A Bibliometric Analysis of Organic Farming and Voluntary Certifications

Abstract

Organic farming, characterised by environmentally friendly and sustainable agricultural practices, has gained significant attention throughout the years due to its potential to address critical issues such as food security, environmental sustainability, and public health. Voluntary certification systems play a pivotal role in ensuring the integrity and quality of organic products in the market. Understanding the research landscape surrounding organic farming and voluntary certifications is of paramount importance for scholars, policy makers, farmers, and consumers. In this context, the present study utilizes a bibliometric approach to achieve a deeper understanding of the trends, key contributors, and key terms in these domains via a bibliometric analysis in order to contribute to the broader goals of promoting sustainable agriculture and informed consumer choices. The evolution of the field is traced, shedding light on seminal papers, influential authors, and prolific journals. The research type is quantitative, using Web of Science, VOSviewer, and bibliometric study as instruments. The results show that, for both terms “organic farming” and “voluntary certifications”, papers usually involve three or more authors and use other sources as the unit of analysis, leaving room for improvement and the filling of a gap in the specialty literature. This insight can guide future researchers and policymakers in focusing on critical areas within organic farming and certification systems, further advancing the field and addressing pressing issues related to sustainability, quality, and consumer awareness.

1. Introduction

Organic farming is a subject of interest given the fact that the United Nations’ second goal is to have zero hunger and, within this goal, they want to improve nutrition [1]. Organic farming is an important aspect since its significance has been growing in recent years due to increasing awareness of environmental and health-related issues. In terms of environmental sustainability, organic farming brings the following benefits. It significantly reduces the use of synthetic pesticides, herbicides, and fertilisers, which can have harmful effects on the environment. This reduces chemical runoff into water bodies and minimizes soil and water pollution. Another effect is the fact that organic farming focuses on healthy soils, which are more resilient, are better at retaining water, and sequester carbon, helping combat climate change. Organic farms often prioritize biodiversity by providing habitats for a wide range of species. This helps support pollinators, beneficial insects, and other wildlife, contributing to overall ecosystem health.

Voluntary certifications provide a standardized way to validate a product’s source. They are a valuable form of recognition in industries where quality and safety are paramount. Holding a certification can give products a competitive edge in the food market. It can make a product more attractive to potential customers and can potentially lead to better sales. Certifications often help establish industry standards and best practices. They encourage consistency and uniformity in processes, procedures, and the quality of products and services.

The method which achieved the most insight into the two topics was the bibliometric analysis, using a table with multiple dimensions to describe certain topics. It has been conducted before by Çelïk and Uslu [2], in their paper, in order to achieve an overview of flow theory. However, in this article, this method will be applied to the terms “organic farming” and “voluntary certifications”. This article brings an amount of information and innovation via the methodology, the terminology, and the instruments used. The methodology and instruments are unique for the variate methods and instruments used like the bibliometric analysis, which is used to study various aspects of the academic and scientific literature, including publications, citations, and bibliographic data. It involves analysing patterns and trends in scholarly publications to gain insights into the structure and impact of research in a particular field or discipline. Therefore, the terminology chosen for this research is organic farming and voluntary certifications, which brings novelty because these terms have not been used together in an article in this manner before. Another reason for choosing these terms is that they are of high interest at the moment.

This research aims to achieve a deeper understanding of the trends, key contributors, and key terms in these domains via a bibliometric analysis, in order to contribute to the broader goals of promoting sustainable agriculture and informed consumer choices.

Therefore, the objectives of this study are:

O1. To identify the number of citations over time for the articles containing the terms “organic farming” and “voluntary certifications”.

O2. To identify the keywords with the highest occurrence used in publications based on the terms “organic farming” and “voluntary certifications”.

O3. To identify the most-co-cited authors in publications based on the terms “organic farming” and “voluntary certifications”.

O4. To identify the ratio of articles per dimension (number of authors, study attribute, study type, analysis unit, sample size, data collection method, and open accessibility).

2. Organic Agriculture and Voluntary Certifications Context

2.1. Organic Agriculture

The subject of organic farming has gained a lot of popularity and interest in recent years in the contemporary agricultural environment and elsewhere. The most frequently mentioned topics in organic farming are sustainability, ecological harmony, and reduced environmental impact. By analysing certain aspects such as historical context, methodologies, outcomes of organic farming, and future directions, this article proposes to offer a better understanding of the subject and its main points of interest throughout its relatively short written history.

The concept of organic farming appeared in the period prior to 1940 as an alternative method to traditional farming that brought solutions to most of the negative farming consequences encountered such as soil degradation, chemical pollution, and loss of biodiversity [3]. In 1980, organic agriculture gained significant recognition when the USDA published its Report on Recommendations on Organic Farming [4]. Further on, The Organic Foods Production Act of 1990, often referred to as the Organic Act, is a piece of United States federal legislation that laid the foundation for the regulation and certification of organic agricultural products [5]. However, there was a similar law in the European Union, namely Regulation 2092/91, that played a significant role in establishing the initial framework for organic agriculture within the European Union [6]. The regulation was regarding organic farming and the certification of organic agricultural products.

