Regus Flor

Laffont-Schwob Isabelle

Rayhane Hamrouni

Nathalie Dupuy

Farnet Da

Silva Anne-Marie

Anne-Marie Farnet
email: anne-marie.farnet@imbe.fr

Da Silva

Isabelle Laffont-Schwob

Flor Regus

Pré

Keywords: copper accumulation, soil pollution, sustainability, transfer of pollutants, viticulture

The production of wine dates to ancient civilization and has heavily influenced different landscapes around the globe. Nowadays, wine is still an important sector in terms of land use and income source in many countries, more specifically in the European Mediterranean region.

However, to control pests and regulate wine growth, the extensive use of pesticides is common.

The effects and persistence of agrochemicals in the environment is well known and defined in scientific literature as well as the environmental and human health risks of these compounds.

The purpose of this review was to do a state of art of worldwide production of academic literature using bibliometric principles and analysis to identify thematic areas of this type of agriculture, and its challenges in a changing world. For this review the focus is on current practices to see what may evolve for more sustainable viticulture. It was found that the three main producers of wine i.e. Spain, France and Italy are also three top producers of scientific literature on this topic. The use of bibliometric methodologies defined the main thematic areas on this subject as following: soil-plant transfer of agrochemicals, heavy metal accumulation in vineyard soils, management practices in viticulture, water pollution transport, effects of viticulture on the living part of soil, sustainable alternatives to pesticides. We found that Spain, France and Italy work the most on developing sustainable alternatives for agricultural practices, however sustainable alternatives and practices were also the least developed thematic in general.

INTRODUCTION

The incidence of extreme weather events such as of heat waves, intense rainfall and agricultural drought is likely to increase within the next decade (IPCC 2021). Climate change is troublesome for agriculture since it influences water stress, duration of growing season as well as the intensity and frequency of heat waves [START_REF] Aryal | Climate change and agriculture in South Asia: Adaptation options in smallholder production systems[END_REF]. Along with the effects caused by climate change another issue in agriculture is the toll conventional agricultural practices have in the environment. In order to meet the demand of agricultural goods, agriculture leans on techniques such as tillage and the excessive use of agrochemicals to ensure supply in an overpopulated world [START_REF] Wezel | Agroecological practices for sustainable agriculture. A review[END_REF][START_REF] Meena | Impact of agrochemicals on soil microbiota and management: A review[END_REF]. This unsustainable use of agricultural land and resources creates an imbalance in the ecosystems in terms of nutrient cycling, soil and water quality [START_REF] Garini | Drivers of adoption of agroecological practices for winegrowers and influence from policies in the province of Trento, Italy[END_REF].

A culture particularly fragile to the effects of climate change is viticulture. Wine quality strongly depends on climate and land [START_REF] Fraga | An overview of climate change impacts on European viticulture[END_REF][START_REF] Marín | Challenges of viticulture adaptation to global change: Tackling the issue from the roots[END_REF][START_REF] Santos | A review of the potential climate change impacts and adaptation options for European viticulture[END_REF].

Most of the world's wine grapes production, and wine production, is located in Mediterranean Europe between France, Spain and Italy [START_REF] Jackson | [END_REF][START_REF] Oiv | Statistical Report on World Vitiviniculture[END_REF]. Viticulture is no strange to the issue of unsustainable practices, and Mediterranean viticulture is highly dependent on the use of agrochemicals [START_REF] Prosdocimi | Soil water erosion on Mediterranean vineyards: A review[END_REF]. There are two factors that make viticulture in the Mediterranean region highly dependent in agrochemicals. Mediterranean soils are characterized by low organic matter and nutrient content and the Vitis vinifera plant is highly sensitive to phytopathogens (such as Plasmopara viticola or Botrytis cinerea) [START_REF] Serpa | Impacts of climate and land use changes on the water quality of a small Mediterranean catchment with intensive viticulture[END_REF]. Amongst agrochemicals used in viticulture, pesticides against phytopathogens, are extensively used [START_REF] Campbell | Efficacy of fungicide treatments for Plasmopara viticola control and occurrence of strobilurin field resistance in vineyards in Georgia[END_REF]. The use of pesticides has been extensively studied in the scientific field because of their potential toxicity [START_REF] Schreck | Neurotoxic effect and metabolic responses induced by a mixture of six pesticides on the earthworm Aporrectodea caliginosa nocturna[END_REF].One example of the risk for toxicity in humans is described in recent studies in developing countries showed that, although this part of the world uses only 20 % of the world's agrochemicals, this region suffers 99 % of deaths induced by pesticide poisoning and victims are mostly farmers [START_REF] Curl | Synthetic pesticides and health in vulnerable populations: Agricultural Workers[END_REF].

