Transforming Agricultural Living Labs into Lighthouses Contributing to Sustainable Development as Defined by the UN-SDGs

Abstract

The UN Sustainable Development Goals (SDGs) were intended to be met by 2030, but recent reviews show that this will not be achieved, and recommendations have been made to heads of state, governments, the international community, and member states to strengthen their efforts. Focusing on agriculture, we argue that a bottom-up effort is also needed in living labs, one that truly involves farmers, as they are now confused about, and resistant to, top-down rules and regulations. To provide clarity, we suggest the following: (i) selecting key SDGs by considering the proportionality principle, and (ii) defining ecosystem services in terms of indicators and thresholds for income, the production of healthy food, the protection of water quality, contribution to energy preservation and climate mitigation, and the protection of life on land, including soil health (SDGs 1, 2, 3, 6, 7, 13, 15). Indicators and thresholds have to be clear and measurable and achievable within reasonable costs. The introduction of innovative sensing techniques allowed the rapid generation of relevant soil data in the field of living labs. When meeting all thresholds, a “lighthouse” is established to act as an inspiring example for farmers with similar soils in a given region. Policies should focus on achieving thresholds of a set of indicators rather than on prescribing certain top-down management measures.

1. Introduction

For many years, sustainable development was an abstract concept that could be widely supported, as many interpretations of the concept were possible. Who would disagree? This changed in 2015 when 17 specific goals with targets and indicators were proposed and accepted by 193 governments at a UN Session in New York. However, since that time, implementation has not proceeded to adequately reach the goals by the intended deadline of 2030. The 2023 progress report (https://sdgs.un.org (last accessed on 20 June 2024)) showed that, of the 140 targets, only 12% are on track, 48% are moderately or severely off-track, and 30% show no progress. The Secretary General of the UN, Mr. Antonio Guterres, is quoted in this progress report as saying, “Unless we act now, the 2030 agenda will become an epitaph for a world that might have been”.

Five major recommendations are made in the UN progress report to improve the implementation process, but they are addressed to heads of state, governments, the international community, and member states. With due respect, we argue that this top-down focus may not be sufficiently effective as only a true bottom-up commitment of engaged stakeholders can, in our view, change developments in a positive direction. When focusing on agriculture, farmers are the largest group of stakeholders. For them, due to poor communication, the SDGs and proposed targets and indicators are, at this point in time, still rather abstract top-down concepts, while the connection with their actions remains largely unclear. The gap between the policy and farmer arenas is too wide in many countries and the research community is in a unique position to help close the gap [1]. Farmers ask for fact-based policies with clear goals, supported by well-defined measurements [2]. Improving interaction between the research and farmer communities on the worldwide UN’s Sustainable Development Goals (and on the European Green Deal that was derived from them) is, therefore, essential to achieving practical results in the real world. Recently, the EC proposal for a Directive on Soil Monitoring and Resilience specified requirements for soil health as part of the Green Deal [3]. If farmers are not truly engaged, the agriculture-related SDGs are bound to remain an elusive “epitaph for a world that might have been”.

The scientific community seems to be struggling to address the SDG challenge as only a truly inter- and transdisciplinary approach can be successful resulting in a comprehensive but still scientifically sound systems analysis that can effectively address complicated “wicked” problems that don’t have single straightforward solutions [4]. This systems analysis should be based on the requirements of the SDGs, expressed in terms of indicators and characteristic threshold values for ecosystem services in line with the SDGs, and involve stakeholders from the start in a bottom-up procedure. The European Union has recognized this and calls for the establishment of “living labs” (to be discussed below) that explore the joint development of innovative forms of management by farmers and researchers [5,6,7,8].

Focusing on agriculture, a recent attempt was made to try to connect farmers with the SDG concepts by jointly exploring how existing field expertise and relatively simple and cheap available methodology could be used to assess indicators and threshold values of ecosystem services associated with some key SDGs [9]. The authors conclude that at this point in time, much information is already available to assess such services but that a focus on additional research is needed for some services related to soil biology and biodiversity. They thereby define this as a specific future research approach.

