivation (Tokubetsu Saibai) synergizes CA’s targeted chemical reductions with OA’s biodiversity principles, maintaining yields while minimizing the environmental impact. Additionally, permaculture extends its eco-friendly principles to non-traditional systems, such as urban vertical farms and post-disaster soilless cultivation in Fukushima. Despite their high energy consumption, these systems address localized needs while aligning with permaculture’s core ethics. Ultimately, permaculture offers an outcome-oriented and context-based approach to eco-friendliness, challenging the conventional focus on global standards and encouraging a rethinking of what works best here for both people and the environment.
Agriculture plays a crucial role in global development, but faces significant challenges, such as the rising food demand and environmental degradation [1, 2]. Many countries have implemented strategies to address these challenges; for example, Japan's MIDORI Strategy aims to increase food production efficiency by at least 30% by 2030, while reducing pesticide usage by 50% and chemical fertilizer application by 30% by 2050 [3]. These initiatives reflect a global recognition of the need for eco-friendly agricultural systems—approaches that minimize the environmental impact while maintaining or enhancing productivity. Organic agriculture (OA) is at the forefront of this movement [3].
OA avoids synthetic fertilizers, pesticides, and genetically modified organisms (GMO) but favors organic and microbial inputs to enhance soil fertility and yield while minimizing environmental impact [2, 4, 5]. OA encompasses various practices based on the following principles: health, ecology, fairness, and care [5]. It generally involves the use of bio-pesticides or the introduction of novel organisms as alternatives to synthetic pesticides. Additionally, it emphasizes the application of plant- or animal-based compost instead of chemical fertilizers, the adoption of no-till farming practices, and the principles of natural farming [6]. While these practices aim to reduce chemical inputs and promote ecological balance, some merely meet certification standards, such as overusing biopesticides or cattle manure compost. This raises a critical reflection: are all OA practices truly sustainable and environmentally friendly?
Conventional agriculture (CA), traditionally reliant on chemical inputs to maximize yields, has long been linked to soil degradation, biodiversity loss, and water pollution [4, 7, 8]. However, CA has undergone significant evolution, incorporating practices such as conservation tillage, integrated nutrient management, precision drip irrigation and soilless cultivation [9]. These adaptive practices not only enhance soil structure and organic matter content but also promote microbial diversity and consequently are beneficial for long-term soil fertility and overall agricultural sustainability [10, 11]. Overall, CA is moving toward more environmentally conscious. However, many of these practices are excluded from eco-friendly discourse due to rigid organic certification criteria. This raises a question: whether are all CA practices inherently unsustainable and not environmentally friendly?
This exclusion creates a false dichotomy between organic and conventional farming, positioning them as mutually exclusive rather than complementary approaches to achieving sustainability and eco-friendliness [12, 13]. This dichotomy presents a major challenge for the advancement of eco-friendly agriculture [14]. Therefore, it is necessary to break this false dichotomy and integrate the best elements of both OA and CA into a more inclusive and eco-friendly farming mode.
Permaculture offers a solution for addressing this challenge. It was developed by Mollison and Holmgren in the 1970s in response to growing concerns over the negative environmental impacts of industrial agriculture [15]. Permaculture emphasizes the design of agricultural systems that mimic natural ecosystems, promoting sustainability through minimal external inputs and closed-loop nutrient cycling [16, 17]. Permaculture integrates organic farming, agroecology, and traditional ecological knowledge to enhance resource efficiency, promote biodiversity, and build resilient, self-sustaining agroecosystems [18]. Therefore, it does not follow rigid certification schemes like CA or OA. Instead, it promotes a holistic approach that prioritizes long-term environmental sustainability and social equity.
The principles of permaculture, such as using renewable resources, reducing waste, and fostering biodiversity, offer solutions that complement both organic and conventional farming practices. For instance, integrating agroforestry, cover cropping, and mixed-species planting can improve soil health, boost productivity, and minimize dependence on chemical inputs [19, 20]. Permaculture offers a pathway to integrate the strengths of both organic and conventional farming systems. It supports the development of a more sustainable and environmentally friendly agricultural model that transcends traditional categories. Its flexible principles can be adapted to diverse ecological and socioeconomic contexts, making permaculture a valuable tool for addressing global agricultural challenges. This review first examines OA and CA practices, evaluating their environmental merits and limitations to establish the basis for a more inclusive, eco-friendly farming. Then it explores how permaculture can integrate the strengths of both systems and develop a truly eco-friendly and sustainable approach. Finally, it examines the potential benefits and obstacles of the reconstructed eco-friendly agricultural system, offering solutions to advance truly eco-friendly agricultural system beyond the OA-CA divide.