Organic farming operates on a set of guiding principles that distinguish it from conventional farming methods [7]. These principles encompass ecological balance, biological diversity, and sustainable practices. One of the most important aspects is soil health and fertility management via practices such as composting, cover cropping, and crop rotation [8]. By eliminating synthetic chemical inputs in favour of natural and organic fertilisers, organic farming seeks to nurture the soil microbiota and enhance the soil structure, which in turn support sustainable crop production. Its purpose is to not use synthetic pesticides and genetically modified organisms (GMOs) in order to avoid harming the environment. The alternative applied by organic farmers is to integrate pest management (IPM) strategies, which means using methods like biological control, crop rotation, and the introduction of beneficial insects [9].

The reduced impact of organic farming on the environment compared to that of traditional methods can be attributed to multiple sectors. One of them is the avoidance of using synthetic fertilisers and pesticides, which results in diminishing chemical runoff into water bodies and minimizes soil degradation [10]. This has a positive cascading effect on local ecosystems and overall environmental health. Consumers often associate organic produce with lower pesticide residues, which can contribute to improved human health outcomes.

Some studies state that the future of organic farming lies in innovation and adaptation [11]. Researchers are exploring ways to optimize organic systems, combining traditional practices with cutting-edge technologies. Agroecology, which is a method that integrates ecological principles with agricultural practices, holds promise in closing the gap between organic and conventional approaches [12].

Organic farming stands as a testament to humanity’s quest for sustainable and harmonious coexistence with the environment [13]. Its historical evolution, principles rooted in ecological balance, distinctive agricultural practices, and far-reaching implications for both the environment and human health underscore its significance [14]. As the world is confronted with the challenges posed by climate change and food security, the continued exploration and refinement of organic farming practices offer a hopeful path toward a more resilient and ecologically conscious agricultural future [15].

2.2. Voluntary Certifications

Voluntary certifications have emerged as a prominent mechanism used in various industries to convey quality, sustainability, and adherence to specific standards. They serve the necessity of informing the consumer about certain additional aspects of the product. In a globalized marketplace saturated with an array of products and services, certifications serve as distinguishing mechanisms that communicate attributes which may not be obvious to consumers because the differences between a product obtained by conventional farming methods and organic farming are minute and, most of the time, not easily observed by regular customers [16]. The information provided by these certifications could be about product quality, environmental sustainability, labour practices, and ethical considerations.

Furthermore, voluntary certifications are often seen as a new request from a more demanding modern consumer and their preferences [17]. As societal awareness regarding issues like environmental degradation, human rights violations, and health concerns rises, consumers seek assurances that their choices align with their values. Certifications thus function as a means to close the gap between consumer expectations and producer practices [18].

Voluntary certifications can offer producers a competitive edge by differentiating their products in the marketplace [19]. By adhering to recognized standards, producers can tap into consumer segments that prioritize ethical and sustainable considerations. However, obtaining and maintaining certifications can be resource-intensive, particularly for smaller producers with limited budgets [20]. This raises concerns about the potential exclusion of small-scale producers from participating in the certification system [21].

On the other hand, the proliferation of certifications can also lead to confusion, where consumers are overwhelmed by the sheer number of labels, making it challenging to distinguish between genuinely impactful certifications and superficial ones [22].

The influence of voluntary certifications on market dynamics can create a new standard of product that commands a higher price than the average because of the perceived quality and sustainability of the product [23]. This might influence producers to adhere to more and more certification practices, thereby driving overall industry improvements. However, this can also lead to a practice in which the companies adopt the appearance of sustainability without substantial changes in their methods [24].

The European Parliament and Council, in December 2021, amended various existing regulations related to agricultural products, quality schemes, geographical indications of aromatized wine products, and measures for agriculture in the outermost regions of the European Union [25]. There are several types of voluntary certification that are worth mentioning and that will be explained in the following paragraphs.

A “Traditional Certified Product” (or TCP) or Traditional Specialty Guaranteed (TSG) usually indicates a product with a certification obtained based on the use of traditional or heritage methods of production, often tied to cultural practices, craftsmanship, or historical production techniques [26]. They also acknowledge and preserve traditional knowledge, skills, and techniques associated with a specific region or culture.

Examples of traditional certified products include various types of foods and agricultural products. An example is Gueuze, which is a traditional beer produced in and around Brussels, Belgium. These products have specific certifications that not only protect the authenticity and reputation of the products but also contribute to the preservation of cultural heritage and the economic development of the regions where they are produced [27].

A Protected Designation of Origin (or PDO) works as a type of geographical indication (GI) used to identify and protect products that are closely linked to a specific geographical area. PDO is a form of intellectual property protection that prevents products from being produced in other regions and using the same name, thus preserving the uniqueness and traditional production methods associated with the product [27].

A well-known example of a PDO product includes Kalamata olive oil, which is entirely produced in the region of Kalamata in Greece. These products have distinctive qualities and characteristics tied to their specific regions of origin, and the PDO designation helps protect their authenticity and prevent imitation [28].

A Protected Geographical Indication (PGI) works as a type of geographical indication (GI) used to identify and protect products made in a certain area and that have particular qualities, characteristics, and a reputation that are essentially attributable to that location [29].

A well-known example of a PGI product includes Westfälischer Knochenschinken ham which is produced in Westphalia, Germany.

However, it should be noted that these voluntary certifications are regulated by the EU. Regulation (EU) 2017/625 is a comprehensive regulatory framework that reflects the EU’s commitment to ensuring the safety and integrity of the food and agricultural sectors [25].

3. Material and Methods

In this study, we employed the Web of Science platform, a renowned and widely recognized bibliographic database, as a primary tool for conducting the bibliometric analysis.