The current study continues this analysis by focusing on an existing farm acting as a living lab that aims to become a lighthouse. This joint effort by researchers and farmers is intended to connect the sustainability discourse with real-life farming practices, with the ultimate objective of providing an inspiring example for other farmers to follow and for the policy arena to develop clear and transparent rules and regulations. Note that every farm is unique and has to be studied as a separate entity. There are no replicates. A gradual increase in the number of living labs and lighthouses is likely to result in a feeling of ownership by farmers contributing to achieving sustainable development in practice.

2. Materials and Methods

2.1. Focusing Research on a Restricted Number of SDGs and on Living Labs

The 17 SDGs with 159 targets and 234 indicators present an overwhelming, and therefore possibly paralyzing, challenge to stakeholders, which is one reason why the SDG targets are not being met. We, therefore, propose the following: (i) focusing on a limited number of SDGs being considered for agriculture; (ii) choosing a research approach that focuses on applying clear indicators and thresholds as well as relatively simple and cheap measuring methodologies; and (iii) cultivating close interactions with farmers in the “living lab” concept, which is to be discussed below.

When focusing on agriculture, not all SDGs are of primary importance. Attention will not only be placed on (i) the traditional role of producing healthy crops to combat hunger (related to SDG2 and SDG3) but also on the following: (ii) clean groundwater and surface water (SDG6), (iii) energy preservation (SDSG7) and increasing carbon sequestration and limiting greenhouse gas emissions for climate mitigation (SDG13), as well as (iv) reducing biodiversity and land degradation (with the latter to be expressed by soil health) (both SDG15). Of course, poverty in rural areas (SDG1) is highly affected by agricultural conditions in all parts of the world and needs to be considered in terms of farmer income. Sustainable production and consumption (SDG12) are relevant, but have much in common with SDG2 and SDG3 and need to consider the entire production and distribution chain. SDG7 is usually relatively low in agriculture as compared with other activities in industry, traffic, and construction. Here and elsewhere, the proportionality principle applies; the degree of attention for a given item should be in agreement with its particular local and national significance and impact. Limited relevance also applies to gender equality in the so-called developed world (SDG 5), decent work and economic growth (SDG8), reduced inequalities (SDG 10), industry, (SDG9), cities (SDG11), peace, justice, and strong institutions (SDG 16). Quality education (SDG4) is important but will improve when more clarity is provided as to how the various SDGs can be realized in the real world. In conclusion, six SDGs that have a major significance for agriculture will therefore be considered in this exploratory paper.

As mentioned above, engagement of land users is essential for progress, and research in living labs is therefore recommended, following the EU Mission protocol for “A Soil Deal for Europe” [6]. Living labs are defined as “spaces for co-innovation, through participatory, transdisciplinary systemic research” that “contribute to Green Deal targets for sustainable farming, climate resilience, biodiversity and zero-pollution”. The EU Green Deal corresponds with the worldwide UN-SDGs. “Living labs” reflect the need for researchers to work closely with stakeholders that contribute their tacit knowledge, thereby jointly developing practical solutions to overcome barriers to sustainable development. When successful, “living labs” become “lighthouses”, defined as “single sites, like a farm or a park, where to showcase good practices. These are places for demonstration and peer-to-peer learning.” Every farm is a living lab and every farm is different even in the same region and on similar soils, as each individual farmer cherishes his own particular practices of adaptive management. This represents his or her basic strength that should be appreciated and acknowledged by researchers as joint research is being executed in living labs. Emphasis will be on defining a relatively simple and cheap methodology that land users can understand and perceive as being relevant for their particular farming system as they aim for sustainable development while making a decent living.