To conduct this review, we adopted a narrative review approach, instead of a systematic review. Relevant literature was collected through academic search engines such as Scopus, Web of Science, ScienceDirect, SpringerLink, and Google Scholar, as well as from institutional publications and reports (e.g., FAO, IFOAM, and CGIAR). Sources were selected based on their relevance to eco-friendliness and sustainability in CA, OA, and PC. Priorities were given to the literature, which offered diverse disciplinary perspectives (e.g., ecological, agronomic, and sociological) and practical examples or case studies. This synthesis aims to clarify how eco-friendliness and sustainability can be reconstructed through the lens of PC and how it can draw on the strengths of both conventional and organic agriculture.
Organic agriculture (OA) is a food production system that maintains soil, ecosystems, and human health by relying on ecological processes, biodiversity, and cycles instead of chemical inputs [5, 21]. Guided by four core principles—health, ecology, fairness, and care—it offers both theoretical and practical frameworks [2, 5].
Initially, OA aimed to produce healthier, safer, and environmentally friendly food, forming a “moralized market” [22]. However, as it became institutionalized, its focus shifted toward profitability and market expansion [23]. Scholars have noted its increasing resemblance to CA, raising concerns about its sustainability with its “conventionalization” [24]. The following sections analyze OA’s classification and complexities regarding sustainability and eco-friendliness. Based on compliance with certification standards, OA can be divided into non-certified organic agriculture (non-COA) and certified organic agriculture (COA) [25, 26]. This classification highlights the diversity within OA and forms a basis for evaluating its sustainability and eco-friendliness.
2.1 Non-certified organic agriculture: environmentally responsibleNon-COA includes diverse practices rooted in traditional knowledge or local ecological conditions, offering accessibility to small-scale and indigenous farmers [27]. The target of most non-COA farmers is household food needs and local markets rather than global trade, while achieving ecological and cultural soundness [28]. For instance, in 1993, the Cuba government successfully enhanced food self-sufficiency and minimized chemical use through crop rotations, polycultures, green manures, bio-fertilizers, and integrated crop-livestock systems [29].
In Japan, there are also several non-COA practices that can be categorized into three groups: ecosystem mimicry, input reduction, and cultural integration. Shizenno, natural cultivation, and natural farming (as practiced by Mr. Masanobu Fukuoka and Mr. Mokichi Okada) fall under ecosystem mimicry [30]. Despite differences in fertilization, weeding, and tillage practices (Table 1), these systems share a core principle of cooperating with natural processes and excluding synthetic inputs. Thus, they strive to minimize the impact of agricultural activities on the environment. For example, a study conducted from 2010 to 2011 investigated pest control mechanisms in Akinori Kimura’s orchard in Hirosaki, Aomori Prefecture, where apples were grown using natural cultivation methods [31]. The results revealed that Kimura’s orchard (natural cultivation) had a significantly higher insect diversity and approximately five times the insect population than conventionally managed orchards [31]. Similarly, Tatsumi et al. [32] found that natural farming in Hokkaido’s paddy fields resulted in a higher abundance and diversity of nutrient-cycling microbes than conventional farming, further supporting their potential in enhancing ecosystem health.
The input reduction group includes farming methods that minimize external inputs, such as no-fertilizer, no-pesticide farming, and no-till or reduced-till farming [33]. These approaches focus on preserving soil health, reducing environmental impact, and enhancing ecosystem resilience. Research indicates that no-till systems can improve soil organic matter and reduce greenhouse gas emissions compared with conventional tillage [34]. A notable example of this approach in India is Zero-Budget Natural Farming (ZBNF). It aims to minimize farmers’ reliance on external inputs by eliminating the use of synthetic fertilizers and pesticides, and promoting the utilization of locally available
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natural resources [35]. These practices include the application of Jeevamrutha, a natural microbial mixture made from local cow dung, cow urine, soil, and water, as well as mulching and minimal tillage [35, 36]. Such methods not only reduce farmers’ production costs but also generate multiple ecological benefits. Studies in tropical regions, such as Andhra Pradesh, indicate that ZBNF improves soil fertility, water-use efficiency, and system resilience under climatic stress [37]. Given the demonstrated ecological and economic benefits, the Government of Andhra Pradesh has committed to implementing ZBNF across approximately six million farms through state-sponsored training and extension services, with plans targeted for 2024 [38].