The first step was to search for the terms “organic farming” and “voluntary certifications” in the Web of Science database. The search in Web of Science consisted in having all fields when searching for the two terms. The results of the search in Web of Science were filtered by the number of citations, with the first 1000 records with the highest number being kept for each term. Two databases were formed, each containing 1000 records. The databases were uploaded to VOSviewer and several computations were performed. These computations consisted of finding the most-co-cited authors and the most-used keywords.

For the next steps, two specialists in Agriculture were chosen in order to select from the two databases at least one article per year based on its relevancy towards each term. For “organic farming” there were 38 selected studies, while for “voluntary certifications” there were 28. These studies were subjected to a detailed bibliometric analysis. This bibliometric analysis gives a thorough investigation via its 9 dimensions.

VOSviewer version 1.6.18, which was designed by Ness Jan van Eck and Ludo Waltman [30], was used for co-occurrence maps and keyword analysis.

4. Results and Discussion

The results section consists of two subchapters; the first one contains information about organic farming, and the second one is about voluntary certifications. At the same time, each subchapter consists of two subsections, one describing the VOSviewer computations and one on the bibliometric study.

4.1. Organic Farming

When searching for the construct “organic farming” in Web of Science, the returns consist in a total of 27,725 results. These publications belong to various domains as specified in each journal description, such as Environmental Sciences (6158 publications), Agronomy (4229 publications), Agriculture Multidisciplinary (3635 publications), Soil Science (3515 publications), and others (Figure 1).

However, from all the domains, the ones which were in our interest were chosen. These domains are Agronomy, Agriculture Multidisciplinary, Agricultural Economics Policy, Agricultural Engineering, Economics, Business, Management, and Behavioural Sciences. After filtering using this selection, 9162 publications were further kept for study. From these, only open access publications were chosen, and the results narrowed down to 3040 documents.

It is observable that there is a peak in publications around the year 2021, while the peak for the highest number of citations is in 2022. The focus in Figure 2 is regarding the peak of publications in the year 2021. A possible explanation for this is that the EU released a new regulation in 2017 [25] that was delayed until 2021 for pandemic reasons. This regulation has generated a large amount of research tackling any probable implications during that time.

The year 2023 should not be considered as a decrease since the extraction of publications happened in the month of August; the year 2023 is still going on and, therefore, having an upward trend. Next, the results were ordered based on the number of citations and the first 1000 publications with the highest number of citations were exported to a separate file for bibliometric analysis.

4.1.1. Results Based on VOSviewer Computations

For both terms, there were two types of VOSviewer computations performed: The first one is about showing co-authorship and the second one is about the most-used keywords in the selected studies.

Figure 3 is showing the co-authorship relations in the selected publications. The type of analysis chosen was “Co-authorship” and the counting method was set to “Full counting”. The minimum number of documents per author was set to 1. However, of the 4079 authors of the publications, only 375 meet this threshold. As it is observable from Image 3 the coloured bubbles represent only the authors which had co-authored with other people (meaning the 375). The size of the bubbles represents the authors which had the highest number of co-authors. The top three co-authors are Etl van Beuren, P Maeder, and M Casagrande.

The co-occurrence keywords map is presented in Figure 4. The type of analysis chosen was “Co-occurrence” and the counting method was set to “Full counting”. The minimum number of occurrences of a keyword was set to 1, having in total 5717 keywords. The keywords which have the highest number of occurrences are presented in

Table 1. The ranking of the most frequently occurring keywords for the term “organic farming”.

Ranking	Keyword	Occurrences
1	Management	178
2	Organic farming	166
3	Agriculture	110
4	Nitrogen	98
5	Yield	87
6	Systems	85
7	Biodiversity	84
8	Quality	80
9	Soil	75
10	Farming systems	60
11	Sustainability	60
12	Organic-matter	60
13	Growth	55
14	Cropping systems	53
15	Carbon sequestration	46

. The first look at Table 1 shows that “management” is the most-used keyword in the selected database; this happens because a lot of articles are written on the management perspective of organic agriculture. A few articles have as a focus management practices, meaning that they study weed control, crop residue management, and organic fertiliser application methods in order to observe the differences between the current and previous years and whether these factors are influencing the overall performance [31].

Besides the biggest bubbles which represent the highest occurrences of keywords, they are also categorized into clusters based on colour as follows:

• Cluster 1 (dark-blue colour) represents the topic of biodiversity; some of the other keyword structures are agrobiodiversity, conservation, ecosystem services, vegetation, agroecology, etc.;
• Cluster 2 (light-blue colour) represents the topic of farming systems; some of the other keyword structures are soil fertility, food security, soil quality, conservation agriculture, etc.;
• Cluster 3 (red colour) represents the topic of organic farming; some of the other keyword structures are quality, yield, growth, cropping systems, etc.;
• Cluster 4 (yellow colour) represents the topic of soil systems; some of the other keyword structures are nitrogen, soil, phosphorus, climate change, etc.;
• Cluster 5 (purple colour) represents the topic of agriculture; some of the other keyword structures are sustainability, knowledge, adoption, food, conversion, etc.;
• Cluster 6 (green colour) represents the topic of performance and chemical composition; some of the other keyword structures are organic, design, microorganisms, health, pollution, bacteria, etc.;
• Cluster 7 (orange colour) represents the topic of carbon; some of the other keyword structures are organic matter, carbon sequestration, biomass, fertiliser, microbial biomass, tillage, etc.

