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. 2021 Jan 7;16(1):e0244619. doi: 10.1371/journal.pone.0244619

Social networks influence farming practices and agrarian sustainability

Amaia Albizua 1,2,*, Elena M Bennett 2, Guillaume Larocque 3, Robert W Krause 4,¤, Unai Pascual 1,5,6
Editor: Sieglinde S Snapp7
PMCID: PMC7790232  PMID: 33411756

Abstract

The social-ecological effects of agricultural intensification are complex. We explore farmers’ perceptions about the impacts of their land management and the impact of social information flows on their management through a case study in a farming community in Navarra, Spain, that is undergoing agricultural intensification due to adoption of large scale irrigation. We found that modern technology adopters are aware that their management practices often have negative social-ecological implications; by contrast, more traditional farmers tend to recognize their positive impacts on non-material benefits such as those linked with traditions and traditional knowledge, and climate regulation. We found that farmers’ awareness about nature contributions to people co-production and their land management decisions determine, in part, the structure of the social networks among the farming community. Since modern farmers are at the core of the social network, they are better able to control the information flow within the community. This has important implications, such as the fact that the traditional farmers, who are more aware of their impacts on the environment, rely on information controlled by more intensive modern farmers, potentially jeopardizing sustainable practices in this region. We suggest that this might be counteracted by helping traditional farmers obtain information tailored to their practices from outside the social network.

Introduction

Agriculture is undergoing a transformation, mainly through intensification, worldwide [1]. This is reflected in the increased numbers of industry-oriented farms, characterized by large-scale monocultures with high use of pesticides and fertilizers and, which often go hand in hand with investments into irrigation technology. Globally, this intensification process is driven by a push for higher yields [2] and the allocation of increased amounts of food crop production toward biofuel production to meet energy demand [3]. This agricultural intensification is a major driver of biodiversity loss [4], which ultimately reduces non-food ecological benefits at the landscape scale, including pollination services [5], regulation of pests [6], soil quality [7], water quality [8] and cultural benefits, such as sense of place [9, 10]. Moreover, intensification of agrarian systems also alters institutions (norms and rules) and social relations in farming communities [11].

Here we adopt the nature’s contributions to people (NCP) framework of IPBES [12, 13] in the context of agriculture [14]. There are several studies about farmers’ perceptions and values regarding NCP [1517] or about how farmers influence one another in their land management activities and perceptions [12, 18, 19]. However, farmers’ awareness about their co-production of NCP and what affects farmers’ interactions when they make land management decisions (i.e. the way such a rural network structure emerges) is not well known [20, 21]. Farmers’ awareness of their potential to influence multiple NCP is crucial since it represents the first step for transformative change [4]. Moreover, most of the negative NCP due to agricultural intensification are not directly addressable by either central governments or by individuals because they emerge from the interdependent actions of many decision-makers, at different levels [22]. For example, if a given farmer aims to improve the status of underground water, she can opt to use fewer or no fertilizers or reduce pesticide use. However, if neighboring farmers do not follow suit, the impacts of one individual’s changes would likely be minimal. It is also difficult to be addressable by a central government because top-down technical approaches frequently fail to build on the local knowledge, innovative capacity, and expertise of farmers of rural communities [23].

Farmers’ social networks can address the environmental problems of agriculture by expanding the number of farmers using beneficial land management practices through practices such as information sharing [24]. Farmers are embedded in social networks through which information and resources are exchanged with other farmers and organizations [25]. These multi-scale interactions can allow co-operative actions and dissemination of the “know-how” between rural community members, ultimately contributing to spread of the dominant management practices in the network [24]. The influence of farmers’ networks on management has been studied previously [26, 27]. Some studies, e.g. [28] have found that converting land to crop production was correlated to the addition of ties in a local producer’s network, while the diversity of land use types was correlated with the number of institutional ties. Through the comparison of knowledge and resource exchange multi-level network structures [25], discovered that access to knowledge and resources put intensive farmers in a privileged position of power allowing to influence other farmers’ land use decisions and pushing out small farmers who practice more sustainable forms of agriculture.

Yet, understanding how patterns of ties, and thus social networks, emerge is missing and crucial. To deal with social network creation understanding, we need to understand that there are three comprehensive drivers influencing the formation of social ties [29]: (1) network structure; (2) nodal attributes, and (3) external contextual factors. Network structure refers to endogenous network processes, like reciprocity (you sharing knowledge with me, makes me more likely to also share knowledge with you), transitivity (I ask those for advice that my advisors also ask for advice), or centralization (most people ask you for advice). Nodal attributes refer to the farmers’ characteristics, such as their perceptions, age, gender, etc. When social tie formation depends on attributes of the nodes and how these attributes interact with the network structure (e.g., differences in network activity) and with the attributes of other nodes (e.g., homophily) we talk about nodal attribute drivers [29, 30]. Finally, external contextual factors are factors that do not depend on farmers, such as the lithology of the land they cultivate, or the distance between plots.

With the goal of linking whether farmers’ awareness regarding their NCP co-production is part of the main factors for social networks creation, we develop two main objectives. Our first objective is to explore farmers’ views on their role in increasing or decreasing NCP through their farming practices. We hypothesize that farmers’ perceptions about NCP are aligned with their land management practices and, thus, with the outcomes of their management in terms of co-production of certain NCP over others. An example could be that farmers practicing intensive agriculture are aware of obtaining higher yields (material NCP) but they may also be aware of deteriorating traditional knowledge and landscape aesthetics (non-material NCP) so that this awareness and acceptance of such trade-offs between NCP lead to agriculture intensification spread. Our second objective is to examine to what extent structurally driven relationship formation influence the connections among farmers ultimately affecting their land management decisions. Hence, our second hypothesis is that farmers sharing similar land management practices and a similar awareness about NCP co-production are significant factors for creating the ties within farmers’ social network.

We use a case study and data from a farming community in a village in the region of Navarre, Spain. The agricultural practices in this village are undergoing a major intensification process, which affects farmers’ informal networks as well as their awareness of the impact of their management on NCP [11, 17, 31]. We interpret variations in farmers’ engagement with the agrarian ecosystem [32] to ultimately aim at understanding the ecological consequences of their land management decisions [33]. This is especially relevant in a context where farmers’ engagement with sustainability is still very low [34, 35] even if there are increasing resources devoted to rural sustainability (e.g., via the European Common Agricultural Policies).

Materials and methods

Study area

We studied a farming community from a village of the Navarre region in Spain (Fig 1). The name of the village will remain anonymous to protect the identity of the participants in the study. This village is located in the Zona Media and Ribera Alta zones of the Ebro River watershed, which hold 22.5% of Navarre’s population [36], and which has a Mediterranean climate and an arid and semi-arid climates, respectively (as per the Papadakis classification). This village underwent agricultural intensification through the adoption of large-scale irrigation—i.e. the Itoiz-Canal de Navarra project—that began in 2006 and it is still undergoing, having converted 22,445 ha to modern irrigation across twenty-two villages in its first Phase. The Navarre government, coordinated with other Spanish administrations and European strategies, has provided farmers with infrastructure and public subsidies to favour the adoption of modern irrigation as a means to deal with current rural development challenges (e.g., productivity losses and climate variability). This has affected farmers’ land management and perceptions about their practices’ impacts.

Fig 1. Location of Navarre province, Spain.