2.2. The Living Lab Being Studied

The Geling farm is located in Zeewolde in the Flevoland polder, the Netherlands. (https://geling.info/, accessed on 20 June 2024) and is considered to be a “living lab”, as defined above. The farm covers 130 ha and soils are relatively homogenous and consist of calcareous heavy clay (33% clay, 40% silt, 16% sand, 7.2% CaCO₃, and 3.9% soil organic matter) with the code Mn45A in Dutch Soil Classification (https://www.broloket.nl, accessed on 20 June 2024). This type of soil covers 42,775 ha in the Netherlands. The US Soil Taxonomy classifies the soil as a very fine, mixed mesic Typic Fluvaquent [10] and as an Eutric Fluvisol in the system of the World Reference Base [11]. A cropping sequence is followed consisting during the last ten years of potatoes, winterwheat, onions, sugarbeet, maize and again potatoes, maize, onions, sugarbeet, and winterwheat. Covercrops, consisting of clover and mustard, are usually grown after wheat and onions. Winterwheat provides plant-covered soil in winter. The farmer is aware of possible soil compaction when soils are wet in fall and spring and occasionally in summer. He uses tires with a width of one meter on their tractors to decrease pressure exerted on the soil and they have devised innovative systems to remove potatoes and sugarbeet from the field during harvest without driving on the land with tractors and trailers. This had a favorable effect on soil structure and the associated rooting depth, thereby decreasing the negative impact of dry periods on crop growth. Particular attention is being paid to the application of fungicides and herbicides considering their potential negative effect on environmental quality. Emphasis is on the application of several biocides targeting specific fungi and weeds, avoiding relatively high applications of standard biocides, which is more common. AscraXpro and Trimaxx were used to combat fungi, applying low concentrations of less than one liter/ha. Weeds were treated with Atlantis Star, Capri-Twn, Traton, U46MCPA, all at low concentrations of less than 0.1 kg/ha (see also

Table 1. Results of soil analyses of chemical compounds associated with biocides and pesticides applied in 2023 on the studied field of the living lab. Methods used are part of the quantitative multi-pesticide screening GC-MSMS, except for Priothioconazool: GC-MSMS+LC-MSMS.

Crop Protection 2023	Product	Active Ingredient	Reporting Limit, mg/kg	Result, mg/kg
Biocides	Ascra Xpro	Fluopyram	0.01	<0.01
		Bixafen	0.01	<0.01
		Prothioconazool	0.01	<0.01
	Trimaxx	Trinexapac-ethyl (175 g/L)	0.01	<0.01
Herbicides	Lontrel	Clopyralid	0.5	<0.5
	Atlantis star	Iodosulfuron-methyl-natrium	0.01	<0.01
		Mesosulfuron-methyl	0.01	<0.01
		Thiencarbazon-methyl	0.01	<0.01
	Capri twin	florasulam, pyroxsulam	0.01	<0.01
	Traton	Metsulfuron-methyl	0.02	<0.02
		Tribenuron methyl	0.02	<0.02
	U46 MCPA	MCPA	0.01	<0.01

).

Research was focused on one field of the farm, where wheat had been grown most recently, as testing of operational methodology was the main aim of this study. Sampling was carried out in the fall of 2023. To be shown later, this field satisfies all indicators. If the same applies to all fields, this living lab will qualify as a lighthouse.

2.3. Methods to Assess Indicators and Threshold Values of Ecosystem Services

Two considerations have guided the assessment of indicators and threshold values in this study. (i) A recent Dutch study [12] defined environmental conditions in the twelve provinces of the Netherlands and listed necessary emission reductions, as required by current environmental regulations. Conditions differ significantly among the provinces and the province of Flevoland, where our living lab is located, has overall favorable environmental conditions. This regionalized approach is in agreement with the recent proposal by the European Commission to define environmental goals for “districts” with relatively homogeneous climate and soil conditions [3] and (ii) consideration of the proportionality principle, implying that the degree of attention for certain items should be in balance with its significance; attention should be focused on items that have a truly significant impact on environmental conditions.

The various ecosystem services to be considered are shown in Figure 1.