In addition, there are some cultural integration practices, such as rice-fish co-cultures [39]. Rice-fish co-culture has gained popularity due to its proven benefits in supporting multiple ecosystem services that enhance both environmental health and human well-being [39]. It offers a range of ecological and agricultural benefits such as reduce methane (CH₄) and nitrous oxide (N₂O) emissions, enhanced soil quality because of abundant earthworms, and minimized synthetic pesticides [33, 39].
These non-COA practices share a philosophy of minimizing ecosystem disturbance, collectively contributing to sustainable agriculture. However, their drawbacks include lack of certification, limited market access, low consumer recognition, and reduced yields.
2.2 Certified organic agriculture: critical evaluation 2.2.1 Sustainable value-based COAWithin COA, there are two distinct paradigms: value-based and profit-based COA [24, 25]. The former adheres strictly to OA’s foundational principles: health, ecology, fairness, and care [5]. Unlike profit-driven approaches, they focus on diversified production systems, such as small-scale, diversified systems (e.g., polycultures, agroforestry, crop-livestock integration) and reply on-farm inputs such as compost and green manure [24, 26]. Therefore, these systems contribute to long-term environmental sustainability, biodiversity, and soil health. For example, pollinator diversity increased by 30% and soil organic carbon increased by15–20% according to Batáry et al. [40] and Gattinger et al. [41]. Their use of plant residues, animal manure, and perennials reflects strong alignment with IFOAM principles and measurable ecological benefits.
2.2.2 Unsustainable profit-based COAIn contrast, profit-driven COA strictly follow certification standards but may not fully align with OA principles, as they prioritize mass production to meet market demand [24, 42]. Therefore, it prioritizes maximizing profitability over environmental sustainability. This trend is called ‘conventionalization’ or ‘industrialization’ of OA [43, 44]. For example, the global organic market grew from 15 billion euros in 2000 to nearly 135 billion euros in 2022, an eightfold increase over two decades [23].
The rapid growth of profit-based organic agriculture has raised concerns about its environmental benefits [45]. One issue is the widespread practice of monocropping, which reduces soil microbial activity by 30–40% and leads to nutrient imbalances [46]. Another concern is the heavy use of permitted fertilizers and pesticides, such as organic fertilizers, cattle manure compost, and biopesticides. For example, Skinner et al. [47] reported that excessive cattle manure application (≥20 t/ha) increased soil nitrate levels by 50%, causing nutrient leaching and eutrophication. Similarly, Dahan et al. [48] found that nitrate concentrations below the root zone were 357.0 mg/L in intensive organic farming compared to 37.5 mg/L in conventional farming with drip irrigation in Israel.
OA has shown potential in reducing chemical inputs and promoting environmental protection, as shown by non-COA practices. Despite facing systemic barriers, such as low yields and limited market recognition, they are in accordance with sustainability principles and contribute to environmental protection. However, not all OA practices are sustainable or environmentally responsible. Existing studies on both value-based and profit-based COA further demonstrate that it is crucial to critically examine the assumption that OA is inherently environmentally sustainable just because it avoids chemical inputs [4]. For example, profit-based COA practices strictly adhere to organic certification standards and replace inorganic inputs with organic inputs [42]. However, environmental protection has been neglected. This is because they often put market demand for quantity and profitability ahead of environmental protection [24].
Therefore, the environmental challenges associated with agriculture cannot be addressed using OA alone. CA has evolved to incorporate innovative and transformative strategies for mitigating environmental harm. However, because of the traditional image, which is heavily reliant on chemical inputs, it has been excluded from the eco-friendly agriculture group. The following section critically evaluates the simple belief that CA is inherently not eco-friendly.
Conventional agriculture (CA) remains the dominant food production system, covering about 70% of cultivated land worldwide [49]. While it makes great contributions to feeding the world, it has also caused severe environmental damage, thus inducing fierce criticisms. However, like OA, CA is not a single system but a diverse one with practices ranging from environmentally destructive to relatively sustainable. Thus, it is essential to critically evaluate its environmental impacts by considering its various practices rather than focusing solely on its unstainable forms.
3.1 Environmentally-damaging CA practicesAs demonstrated, CA often involves heavy reliance on chemical inputs, intensive tillage, and monocropping [4, 7]. These core features have made CA synonymous with environmental harm, including soil degradation, water pollution, greenhouse gas emissions, and biodiversity loss [4].