Fig 1

The adoption of large-scale irrigation has led to several changes in land management by farmers [25]. There has been an increase in the size of the cropped land per farmer through a land re-parcelling process, since the minimal arable land in this modern irrigated system is now 5 Ha [17, 11, 31]. Before the irrigation development project there used to be many small-scale farmers laboring small plots (<1 ha) of vegetables and woody crops such as olive and almond trees, often under traditional irrigation systems [11]. Farmers who owned land in the areas affected by the modern irrigation project had to choose among three options: they could adopt modern irrigation, partnering with other farmers if they own less than five hectares; switch to lands in other areas with rainfed systems; or sell or rent out their land [11, 37]. Farmers adopting modern irrigation have introduced new crops such as corn (Zea mays), forage, or biofuels plantations [11]. Now many farmers employ pressure sprinklers and use higher doses of mineral fertilizers and pesticides. As a result of agricultural intensification in this region higher nitrate pollution of land and water, both in rivers and underground water has occurred [38], among other negative environmental impacts [39]. Likewise, alternative-farming practices such as small-scale and organic farming are being rapidly displaced [11].

Land and labor allocation dynamics have also changed in the region. In this regard, local cooperatives, after the large-scale irrigation project installation, and because of land concentration, coordinate farmers and landholders’ land and labor exchanges [25]. Many older farmers not willing to invest in the new technology have abandoned farming and they often rent their lands to other farmers [11]. Normally, land management is allocated to younger farmers who are more prone to adapt farming to new technologies, including irrigation. Many landholders have also left their land to the agricultural cooperatives that distribute the land among active farmers for cultivation. Moreover, new kinds of cooperatives, such as those for ownership of machinery, have been created to share new machinery by farmers in the region.

Data and methods

Sampling for the social network analysis

We used a list of all landowners and farmers affected by the irrigation project, provided to us by the irrigation community, and from key local informants (e.g. agrarian cooperative workers) to identify members of the farming community. We then used snowball sampling until no additional farmers or landholders’ names were generated.

We got a response rate of 77% through the combination of the list and the snowball sampling (81 farmers and landowners out of the 106 people approached). The diversity of farmers was purposely searched (see [17]). The surveyed farmers, when asked about their network contacts, nominated 80 additional people (i.e. farmers and other rural community members such as rural advisors, cooperative workers, and sellers) leading to a total network of 161 people. However, only the originally approached farmers that responded to our survey (N = 81) are included in the Exponential Random Graph Model (ERGM) (explained below). Only these respondents provided information about their NCP perceptions and management behavior, which are crucial factors of our analysis.

The McGill University Faculty of Agriculture and Environmental Sciences Research Ethics Board reviewed and approved this project by delegated review in accordance with the requirements of the McGill University Policy on the Ethical Conduct of Research Involving Human Participants and the Tri-Council Policy Statement: Ethical Conduct For Research Involving Humans. Consent was informed and obtained verbally. The study did not include minors.

Semi-structured interviews

We collected data via in-person semi-structured interviews with farmers and landholders during June-August 2017. Through the interviews, we compiled information regarding the type of management they performed, as well as their perception regarding which NCP they co-produced through their land management and farming techniques. Also, a name generator with a free recall was used [see e.g., 22]. We asked farmers to mention up to five people [as in 43] who they considered to influence their land management decision-making. We later asked about their perceptions regarding which NCP they perceived they were impacting upon through their land management and farming choices. We asked respondents both with whom they shared knowledge and from whom they received knowledge useful for their farming practices. We asked openly about the knowledge exchange, which helped to make a list of possible topics they talked about within the farming community. We performed 32 additional interviews with organizations related to the local agrarian sector (the surveyed farmers had mentioned 27 of the organizations interviewed). To understand how other organizations can influence farmers’ land management decision-making, five other organizations were selected based on a literature review and the experience of the lead author who has been researching in the area since 2013. This additional information is considered relevant to better understand the context and to triangulate the information so that we can make a better interpretation of the results.

Semi-structured interviews qualitative analysis

All interviews were recorded in audio-only format and transcribed only the statements associated with farmers’ views about their awareness about how they co-produced NCP through their land management. These statements were additionally organized according to whether they were positive or negative, the scale at which NCP were delivered, and whether the contributions were self or other-oriented. Key parts from farmers’ and organizations’ interviews that were relevant to better understand results were identified (and showed in quotes below). ‘Few’, ‘some’, ‘many’ and ‘most’ are used consistently to mean less than 25 per cent, up to 50 per cent, up to 74 per cent and 75 per cent or more of the corresponding sample, respectively. This was useful to conduct a narrative analysis—i.e. making sense of our interview respondents’ individual stories to highlight important aspects of their stories that will best resonate with the results.

Each question was split in categories being able to convert some of the qualitative information into measurable data. Then, we mapped connections in the data to those specific categories through statistical analysis such as hierarchical cluster analysis.

Hierarchical cluster analysis to understand rural community composition

We performed two hierarchical cluster analysis (HCA) to classify farmers and landholders into three groups representing different ways of land management and, different NCP co-production awareness. We included the data from the 81 farmers and the groups were created according to 1) their land management decision-making (Management Cluster- MC) and, 2) their perceptions regarding which NCP they perceived they impacted on with their land management (NCP Cluster—NCPC). For the Management Cluster (MC) the variables included were: the type of fertilizers used (organic, mineral, mixed), the type of irrigation performed (sprinkler or drip), the surface of the cultivated lands (Ha) and the crops grown (cereals, maize, grass, vineyard, energetic crops or others (including vegetables and fruit trees). Grouping farmers concerning their farming practices allowed identifying, to some limited extent, their engagement with the landscape. For the NCP Cluster (NCPC), 14 variables were included representing different contributions they could enhance through their land management. Such NCP had previously been identified by farmers in the region [17] where socio-cultural values about NCP were identified (the NCP values include as the provision of food, biodiversity, land fertility, habitat, water regulation, climate regulation, pests regulation, land pollution absorption and soil erosion; as well as relational values such as education, traditions, landscape aesthetics, traditional knowledge and personal recreation). See S1 Table to understand the interpretation of the performed HCAs.

Analysis of differences among farmers’ groups in terms of awareness of NCP co-production

First, we explored if there were significant differences in terms of land management among the three groups of farmers given their differentiated NCP co-production awareness. Second, we examined the NCP co-production awareness among the three groups of farmers with different land management strategies using a Kruskal-Wallis test [4042]. A False Discovery Rate (FDR) control approach was used to counteract the problem of multiple comparisons [43].

Selection of drivers to understand social tie formation

To understand the role of farmers’ network structures on land management decision-making, we used a mixed exploratory and hypothesis-driven approach for testing the following structurally driven tie formation factors among farmers in the network: reciprocity, transitivity, network activity, and network popularity [30, 44]. Transitivity, in this context, means that advisors of advisors are also sought for advice. Network activity and popularity refer to the number of outgoing ties (i.e, the number of farmers asked for knowledge on farming practices from a given farmer), and incoming ties (the number of farmers seeking knowledge on farming practices from that given farmer). These indicators show the presence of leaders in the farming community, who are consulted farming advice more frequently due to their social position as well as farming experience and knowledge. Leaders can bring people together [45] and may influence others’ values [18, 19, 46].

We also included attribute driven factors influenced by farmers’ characteristics. Homophily is the tendency for actors to seek information from those who share the same characteristics. We tested for homophily in social variables such as age, NCP awareness, and land management to see if those factors influenced the network configuration. Sharing information with others that practiced similar farming strategies is recognized as a probable practice [47].

Regarding biophysical contextual factors, we included geographic proximity in the model, which has been shown to be a major contributor to network formation (see e.g., [44]). The presence of an agricultural plot within 1 km was selected as the distance metric, with the expectation that neighbouring farmers, i.e., located nearby, are more likely to be asked for knowledge on farming practices than distant farmers. See S2 Table for a more detailed justification of why other geographic and ecological environment-related variables could not be included in the model.