Many authors have identified the accumulation of pesticides in vineyard soils as a threat [START_REF] Komárek | Contamination of vineyard soils with fungicides: A review of environmental and toxicological aspects[END_REF][START_REF] Sánchez-Martín | Soil properties influencing the adsorption and mobility of penconazole in vineyard soils[END_REF][START_REF] Semhi | Chemical effect of pesticide application on soils: Evidence from rare earth elements[END_REF]. The accumulation of pesticides also poses an environmental risk since there is a risk of diffusion of the parent chemical compounds and their by-products [START_REF] Sonoda | Copper and zinc in vineyard and orchard soils at millimeter vertical resolution[END_REF][START_REF] Zambito Marsala | First evaluation of pesticides occurrence in groundwater of Tidone Valley, an area with intensive viticulture[END_REF].

Copper-based compounds are amongst the most used pesticides to prevent fungal infections in vineyards [START_REF] Fernández-Calviño | Enzyme activities in vineyard soils long-term treated with copperbased fungicides[END_REF]. Because of its accumulation in soils, copper tends to reach toxic concentrations, affecting the living part of the soil [START_REF] Campillo-Cora | Copper and zinc in rhizospheric soil of wild plants growing in long-term acid vineyard soils. Insights on availability and metal remediation[END_REF][START_REF] Mackie | Long-term copper application in an organic vineyard modifies spatial distribution of soil micro-organisms[END_REF][START_REF] Rusjan | Copper accumulation regarding the soil characteristics in Sub-Mediterranean vineyards of Slovenia[END_REF]. Due to accumulation of copper on the environment, in 2009, the European Union regulated the use of agrochemicals and decided to list copper as a candidate for substitution Regulation (EC) No.1107/2009. The decision to find a substitute for copper was again ratified in 2018 with Regulation (EU) 2018/1981.) Environmental affairs are a transverse issue covering different areas such as ecology, human health and policy making. The transverse specificity of environmental issues is not new.

For example, in 2004, concept "One Health" was developed. This concept looks at ecosystem's health, fauna, and human health at once [START_REF] Destoumieux-Garzón | The One Health concept: 10 years old and a long road ahead[END_REF]. This new concept highlights the need to have a holistic approach based on interdisciplinarity embracing all the components of an ecosystem including living soil, plants, animals, and humans. Due to the transverse properties of environmental affairs, analysis of scientific literature can be a complex task, with bias linked to non-systematic requests on literature databases. The use of bibliometric methods can help overcome this complex task. Bibliometric methods have been established in the scientific field (specially applied sciences) to study different aspects of science [START_REF] Ellegaard | The bibliometric analysis of scholarly production: how great is the impact?[END_REF] in order to establish a state of art. Bibliometric methods are used to analyze scientific production, techniques and methodologies available by measuring and interpreting the production metadata of scientific publications [START_REF] Subramanyam | Bibliometric studies of research collaboration: A review[END_REF]. For this review, a bibliometric approach was used to create a state of art regarding the conventional practices in viticulture that focuses on pesticides. The work consists of studying the evolution of annual publications (between 1990-2020) and the different countries affiliated to each publication. This later allowed the analysis of thematic areas by grouping keywords from the publications into clusters. The creation of clusters later allowed us to see the geographical distribution of thematic areas.

MATERIALS AND METHODS

The scientific database Web of Science was used to obtain scientific publications that include the studies of problematics in viticulture regarding the use of pesticides. On September 27, 2021, a search was done and the metadata were downloaded using the words ("viticulture" OR "grape" OR "grapes" OR "wine" OR "wines" OR "vineyard" OR "vineyards") AND ("pesticide" OR "pesticides" OR "copper*", "Cu") AND ("phytopathogen" OR "phytopathogens" OR "soil" OR "soils" OR "plant health") were used as keywords. The star symbol (*) was added to include the different forms of a word, for instance the word "copper*" will also cover "copper based". Time frame was set to 1990-2020 to observe the evolution of this topic over time. For this search all fields available were used. This was done to maximize the collected data since the analysis accounts for article subject and geographical affiliation. No additional sub-databases or collections were used. The analyze citation tools from web of science was used to assess the evolution of keywords over time, geographical distribution of publications and authorship as well as the distribution of publications throughout journals.