3.1.1 Heavy reliance on chemical fertilizersHeavy reliance on chemical fertilizers is a major contributor to environmental damage. Their global use increased from 46.3 million metric tons in 1965 to 187.92 million tons in 2022, a 306% rise, with nitrogen fertilizers growing from 18.66 million to 109.17 million metric tons [49]. Although fertilizers increase crop yields, excessive application causes serious environmental issues [50]. Studies report soil degradation, including reduced organic matter and microbial diversity [51, 52]. One study found that 47% of China’s rice field soils suffer degradation, with degraded soils showing 39.7% lower salinity, an 11.0% decrease in pH, and a 10.7% decline in bulk density compared to less degraded soils, indicating poorer soil quality and structure [53]. Another key impact is eutrophication of aquatic ecosystems. For example, fertilizer runoff from the US Midwest has caused nutrient loading in the Gulf of Mexico, resulting in eutrophication, algal blooms, and oxygen depletion that threaten aquatic life [54].
3.1.2 Excessive use of synthetic pesticidesAnother significant aspect of CA is the widespread use of pesticides, which has dramatically increased over the past decades. Pesticides use globally rose 1.81 million metric tons in 1990 to 3.69 million metric tons in 2022, a 108% increase [49]. While they help protect crops, excessive use not only contaminates water and soil but also disrupts ecological balance by harming beneficial microbial communities and reducing biodiversity [55]. The United States Geological Survey (USGS) reported that over 90% of water and fish samples collected from U.S. streams contained pesticide residues [56]. Pollinators are also affected: the western bumble bee (Bombus occidentalis) populations have declined by 57% decline from 1998 to 2020 and the model even predicates a 93% decline by the 2050s due to neonicotinoids [57]. Such losses threaten the productivity of pollination-dependent crops. These examples illustrate the dual-edged nature of pesticides in conventional agriculture.
3.1.3 Monoculture and intensive tillageMonoculture systems and intensive tillage have also caused significant environmental challenges [4]. Monoculture systems account for around 80% of more than 1.5 billion hectares of arable land in the world [58]. Similarly, intensive tillage is also prevalent practice in CA. While both enhance short-term productivity, their long-term impacts are detrimental. Monoculture depletes soil nutrients, reduce biodiversity, and increases vulnerability to pests and diseases [58]. Intensive tillage enhances soil erosion, alters soil structure and microbial communities, and leads to carbon loss, further worsening climate change [59]. Despite these issues, CA also includes environmentally responsible practices, including reduced-input methods, indigenous methods, and modern technology-reliant methods.
3.2 Environmentally-protecting CA practices 3.2.1 Input-reduced practicesIncreasing evidence shows that reducing chemical inputs can mitigate environmental harm without compromising yield. A prominent example is Japan’s Tokubetsu Saibai (“special cultivation”), which aims to reduce targeted pesticides and chemical fertilizers by at least 50% compared to conventional levels [60]. This approach has gained significant popularity in rice cultivation recently. Shimizu and Shimano found that species richness and diversity in rice fields under special cultivation were twice as high as those in conventionally cultivated rice fields, highlighting its positive effect on biodiversity conservation [61].
Integrating chemical fertilizers with organic amendments has also proven beneficial for both the environment and crop productivity [62]. For example, Liu et al. conducted a 14-year field experiment in a rice-wheat system in China. They found that reducing chemical fertilizer use while increasing organic inputs, such as straw return, significantly enhanced soil labile organic carbon, enzyme activity, and microbial diversity compared to using chemical fertilizers alone. This improved nutrient cycling and soil health [63].
3.2.2 Indigenous practicesPractices such as conservation tillage, crop rotation, and polyculture are beneficial for protecting soil from erosion and nutrient deficiency caused by intensive tillage, continuous planting and monoculture [62, 63]. A 17-year study in northern China demonstrated that conservation tillage significantly increased soil available nitrogen, phosphorus, potassium, and carbon sequestration, improving soil health and fertility. This practice also raised crop yields by 12.2–20.1% compared to intensive tillage [64]. Similarly, long-term trials by Triberti et al. demonstrated crop rotation’s ability to boost soil fertility and carbon sequestration [65]. Polyculture systems also enhance soil health and crop productivity by utilizing plant diversity to optimize resource use and reduce pest and disease compared to monoculture system [66]. A well-known example is the Three Sister planting system in North America: [67]. This system integrates corn, beans, and squash, and each crop plays a complementary role: corn provides structure, beans fix nitrogen, and squash suppress weeds [67]. This method promotes sustainability and resilience. Although mainstream CA practices have caused environmental degradation, not all CA practices are inherently unsustainable and non-eco-friendly. Sustainability is not exclusive to OA [7]. Advanced technologies in CA include precision irrigation and fertilization, plant factories using artificial lighting and soilless cultivation, input-reduced practices such as special cultivation in Japan, and indigenous methods like companion planting in America [68, 69]. When thoroughly applied and carefully managed, these CA practices can mitigate many environmental hazards [68, 69]. Thus, it is crucial to rethink the view that all CA practices are harmful, and recognize that some, though currently minor, hold significant potential for sustainability and environmental benefits (Fig.1).