Crop yields and economic data for the living lab were assembled for a period of 11 years, covering ecosystem services associated with SDG1 and 2. Agricultural production levels are compared with levels obtained elsewhere in the country and thresholds will thus have an empirical character. Farmers’ income is compared with national statistics and has a confidential character based on the opinion of a particular farmer. The presence of soil pollutants was investigated with standard chemical methods to determine contents of heavy metals and corresponding thresholds were defined [13] (SDG3). The occurrence of pesticides was established by the Quick Polar Pesticides (QuPPe) method [14] (https://eurl-pesticides.eu (accessed on 10 May 2024)). Groundwater and open surface water quality was measured following requirements of the EU Water Guideline [15]. The chemical indicator for groundwater is the nitrate concentration with a threshold of 50 mg/L NO₃⁻/L. For surface waters, N-total and P-total are considered, with thresholds of 4 mg/L and 0.3 mg/L, respectively. Biological indicators use the EKR score (Ecological Quality Ratio): water flora, macrofauna, and fish, all with thresholds of 0.50. Open surface water occurred at a distance of 6.6 km from the living lab, which is part of one of 19 “sections” in Flevoland where water quality is periodically being measured by the provincial Water Board (www.zuiderzeeland.nl (accessed on 10 May 2024)). The chemical composition of drain outflow in the fall was measured with standard techniques to assess possible leaching of agrochemicals in ditches surrounding fields, even though direct links with open water were absent (SDG6). Energy consumption (SDG7) is an example where, again, the proportionality principle applies. Total energy use in the Netherlands was estimated to be 2939 pJ in 2019 (www.cbs.nl, accessed on 10 May 2024). Of this, agriculture, forestry, and fisheries used 178 pJ (6% of the total), leaving an estimated 4% for agriculture. The remaining 94% is used by industry, energy generation, traffic, households, and construction. Farmers already restrict use of their machinery because of high fuel costs, while most now have sun collectors on their roofs generating green energy. When restricting energy use at the national level, agriculture is not, nor should it be, a prime target, and this SDG will not be further pursued here. Emissions of greenhouse gases CH₄ and N₂O in Flevoland were estimated following [16]. CO₂ emissions were estimated by the Soil Carbon Check in terms of soil basic respiration [17].

Biodiversity, one element of SDG15, is considered in a regional context, and no clear indicators, let alone thresholds, are as yet defined that apply to farms, acting as living labs. In the context of the European NATURE2000 program, 162 nature areas have been proposed for the Netherlands (www.nature2000.nl, accessed on 5 April 2024) and the nearest one for the living lab being studied is 6.6 km away. As the prime responsibility of any agricultural living lab is to avoid the release of pollutants to air and water that can reach nature areas, the level of their release can be considered as a measure for their contribution to the preservation of regional biodiversity.

2.4. Methods to Assess Soil Health

Soil health assessment (part of SDG15) was based on measuring twelve indicators, including the erosion rate, as recently proposed by the European Monitoring and Resilience Guideline [3], summarized in three categories in Figure 2 with soil carbon in a central position.

The indicators are based on the needs of growing roots that directly reflect the relation of growing plants with the soil, and the erosion rate, which is indirectly relevant, will therefore be considered separately. The following three soil health categories are considered: (i) physical aspects of soil health (e.g., electrical conductivity, soil structure, and soil moisture regime); (ii) chemical aspects of soil health (soil fertility, pollutants); (iii) biological aspects of soil health (soil biodiversity); and in a central position, (iv) carbon (carbon content and various carbon compounds).