Finally, this search does not account for grey literature or another scientific database. The metadata of this bibliographical search was analyzed using the software Matheo Analyzer, France. Keywords of each publication were extracted and grouped in clusters to reveal thematic areas. Keyword clusters were created using K-means methods following [START_REF] Malechaux | Exploring the scientific interest for olive oil origin: a bibliometric study from 1991 to 2018[END_REF]. K-Means is an algorithm for data clustering. The keywords are grouped into K clusters (user-determined number) based on a specific distance measurement, so that the sum of distances between each keyword and its cluster centroid is minimized. The procedure consists of the following three steps:

(i) The algorithm is initiated by creating K different clusters. The samples, included in the analysis, are first randomly distributed between these K different clusters.

(ii) As a next step, the distance between each keyword and its respective cluster centroid is calculated.

(iii) keywords are then attributed to the nearest cluster (K1 or K2) based on the samplecluster centroid distance.

The number of iterations is the number of times that the K-means algorithm is repeated to obtain an optimal clustering solution, each time starting with random initial clusters. Keywords occurring at least 15 times were used to build the clusters. The keywords used in the search (viticulture, grape, pesticides, copper etc.) were left out of the data clustering to avoid bias and high word co-occurrence on the analysis. These parameters were set to have quality clusters with strong links between the keywords in each cluster. The results for this bibliometric review are limited to Web of science since different citation collection methods from various databases would have led to a set of data that are not compatible with software Matheo Analyzer.

RESULTS AND DISCUSSION

The use of these parameters resulted in a database of 1317 publications. This includes 1205 scientific articles, 114 proceeding papers, 37 review articles, 12 book chapters. Focusing on a single scientific Database Web of Science provided a large range of results for this topic.

Evolution of publications through time

The development of new technologies allowing the rapid acquisition of data influences the increase in publications over time. Figure 1 shows the number of publications over time from 1990-2020. This figure also includes an exponential regression to reveal the inflection point. The first period covered by this search, between 1990-1994, only six papers were published. This number increased to 97 between 2000-2004, i.e. an increment of 16 times.

Together with technological and scientific developments, different political events could explain this increase in publications. For example, in 2002, the European commission restricted the use of copper, Regulation (EU) 2018/1981. Then in 2003, an EU commission study showed that viticulture was the largest pesticide consumer per acre of all large-scale cultivated crops in the European Union [START_REF] Moneyron | Linking the knowledge and reasoning of dissenting actors fosters a bottomup design of agroecological viticulture[END_REF]

Evolution of keywords over time

The evolution of the selected keywords overtime was also analyzed. Figure 2 represents the number of times a specific keyword was used in an article in each time frame. The words copper, pesticide, and soil increased over time. Overall, this highlights how the focus on this problematic lies mostly on the effects of pesticides and copper-based pesticides in soil. A pivotal change after 2000-2004 can be observed. After 2004, soil indeed becomes the most used keyword followed by copper and then pesticides. The last period, between 2015-2020, illustrates how the effect of copper-based pesticides can be considered as an issue for soil properties and fertility and thus for the sustainable production of grapes and wine.

Geographical distribution of publications and authorship.

From 1990 to 2020, there were 86 different countries working on this topic. When observing the geographical distribution of scientific literature, it appears that research groups are scattered around the globe. Some examples of this, are counties such as Australia [START_REF] Ying | Dissipation of herbicides in soil and grapes in a South Australian vineyard[END_REF], Spain [START_REF] Pose-Juan | Pesticide residues in vineyard soils from Spain: Spatial and temporal distributions[END_REF] and Slovenia [START_REF] Nasir | Pesticides and trace metals residue in grape and home made wine in Jordan[END_REF]. For this section, we will focus on the top10 publishing countries. These countries have contributed for more than 87% of total publications in this database. These countries were Spain (199), France (157), Italy (183), China (138), USA (133), Brazil (101), Australia (88), India (50), Romania (47) and Germany (44). First, it is not surprising that Spain, France, Italy appear within the top ten countries publishing on that topic. Indeed, these countries are the main producers of wine (millions of hectoliters) in the world according to the 2019 Statistical Report on World Viticulture (OIV 2019).

Figure 3 shows two maps: map A shows the total number of articles published between 2014-2018 for the top-10-publishing countries and map B shows the total production of wine (millions of hectoliters) according to the report by OIV (2019) for the same countries. All countries in Figure 3, except for India, are considered major wine producers. Wine production in India is low, though there is a large area in this country dedicated to the production of table grapes. In 2018, India had 151 thousand hectares of vineyards, accounting for 2% of vineyards on the globe. Time frame for these maps is limited to 2014-2018 as these years are the only ones reported to this date for wine production by the OIV.