Exponential Random Graph Model (ERGM)

We used Exponential Random Graph Model (ERGM) for the analysis of the advice network. ERGMs model the formation of network ties by comparing the observed network with randomly generated networks on specific counts of network substructures (e.g., the number of ties in the network, the number of reciprocated ties, the number of triangles, the number of ties within and between certain groups etc.). The parameters of the ERGM each correspond to one of these substructure counts with a positive parameter meaning that the respective structure (e.g., number of reciprocated ties) is occurring more often than expected by chance (given the rest of the model), while a negative parameter means that the respective structure is occurring less often than expected by chance (given the rest of the model). In our model, we included parameters for the substructures of interest, for instance, the number of ties within the different land management types. A positive parameter here would indicate that farmers are more likely to ask those farmers for advice that share similar land management styles, while also controlling for, among others, the tendencies that farmers ask those for advice that they ask themselves (reciprocity), that they ask those for advice that their advisors also ask for advice (transitivity), and that they might ask those farmers that manage land close to them or those of similar age. Network structures are highly dependent on each other and thus changing one structure (e.g., increasing the number of reciprocated ties) also changes the frequency of other network structures (increasing reciprocated ties also increases transitivity), hence complex network models like ERGMs are required to properly model network processes and take their interdependencies into account. For a detailed introduction into ERGMs see [50].

The ERGM was used to test whether land management related knowledge relationships are associated with a similarity of farming types, social characteristics, and geographical proximity. ERGMs permit testing all of these variables simultaneously and predicting edge formation [48], therefore informing about how land management related rural networks are created. We fit the ERGMs using the ergm (v2018.10, Handcock and Gile, 2010; Handcock et al., 2014) package for R statistical software (R version 3.6.3) programming language (R Team et al., 2020). We constrained the simulations to a maximum of 5 nominees. Sometimes, especially when the number of configurations included is high or the models are not well specified, ERGMs do not converge [29]. To deal with this we started with a simple model and added more configurations incrementally if there were reasons to believe they were important (see S2 Table regarding our reasoning to include environmental variables). After obtaining a structural baseline model, we first tested each new set of parameters, added to the simple, smaller model, and then later tested a final model with all the previously significant parameters. This way we can explore the data in several directions and preselect relevant effects while reducing the number of false positives by testing all relevant effects jointly in a final model.

Missing data

Generally, farmers answered about awareness of their co-production of NCP. However, some of the landholders who did not manage land anymore did not answer this question, and, for this reason, we took a subsample of 55 farmers regarding the analysis about their perceptions of NCP co-production. As for the ERGMs analysis, this can be reliably estimated under missing data (assuming the data is missing at random), as long as the missing data is only on the network ties [49]. Missing covariates, however, cannot easily be handled within the ERGM framework because the model is only generative regarding network links and treats all covariates as exogenous (this means that missing covariate values cannot be internally imputed during the estimation). We thus base our findings for the ERGM only on a subsample of 80 respondents on which we have nearly complete information. One farmer was the only one who used purely organic farming techniques and asked no-one else for knowledge on farming practices, nor did anyone ask this farmer for such a knowledge. This farmer thus represented a very special case and was excluded. It has been shown that ERGMs still provide reliable results with 20–30% missing data [50, 51].

Results

Farmers’ awareness about their role in NCP co-production

We found different levels of awareness among farmers regarding how they can affect NCP within the agricultural landscape given their land management decisions. Not surprisingly, the provision of food was the most highly cited material contribution of farmers to NCP. Around 96% of the farmers answering this question thought they contributed to the provision of food through their crop production. This was followed by some cultural contributions, such as impact on their own recreation (87%) and farmers’ influence on landscape aesthetics (80%). Farmers we interviewed also mentioned perceptions about their impacts in creating an adequate habitat to enhance biodiversity (75%) and to support water regulation (67%). In contrast, their impact on land pollution and climate regulation was the least cited, being mentioned by only 29% of farmers (See Fig 2).

Fig 2. Percentage of farmers aware of their NCP perceived as co-produced through their farming.

Fig 2

Differentiated groups of farmers and their differences regarding management and NCP co-production awareness

The result of the first HCA grouped farmers according to their land management (MC) into three groups: modern technology adopters (N = 45), traditional farmers (N = 21), and landowners (N = 15). The second HCA was based on their awareness of their role to co-produce NCP (NCPC) and it also revealed three different groups: farmers conscious of their negative impacts on non-material NCP (N = 19); farmers aware of their contribution to climate regulation and landscape aesthetics (N = 42); and farmers more aware of their role enhancing the habitat conditions, maintaining cultural traditions and traditional knowledge, and regulation of pests (N = 20). See Table 1 for more detail on the characteristic of each group.

Table 1. Network nodes characteristics in the two hierarchical cluster analysis (Based on 81 community participants).

HCA1 based on management HCA2 based on NCP co-production awareness
Modern farmers (N = 45) hold large areas with agro-industry oriented crops (maize, grass, biofuels, cereals), sprinkling irrigation, mixed fertilization They make all decisions about farming and investments. They normally contract labor. Conscious of their negative impacts (N = 19) These farmers realize their practices enhance soil erosion, land pollution, and habitat degradation.
Traditional farmers (N = 21) hold plots between 0–5 hectares of “other” crops (vegetables, fruit trees such as olive or almond trees). Hardly any sprinkling irrigation, not main commercial crops (maize, vineyards, and biofuels). Mixed variety of fertilizers. Normally small-scale farmers do not rely only on agriculture, but have other sources of income or are retired farmers. Climate regulation and landscape advocates (N = 42). These farmers consider they helped on climate change mitigation through the store of carbon underground and above ground in more perennial crops such as wooden crops. Likewise, they are aware that their farming practices, types of crops, and rotations contribute to improving landscape aesthetics.
Landholders (N = 15) are not directly associated with farming and they do not make decisions on it either on technology investments. They are normally retired farmers who own many small surfaces of arable land in the village and rent those lands to other farmers to labor them. Traditionalists and habitat supporters These farmers enhance regulating and cultural contributions (N = 20) Aware of their role to enhance the habitat conditions, traditional knowledge, traditions maintenance, and regulation of pests.

We did not find any significant differences (after adjusting for multiple comparisons) among the farmers performing different kinds of land management in their awareness of NCP co-production. However, we did find some indications that some land management decisions, such as the type of irrigation and fertilizer use, crop selection, and, to a lesser extent, the area of land farmed, are correlated with the NCP co-production awareness (see Fig 3). Those using drip irrigation and who normally cultivated “other” crops encompassing wooden fruit trees and vegetables were normally aware of their contribution to climate regulation, landscape aesthetics, traditions, and habitat. Interviews revealed that some traditional farmers considered planting fruit trees a way to regulate the climate and to regulate land pollution. They explained that trees had higher capacity to absorb carbon and retain pollutants, in comparison to other crops. Likewise, they attributed the improvement of the landscape aesthetics to the trees they grew. Traditional farmers also normally linked the way they pruned the vineyards or the olive trees to keeping traditional knowledge and traditions.

Fig 3. Land management differences among the groups of farmers with different NCP co-production awareness.

Fig 3

In contrast, many modern irrigation adopters emphasized that such implementation had largely changed their management and they believed they were not contributing to traditions and traditional knowledge anymore. However, some of them remarked that although the farming techniques had largely changed, they kept in mind lessons of the past: “You always remember what ancestors told you and you follow such advice. It’s good to know about everything: the new and the old techniques”. Moreover, those cultivating cereals (normally in large plots) and using mineral fertilizers were aware of their management’s negative impacts on the agrarian ecosystem. Interviews showed that those aware of their negatives effects particularly thought they were eroding and polluting the land.