Physical aspects of soil health focus on electrical conductivity (EC), soil structure, and moisture regimes. EC is particularly relevant for salty soils and is not relevant for this living lab. Soil structure is usually determined by standard bulk density and penetration measurements [18]. Field observations during this investigation showed, however, that soil structures in surface soil were highly heterogeneous, resulting in inconclusive variable data when applying standard methods. A guiding principle of soil health assessment should be the observation of rooting patterns reflecting the reaction of growing plants to soil conditions and such observations were made. The soil moisture regime, corresponding with “soil water holding capacity” in [3], is commonly defined in terms of the static “available water” concept expressing the water content between “field capacity” (−0.3 bar) and wilting point (−15 bar). These two values vary, however, significantly among different plants and soils and cannot reflect possible upward movement of water from the groundwater to the rootzone. “Available water” for Dutch conditions was defined by distinguishing easily available water (between pressure heads of −0.1 bar and 0.4 bar) and less available water (between −0.4 bar and −16 bar) [19]. Introduced in the 1930s [20], the static concept of “available water” can now and should be improved by dynamic modeling of the soil water regime, as defined for major soils in the Netherlands [19,21]. Chemical aspects of soil health cover plant nutrients and pollutants. Fertilization recommendations follow standard procedures that are widely applied. Soil pollution was assessed by applying methods to measure bioavailability of heavy metals [13]. Particular attention was paid to the occurrence of pesticide remnants in soil that could be subject to leaching to groundwater and surface waters [14]. Biological aspects of soil health were characterized in terms of soil biodiversity measured by modern sensing techniques, based on the PLFA (Polylipid Fatty Acids) methodology, with threshold values derived from the literature [22,23,24,25,26]. As discussed for SDG13, calculated soil mineralization rates by the Soil Carbon Check define basic soil respiration, expressing soil respiration as another measure for soil biodiversity [3]. Carbon content was defined by the organic matter content as measured by new sensing methodology, defined by the Soil Carbon Check [17,27].

3. Results and Discussion

3.1. Ecosystem Services Provided

SDG1: The farmer running the living lab considered his income to be satisfactory, as it was higher than the average yearly income of Dutch farmers in 2020 of EUR 56,700 before taxes, as reported by the Dutch Bureau of Statistics. SDG2 and 3: Production levels of the various crops grown during the last ten years, comparing yields with average yields (gross values) for the entire country, are as follows: ware potatoes 65 vs. 50 tons/ha; winterwheat 10 vs. 9 tons/ha; sugarbeet 125 vs. 90 tons/ha; onions 50 vs. 50 tons/ha. Crop yields obtained at this living lab were clearly significantly higher for most crops as compared with national averages. This confirms the general opinion that young clayey Flevoland soils have a very high agricultural quality. Soil pollution received particular emphasis in this study, as high contents of heavy metals and pesticides are currently a major concern for arable soils, as they may adversely affect production levels and groundwater and surface water quality. Chemical analyses of heavy metals showed contents below detection level for bioavailable levels of Cd, Cr, Cu, Ni, Pb, Zn, As, Hg, Sn, and Ti, indicating that soil pollution by heavy metals does not present a problem, even though champost is applied regularly and strict control of its composition has apparently avoided possible pollution. Also, remnants of pesticides have not been found above detection levels (Table 1). This has been achieved by selective application of several low-concentration fungicides and herbicides aimed at particular fungi and weeds.

Absence of pollutants in soil will allow the growth of healthy crops. Together with high yields, this allows a positive judgement for SDGs 1, 2, and 3.

SDG6: Groundwater had a measured average low nitrate (NO₃⁻) content of 6 mg/L and <1.3 mg P/L, which are both well below current thresholds. The average nitrate content in percolating water below the rootzone in Flevoland is 20 mg/L, where only 4% of the groundwater has nitrate concentrations above the threshold of 50 mg/L [12]. The proportionality principle applies. Groundwater pollution is not a serious issue here, in stark contrast with other (often sandy) areas in the country. When considering surface water quality, we note that this living lab is far removed from both major surface waters and nature areas (both 6.6 km). This NATURE 2000 area is no. 77, Eemmeer and Gooimeer. The nearest surface water monitoring location of the Flevoland Water Board, at 6 km distance (Wielse Tocht), showed N-total of 4 mg/L (threshold 4.2 mg/L) and P-total of 0.3 mg/L (threshold 0.23 mg/L). The EKR score (the Ecological Quality Ratio) was 0.52 for water flora (threshold 0.50), 0.44 for macrofauna (threshold 0.50), and 0.47 for fish (threshold 0.50). Values are below or near thresholds and are considered to be adequate. However, these values have little relevance for the living lab being considered and only serve here to provide a regional context. The conclusion is a positive judgement for SDG6.