Another descriptive parameter analyzed was the co-authors and their country of affiliation. Authors with the highest number of publications on our search are presented in Table 1. Authors have a minimum of 18 articles (equivalent to approximately 1.4% of the total publications). There is a link between collaborating authors and geographical areas. For example, according to Table 1, Arias-Estévez (the author with the highest number of publications) and Fernández-Calviño are co-authors and their country of affiliation, according to the Web of Science, is Spain. This occurs again with authors such as Nicoloso and Tiecher two co-authors from Brazil. Research collaborations about viticulture between wine-producing countries are very limited. However, the country of affiliation of the authors does not provide an accurate vision of how publications are scattered globally. In Table 1, the same high publishing authors work together, limiting the number of countries of affiliation shown on the table. Thus, this leaves other high publishing countries such as France and Italy out of this Table because the same author does not publish as much on the same topic.

Publication's categories & publishing journals

There was a total of 55 categories identified on this database where the categories with the most articles were: Environmental Sciences/ Ecology with 529 articles, Agriculture 438, ; Chemistry, 250;, Food Sciences Technology, 196;, Plant sciences, 125. It is important to mention that one publication can belong to more than one category. The categories before mentioned represent the categories covered by most journals in this database, where a total of 461 publishing journals can be found. The journals with the highest number of publications are shown in Table 2. Along with journal's categories, the Journal Impact Factor (JIF) is also presented in Table 2. The JIF is an index based on the number of citations of publications during a specific time. The JIF was created in 1955 as a way to source journals [START_REF] Garfield | The history and meaning of the journal impact factor[END_REF]. A large range of JIF from 1.327 to 10.588 can be found in Table 2. This large range of JIF is not surprising since it changes depending on the field [START_REF] Althouse | Differences in impact factor across fields and over time[END_REF]. For example, for Environmental Sciences, JIF ranges from 0.323 to 38.532 according to the Web of Sciences' Journal citation report (Journal Citation Reports, 2021). The total number of times an article was cited is presented in Table 3. Citations on this table varies from 241 to 435.

Table 3 gives an idea of the readers' interest within this topic. For example, the most cited article by [START_REF] Komárek | Copper contamination of vineyard soils from small wine producers: A case study from the Czech Republic[END_REF] compiles studies regarding the contamination of vineyard soil with organic and inorganic fungicides. It is followed by [START_REF] Wezel | Agroecological practices for sustainable agriculture. A review[END_REF] where agricultural practices are evaluated and compared. In this article, organic fertilization, biological pest control, crop selection, reduce tillage and drip irrigation showed a high potential for the future in agriculture. The third article by Štajnbaher et al. (2003) describes a methodology to analyze different pesticides. The fourth article produced by [START_REF] Brun | Evaluation of copper availability to plants in copper-contaminated vineyard soils[END_REF] looks at the transfer of copper accumulation from soil to plants (specially the roots). Finally, the last article by [START_REF] Giusquiani | Urban waste compost: effects on physical, chemical, and biochemical soil properties[END_REF] in this table looks at the effect of soil amendments on different parameters such as C, Cu and Pb. In this table, the main categories are Environmental Science, Agronomy and Plant Sciences to mention a few.

Keyword Clusters

A total of six clusters were created. The clusters are presented in Figure 4, showing the keywords associated to each cluster. To facilitate reading, only keywords that appear 16 times or more are presented in the Figure . Due to cluster building parameters, not all publications were included in these clusters. Each cluster is described below:

• Cluster 1(Soil-plant transfer of agrochemicals)

The main thematic present in this cluster is the effects of persistent compounds in a soilplant system. This cluster indeed contains words such as residue, sorption, dissipation, and liquid chromatography.: These are all terms used to describe the behavior and transport of persistent compounds from soil to plant as well as techniques like liquid chromatography used to quantify such compounds. For exemple, [START_REF] Matei | Cadmium and lead occurrence in soil and grape from Murfatlar vineyard[END_REF], and [START_REF] Vázquez | Assessment of metal bioavailability in the vineyard soil-grapevine system using different extraction methods[END_REF] look at the presence of heavy metals in a soil-plant interactions and the transport of pollutants from soil to the plant. Another thematic of this cluster is the risk of exposure associated with the transfer of persistent agrochemicals to the final product (wine or table grapes). For instance, this topic regarding the risk of exposure is included in publications from Wightwick et al. (2013a) or [START_REF] Guang-Guo | Dissipation of herbicides in soil and grapes in a South Australian vineyard-ScienceDirect[END_REF]. For this cluster, China is affiliated to 62 publications and Spain is affiliated to 56 publications. The publications in this cluster account for 20% of all the publications analyzed.