The next figure (Figure 5) represents multiple articles containing keywords from multiple clusters. When hovering over a bubble using the cursor, a few bubbles are highlighted, which means that those highlighted bubbles represent an article which has several keywords. A better representation of an article like that is depicted in Figure 6.

Figure 6 represents an article which contains the two highlighted bubbles, meaning sustainable agriculture and certification.

The following sub-section is showing the results of the bibliometric analysis conducted for the term “organic farming”.

4.1.2. Bibliometric Analysis

In order to complete the third objective set for this study, several publications were selected for a thorough investigation resulting in a bibliometric study. The selection was performed by two authors based on title and abstract reading.

For the term “organic farming”, there were 38 studies selected (they can be found in Appendix A,

Table A1. Table of selected studies for the term “organic farming”.

Year	Names of the Authors	Title	Type of Publication	N (Number of Authors)
1983	Langley, Ja; Heady, Eo; Olson, Kd	The Macro Implications Of A Complete Transformation Of United-States Agricultural Production To Organic Farming Practices	Journal article	3
1992	Mcmaster, Gs; Morgan, Ja; Wilhelm, Ww	Simulating Winter-Wheat Spike Development And Growth	Journal article	3
1995	Halberg, N; Kristensen, Es; Kristensen, Is	Nitrogen Turnover On Organic And Conventional Mixed Farms	Journal article	3
1996	Sullivan, S; McCann, E; deYoung, R; Erickson, D	Farmers’ attitudes about farming and the environment: A survey of conventional and organic farmers	Journal article	4
1997	Loes, AK; Ogaard, AF	Changes in the nutrient content of agricultural soil on conversion to organic farming in relation to farm-level nutrient balances and soil contents of clay and organic matter	Journal article	2
1998	Snapp, SS; Mafongoya, PL; Waddington, S	Organic matter technologies for integrated nutrient management in smallholder cropping systems of southern Africa	Journal article	3
1999	Altieri, MA	The ecological role of biodiversity in agroecosystems	Journal article	1
2000	Olesen, JE; Askegaard, M; Rasmussen, IA	Design of an organic farming crop-rotation experiment	Journal article	3
2001	Rigby, D; Caceres, D	Organic farming and the sustainability of agricultural systems	Journal article	2
2002	Langmeier, M; Frossard, E; Kreuzer, M; Mader, P; Dubois, D; Oberson, A	Nitrogen fertilizer value of cattle manure applied on soils originating from organic and conventional farming systems	Journal article	6
2003	Nieberg, H; Offermann, F	The profitability of organic farming in Europe	Journal article	2
2004	Van Bueren, ETL; Struik, PC	The consequences of the concept of naturalness for organic plant breeding and propagation	Journal article	2
2005	Vogl, CR; Kilcher, L; Schmidt, H	Are standards and regulations of organic farming moving away from small farmers’ knowledge?	Journal article	3
2005	Sorensen, CG; Madsen, NA; Jacobsen, BH	Organic farming scenarios: Operational analysis and costs of implementing innovative technologies	Journal article	3
2006	Mason, H. E.; Spaner, D.	Competitive ability of wheat in conventional and organic management systems: A review of the literature	Journal article	2
2007	Murphy, Kevin M.; Campbell, Kimberly G.; Lyon, Steven R.; Jones, Stephen S.	Evidence of varietal adaptation to organic farming systems	Journal article	4
2007	De Wit, J.; Verhoog, H.	Organic values and the conventionalization of organic agriculture	Journal article	2
2008	Bayramoglu, Z.; Gundogmus, E.	Cost efficiency on organic farming: a comparison between organic and conventional raisin-producing households in Turkey	Journal article	2
2009	Mondelaers, Koen; Aertsens, Joris; Van Huylenbroeck, Guido	A meta-analysis of the differences in environmental impacts between organic and conventional farming	Journal article	3
2009	Lamine, Claire; Bellon, Stephane	Conversion to organic farming: a multidimensional research object at the crossroads of agricultural and social sciences. A review	Journal article	2
2010	Darnhofer, Ika; Lindenthal, Thomas; Bartel-Kratochvil, Ruth; Zollitsch, Werner	Conventionalisation of organic farming practices: from structural criteria towards an assessment based on organic principles. A review	Journal article	4
2010	Adams, Damian C.; Salois, Matthew J.	Local versus organic: A turn in consumer preferences and willingness-to-pay	Journal article	2
2011	Breustedt, Gunnar; Latacz-Lohmann, Uwe; Tiedemann, Torben	Organic or conventional? Optimal dairy farming technology under the EU milk quota system and organic subsidies	Journal article	3
2012	Guesmi, B.; Serra, T.; Kallas, Z.; Gil Roig, J. M.	The productive efficiency of organic farming: the case of grape sector in Catalonia	Journal article	4
2013	Bennett, Mica; Franzel, Steven	Can organic and resource-conserving agriculture improve livelihoods? A synthesis	Journal article	2
2013	Colomb, Bruno; Carof, Matthieu; Aveline, Anne; Bergez, Jacques-Eric	Stockless organic farming: strengths and weaknesses evidenced by a multicriteria sustainability assessment model	Journal article	4
2014	Latruffe, Laure; Nauges, Celine	Technical efficiency and conversion to organic farming: the case of France	Journal article	2
2015	Henneron, Ludovic; Bernard, Laetitia; Hedde, Mickael; Pelosi, Celine; Villenave, Cecile; Chenu, Claire; Bertrand, Michel; Girardin, Cyril; Blanchart, Eric	Fourteen years of evidence for positive effects of conservation agriculture and organic farming on soil life	Journal article	9
2016	Goldstein, Benjamin; Hauschild, Michael; Fernandez, John; Birkved, Morten	Urban versus conventional agriculture, taxonomy of resource profiles: a review	Journal article	4
2017	Jouzi, Zeynab; Azadi, Hossein; Taheri, Fatemeh; Zarafshani, Kiumars; Gebrehiwot, Kindeya; Van Passel, Steven; Lebailly, Philippe7	Organic Farming and Small-Scale Farmers: Main Opportunities and Challenges	Journal article	7
2017	Seufert, Verena; Ramankutty, Navin; Mayerhofer, Tabea	What is this thing called organic?—How organic farming is codified in regulations	Journal article	3
2018	Meemken, Eva-Marie; Qaim, Matin	Organic Agriculture, Food Security, and the Environment	Journal article	2
2018	Finley, Lynn; Chappell, M. Jahi; Thiers, Paul; Moore, James Roy	Does organic farming present greater opportunities for employment and community development than conventional farming? A survey-based investigation in California and Washington	Journal article	4
2019	Dessart, Francois J.; Barreiro-Hurle, Jesus; van Bavel, Rene	Behavioural factors affecting the adoption of sustainable farming practices: a policy-oriented review	Journal article	3
2020	Duran-Lara, Esteban F.; Valderrama, Aly; Marican, Adolfo	Natural Organic Compounds for Application in Organic Farming	Journal article	3
2021	Verdouw, Cor; Tekinerdogan, Bedir; Beulens, Adrie; Wolfert, Sjaak	Digital twins in smart farming	Journal article	4
2021	Durham, Timothy C.; Mizik, Tamas	Comparative Economics of Conventional, Organic, and Alternative Agricultural Production Systems	Journal article	2
2022	Moehring, Niklas; Finger, Robert	Pesticide-free but not organic: Adoption of a large-scale wheat production standard in Switzerland	Journal article	2