Meanwhile, we have demonstrated that certain non-COAs such as natural farming, no-tillage, and rice-fish co-culture, and these value-based COA are relatively environmentally friendly. However, highly industrialized OA, especially those relying on monoculture and organic fertilizers (e.g., cattle manure compost) and biopesticides, may not be environmentally friendly. That highlights that within OA, environmental outcomes vary.
These facts reveal a critical issue: the false dichotomy between OA and CA. They treat each other as mutually exclusive rather than complementary, which hinders progress toward truly ecofriendly and sustainable agriculture. Addressing this requires changing the stereotype towards OA and CA. We believe permaculture (PC) hold potentials to offer a promising solution by bridging the gap between OA and CA, encouraging integration over opposition. In the following section, we will explore how PC can break this dichotomy and facilitate their integration.
Permaculture (PC), a term derived from “permanent, agriculture, culture”, was conceptualized by Bill Mollison and David Holmgren in the 1970s [15]. Mollison defined PC as “the conscious design and maintenance of agriculturally productive ecosystems which have the diversity, stability, and resilience of natural ecosystems. It is the harmonious integration of landscape and people providing their food, energy, shelter and other material and non-material needs in a sustainable way” [70]. It integrates traditional farming practices and modern agricultural sciences to establish resilient systems that reduce environmental foodprints while promoting long-term productivity [15, 17].
4.1.1 Three ethics of permacultureThe three ethics—Earth Care, People Care, and Fair Share— serve as the foundation for all PC’s design and implementation strategies [17, 70]. Earth care focuses on ecosystem health, including soil, water, and biodiversity [15, 17]. People care promotes the well-being of farmers, consumers, and communities [15, 17]. Fair share addresses equitable resource distribution and sustainability, preventing overexploitation and supporting food security [15, 17].
4.1.2 Twelve principles and an underlying principleDavid Holmgren further refined PC into 12 design principles, which serve as practical guidelines for establishing flexible and resilient systems [17]. They are: observe and interact, catch and store energy, obtain a yield, apply self-regulation and accept feedback, use and value renewable resources and services, produce no waste, design from patterns to details, integrate rather than segregate, use and value diversity, use edges and vale the marginal, and creatively use and respond to change [17]. The underlying principle is “maximum potential”, prioritizing “trying to do something” instead of “prohibiting something”. These principles allow for a flexible, adaptable approach that can be applied to various contexts.
4.1.3 Design strategies in permaculturePermaculture design involves zoning, optimizing land use based on use frequency, placing areas as vegetable gardens and composting sites closer to living spaces, and allocating food forests farther away [17, 71]. By improving resource efficiency, this strategy not only aligns with OA’s low-input principles but also offers an eco-friendly CA approach to optimize field management while reducing environmental impact. Another key strategy is eco-friendly pest management through intercropping pest-repellent plants and building hedgerows with natural predators [70], reducing pesticide use and supporting OA and eco-friendly CA practices [70, 71].
4.2 Permaculture: origins and philosophical foundationsPermaculture emerged in response to concerns about the negative impacts of industrial agriculture and unsustainable production and consumption practices [15]. Its origins are influenced by Mr. Masanobu Fukuoka and Mr. Franklin Hiram King [15].
Mr. Fukuoka developed “natural farming” or “do-nothing farming”, emphasizing ‘no fertilizers, no pesticides, no tillage, no weed’ [72]. This philosophy became the foundation of PC, working with nature rather than against it and became a cornerstone of PC’s “observe and interact” and “apply self-regulate and accept feedback” principles [73].
Mr. King documented the 4000-year-old sustainable agricultural practices of China, Korea, and Japan, such as composting, intercropping, and polyculture, as Farmers of Forty Centuries [74]. In the book, King emphasizes the farmer’s small-scale, resource-cycling, and efficient systems [74]. These have had a direct influence on the PC’s resource cycling strategies, spatial optimization, and principles such as “use and value renewable resources and services”, “produce no waste”, “integrate rather than segregate” and “use and value diversity” [15, 17, 75].
Both King’s insights and Fukuoka’s philosophy played a crucial role in shaping permaculture, influencing its ethics, principles, and design strategies. These foundations enabled permaculture to integrate OA and CA into broader sustainable agricultural practices. However, PC has long been misunderstood as another eco-friendly agriculture and placed in the opposite of CA.