SDG13: Detailed analyses of soil carbon by the Soil Carbon Check show that the topsoil contains 3.9% organic matter (SOM). For these soils, the median SOM value is 3% (https://www.broloket.nl, accessed on 20 May 2024) and that value can act as a threshold, showing that soils in the living lab exceed the threshold. The actual carbon content can be transformed by the Soil Carbon Check into 73,480 kg C/ha (equivalent to 270 tons CO₂/ha). Yearly mineralization is estimated at 2065 kg C/ha (equivalent to 7 tons CO₂/ha) and this quantity needs to be added each year to maintain the C level. This is achieved, as every year, on average, 20 tons/ha cattle slurry manure (produced by cows and pigs) is added, in addition to 8 tons/ha of compost or champost (derived from growing mushrooms). The reported mineralization rates calculated by the Soil Carbon Check represent soil basic respiration, as required by the EU Soil Monitoring and Resilience protocol [3].

Emissions of greenhouse gases CH₄ and N₂O in Flevoland are, together with the province of Zeeland, the lowest of all provinces in the Netherlands (SDG13) [12]. On a national level, total emissions of greenhouse gases are estimated (2019 data) to be 160 Mton CO₂ eq/yr (www.emissieregistratie.nl, accessed on 20 May 2024). Most of this (84%) is generated by industry, electricity generation, traffic, and construction. At 26 Mton CO₂ eq/yr, agriculture contributes 15% of the total. But of that quantity, only 8 Mton is attributed to CO₂ (5% of the total), while CH₄ and N₂O contribute 18 Mton (11% of the total). Methane emission is particularly associated with dairy farming and is not relevant for arable farms like the living lab being considered, while N₂O emissions are also low in the well-drained soils found here. On a national level, CO₂ emissions in arable farming are therefore very low, at 5% of the total. This is confirmed for arable land on clay soils in the LULUCF analysis on greenhouse gas emissions reporting to the International Panel on Climate Change [16]. Again, in terms of proportionality, greenhouse gas emissions in the living lab being considered are not a primary target for environmental concern. The conclusion is a positive judgement on SDG13.

SDG15: biodiversity of a particular living lab should be considered in a broader geographic context. Cover crops are part of the management scheme of the living lab. Various forms of green manure are part of the cropping sequence; after onions and sugar beet, winterwheat is sown, and after winterwheat and onions, clover and yellow mustard act as green manure. Overall, the soil is covered by either crops or green manure for approximately 70% of the year on average, in winter and spring. The land is flat, so in contrast to sloping land, lateral erosion (which is reduced by continuous crop coverage) is not a problem. Substantial land cover by green manure can be seen as a contribution to biodiversity. But lack of harmful discharges from this farming system to air, water, and soil (as documented in this study) can serve in addition as a positive contribution to maintaining biodiversity beyond this living lab. Emissions of ammonia (NH₃) followed by deposition in nature areas can be harmful for biodiversity, but this process is limited to farms with cattle, pigs, and chickens that are present in other parts of the country and not in Flevoland, with dominant arable farming. A number of initiatives for improving biodiversity on the farm level have been proposed, including narrow bands with flowers and herbs along fields, widening crop rotations, and mixed cropping. These measures can be applied when they fit into particular management schemes of farmers, as do crop rotations and mixed cropping in this living lab. Such management measures should, however, in our view, not be requirements as part of formal rules or regulations, as their effect on different soils and locations may vary significantly. Regulatory emphasis should be on reaching thresholds of indicators and preferably not on the means to reach these thresholds.