). In

Table 2. Table of the bibliometric analysis for the term “organic farming”.

Bibliographic of Selected Studies		Time Period
		1983–2001		2002–2008		2009–2015		2016–2022		2020–Present		1983–Present
		N1 = 9		N2 = 9		N3 = 10		N4 = 10		N6 = 4		N7 = 38
		f	%	f	%	f	%	f	%	f	%	f	%
Number of authors	One author	1	11.11%									1	2.63%
	Two authors	2	22.22%	5	55.55%	4	40%	3	30%	2	50%	14	36.84%
	Three or more authors	6	66.66%	4	44.44%	6	60%	7	70%	2	50%	23	60.52%
Study Attribute	Book
	Journal Article	9	100%	9	100%	10	100%	10	100%	4	100%	38	100%
	Conference paper/proceedings
	Other
Study type	Quantitative	4	44.44%	6	66.66%	6	60%	5	50%	2	50%	21	55.26%
	Qualitative	4	44.44%	3	33.33%	4	40%	4	40%	2	50%	15	39.47%
	Mixed	1	11.11%					1	10%			2	5.26%
Analysis unit	Farms	3	33.33%	1	11.11%	2	20%	1	10%			7	18.42%
	Other	5	55.55%	5	55.55%	3	30%	4	40%	2	50%	17	44.73%
	Source	1	11.11%	3	33.33%	5	50%	5	50%	2	50%	14	36.84%
Sample size	One thousand and below	5	55.55%	6	66.66%	5	50%	5	50%	1	25%	21	55.26%
	Over one thousand					1	10%	1	10%	1	25%	2	5.26%
	Not quantitative	4	44.44%	3	33.33%	4	40%	4	40%	2	50%	15	39.47%
Data collection method	Survey			3	33.33%			2	20%	1	25%	5	13.15%
	Interview	1	11.11%									1	2.63%
	Literature review	3	33.33%	3	33.33%	4	40%	4	40%	2	50%	14	36.84%
	Mixed (experiment, questionnaire)	5	55.55%	3	33.33%	6	60	4	40%	1	25%	18	47.36%
Access method	Open access	9	100%	9	100%	10	100%	10	100%	4	100%	38	100%
	Not open access

, a bibliometric analysis for the term “organic farming” is displayed.

As can be seen in Table 2, a chronological analysis of the findings in the time period from 1983 to the present is given. Among the selected 38 studies, there are more studies with three or more authors (60.52%), journal articles (100%), and quantitative (55.26%) studies on organic farming.

At the same time, it is seen that among the 38 studies chosen, other is the most chosen as the analysis unit (44.73%) and the sample size in most of the studies is less than one thousand or one thousand (55.26%). The mixed method (47.36%) is used for data collection and all the studies are 100% open access. The fact that the mixed method has the highest percentage can indicate that the multiple methods used can gather various perspectives and more diverse data. An interesting fact is that the highest percentage of articles (44.73%) preferred a different source of information rather than acquiring that data from first-hand sources, such as farms or farmers. This can indicate that researchers would rather focus their work on the existing literature than approach a real-life situation at local farms. This can provide a good opportunity for researchers that want to experience and gather information about organic farming [32].