Most modern technology adopters agreed that the new irrigation was favoring the appearance of new pests and they needed to use higher doses of pesticides, despite being aware of its negative effects on habitats and biodiversity. One of the modern irrigation adopters explained “I understand that every year, 2–3 of the products we use are prohibited because they are bad for our health and the environment. However, there is no real support to shift to organic farming at a large-scale, which is necessary because if your neighbors apply those products, they make it really difficult for you. That is, if I started organic farming, all the slugs would come to my plot. The slugs will eat all my maize. I am now using transgenic maize to prevent this. Moreover, when selling my crops to the Germans, if they find other (illegal) products in the organic farming requisites, not only will they not buy my crop but I will also get a sanction. If organic farming is not supported at large-scale I will not risk my money. Nowadays, there is only propaganda but no real support”.

Some of the traditional farmers also admitted they needed to use conventional pesticides because of the amount of pests in their plots. One of them stated: “I believed that the herbicides and fungicides we use include a component to make the pests resistant so that we need to increase the doses we apply. I have a plum tree that when my father was alive we didn’t apply anything and we got extraordinary plums; nowadays, if I don’t apply products, I don’t get anything”.

Few traditional and modern farmers elaborated their ideas regarding how they affected land erosion. From those, all traditional farmers explained they benefitted the control of erosion through their management: “I take care of the crops by making rotations to favour the retention of the soil”. Many modern farmers (55%) thought they were eroding their lands through the labours and the type of irrigation they did, whereas only some (33%) thought their management positively affected the regulation of erosion: “If there are crops, there is no erosion. I grab the soil through the crops roots I grow”.

Regarding the capacity of land to regulate land and underground water pollution, few traditional farmers and landholders explained their perceptions in this regard, whereas some modern farmers had contrasting viewpoints: some thought they benefitted the agrarian ecosystem because of the type of crops they selected, the rotations they conducted and the amount of vegetal mass they had in their land: “I grow regulating species to get the CAP payment”, whereas others thought they were polluting the agroecosystem.

When assessing how different types of farmers (in terms of MC) perceived their NCP co-production, we neither found any significant difference among the group of farmers but we did find similar tendencies complemented by qualitative insights: traditional farmers (who cultivate small plots, grow vegetables and fruit trees with drip irrigation systems and mixed fertilizers) had a higher awareness of their role in enhancing traditional knowledge, traditions, and landscape aesthetics (see Fig 4). Likewise, (but to a lower extent) they also thought they contributed to climate regulation. For more details on those differences see S3 and S4 Tables.

Fig 4. NCP co-production awareness differences among the groups of farmers with distinct land management strategies.

Fig 4

Both, traditional and modern farmers thought they contributed to landscape aesthetics. As previously commented, most traditional farmers related planting trees with the improvement of landscape. Modern farmers linked this contribution with the adoption of large-scale irrigation: “Before (Itoiz-Canal de Navarra) you arrived to this village in summer and it looked like a desert. We used to finish harvesting in San Fermin and everything was yellow, none can imagine how much those villages have changed. Nowadays, you wake up in the morning and see all the fields irrigated, the maize so green”.

Exponential Random Graph Model (ERGM) social network results

The results of the ERGM (Table 2) indicate that knowledge on farming practices seeking is strongly reciprocal; that is, farmers are likely to ask advice from farmers that also ask them for advice in return, and highly transitive, as can be seen in the positive gwesp term. Neither gw-in- nor outdegree are significant, that is, there are no significant hubs in the network.

Table 2. ERGM results for farmers knowledge-seeking presenting the estimated value in the model for each of the parameters considered (Estimate), their standard error (SE) and the p-value (p).

Parameter Estimate SE p
Edges (ties) -5.594 0.673 <.001
Mutual (reciprocity) 7.472 0.638 <.001
gwesp(α = 0.3) (transitivity) 0.457 0.121 <.001
gw-indegree (α = 0.9) (popularity) 0.098 0.505 .845
gw-outdegree (α = 0.1) (activity) -0.770 0.544 .157
absolute age difference (homophily age) -0.011 0.006 .083
shared crops (homophily crops) 0.207 0.076 .006
distance (1km) -0.147 0.143 .304
indegree MC2a 0.559 0.693 .420
indegree MC3a 1.363 0.672 .043
outdegree MC2a -2.463 0.753 <.001
outdegree MC3a -2.637 0.671 <.001
same MC (homophily management) -0.167 0.488 .732
indegree NCPC2b -0.897 0.366 .014
indegree NCPC3b -0.114 0.411 .781
outdegree NCPC2b 0.942 0.351 .007
outdegree NCPC3b 0.063 0.425 .883
same NCPC (homophily perception) -0.190 0.140 .175

Note. AIC: 784.5 BIC: 906.

aReference category: MC1.

bReference category: NCP1.

Farmers sharing the same crops are more likely to seek knowledge on farming practices from each other while farming land close to each other or the age-difference does not significantly influence the knowledge-seeking behavior.

The results for the MC reveal that old landholders (MC3) are more likely to be asked for farming practices knowledge (reference category MC1), and traditional farmers (MC2) and old landholders (MC3) are less likely to ask for such a knowledge. For the NCPC awareness clusters, we find that farmers who think they contribute to climate regulation and landscape aesthetics (NCPC2) are less likely to be asked for their knowledge on farming practices, and more likely to ask others for such a knowledge. There seems to be no preference to ask farmers within the same NCPC or management behavior for advice.

Additionally, a more detailed analysis of the knowledge-seeking behavior modeling the connectivity between the management clusters revealed that traditional farmers (MC2) in this sample do not ask each other for knowledge on farming practices, nor do they ask old landholders (MC3). Likewise, old landholders (MC3) do not seek knowledge from traditional farmers (MC2). These results indicate that modern farmers (MC1) are crucial for the information flow throughout the community.

Complementary to ERGM results, Fig 5 reveals that modern farmers (in red) occupy central positions and are very active in both giving and receiving knowledge about land management and are often aware of their negative effect on the agrarian ecosystem. In contrast, most traditional farmers are in the periphery and often isolated, not being asked or asking for knowledge to others. Such traditional farmers (in blue) are often aware of their role to support the agrarian ecosystem habitat, as well as those aware of their capacity to regulate climate and contribute to landscape configuration (Figs 35). Therefore, we can deduce that most farmers aware of their regulating and cultural NCP do not play an important role in this network. However, modern farmers control the information flow, being able to spread intensive farming practices in this community. Fig 5 allows us to visualize how farmers performing intensive practices dominate over traditional practices, even when some of such modern farmers recognize their impacts on the agrarian ecosystem.

Fig 5. The knowledge on farming practices network of the farming community in the village of Navarre in 2017.

Fig 5

Discussion and conclusions

We found that most farmers were aware of their co-production of NCP through their land management decisions, though modern and traditional farmers’ awareness of their contributions differed. We found a higher degree of homogeneity among traditional farmers in terms of their perceptions about non-material NCP, such as climate change regulation, traditional knowledge, cultural traditions, and landscape aesthetics contribution. In addition, we found much greater heterogeneity in terms of the awareness about NCP among modern farmers cultivating large plots (>100 Ha) especially regarding the negative ecological and cultural impacts of their management on non-food NCP. Further, while many modern farmers were not aware of their role in co-producing non-food NCP, and some (around 30–40% of those answering) recognised their negative effects, still others justified their management based on their perceived overall positive impact in the agrarian ecosystem.