• Cluster 2 (Heavy metal accumulation in vineyard soils) This cluster includes pollution and accumulation of heavy metals in soils, and ICP-MS (Inductively coupled plasma -mass spectroscopy) as a technique for their analysis. The main thematic here is soil inorganic pollution in vineyards due to heavy metals. This cluster focuses on the occurrence of heavy metals and their persistence due to low degradation rates in vineyard soils as described in [START_REF] Bălc | Assessment of chemical elements in soil, grapes and wine from two representative vineyards in Romania[END_REF]. It also deals with the accumulation of copper in soil due to the use of pesticides as highlighted by authors such as [START_REF] Wightwick | Copper fungicide residues in Australian vineyard soils[END_REF] and [START_REF] Komárek | Copper contamination of vineyard soils from small wine producers: A case study from the Czech Republic[END_REF], and with the behavior of copper in soils [START_REF] Blotevogel | The fate of Cu pesticides in vineyard soils: A case study using δ65Cu isotope ratios and EPR analysis[END_REF][START_REF] Rusjan | Copper accumulation regarding the soil characteristics in Sub-Mediterranean vineyards of Slovenia[END_REF]). Another theme discussed in this clusters is the bioavailability of heavy metals and more precisely how bioavailability influences the toxicity and risk due to heavy metals [START_REF] Mirlean | Metal contamination of vineyard soils in wet subtropics (southern Brazil)[END_REF]). The countries publishing the most articles here are Spain, Romania and France.

Publications in this cluster account for 19.8% of all the publications.

• Cluster 3 (Management practices in viticulture)

Cluster 3 includes keywords such as agrosciences. Contrary to the previous clusters, here, a more global view at the agrosystem scale is considered. This cluster is related to the practices and management within the field of viticulture for example weed control [START_REF] Olmstead | Weed control in a newly established organic vineyard[END_REF]. More importantly, this cluster deals with the response of the agroecosystem to certain practices such as the application of copper-based pesticides [START_REF] Brunetto | Copper accumulation in vineyard soils: Rhizosphere processes and agronomic practices to limit its toxicity[END_REF], and the effect of tillage and fertilizers on soil. This cluster also provides information about alternative management techniques such as the use of amendments [START_REF] Dobrei | Improvement of soil physical and chemical properties with green manure for healthy vine and wine by-products[END_REF], and how the use of amendments interacts with agrochemicals present in soil [START_REF] Pinna | Fenhexamid Adsorption Behavior on Soil Amended with Wine Lees[END_REF].

Additionally, this cluster also looks at how alternative management techniques affect land with authors such as [START_REF] Likar | Importance of soil and vineyard management in the determination of grapevine mineral composition[END_REF] and how to reduce the use of pesticides in viticulture [START_REF] Diaconu | Researches regarding the reduction of pesticide soil pollution in vineyards[END_REF]). Countries that had the higher number of articles were France, Spain, and Italy. Publications in this cluster account for 12.6% of all the publications.

• Cluster 4 (Water pollution transport) Keywords in this cluster include water, heavy metal, and trace element. The transfer and diffusion of pollution from viticulture via water is described in this cluster. Water is the main mode of transport of dissolved pollutants from soil particles as described by Oliveira et al. (2015). Themes such as leaching of pesticides and heavy metals caused by rain [START_REF] Meite | Impact of rainfall patterns and frequency on the export of pesticides and heavy-metals from agricultural soils[END_REF], and downstream export of pollutants, such as copper, due to rainfall and runoff from headwater watershed [START_REF] Imfeld | Do rainfall characteristics affect the export of copper, zinc and synthetic pesticides in surface runoff from headwater catchments?[END_REF]) are covered in this cluster. This cluster also looks at the occurrence of pesticides in groundwater bodies because of pesticide use in viticulture [START_REF] Zambito Marsala | First evaluation of pesticides occurrence in groundwater of Tidone Valley, an area with intensive viticulture[END_REF][START_REF] Suciu | Evaluation of groundwater contamination sources by plant protection products in hilly vineyards of Northern Italy[END_REF] as well as estimating ecotoxicity of pesticides in freshwater using models such as Pest LCI 2.0 [START_REF] Renaud-Gentié | Pesticide emission modelling and freshwater ecotoxicity assessment for Grapevine LCA: Adaptation of PestLCI 2.0 to viticulture[END_REF]. In this cluster, copper is listed as having the greatest toxicity potential for freshwater ecosystems [START_REF] Peña | Modeling ecotoxicity impacts in vineyard production: Addressing spatial differentiation for copper fungicides[END_REF]). Here, the main publishing countries are France, Spain, and Italy. Publications in this cluster account for 10.5% of all the publications.