In conclusion, organic farming is a term which was and still is of huge interest to people, since food is an essential product for living. However, in the past years, the focus is yet again on organic agriculture rather than the chemical one [23,24].

4.2. Voluntary Certification

When searching for the second construct “voluntary certifications” in Web of Science, the returns consist in a total of 1258 results. These publications are in different domains; the top three domains are depicted in the picture below. This ranking is automatically performed by Web of Science.

It is observable from Figure 7 that most publications are written in Environmental Sciences, Environmental Studies, and Economics.

However, from all the domains, the ones which were in our interest were chosen. These domains are Economics, Business, Management, Agricultural Economics Policy, Environmental Sciences, Food Science Technology, Agriculture Dairy Animal Science, Agronomy, Ecology, Agriculture Multidisciplinary, Business Finance, International Relations, and Agricultural Engineering. The number of citations of the resultant publications is depicted in the image below. It is observable that there is a peak in publications in the year 2019, and a peak in the number of citations in the beginning of the year 2022. The year 2023 should not be necessarily considered as a decrease since the extraction of publications happened in the month of August; the year 2023 is still going on and, therefore, the image shows an upward trend in publications until 2019 and then a downward trend. For the number of citations, the upward trend lasts until the beginning of 2022, while the results for 2023 are not relevant since the year is not over yet, meaning it is impossible to say if there will be a downward trend.

The focus in Figure 8 is regarding the peak of publications in the year 2019. A possible explanation for this is that the EU released a new regulation in 2017 [25] that was delayed until 2021. This regulation has generated a large amount of research tackling any probable implications. Since the results found for the term “voluntary certifications” were few, it was decided to search in Web of Science for each certificate separately. Therefore, in

Table 3. The publications indexed in the Web of Science database per term searched.

Term Searched in Web of Science	Results Returned in August 2023	Results Returned in July 2023
Traditional Certified Product	261	240
Protected Designation of Origin	1325	1260
Protected Geographical Indication	744	720
Traditional Specialty Guaranteed	89	78
Certified Ecological Product	128	97

, the terms searched in Web of Science and the returned results (between a first search in July 2023 and a second one in August 2023) are observable.

It is observable from Table 3 that there is an increase in publications, even from one month to the next.

4.2.1. Results Based on VOSviewer Computations

Figure 9 represents the first computation made using VOSviewer regarding co-authorship. Since the results obtained for “voluntary certifications” were not many, it was decided to compress all the files obtained for “voluntary certifications” and the following terms “Traditional Certified Product”, “Protected Designation of Origin”, “Protected Geographical Indication”, “Traditional Specialty Guaranteed”, and “Certified Ecological Product”. There was a total of 3222 articles. In those articles, there was a total of 3428 authors. The type of analysis chosen was “Co-authorship” and the counting method was set to “Full counting”. The minimum number of documents per author was set to 1. However, of the 3428, only 66 meet this threshold.

The size of the bubbles represents the authors which had the highest number of co-authors. Therefore, Milder, Lambin, and Carlson were the authors with the most co-authors.

The second type of computation made using VOSviewer is regarding the most-used keywords in the 3222 articles selected. The type of analysis chosen was “Co-occurrence” and the counting method was set to “Full counting”. The minimum number of occurrences of a keyword was set to 1, having in total 5104 keywords. VOSviewer has a limit of 1000 records; therefore, it used only the first 1000 keywords from the sample. The cohort of keywords is depicted in Figure 10.

The keywords which have the highest number of occurrences can be found in

Table 4. The ranking of the most frequently occurring keywords for the 6 terms regarding voluntary certifications.

Ranking	Keyword	Occurrences
1	Quality	150
2	Certification	114
3	Origin	80
4	Sustainability	77
5	Food	75
6	Geographical indications	61
7	Protected designation	51
8	Governance	51
9	Impact	50
10	Performance	50
11	Protected designation of origin	50
12	Management	49
13	Willingness-to-pay	43
14	Geographical origin	41
15	Preferences	35

and are depicted in Figure 10. Besides the biggest bubbles which represent the highest occurrences of keywords, they are also categorized into clusters based on colour as follows:

The cluster with the dark-blue colour represents the topic of quality and geographical origin; some of the other keyword structures are food, classification, traceability, authenticity, etc.;

The cluster with the red colour represents the topic of certification and sustainability; some of the other keyword structures are performance, impact, conservation, fair trade, management, etc.;

The cluster with the pink colour represents the topic of protected designation of origin; some of the other keyword structures are protected geographical indication, buying intention, food quality labels, etc.;

The cluster with the light-yellow colour represents the topic of land use; some of the other keyword structures are agroecology, forest, plantations, etc.;

The cluster with the purple colour represents the topic of origin; some of the other keyword structures are products, information, awareness, consumer behaviour, etc.;

The cluster with the green colour represents the topic of identification; some of the other keyword structures are diversity, milk, cheese, texture, etc.;

The cluster with the orange colour represents the topic of geographical indication; some of the other keyword structures are preferences, consumers, trade, rural development, price premium, etc.

In Table 4, it can be observed that “quality” is the most-used keyword in publications regarding “voluntary certifications”. This happens because, in markets where consumers favour eco-friendly products, they cannot independently verify a product’s environmental quality; that is why these certifications come as a response to this problem [33].

A different type of analysis can be performed on the keywords based on the year of publication; therefore, Figure 11 shows their interconnection evolution.