We also found that farmers’ awareness about NCP co-production and their land management decisions were correlated with the structure of the social networks among the farming community. Farmers sharing similar land management practices and awareness of NCP co-production affect ties within the social network. Intensive farmers were most active and took central positions in the exchange of farming knowledge. In contrast, traditional farmers were often more isolated within the network (Fig 5), not sharing their farming knowledge with the rest of the farmers. This implies that those farmers who were more conscious about the social-ecological implications of their land management were less likely to be sought for knowledge on farming practices by other farmers and thus less prone to disseminate their knowledge and perceptions among the community of farmers, as compared to the modern farmers located more centrally in the social network.

These networks are used to promote climate mitigation [24] and could be used in a similar way for the spread of (un)sustainable farming practices. Our results point towards the roles and responsibilities of modern vs. traditional farmers when both kinds of farmers choosing different co-production pathways [53]. Moreover, the cognitive and management dimensions linked to knowledge sharing are critical to understanding how dominant farming practices (intensive practices in this case), can be spread at the landscape scale [24, 25].

Several factors could help explain the social mechanisms behind our results. In line with what other authors, such as [52] found in the Philippines, despite higher investment and labor requirements, modern farmers find large-scale irrigation attractive, losing the longer term perspective of the benefits associated with traditional and diversified farming despite educational programs. This result aligns with what [34] found and which points towards the idea that it is not always a lack of knowledge that prevents changes in agricultural practices. In other words, just sharing knowledge with dominant farmers is necessary but not sufficient. What is needed for understanding the spread of intensive practices is a focusing on the more systematic and structural causes that make dominant intensive farming to spread [53]. The integration of rural economies into global commodity markets makes farmers increasingly dependent on enhancing yields through intensive practices [1, 54, 55]. It is at the national and international incentive structures that promote agricultural commoditization and agribusiness models that require increased scrutiny and change to favour farmers’ awareness and the distribution of their influence in spreading farming practices at the landscape level. On the positive side, we also found that some modern farmers would be willing to shift the way they use agrochemicals if there were real institutional support for such change aligned with their larger scale operations. This finding reveals that as [53] found, one of the main drivers for land management decisions at local scale is still government intervention to provide clear economic incentives and regulation.

The introduction of large-scale irrigation seems to be exposing those traditional farmers to unexpected losses in local knowledge and the substitution of crops not suiting carbon store capacity, like fruit trees [11]. Further research is needed regarding how those types of farms are becoming invisible for policies and markets, making at the same time very difficult their interests be supported, and consequently, their intangible contributions, such as traditional knowledge, can be lost over time [56].

Reciprocity and transitive closure playing an important role in the network are typical findings (Siciliano, 2015; Thomas and Caillon, 2016). Giving knowledge and providing help costs resources and is often repaid by knowledge and help in return. Modern farmers controlled the flow of information since traditional farmers and landholders did not normally ask each other for advice. Modern farmers sought, however, more advice from landowners than they did from each other or traditional farmers. This finding may be related to the fact that modern farmers normally cultivated landholders’ plots and, therefore, asked them about their land management preferences.

In contrast, exogenous factors, such as proximity to other farmers, were not a driving factor in forming network structure (as happened [57] in their case study about agroforestry advice networks in Ghana). Houses proximity may be more important than the proximity of the cultivated plots or easily available modern technology (e.g., mobile telephones) reduces the importance of shorter distances.

It can be difficult to make generalizations with a case study of a small community. However, we find important contextual similarities with other rural communities in Western Europe [56] and worldwide [54]. Additionally, we did not have longitudinal data on the networks and attributes. This reduce our ability to assess how advice networks in rural communities over time may influence farmers’ land management decisions and how dynamic variables, including changes in awareness about climate change, may affect the formation of rural networks (see, e.g., [58], for the problem of how to disentangle network selection and network influence processes).

Despite these caveats, rural network analysis can be useful for understanding the network configuration of rural farming communities to improve rural policy development since it permits understanding interactions between awareness, land management decisions, and knowledge/advice sharing at the landscape level. Being aware of modern farmers’ position that enables them to control the flow of knowledge shows how difficult it can be to spread less intense farming practices [25]. Considering that those modern farmers’ perceptions and their management practices are significant factors for the creation of the advice network structure, we should incentive structures that make farmers more aware of their contribution to climate regulation to take a more active role within their networks. Incentivizing traditional farmers’ practices diffusion through their higher participation in advice-giving structures (e.g. within the local cooperatives), as well as withdrawing some power from modern farmers could be one way of changing this situation.

Supporting information

S1 File. Farmers, landholders and rural organizations interviews.

(DOCX)

S1 Table. Characterization of one of the clusters regarding farmers’ land use management.

(DOCX)

S2 Table. Environmental variables considered being included in the model.

(DOCX)

S3 Table. Land management differences among the groups of farmers with NCP co-production awareness.

(DOCX)

S4 Table. ERGM to check homophily in the type of farming effect in ties formation.

(DOCX)

S5 Table. ERGM to check to belong to uneven types of farming effect in ties formation.

(DOCX)

S1 Dataset. Original dataset and main analysis.

(XLSX)

Acknowledgments

A.A. wishes to express her gratitude to her mother, Gloria Aguinaco Otxaran, who has taken care of her first baby while she working on this project. We would also like to thank two anonymous reviewers and the editor for helpful comments and advice to improve the paper.

Data Availability

All relevant data are within the manuscript and its Supporting information files.

Funding Statement

AA, Eusko Jaurlaritza(Postdoctoral Scholarship); https://www.euskadi.eus/informacion/ayudas-al-personal-investigador-programa-posdoctoral/web01-a2hunib/es/; Ministerio de Economía y Competitividad(ES)(MDM-2017-0714). EB, Canadian Network for Research and Innovation in Machining Technology, Natural Sciences and EngineeringResearch Council of Canada RK, European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 648693).

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Decision Letter 0

Sieglinde S Snapp

10 Sep 2020

PONE-D-20-24320

What affects farmers’ advice networks: implications for agrarian sustainability

PLOS ONE

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The reviewers were split in their assessment, reviewer one recommended reject and reviewer 2 recommended minor revision. I reviewed and agree in the main with reviewer one, that the statistics section is not written with sufficient detail so it is quite difficult to discern how the study was conducted. Also, that the study would have benefited from qualitative data, which was collected based on the methods description, yet not reported on. So I recommend a major revision addressing these points, and indeed all the reviewers comments - at which time it will be possible to ascertain the statistical validity of the study and the key insights derived from it.

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Reviewer #1: Summary of manuscript

- In this study, the authors investigate a farming community in Spain undergoing agricultural intensification to identify farmers’ perceptions of their impacts on the local ecosystem and how farmer social network ties differ across different management groups. Overall this study addresses important implications around farmer social networks and how these dynamics may contribute to dominant management practices. However, the connections made by the authors are founded in weak statistical associations, and the major conclusions claimed by this study overstate these weak associations. Specifically, the main results presented highlight differences in management practices and NCP awareness for different groups of farmers, however according to the authors these differences did not hold up after accounting for multiple comparisons error, therefore they cannot be presented as differences as the main conclusions state. For this reason, I do not recommend publication for this manuscript.

Abstract and Introduction

- Abstract does summarize research questions and key findings, however much of the manuscript focuses on Nature Contributions to People (NCP) concept, and this is not mentioned in the abstract.

- Overall language editing is recommended to improve clarity and sentence structure.

- The introduction should include more literature focusing on the linkages between agricultural intensification practices being both unsustainable/environmentally degrading and the authors’ argument that these stronger social networks undermines/pushes out small-scale organic farmers who could be creating more positive environmental interactions in the landscape.