• Cluster 5 (Effects of viticulture on the living part of soil) Some of the keywords included in this cluster are toxicity and enzymatic activity. This cluster covers different themes regarding the living part of soils in vineyards. The negative effects of pesticides in soil resulting from viticulture as land use are described. Firstly, the toxicity of different pesticides in soil is discussed in different articles for example [START_REF] Komárek | Contamination of vineyard soils with fungicides: A review of environmental and toxicological aspects[END_REF]; and more precisely how the accumulation of pesticides, such as copper-based fungicides, has an effect of soil's enzymatic activities [START_REF] Fernández-Calviño | Enzyme activities in vineyard soils long-term treated with copperbased fungicides[END_REF][START_REF] Wightwick | Effects of copper fungicide residues on the microbial function of vineyard soils[END_REF]. This clusters also includes the degradation of pesticides by soil microbes [START_REF] Hugo | Accelerated microbial degradation of nematicides in vineyard and orchard soils[END_REF][START_REF] Tykva | Metalaxyl biodegradation by bacterial and mold isolates from Portuguese vineyard soils[END_REF]. Additionally, this cluster lightly covers ecotoxicological soil studies considering different soil invertebrates such as Enchytraeus aldibus [START_REF] Ruyters | Copper toxicity in soils under established vineyards in Europe: A survey[END_REF] and Typhlodromus pyri [START_REF] Gadino | Impact of vineyard pesticides on a beneficial arthropod, Typhlodromus pyri (Acari: Phytoseiidae), in laboratory bioassays[END_REF]. Finally, the effects of different practices used in viticulture on soil microbes (Okur et al. 2009;[START_REF] Probst | Vineyard soils under organic and conventional management-Microbial biomass and activity indices and their relation to soil chemical properties[END_REF] are also covered. Countries that published the most in this cluster are Brazil, France, and Spain.

Publications in this cluster account for 9.7% of all the publications.

• Cluster 6 (Sustainable alternatives to pesticides) Keywords in this cluster include biological control and farming practices. Unlike cluster 3, this cluster describes alternatives that intend to make viticulture more sustainable, rather than describing the management of vineyards, while focusing on alternatives to reduce pesticide use.

For example, it includes the use of i) more resistant vine varieties in order to manage fungal infections [START_REF] Pedneault | Fungus resistant grape varieties as a suitable alternative for organic wine production: Benefits, limits, and challenges[END_REF], ii) cover crops to select beneficial arthropods while decreasing antagonistic arthropods [START_REF] Vogelweith | Cover crop differentially affects arthropods, but not diseases, occurring on grape leaves in vineyards[END_REF], and lastly iii) amendment to mitigate bioavailability of heavy metals [START_REF] Cutillas-Barreiro | Pine bark amendment to promote sustainability in Cu-polluted acid soils: effects on Lolium perenne growth and Cu uptake[END_REF]. Moreover, the term biocontrol is persistent within this cluster. Here, examples of biological control are either considered in the form of microorganism such as Bacillus ginsengihumi [START_REF] Calvo-Garrido | Microbial Antagonism Toward Botrytis Bunch Rot of Grapes in Multiple Field Tests Using One Bacillus ginsengihumi Strain and Formulated Biological Control Products[END_REF], or of metabolites produced by microorganism [START_REF] Billet | Vineyard evaluation of stilbenoid-rich grape cane extracts against downy mildew: A large-scale study[END_REF][START_REF] Zhihui | Utilization of winery wastes for Trichoderma viride biocontrol agent production by solid state fermentation[END_REF].

This cluster has the least number of articles (it accounts for 7.6% of all the publications) and France and Italy share the largest quantity of articles followed by Spain.

Cluster distribution throughout Journals

Currently, the published research on the topic of vineyards is evolving from techniques and tools specific to agriculture to other objectives coming from different scientific domains of environmental sciences. This can be appreciated by looking at the names of the journals that publish articles within these clusters as presented in Figure 5. This Figure shows the top publishing journals for each cluster. These journals also happened to be within the group of journals that publish the most data on the selected topic (see Table 2). In here the journals with the highest number of papers are those that published under the category of Environmental Science, Agronomy, Biological Sciences to mention a few categories. These journals focus on interdisciplinary sciences, such as Environmental Sciences, meaning they all publish in interdisciplinary categories. For example, the Journal of Agricultural and Food chemistry published within categories such as Agriculture, Applied Science and Food Science and Technology.