It is observable in Figure 11 that keywords like geographical indications, labels, and rural development are hot topics which have grabbed attention in the past two years, in comparison with traits, feed, contamination, and market that are topics which have been discussed since the beginning of 2016.

The following sub-section is showing the results of the bibliometric analysis conducted for the term “voluntary certifications”.

4.2.2. Bibliometric Analysis

In order to complete the fourth objective set for this study, a number of studies were selected by two specialists for a thorough investigation resulting in a bibliometric study.

For the term “voluntary certifications”, there were 28 selected studies (they can be found in Appendix B,

Table A2. Table of selected studies for all 6 terms regarding “voluntary certifications”.

Year	Names of the Authors	Title	Type of Publication	N (Number of Authors)
2004	Mas, AH; Dietsch, TV	Linking shade coffee certification to biodiversity conservation: Butterflies and birds in Chiapas, Mexico	Journal article	2
2005	Stull, CL; Reed, BA; Berry, SL	A comparison of three animal welfare assessment programs on California dairies	Journal article	3
2006	Hamilton, SF; Zilberman, D	Green markets, eco-certification, and equilibrium fraud	Journal article	2
2007	Garcia, C; Mane-Vivien, D; Kushalappa, CG; Chengappa, PG; Nanaya, KM	Geographical indications and Biodiversity in the western ghats, India: Can labeling benefit producers and the environment in a mountain agroforestry landscape?	Journal article	5
2007	Soratto, AN; Varvakis, G; Horii, J	Certification adds value to Brazilian cachaga	Journal article	3
2008	Canada, JS; Vazquez, AM	Protected designations of origin and innovations: The olive oil branch in Sierra Magina (Andalusia)	Journal article	2
2008	Marette, S; Clemens, R; Babcock, B	Recent International and Regulatory Decisions About Geographical Indications	Journal article	3
2009	Blanco, E; Lozano, J; Rey-Maquieira, J	A dynamic approach to voluntary environmental contributions in tourism	Journal article	3
2010	Sepulveda, WS; Maza, MT; Mantecon, AR	Factors associated with the purchase of designation of origin lamb meat	Journal article	3
2010	Clark, MR; Kozar, JS	Comparing Sustainable Forest Management Certifications Standards: A Meta-analysis	Journal article	2
2011	Iraizoz, B; Bardaji, I; Rapun, M	Do ‘Protected Geographical Indications’ (PGI)-certified farms perform better? The case of beef farms in Spain	Journal article	3
2012	Charlier, C; Ngo, MA	Geographical indications outside the European Regulation on PGIs, and the rule of the free movement of goods: lessons from cases judged by the Court of Justice of the European Communities	Journal article	2
2012	Augustin-Jean, L	Standardization vs. Products of Origins: What Kinds of Agricultural Products Have the Potential to Become a Protected Geographical Indication?	Journal article	1
2013	Esparon, M; Stoeckl, N; Gyuris, E	Eco Certification In Queensland’s Wet Tropics World Heritage Area: Is It Good For Business?	Journal article	3
2014	Braghieri, A; Girolami, A; Riviezzi, AM; Piazzolla, N; Napolitano, F	Liking of traditional cheese and consumer willingness to pay	Review	5
2015	Sellers-Rubio, R; Mas-Ruiz, FJ	Economic efficiency of members of protected designations of origin: sharing reputation indicators in the experience goods of wine and cheese	Journal article	2
2015	Mol, APJ; Oosterveer, P	Certification of Markets, Markets of Certificates: Tracing Sustainability in Global Agro-Food Value Chains	Journal article	2
2016	Gracia, A; de-Magistris, T	Consumer preferences for food labeling: What ranks first?	Journal article	2
2017	Anastasiou, CN; Keramitsoglou, KM; Kalogeras, N; Tsagkaraki, MI; Kalatzi, I; Tsagarakis, KP	Can the Euro-Leaf Logo Affect Consumers’ Willingness-To-Buy and Willingness-To-Pay for Organic Food and Attract Consumers’ Preferences? An Empirical Study in Greece	Journal article	6
2017	Quinones-Ruiz, XF; Penker, M; Belletti, G; Marescotti, A; Scaramuzzi, S	Why early collective action pays off: evidence from setting Protected Geographical Indications	Journal article	6
2018	Darnall, N; Ji, H; Vazquez-Brust, DA	Third-Party Certification, Sponsorship, and Consumers’ Ecolabel Use	Journal article	3
2018	Oya, C; Schaefer, F; Skalidou, D	The effectiveness of agricultural certification in developing countries: A systematic review	Journal article	3
2019	Fiankor, DDD; Martinez-Zarzoso, I; Brummer, B	Exports and governance: the role of private voluntary agrifood standards	Journal article	3
2020	Schleifer, P; Sun, YX	Reviewing the impact of sustainability certification on food security in developing countries	Review	2
2021	Discetti, R	Campaigning for sustainable food: sustainably certified consumer communities	Journal article	1
2022	Praneetvatakul, S; Vijitsrikamol, K; Schreinemachers, P	Ecolabeling to Improve Product Quality and Reduce Environmental Impact: A Choice Experiment With Vegetable Farmers in Thailand	Journal article	3
2023	Hristov, H; Erjavec, K; Pravst, I; Juvancic, L; Kuhar, A	Identifying Differences in Consumer Attitudes towards Local Foods in Organic and National Voluntary Quality Certification Schemes	Journal article	5
2023	Malak-Rawlikowska, A; Majewski, E; Kaminska, I	Unlocking The Potential Of The European Union Quality Schemes For Polish Regional And Traditional Food Products	Journal article	3

). In

Table 5. Table of the bibliometric analysis for the 6 terms regarding “voluntary certifications”.