3.2. Soil Health Assesment

Three sets of indicators are considered for soil health, the other element of SDG15 [3,6]. Considering physical aspects of soil health, electrical conductivity (EC) was 0.56 dS/m, well below the EU threshold of 4 dS/m. This soil is not saline. Soil structure could not be characterized by applying standard methods for bulk density and penetration resistance because of soil heterogeneity. Field observations during this investigation showed that soil structures in surface soil were highly heterogeneous; loose fragments were mixed with relatively dense fragments, and taking relatively small samples for bulk density measurements and penetration resistance results in a wide variety of values without any predictive quality. A guiding principle of soil health assessment should be the observation of rooting patterns reflecting the reaction of growing plants to soil conditions. Observations showed that roots were concentrated in the loose fragments in surface soil and locally penetrated a relatively dense layer from 30 to 50 cm. Below that depth, root growth proliferated to 80 cm, providing necessary moisture to growing plants. This condition does not correspond with the traditional concept of a homogeneous “effective rootzone”, as used in plant growth modeling, and that is why the 80% Yw rule, referring to “water-limited yield Yw”, to estimate thresholds for the production level, cannot be applied here, except when rooting heterogeneity can be expressed by the model [28]. The thickness of the rootzone is also important when estimating the traditional volume of “available water” as an expression for the ”soil water regime” [3]. Rooting to 80 cm depth corresponds with a high volume of 175 mm “available water” in this soil [19]. This quantity can be judged by comparison with “available water” for the same soil type with a possibly different % organic matter content or with compacted layers, as the soil health concept is focused on a given soil type, which most likely has been subjected to different forms of management. This was, for example, demonstrated by modeling plant production for six Italian soils, including an assessment of the effects of climate change that can only be obtained with exploratory modeling [29]. This modeling approach was not applied in this study. Particularly, the lack of severe compaction, stopping root development, and the observed deep rooting, as well as the high organic matter %, indicate that the required indicator “soil moisture regime” (represented by the proxy value of “available water”) is positive for this living lab.

Considering chemical aspects of soil health, soil fertility was based on the fertilizer recommendations of the “soil health indicator” [27]. Commercial soil testing is applied by 85% of Dutch farmers as a tailor-made contribution to management practices, defining not only fertilization rates of the macronutrients N, P, and K but also micro-nutrients, when relevant [27]. Sampling is carried out at the start of the growing season and additional, identical measurements in the context of a soil health determination would be redundant and not meaningful. In our view, farmers will satisfy soil health requirements for plant nutrients if they apply fertilization recommendations received. This approach is more realistic than requiring independent and separate large sets of chemical determinations, as proposed elsewhere [30,31]. The US National Soil Health Institute initially also required more than twenty indicators, but has now reduced the number to three, covering carbon content and dynamics and aggregate stability [32], implicitly assuming that fertility management is handled by standard procedures. Considering biological aspects of soil health, soil biodiversity received particular emphasis by measuring microorganisms with the PLFA procedure, as shown in Figure 3. All values for the living lab soil were either very close to or below general thresholds. The presence of a number of microbial populations indicates the biodiversity of this particular soil. We do not propose that the PLFA analysis should now be applied in standard procedures, but results are shown here to demonstrate that these data are easily obtained with an innovative methodology and can play a role when further developing the soil biodiversity concept in future. Considering carbon, the organic matter content of the soil was 3.9%, while 3.0% can be considered as a threshold.

Overall, the conclusion can be that this soil is healthy.

3.3. Providing a Clear and Operational Procedure Aimed at Meeting the SDGs

During our joint living lab research, the general concept of sustainable development was transformed from a top-down policy-oriented set of complicated and confusing environmental rules and regulations (as experienced by the farmer-owner of the living lab and his colleagues) into concrete goals for a number of ecosystem services with associated indicators and thresholds. Also, a selective focus on key SDGs, followed by applying the proportionality principle, reduced distracting complexity, the latter by identifying which SDGs were most limiting at the living lab being studied. In this context, a Dutch regional study [12] was helpful and in line with the recommendation of the European Union to focus on districts [3]. Following this procedure, a largely all too often negative and reactive approach by the stakeholders involved to top-down rules and regulations could be changed into a pro-active attitude producing inspiring and positive results. The joint action between researchers and the farmer resulted in mutual engagement and commitment.