Geographical distribution of clusters

The number of publications linked to a particular cluster is heterogenous. Publications in clusters 1, 2 and 3 account for approximately 54% of all publications of this database.

Geographical distribution varies amongst clusters

There is a large involvement of France, Spain, and Italy in each cluster.

In cluster 1, France, Spain and Italy have participated in 46 % of the publications e.g. a publication by [START_REF] Andrades | Significance of Soil properties in the adsorption and mobility of the fungicide metalaxyl in vineyard soils[END_REF], regarding the importance of soil properties in fungicide mobility in vineyard soil, where Spain is the country of affiliation. For cluster 2, France, Spain and Italy participated in 42% of the publications regarding the accumulation of pollutants in soil e.g. [START_REF] Blotevogel | The fate of Cu pesticides in vineyard soils: A case study using δ65Cu isotope ratios and EPR analysis[END_REF] describing the fate of copper in vineyard soils. In this article France is a contributing country. For cluster 3, Spain, France and Italy participated in 42% of the publications. For example, the article from an Italian team, [START_REF] Pinna | Fenhexamid Adsorption Behavior on Soil Amended with Wine Lees[END_REF], described the effect of practices in vineyards such as the use of amendments in an article.

When it comes to the other three clusters 4, 5 and 6, explaining the effects of viticulture, these three countries have an even larger representation compared to other countries. These three clusters account for a total of 27% of all the literature. In cluster 4, regarding the transfer of pollution to water resources, these countries have contributed to approximately 42% of the publications (for instance Italy with publications such as [START_REF] Suciu | Evaluation of groundwater contamination sources by plant protection products in hilly vineyards of Northern Italy[END_REF]. In cluster 5 regarding the effects of these practices in soil microorganisms, these countries have contributed to approximately 44% of the publications, e.g. Spain with the publication from [START_REF] Fernández-Calviño | Enzyme activities in vineyard soils long-term treated with copperbased fungicides[END_REF] where the co-authors look at soil enzymatic activities to assess the damages linked to the use of copper based fungicides. It is important to note that, particularly for this cluster regarding ecotoxicity, most of the studies dealt with the effects of pollutants at a molecular level (for example enzymatic activities) or using ecotoxicological models, while studies assessing toxic effects on soil invertebrates are few. Finally in cluster 6, regarding sustainable alternatives to pesticides, these countries (Spain, France, and Italy) participated in at least 46% of the publications e.g. a publication from [START_REF] Calvo-Garrido | Microbial Antagonism Toward Botrytis Bunch Rot of Grapes in Multiple Field Tests Using One Bacillus ginsengihumi Strain and Formulated Biological Control Products[END_REF], discussing biocontrol against phytopathogens based on microbial antagonisms. Geographical heterogeneity of the clusters indicates there is a consensus on the fact that there are high pollutant concentrations in soil-plant systems as a product of conventional practices in viticulture. The three main producers of wine, France, Spain and Italy are extensively present in the thematics from clusters 4, 5 and 6while other countries, such as China and Romania, focus more on the present state of pollution, themes cover in clusters 1-3.

Cluster evolution over time

Figure 6 shows the evolution of clusters over time from 1990-2020. Increase in publications for each cluster seems to double every four years. Cluster 1 and Cluster 2 had the greater increase between years 2005-2009, suggesting that researchers focused on the interactions between soil and plant since these clusters focus on the fate of pollutants in soil and final products (i.e. wine and grapes). It was around this time that legislation started to regulate agricultural practices that have a negative effect on soil. Clusters 3 and 4 have had an increase since the period 2000-2004. This concerns management of viticulture as well as transfer of pollution. During this time (2000)(2001)(2002)(2003)(2004), the increase in cluster 5 was stronger. However, in the time frame between 2015-2020, there was a drastic increment in articles for cluster 3 (Figure 6) and it is during this time period (2018), that the use of copper was restricted to 28kg/ha of copper in a time frame of 7 years by the European Commission Regulation (EU) 2018/1981.