- Introduction needs more synthesis of literature – expand on previous studies that look at topics mentioned. Additionally, the authors have not properly formatted the citations, such that numbered in-text citations do not have matching numbered references in references section. This makes it difficult to assess the literature being cited and identify key references.

- Current structure includes Introduction and Conceptual Framework. For the structure of this journal, include conceptual framework as part of introduction, not a separate section.

Figures and Tables

- Figures 2 and 3 do not appear to be necessary – just show sampling of participants for social network analysis and sampling of interview participants. This can just be described in the methods.

- Table 1 – Characteristics of groups determined by HCA - How were characteristics compiled? Thematic analysis of interviews?Interview response analysis not described in methods

- Figures 5 & 6 – Contain confusing captions that do not match with description of radar charts. Captions state that results of statistical differences found before accounting for multiple comparisons, given differences found did not hold up after accounting for multiple comparisons error, authors should not indicate statistical differences.

- Figure 7 – Advice network of the farming community: Unclear figure – caption does not accurately describe figure – more description needed to understand figure. Does not clearly demonstrate results

- Supplementary material not appropriately labeled given journal conventions.

Methods

- Line 186 - Semi-structured interviews - Unclear how the results of these interviews were used – This data does not appear to be represented in results section?

- Line 197 – Hierarchical Cluster Analysis - More detail on method needed – variables used, number of farms subjected to analysis, method used to select groups etc.

- Overall there is not enough detail in methods description to determine if statistical analysis has been performed rigorously. More detail is needed to explain statistical approach.

Results, discussion, conclusion

- In general, tables and figures should be better supported in the text. There is not enough description of results in text.

- More literature needs to be connected to discussion. What have other studies looking at agricultural intensification found as far as dynamics between large-scale intensified farms and those maintaining traditional practices?

- Conclusion seems to be an over-reach given the results and weak statistical basis.

- References - Improperly formatted – Numbers not listed in reference section, instead references organized by author, therefore unable to connect citations in text to reference list. This is a major oversight that makes critical examination of the literature difficult.

Overall, the subject of this study is valid and the authors have sufficient data to analyze, however I think this study could benefit from a more mixed-methods approach, incorporating more qualitative data from interviews collected to complement the quantitative approach used here.

Reviewer #2: General comment

Relevant paper, well-written. Methods appropriate but analysis could dig deeper. The data collected are new and appear to be well collected and analyzed. The material is quite informative and does indeed significantly add to our knowledge on the role of social networks. These findings are well discussed in the paper, with some surprising and quite interesting findings emerge, including role of social networks, farmer perceptions and awareness for the distinct groups of farmers. The tables and figures on sample selection and characteristics are informative.

Some more specific comments

study area the authors should:

• Provide more general characteristics of the region. Since the village identity has to remain hidden.

• Line 142 and 143: explain the increase in land from what was used previously and what is the current expansion?

• Line 144- 145: expand by explaining the crops grown previously that lead to the new crops adopted. the authors should explain the rate of fertilizer that was used previously and the new rate.

• Line 146 to 149: explain what is the rate of nitrate here?

Data and methods

the authors should:

• Line 166-167: explain the reasons of receiving no response for the group of farmers that was initially selected and lead to the selecting more farmers.

• Explain how the researchers controlled for bias in the selection of the 80 additional people.

• Line 168-170: explain the criteria’s used in nominating the additional people in the survey.

• Line 174: show the number of interviews done for each group of farmers and landholders?

• Line 230: did the authors check for robustness after removal of the insignificant variables?

Results

• The opening line, 284 talks about awareness, but the heading is perception this contradicts with the next section that discusses awareness?

• Line 286-291: mention the percentage for the highest and lowest levels in the results shown in the figure.

• Line 296 is contracting, were they two or three distinct groups?

• Line 295-309: The figures in the parenthesis for intensive, small-scale farmers and landowners do not match with those provided in table 1 (HCA1 based on management)

conclusion and discussion

The authors doesn't explain in the discussion section how the results link to agriculture intensification, more information is needed..

**********

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Reviewer #1: Yes: Alison Nord

Reviewer #2: No

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Attachment

Submitted filename: PONE-D-20-24320_reviewer.pdf

PLoS One. 2021 Jan 7;16(1):e0244619. doi: 10.1371/journal.pone.0244619.r002

Author response to Decision Letter 0


29 Oct 2020

We are grateful to the editors and the two reviewers of our manuscript for their insightful and useful comments. We provide below a detailed account of how we have addressed each of their remarks. We think that the manuscript now better explains the statistical analyses undertaken, and we have added more insights about the qualitative data collected. We hope the reviewers find the resubmitted manuscript stronger and sharper. We have especially worked to link the introduction and discussion to the literature connecting agricultural intensification practices with community social networks to show how intensification may push out more traditional, small-scale farmers. We hope the reviewers agree that the concluding discussion is now more robust in acknowledging that while some of our findings are not statistically significant, the qualitative research points at some trends that are worth noting. We hope that the re-submitted manuscript meets now the required scientific standards of PlosONE. Please do not hesitate to contact us for any further clarification on how we have interpreted or addressed the comments below.

Yours sincerely,

Dr. Amaia Albizua

Dr. Elena Bennett

Dr. Guillaume Larocque

Dr. Robert Krause

Dr. Unai Pascual

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming.

Amended, style and file naming has been corrected.

2. Thank you for including your ethics statement: 'The case study had the required university ethics approvals from McGill University.'

a. Please amend your current ethics statement to include the full name of the ethics committee/institutional review board(s) that approved your specific study and confirm that your named institutional review board or ethics committee specifically approved this study.

We included in Methods section: “The McGill University Faculty of Agriculture and Environmental Sciences Research Ethics Board reviewed and approved this project by delegated review in accordance with the requirements of the McGill University Policy on the Ethical Conduct of Research Involving Human Participants and the Tri-Council Policy Statement: Ethical Conduct For Research Involving Humans.”

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Amended.

3. We note that you have stated that you will provide repository information for your data at acceptance. Should your manuscript be accepted for publication, we will hold it until you provide the relevant accession numbers or DOIs necessary to access your data. If you wish to make changes to your Data Availability statement, please describe these changes in your cover letter and we will update your Data Availability statement to reflect the information you provide.

We have given a doi to the original data and the analysis performed. This is S7 in the supplementary material. https://doi.org/10.6084/m9.figshare.13089098.v1

4. Please ensure that you refer to Figure 1 in your text as, if accepted, production will need this reference to link the reader to the figure.

Amended.

5. Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information.

Amended.

Additional Editor Comments (if provided):

The reviewers were split in their assessment, reviewer one recommended reject and reviewer 2 recommended minor revision. I reviewed and agree in the main with reviewer one, that the statistics section is not written with sufficient detail so it is quite difficult to discern how the study was conducted. Also, that the study would have benefited from qualitative data, which was collected based on the methods description, yet not reported on. So I recommend a major revision addressing these points, and indeed all the reviewers comments - at which time it will be possible to ascertain the statistical validity of the study and the key insights derived from it.

We have added more detail in the methods section, regarding how the statistics were analyzed and the study conducted. We now explain that there were two kinds of interviews for data gathered in the research. One conducted among farmers and landholders and the other one conducted among rural organizations. Only the data coming from farmers and landholders was used to make the social network analysis and the statistics about farmers’ awareness regarding their role in co-producing NCP (see page 10 and 11 in the Manuscript). We have now added a section called: “Semi-structured interviews response analysis” (page 10 and 11 in the Manuscript). Here we explain how we used information from the surveys and how such data feeds a qualitative analysis to complement the results obtained through statistics. Please see below more detailed responses to the reviewers.