4.3 Current misconceptions of permaculture and critiques 4.3.1 Permaculture misclassified as a subset of organic agricultureSince its emergence, PC has gained increasing attention in the scientific literature [16], but has been conflated with OA due to shared features like reducing chemical inputs [76, 77]. For example, some supermarkets label PC produce as “a particular form of organic farming with complementary aspects” [77]. This misclassification stems from focusing on shared features while overlooking PC’s unique principles. Unlike OA, which rigidly bans chemical fertilizers and pesticides, PC emphasizes adaptive, ethics-driven decision-making, allowing context-based use. This key distinction is ignored when PC is seen as a variation of OA.
4.3.2 Permaculture presented in opposition of conventional agricultureSimilarly, PC is often positioned contrary to CA because of CA’s reliance on monoculture, intensive tillage and chemical inputs, which degrade the environment [78]. However, the view that PC and CA oppose ignores CA’s evolving transformations toward sustainability, including conservation tillage, chemical inputs-reduced practices, and crop rotation and intercropping. These evolving practices are in accordance with PC’s principles of “integrate rather than segregate”, “use and value diversity”, and “use and value renewable resources” [17]. Therefore, framing PC and CA as mutually exclusive overlooks the synergies between evolving changes in CA and the systematic design strategies of PC.
By reassessing misconceptions of PC, it becomes clear that PC can transcend the OA-CA divide. A value-driven eco-friendly agricultural system (Fig.2) is based on permaculture’s core ethics and design principles. It provides holistic, context-specific solutions to current environmental challenges.
As previously discussed, the dichotomy between OA and CA emerged in the 20th century as part of efforts to standardize agricultural practices. While OA certification (e.g., USDA Organic) imposes strict prohibitions on synthetic inputs, CA relies on chemical optimization for yield maximization [2]. This binary has contributed to an overly simplified method for evaluating sustainability and eco-friendliness which system it belongs to OA or CA. Despite differing views on chemical inputs, both systems often follow global standardized practices that neglect local ecological, cultural, and socio-economic contexts [79]. This limitation is especially clear as climate instability and regional environmental crises worsen, such as soil degradation in sub-Saharan Africa and radioactive contamination in Fukushima [80]. Consequently, neither system can be considered entirely eco-friendly and sustainable, nor wholly unsustainable [2]. The prolonged OA-CA dichotomy increasingly hinders progress toward truly sustainable agriculture. Permaculture offers a transformative alternative by redefining eco-friendliness. It views sustainability not as a fixed label based on inputs but as a dynamic, context-driven process grounded in ecological design and systems thinking, guided by three ethics—Earth Care, People Care, and Fair Share [15, 17].
5.1 Rethinking eco-friendliness in traditional soil-based agricultureAs demonstrated, the chemicals-heavy reliant CA has caused various environmental problems and in response to these problems, chemicals-free OA has gained global attention with more and more farmers turning to it from CA [49]. However, there are some farmers who initially transitioned from CA to OA later reverted to CA due to several practical challenges [81]. Research by Harris et al. (UK), Läpple (Ireland), and Flaten (Norway) found that most farmers reverted from CA to OA mainly due to economic challenges [82, 83, 84]. Lower yields in organic production did not offset the higher costs associated with organic fertilizers [82, 83, 84]. Additionally, the high certification costs and labor-intensive weed management are also significant factors [85]. As a result, farmers often find themselves caught in a cycle of switching between CA and OA.
Rooted in the core ethics of Earth Care and People Care, PC provides an alternative to the binary between OA and CA. Instead of treating OA and CA as mutually exclusive categories, PC encourages a context-based approach to allow an incremental transition from CA to OA. This incremental transition is achieved through combining chemical fertilizers with organic fertilizers, implementing crop rotations and intercropping rather monoculture, or integrating agroforestry and mulching to gradually reduce external inputs [86, 87]. A notable example is Japan’s Tokubetsu Saibai system, which exemplifies such a hybrid approach. While products under these combined strategies may not meet organic certification standards, such practices have demonstrated notable economic and ecological benefits. For example, Wei et al. [88] found the combined application of organic and chemical fertilizers significantly increased crop yields (wheat, maize and rice) on average by 29% and 8% compared to organic fertilizers alone and chemical fertilizers alone respectively. Similarly, a long-term study using soils from sub-Saharan Africa, including dry savannas in Zimbabwe, humid forests in Ghana, and moist savannas in Kenya, demonstrated that combining organic residues with mineral fertilizers influences nitrogen cycling differently depending on soil texture and quality [89].