The decision making for this legislation could have been based on themes included in clusters 1, 2 and 4 since most legislation regarding environmental issues is based on scientific facts [START_REF] Liu | Linking science with environmental decision making: Experiences from an integrated modeling approach to supporting sustainable water resources management[END_REF]. For cluster 6, the number of articles was not high until 2009, when European legislation started to watch the concentrations of some pesticides. As seen in Figure 6, topics regarding ecotoxicity and sustainability (clusters 4, 5, 6) have been on the rise. One example of this change in trend is showed in the article by [START_REF] Droz | Copper content and export in European vineyard soils influenced by climate and soil properties[END_REF], looking at the transport of copper in soil as well as modeling of copper concentrations in soil.

CONCLUSION

In the last couple of years, publications regarding the effects of viticulture on the environment have been on the rise, proving there is an increasing interest about the relationship between the use of pesticides and soil health. The present bibliometric investigation from 1990 to 2020 on the conventional practices in viticulture that focuses on pesticides shows an increase in publications overtime since 1990.

France, Spain and Italy were responsible for15% of the total wine production globally and of the production of 37% of all publication during period 2014-2018. This bibliometric analysis puts the European Union as one of the leaders of research on this topic. The strong European presence throughout this topic indicated the important economic, social, and political influences besides the scientific and agricultural perspective. Since many European countries have an ancient wine culture, viticulture has a vital socio-economical role in these countries. However, co-authors' country of affiliation is not a proper indicator of geographical distribution of literature since authors tend to collaborate more with peers within the same geographical location.

The creation of keywords clusters allowed the observation of main research themes and there is heterogeneous geographical distribution of a publication's country of affiliation in each cluster. The two major themes were the presence of pesticides in a soil-plant systems and the accumulation of pesticides in vineyard soils. The adverse effects of current agricultural practices in viticulture have been extensively studied. However, there is a lack of ecotoxicological studies targeting the effects of pesticides in macro or mesofauna communities of the soil. Themes regarding ecotoxicity and sustainable alternative to pesticides are the least developed.

Okur, N., Altindı̇Şlı̇, A., Çengel, M., Göçmez, S., & Kayikçioğlu, H. H. (2009).

Microbial biomass and enzyme activity in vineyard soils under organic and conventional farming systems. Turk Tarim ve Ormancilik Dergisi/Turkish Journal of Agriculture and Forestry 33(4) Oliveira, V. de S., Lima, A. M. N., Salviano, A. M., Bassoi, L. H., & Pereira, G. E. (2015).

Heavy metals and micronutrients in the soil and grapevine under different irrigation strategies.

Brazilian society of soil science, 39, 162-173.

  . Years 2005-2009 saw a pivotal change in the number of publications. During this time (2005-2009), publication numbers had almost doubled compared to period 2000-2004. By 2009, the European Union listed copper as a compound that should be substituted in agriculture. After 2009, the number of publication of articles doubled every 4 years. This trend is likely to continue since there is more political pressure about this problematic.: The decision to look for alternatives to copper in agriculture was again rectified in 2018 Regulation No. (EU) 2018/1981.

Fig 1 :Fig 2 :Fig 3 :Fig 4 :Fig 5 :Fig 6 :

 123456 Fig 1: Number of publications in the search over time (1990-2020), including an exponential

Table 1 .

 1 Top 10 publishing authors, from 1990-2020, including the number of total publications on the topic, geographical affiliation of the authors, authors' total number of citations (without self-citations) and most cited articles. Total number of citations represents the total number of citations for the author. It is important to note that authors might not be the first author of the paper.

	Name	Number of	Country of	Total citations	Most	cited
		publications	affiliation		article
	Arias-	49	Spain	696
					(Fernández-
	Estevez
					Calviño et al.
					2010)
	Brunetto	44	Brazil	370	(Brunetto et al.
					2016)
	Fernández	38	Spain	543
					(Fernández-
	-Calviño
					Calviño et al.
					2010)
	Novoa-	28	Spain	370
					(Fernández-
	Muñoz
					Calviño et al.
					2009)
	Sanchez-	26	Spain	378	(Herrero-
	Martin				Hernández et al.
					2011)
	Ceretta	25	Brazil	228	(Miotto et al.
					2014)

Funding for this manuscript was received by ITEM institute under the project ALCOVE (AMX-19-IET-012).

Table 2. Top 15 publishing journals within this search including the total number of publications on the topic in the Web of Science database , journal's Impact factor (JIF2020) and Categories include their ranking for category. The most cited article on each journal of this search is listed as "the most cited article within search."

Journal name

Total of articles within search JIF2020 [START_REF] Giusquiani | Urban waste compost: effects on physical, chemical, and biochemical soil properties[END_REF]