Bibliographic of Selected Studies		Time Period
		2004–2008		2009–2013		2014–2018		2019–2023		2020–Present		2004–Present
		N1 = 7		N2 = 7		N3 = 8		N4 = 6		N5 = 5		N6 = 28
		f	%	f	%	f	%	f	%	f	%	f	%
Number of authors	One author			1	14.28%			1	16.66%	1	20%	2	7.14%
	Two authors	3	42.85%	2	28.57%	3	37.5%	1	16.66%	1	20%	9	32.14%
	Three or more authors	4	57.14%	4	57.14%	5	62.5%	4	66.66%	3	60%	17	60.71%
Study Attribute	Book
	Journal Article	7	100%	7	100%	7	90%	5	83.33%	4	80%	26	92.85%
	Conference paper/proceedings
	Other					1	10%	1	16.66%	1	20%	2	7.14%
Study type	Quantitative	3	42.85%	6	85.71%	2	25%	3	50%	2	40%	14	50%
	Qualitative	3	42.85%	1	14.28%	2	25%	1	16.66%	1	20%	7	25%
	Mixed	1	14.28%			4	50%	2	33.33%	2	40%	7	25%
Analysis unit	Farms							1	16.66%	1	20%	1	3.57%
	Other	6	85.71%	6	85.71%	8	100%	4	66.66%	3	60%	24	85.71%
	Source	1	14.28%	1	14.28%			1	16.66%	1	20%	3	10.71%
Sample size	One thousand and below	4	57.14%	6	85.71%	4	50%	4	66.66%	3	60%	18	64.28%
	Over one thousand					2	25%	1	16.66%	1	20%	3	10.71%
	Not quantitative	3	42.85%	1	14.28%	2	25%	1	16.66%	1	20%	7	25%
Data collection method	Survey	1	14.28%	2	28.57%	1	12.5%	1	16.66%	1	20%	5	17.85%
	Interview					1	12.5%	1	16.66%	1	20%	2	7.14%
	Literature review	3	42.85%	2	28.57%	1	12.5%	1	16.66%	1	20%	7	25%
	Mixed (experiment, questionnaire)	3	42.85%	3	42.85%	5	62.5%	3	50%	2	40%	14	50%
Access method	Open access	7	100%	7	100%	8	100%	6	100%	5	100%	28	100%
	Not open access

, a bibliometric analysis for the term “voluntary certifications” is displayed.

As can be seen in Table 5, a chronological analysis of the findings in the time period from 1983 to the present is given. Among the selected 28 studies, there are more studies with three or more authors (60.71%), journal articles (92.85%), and quantitative (50%) studies on the six terms regarding voluntary certifications.

At the same time, it is seen that among the 28 studies chosen, other is the most chosen as the analysis unit (85.71%) and the sample size in most of the studies is less than one thousand or one thousand (64.28%). The mixed method (50%) is used for data collection and all the studies are 100% open access. The fact that the mixed method has the highest percentage can indicate that the multiple methods used can gather various perspectives and more diverse data.

Voluntary certifications are an emerging notion and are starting to be more present nowadays; also because they are a present theme in the vision of the European Commission. Information can still be gathered about this topic since it is not yet fully developed.

The presented method is just an example and a starting point for future studies. One discussion can be related to the paper selection process; this can be adapted and improved. In addition, for the bibliometric study table, more dimensions can be inserted or removed.

A controversial discussion is about the credibility of certified environmental management systems. One article in particular addresses the perceived credibility of these certificates and how crucial they are for their implementation and use. Their key findings are that the credibility of EMS certification is heavily influenced by the companies that certify them, poor-quality audits can lead to the possession of certifications, emphasizing the universality of using certified systems, a positive perception of certified EMSs in companies promotes the widespread use of these certificates, and the credibility of these systems can be enhanced by publishing audit reports. Their conclusion is that the credibility of the certification process is paramount, especially in the context of EMSs and given the fact that, over the years, there has been a significant focus on ecological credibility, particularly concerning the direct and indirect environmental impacts of products [34].

5. Conclusions

The results of our bibliometric analysis have provided a comprehensive overview of the research landscape surrounding organic farming and voluntary certifications. The clustering of keywords highlights the diverse range of topics and themes that have emerged within this field. These clusters encompass a broad spectrum of concerns and areas of inquiry, including quality and geographical origin, certification and sustainability, protected designation of origin, land use, product origin, identification, and geographical indication. Notably, the prominence of the keyword “quality” underscores the central role of quality assurance and assurance in the context of voluntary certifications, particularly in markets where consumers seek eco-friendly products but lack the means to independently verify their environmental quality. Voluntary certifications, as indicated by the prevalence of this keyword, address this informational gap, providing consumers with the confidence that products adhere to rigorous environmental and ethical standards. When analysing the bibliometric analysis, both terms have similar results; mainly when referring to the study type, organic farming has more quantitative studies (55.26%) than voluntary certifications (50%). The same happens for the number of authors but in reverse, meaning that voluntary certifications have a slightly bigger percentage (60,71%) than organic farming does (60.52%).