Reviewer 1

- In this study, the authors investigate a farming community in Spain undergoing agricultural intensification to identify farmers’ perceptions of their impacts on the local ecosystem and how farmer social network ties differ across different management groups. Overall this study addresses important implications around farmer social networks and how these dynamics may contribute to dominant management practices. However, the connections made by the authors are founded in weak statistical associations, and the major conclusions claimed by this study overstate these weak associations. Specifically, the main results presented highlight differences in management practices and NCP awareness for different groups of farmers, however according to the authors these differences did not hold up after accounting for multiple comparisons error, therefore they cannot be presented as differences as the main conclusions state. For this reason, I do not recommend publication for this manuscript.

Thank you for sharing this important comment. We would like to clarify that while (only) the results about farmers’ perceptions are not statistically significant, we approach farmers’ perceptions qualitatively, making this point more clear. We find out that the type of management and farmers’ awareness are significant variables when included in the Exponential Random Graph Model (ERGM). Thus, we believe that it is pertinent to highlight the results regarding what matters for the creation of community networks and how some types of farmers have a dominant role in the sharing of information, which we believe is grounded on data.

Abstract and Introduction

- Abstract does summarize research questions and key findings, however much of the manuscript focuses on Nature Contributions to People (NCP) concept, and this is not mentioned in the abstract.

Well spotted and amended. We have changed the sentence where we said that few studies address farmers’ perceptions about their influence on agrarian ecosystems by: farmers’ awareness regarding their role to co-produce NCP.

- Overall language editing is recommended to improve clarity and sentence structure.

Thank you. We have asked a native speaker to help us with the editing of the manuscript.

- The introduction should include more literature focusing on the linkages between agricultural intensification practices being both unsustainable/environmentally degrading and the authors’ argument that these stronger social networks undermines/pushes out small-scale organic farmers who could be creating more positive environmental interactions in the landscape. Introduction needs more synthesis of literature – expand on previous studies that look at topics mentioned.

Thank you for the suggestion. We have included references to the literature including the works by Villanueva et al. 2017; Isaac 2017; Ernstson et al. 2010; Isaac and Matous 2017 and Albizua et al 2020.

Those studies show examples about how farmers’ networks influence their management which simultaneously is connected to land change and biodiversity changes. They correlate such environmental changes with the number and characteristics of the network ties. One example also talks about how multi-level network structures are correlated with the access to information and resources for different kinds of land management being able to push out more vulnerable rural livelihoods.

Additionally, the authors have not properly formatted the citations, such that numbered in-text citations do not have matching numbered references in references section. This makes it difficult to assess the literature being cited and identify key references.

Amended. We are sorry for this mistake, we forgot to refresh the bibliography and left an old version of it in the manuscript. This is amended now.

- Current structure includes Introduction and Conceptual Framework. For the structure of this journal, include conceptual framework as part of introduction, not a separate section.

Thank you. We agree and we have now merged the two to follow journal guidelines on structure.

Figures and Tables

- Figures 2 and 3 do not appear to be necessary – just show sampling of participants for social network analysis and sampling of interview participants. This can just be described in the methods.

- Table 1 – Characteristics of groups determined by HCA - How were characteristics compiled? Thematic analysis of interviews? Interview response analysis not described in methods

- Figures 5 & 6 – Contain confusing captions that do not match with description of radar charts. Captions state that results of statistical differences found before accounting for multiple comparisons, given differences found did not hold up after accounting for multiple comparisons error, authors should not indicate statistical differences.

- Figure 7 – Advice network of the farming community: Unclear figure – caption does not accurately describe figure – more description needed to understand figure. Does not clearly demonstrate results

Thank you for the suggestions. We have taken out figures 2 and 3 and kept the main points about sampling in the methods section. We have now added information in the methods section about how data collection (via surveys) about the different characteristics about land management (page 9). We have now included information about how we conducted the interviews response analysis (a new sub-section added). As for Figures 5 and 6 (now Figures 3 and 4), we follow the recommendations and have corrected the captions. Lastly, also following the reviewer’s suggestion we have improved the caption of the old figure 7 (now Figure 5) and added an additional description in the main text to better explain the information that can be obtained from this figure.

- Supplementary material not appropriately labeled given journal conventions.

Thank you. We have now amended the way the Supp. Material is labelled and added captions with online hiperlinks.

Results, discussion, conclusion

- In general, tables and figures should be better supported in the text. There is not enough description of results in text.

We have revised the text thoroughly and tried to connect the information from tables and figures with the main text (see track of changes document).

Methods

- Line 186 - Semi-structured interviews - Unclear how the results of these interviews were used – This data does not appear to be represented in results section?

- Line 197 – Hierarchical Cluster Analysis - More detail on method needed – variables used, number of farms subjected to analysis, method used to select groups etc.

- Overall there is not enough detail in methods description to determine if statistical analysis has been performed rigorously. More detail is needed to explain statistical approach.

Thank you for these questions. The semi-structured interviews provided the data for the network analysis and responses were transcribed and analyzed taking an inductive approach.

We have now added a section called “interview qualitative analysis”, explaining how the qualitative analysis was done in the methods section and the results have been added at the end of the section called “Differences among farmer groups regarding management and NCP co-production awareness” (pages18,19 and 20 in the manuscript)

The qualitative information shows how traditional farmers seem to be more connected to landscape aesthetics and climate regulation due to the kind of farming they conduct which offers different benefits at the landscape level being more sustainable than other farming paths chosen by other kind of farmers.

We have now included information about the hierarchical cluster analysis used as requested. Moreover, we give an example in the supplementary material about how we have interpreted the Hierarchical cluster analysis results.

Given the above, we hope that the statistical analysis explained in a more clear way within the methods section.

- More literature needs to be connected to discussion. What have other studies looking at agricultural intensification found as far as dynamics between large-scale intensified farms and those maintaining traditional practices?

Thank you for the suggestion to link the discussion from our results to the broader literature touching on this topic. We have now included additional literature, e.g., Kay, 2002 who point towards the roles and responsibilities choosing different co-production pathways.

Martinez-Baron et al., 2018 regarding how climate mitigation practices can spread and scale up, or Albizua et al., 2020 regarding how some intensive farmers displace more traditional and small-scale farmers due to the intensification taking place in the region.

We have also included Chen at al, 2018; Kay, 2002; Cramb, 2011; to explain more systematic and structural causes that make dominant intensive farming to spread at the cost of marginalizing other farming strategies.

- Conclusion seems to be an over-reach given the results and weak statistical basis.

Thank you. We hope the new conclusion section is now more accurate and humble with regard to the intend of the paper and the way the results connect with the main research question.

- References - Improperly formatted – Numbers not listed in reference section, instead references organized by author, therefore unable to connect citations in text to reference list. This is a major oversight that makes critical examination of the literature difficult.

We are sorry for this mistake. This oversight was due to using a different citation style at the beginning which was not corrected at the time of submission. We apologize. We have now made sure to provide the right formatting to the reference list and citations throughout the paper.

We have made a final review in the manuscript and corrected some few references that appear more than once wrongly cited. This last correction only appears in the final manuscript version but not in the track of changes. The manuscript has changed so much that revising all the references twice will take us a lot of time and it is already done in the manuscript without track of changes. We hope this is not a problem.

Overall, the subject of this study is valid and the authors have sufficient data to analyze, however I think this study could benefit from a more mixed-methods approach, incorporating more qualitative data from interviews collected to complement the quantitative approach used here.

Thank you for the critical yet very constructive comments of the reviewer. We have also incorporated some more qualitative data from the surveys to complement the quantitative approach, as well as to shed some further light on those statistical results that while not statistically significant, are still interesting to focus on from a qualitative perspective. We believe those qualitative insights can offer complementarity perspective on the stat results.