This approach prevents yield losses during sudden organic transition, supporting permaculture’s People Care ethic, and improves soil health and biodiversity, aligning with Earth Care. It challenges the view that eco-friendliness means only organic farming, highlighting flexible, context-based strategies as more sustainable for traditional farmers.
While these context-based strategies have shown their potentials in traditional soil-based systems, the redefinition of eco-friendliness should also extend to non-traditional forms of farming, such as soilless cultivation.
5.2 Redefining eco-friendliness in non-traditional soilless cultivation farmingAs global population continues to rise with the most recent estimates of 9.4–10.1 billion by 2050 and an extra of 0–2.7 billion by 2100, the demand for food has increased, urging agricultural systems to produce higher yields with fewer resources [90]. Traditional soil-based agriculture systems, however, have caused numerous challenges, including water waste, soil degradation, and the reduction of limited arable land [91]. In response to these challenges, soilless cultivation techniques, such as hydroponics, aeroponics, and vertical farming have emerged [92].
It is widely acknowledged that soilless cultivation, mainly applied in protected production, represents a promising alternative agricultural system because of its numerous advantages [69, 92]. These advantages include reduced water usage, minimized pesticide needs, and enhanced efficiency of nutrient and space utilization [69, 92]. According to Silberbush and Ben-Asher [68], plants can be grown more densely, requiring only 1/5 of the total area and 1/20 of water compared to traditional soil-based cultivation.
However, despite its numerous advantages, soilless cultivation has drawn criticism for several potential environmental concerns [92, 93]. One major issue is the vast consumption of peat, which is widely used as a substrate for soilless cultivation [90]. Peat is non-renewable over thousands of years, and peatland overuse harms wildlife habitats, hydrology, and carbon storage [94]. Moreover, soilless cultivation requires constant electricity to precisely regulate pH, conductivity, and nutrient levels [95]. Furthermore, energy is essential for sustaining water circulation and artificial lighting, especially in enclosed environments, such as greenhouses and plant factories [95]. It is estimated that energy costs account for 40% of the total cost of greenhouse cultivation [96]. Moreover, because soilless systems typically rely on synthetic nutrient solutions rather than natural inputs, they do not meet the criteria for organic agriculture and are instead classified as conventional agriculture. This classification, combined with its dependency on high-energy inputs, has led some researchers to question the overall sustainability of soilless cultivation.
Soilless cultivation does not meet EU organic standards, which require soil-based production, but this alone should not determine its environmental sustainability [97]. Instead, sustainability should be critically assessed within specific contexts, as encouraged by the ethical design system of PC. This perspective is demonstrated from two aspects: urban horticulture and agriculture in contaminated rural areas.
First, soilless systems offer an effective and sustainable method to provide fresh vegetables or other crops, such as rice, to local markets in urban areas. With approximately 70% of the world’s population living in urban regions by 2050, urban regions are expected to become increasingly densely populated [93, 98]. The development of soilless systems, including vertical farming and plant factories with artificial lighting (PLAL), can help address several pressing urban issues [99]. These benefits include reducing unemployment, supporting small- and medium-sized enterprises, increasing urban access to local fresh food, easing pressure on farmland, and utilizing unused or abandoned spaces like rooftops and industrial sites [93, 99]. For instance, in Tokyo, a densely populated city in Japan, rice is cultivated in underground vaults through four harvest cycles per year without the use of soil, demonstrating the potential of soilless systems in urban areas [100].
From a permaculture perspective, soilless systems in urban regions contribute to Earth Care, People Care, and Fair Share, and thus, can be considered sustainable and eco-friendly. Earth Care is supported by minimizing land and water use and reducing food miles and carbon emissions [101]. People Care is promoted by enhanced fresh and quality food access and improved employment rates. Fair Share is evidenced by fully utilized marginal space and redistributed production closer to consumption centers. Therefore, while soilless systems have high costs and greenhouse gas emissions and are departed from traditional organic standards, they can still align with the ethical principles of PC and serve as an effective method for sustainable and eco-friendly food production in urban areas.
In addition to urban areas, soilless systems are also viable in contaminated rural areas. Fukushima, Japan, experienced a devasting disaster—earthquake, tsunami, and nuclear accident—in 11 March 2011, causing soil contaminated [80]. Prior to the disaster, rice production, along with the cultivation of high-quality fruits such as peaches and pears, was a significant agricultural activity in Fukushima [80]. However, after the disaster, many fields were considered unsafe, and farmers faced land shortages and sales problems due to contamination [102]. This issue has been partially addressed by replacing traditional agriculture with soilless agriculture. Despite criticism of soilless cultivation for high costs and significant power use—over 9% of regional energy consumption—permaculture principles recognize these systems as enabling safe and sustainable cultivation [103]. Soilless cultivation helps minimize harm to the environment by avoiding further degradation of the land from chemicals, aligning with Earth Care. Additionally, it provides local resident with safe, healthy, and fresh produce, as well as job opportunities, which aligns with People care. Overall, soilless cultivation is a crucial system for both the well-being of local resident and the recovery of the region [80, 103].