Reviewer 2

Reviewer #2: General comment

Relevant paper, well-written. Methods appropriate but analysis could dig deeper. The data collected are new and appear to be well collected and analyzed. The material is quite informative and does indeed significantly add to our knowledge on the role of social networks. These findings are well discussed in the paper, with some surprising and quite interesting findings emerge, including role of social networks, farmer perceptions and awareness for the distinct groups of farmers. The tables and figures on sample selection and characteristics are informative.

Thank you for this overall comment on the paper. We have now gone deeper into the analysis, also requested by Reviewer 1, adding some qualitative information from the surveys (see methods and results section) and we have tried to more clearly connect the results from the analysis with literature linking agricultural intensification and dynamics between large-scale intensified farmers and those maintaining more traditional and sustainable agricultural management practices.

Study area the authors should:

• Provide more general characteristics of the region. Since the village identity has to remain hidden.

• Line 142 and 143: explain the increase in land from what was used previously and what is the current expansion?

• Line 144- 145: expand by explaining the crops grown previously that lead to the new crops adopted. the authors should explain the rate of fertilizer that was used previously and the new rate.

• Line 146 to 149: explain what is the rate of nitrate here?

We have provided more general information about the location including e.g, the climatic conditions, the large-scale irrigation project and the total area converted into modern irrigation as well as the impact on the available arable land area due to this development project, as suggested.

We now explain that traditional farmers used to grow vegetables and fruit trees such as olive and almond trees. However, fertilizers rates vary a lot depending on the farmer and we unfortunately failed to collect this information. We know that fertilizers doses increased since most of farmers and the rural advisor informed about this during the interviews but they did not provide exact figures.

Several authors studying nitrate pollution in the region mention that agricultural intensification is leading to higher nitrate pollution of land and water (see e.g., (Ladrera et al., 2019)).

50 mg/ l is the threshold to say the water is polluted by nitrates attending to the Spanish Royal Decree 261/1996, 16 Feb, (for more information see article #3 in https://www.mapa.gob.es/es/agricultura/legislacion/RD_261_1996_tcm30-73046.pdf)

Data and methods the authors should:

• Line 166-167: explain the reasons of receiving no response for the group of farmers that was initially selected and lead to the selecting more farmers.

Thank you for asking to provide more information on this issue. We got a response rate of 77% through the combination of a priori-list and the follow up snowball sampling (see page 9 L172 in the manuscript). Additional people was mentioned by the contacted farmers when we collected information for the social network analysis (N=161) but we just conducted the ERGM analysis on the data gathered from those farmers we initially approached (n=81 farmers). Since NCP is the main focus of this study, we decided to only rely on the data from the subsample (n=81), which we believe is enough data from the case study to provide reliable results (see e.g., Krause et al. 2020 in Social Networks)

• Line 168-170: explain the criteria’s used in nominating the additional people in the survey.

Thank you for the suggestion. We used a free recall system. This is, when we asked to mention up to five other people who they think influence their land management decision (see page 10 L190 in the manuscript). They were not provided a list of names.

• Line 174: show the number of interviews done for each group of farmers and landholders?

We have now clarified that we made the 81 interviews (to all farmers and landholders who wanted to respond and then we classified them) (see page 9 L172 L344 in the manuscript). The numbers for each group appeared in the Results section, in the subsection called “Differentiated groups of farmers”, there you can see: modern farmers (N=45), traditional farmers (N=21), and landowners (N=15) (see table 1 in page 16. L344 in the manuscript)

• Line 230: did the authors check for robustness after removal of the insignificant variables?

We present the results of the full model, including the two previously removed variables, in table 2. The results are robust to inclusion/exclusion of these variables.

• Explain how the researchers controlled for bias in the selection of the 80 additional people.

We tried to approach all the farmers and landholders in the community, trying to cover the whole range of diversity in terms of land management strategies. They were free to mention anyone they considered influential for their land management.

Results

• The opening line, 284 talks about awareness, but the heading is perception this contradicts with the next section that discusses awareness?

We have corrected the language so as to not confuse the readers.

• Line 286-291: mention the percentage for the highest and lowest levels in the results shown in the figure.

Done.

• Line 296 is contracting, were they two or three distinct groups?

You are right, it is confusing. Each HCA found 3 distinct groups of farmers. Corrected now.

• Line 295-309: The figures in the parenthesis for intensive, small-scale farmers and landowners do not match with those provided in table 1 (HCA1 based on management)

Well spotted, thank you. This information is now corrected.

conclusion and discussion

The authors doesn't explain in the discussion section how the results link to agriculture intensification, more information is needed.

Thank you. We have done this now.

We explain that modern farmers, who normally perform more intense farming techniques, were the most active and central in the network to exchange farming knowledge enabling them to spread the “know-how” of their farming strategies whereas traditional farmers who are more isolated don’t share their farming knowledge with the rest of the farmers. This implies that those farmers who were more conscious about the social-ecological implications of their land management were less likely to be sought for knowledge on farming practices by other farmers and thus less prone to disseminate their knowledge and perceptions among the community (see page 24 L479:486). Moreover, we have now included some new references such as: Kay, 2002 who point towards the roles and responsibilities choosing different co-production pathways, or Martinez-Baron et al., 2018 regarding how climate mitigation practices or Albizua et al., 2020 regarding how farming techniques can spread and scale up.

We have also included Chen at al, 2018; Kay, 2002; Cramb, 2011; to explain more systematic and structural causes that make dominant intensive farming to spread.

Attachment

Submitted filename: ResponseToReviewers.docx

Decision Letter 1

Sieglinde S Snapp

14 Dec 2020

Social networks influence farming practices and agrarian sustainability

PONE-D-20-24320R1

Dear Dr. Albizua,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Sieglinde S. Snapp

Academic Editor

PLOS ONE

Additional Editor Comments: I agree with the reviewers that the revised manuscript is greatly improved, we appreciate the careful attention to making these changes and addressing all the comments.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

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PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: I appreciate the author's extensive revisions to the manuscript addressing all major concerns. The addition of qualitative data I think strengthens the results and provided for a much more comprehensive assessment of the subject. I enjoyed reading this finalized version and have no further comments for editing.

Reviewer #2: the author has addressed the comments provided and additional information needed to explain the selection of the study sites and sample that was key and missing in previous version of the manuscript.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

Acceptance letter

Sieglinde S Snapp

22 Dec 2020

PONE-D-20-24320R1

Social networks influence farming practices and agrarian sustainability

Dear Dr. Albizua:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

If we can help with anything else, please email us at plosone@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Sieglinde S. Snapp

Academic Editor

PLOS ONE

Associated Data

    This section collects any data citations, data availability statements, or supplementary materials included in this article.

    Supplementary Materials

    S1 File. Farmers, landholders and rural organizations interviews.

    (DOCX)

    S1 Table. Characterization of one of the clusters regarding farmers’ land use management.

    (DOCX)

    S2 Table. Environmental variables considered being included in the model.

    (DOCX)

    S3 Table. Land management differences among the groups of farmers with NCP co-production awareness.

    (DOCX)

    S4 Table. ERGM to check homophily in the type of farming effect in ties formation.

    (DOCX)

    S5 Table. ERGM to check to belong to uneven types of farming effect in ties formation.

    (DOCX)

    S1 Dataset. Original dataset and main analysis.

    (XLSX)

    Attachment

    Submitted filename: PONE-D-20-24320_reviewer.pdf

    Attachment

    Submitted filename: ResponseToReviewers.docx

    Data Availability Statement

    All relevant data are within the manuscript and its Supporting information files.


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