Thus, rather than labeling soilless cultivation as inherently eco-friendly, permaculture’s Earth Care and People Care ethics offer a framework to evaluate its sustainability. This assessment considers specific local conditions, such as densely populated urban areas and contaminated rural regions like Fukushima.
5.3 Challenges of contextual evaluation of eco-friendliness through PCPermaculture has gained increasing recognition for its potential to offer flexibility and adaptability as a context-based approach. However, there are several challenges in applying this perspective to evaluate sustainability and eco-friendliness in agricultural systems [16]. The first challenge is that the PC itself has several intrinsic limitations that hinder its practical implementation and broader applicability [16]. Among these challenges are high labor demands, issues related to scalability, and currently limited adoption in mainstream agricultural systems [104, 105]. Many PC practices, such as mulching, composting, and polyculture management, require considerable manual effort, posing a barrier to farmers with limited labor availability or time constraints [106]. Furthermore, most successful implementations of PC are concentrated in small-scale households or community gardens because of intensive labor and low productivity problems. This limits the scalability of PC to large-scale commercial farming remains [77]. Finally, the lack of a universally accepted definition, along with the absence of technical guidelines, has further hindered its widespread adoption [104, 105].
Beyond these intrinsic limitations, another primary challenge is the variability in local contexts, including ecological conditions, cultural practices, and socioeconomic factors [107]. What may be considered sustainable and eco-friendly in one region may not be applicable to another because of the contextual differences. Consequently, farmers are required to have a deep understanding of their specific circumstances and be able to adapt to their practices independently, rather than follow the one-size-fits-all process seen in conventional or organic agriculture [108].
In summary, while permaculture offers a promising context-based approach, its practical implementation faces notable challenges that require further research and collaborative efforts to enhance its applicability across diverse agricultural settings.
This study demonstrates the limitations of the binary classification of OA and CA in defining eco-friendliness and sustainability. While both systems have contributed to agricultural development, the OA-CA dichotomy now hinders progress owing to defining sustainability and eco-friendliness as a rigid choice between the two systems [14]. In practice, agriculture includes a wide range of approaches, from input-free natural farming to highly technological and energy-intensive smart farming [109]. Evaluating eco-friendliness based only on system labels, such as organic versus conventional, chemical-free versus chemical-based, soil-based versus soilless, or energy-saving versus energy-intensive, often fails to reflect the complexity of the local ecological, socioeconomic, and cultural contexts. Therefore, there is a pressing need for a more flexible and context-based approach that can reflect the diverse complexities of agricultural systems and practices.
Against this backdrop, permaculture holds significant potential as an alternative for evaluating agricultural eco-friendliness and sustainability. This potential stems from its ability to transcend dichotomous evaluation methods by shifting the focus from input-based assessments to outcome-oriented approaches and from globally standardized methods to locally adapted solutions. These shifts are guided by its core ethics of Earth Care, People Care, and Fair Share [15]. In other words, it can redefine eco-friendliness as a flexible, context-based process rather than a fixed system label. By applying its core ethics across diverse contexts, permaculture encourages gradual improvements in traditional soil-based farming and sustainable innovations in nontraditional systems.
However, despite its conceptual strengths, PC also faces practical limitations such as high labor intensity, challenges in scalability, limited adoption in mainstream agricultural systems, and the necessity for farmers to independently adapt practices to diverse and variable local contexts. To overcome these challenges, the future development of PC must focus on enhancing its practical applicability and clarifying its role as a context-based approach to constructing an eco-friendly agricultural system. First, integrating low-energy smart technologies, such as precision fertilization, can help reduce labor intensity while maintaining ecological sustainability [88]. Second, developing flexible and scalable design models and promoting knowledge-sharing networks among farmers, researchers, and extension officers are essential to support wider applications [110].
This study contributes to a more comprehensive understanding of agricultural sustainability by highlighting the importance of flexible, context-based approaches, such as permaculture. To fully realize the potential of permaculture in fostering resilient and eco-friendly farming systems worldwide, continued research and collaborative efforts among researchers, practitioners, policymakers, and local communities are essential.