As the primary objective of this research was to develop and test operational procedures for assessing ecosystem services and soil health, results refer to one field of the living lab. This living lab will become a lighthouse when other fields of the farm also show a positive score.

3.4. Future Research Needs

This project has demonstrated that, focusing on agriculture, methods are available to measure and estimate most indicators and threshold values for a series of important ecosystem services in line with six SDGs. Application of new methods, based on innovative sensing techniques, as illustrated in this study, will allow more rapid and numerous soil measurements. There are, however, still questions about the character of two ecosystem services that apply to this particular living lab study. (i) Contributions of particular living labs or lighthouses to the quality of surrounding surface waters (SDG6) still need to be better defined, certainly when farms are found at substantial distances from open water and nature areas. (ii) The assessment of contributions by living labs and lighthouses to regional biodiversity needs more attention. Avoiding pollution of air, water, and soils is at this point in time a realistic proxy to express indirect positive contributions to external biodiversity in a regional context. Regional biodiversity is currently being judged in the Netherlands by comparison with ecosystem conditions as measured in the past. The latter is increasingly unsuitable as a reference, if only because of the effects of climate change. What will nature be like in 2050 and should current judgements not consider that? Finally, our study also demonstrates that methods, including modeling, should not be applied automatically without carefully observing field conditions. An example was the study of soil structure, as part of soil health. The traditional methods of measuring bulk density and penetration resistance did not work because of the high structural heterogeneity of surface soil. Only on-site observations allowed the conclusion that roots reached the subsoil through preferred pathways allowing a positive judgement on soil structure. Also, lack of an “effective rootzone” did not allow application of current crop simulation models. Developing methods to characterize root activity in vertically heterogeneous rooting systems needs attention.

3.5. A Way to Deal with “Wicked” Problems

The types of problems being encountered in this study are considered to be “wicked” in the sense that, at first sight, in agriculture, “clear solutions are lacking due to divergent values of stakeholders and problems being embedded within wickedly complex environments” [4]. Many research papers have been published struggling with the “wicked” concept, which is rather discouraging, as the literature does not seem to suggest ways to deal with divergent values and complex environments. Introducing the SDG focus in the agricultural context, “stakeholder values” become clear and specific in an environment where “complexity” is replaced by a number of separate and clear goals with indicators and thresholds. This provides clarity. Sometimes the role of stakeholders is mentioned when addressing “wicked” conservation issues [33], but otherwise, the “wicked” issue is usually restricted to the policy level [34], while stakeholder engagement is crucial when reaching successes in the real world. The role of the SDGs is sometimes mentioned when facing “real-world research”, but then, stakeholders are omitted [35]. Introducing an SDG focus emphasizing the role of stakeholders can enlighten the “wickedness” concept by showing a way to deal with complexity.

3.6. Links with the Policy Arena

A link with the policy arena can be made through agricultural subsidies, among them those provided by the EU Common Agricultural Policy (CAP). Such a link can be based on achieving essential ecosystem services, as discussed in this paper. Following the “one-out-all-out” principle, lighthouses would qualify, and farmers would receive financial support. This means that a positive judgement is only obtained when all indicators are positive, and when some do not meet their threshold, their identification can guide new research. Farmers that try to improve certain indicators that do not yet meet their threshold deserve to be financially supported as well. Farmers that are not interested would receive nothing.

3.7. Soil Health Contributing to Ecosystem Services

The common expression “soil ecosystem services” is misleading, as it suggests that only soils are related to such services. Agricultural production (SDG2) is, of course, also based on a wide variety of agronomic expertise, while hydrologists have major input in assessing water quality (SDG6). Climate mitigation (SDG13) is, again, strongly affected by climatological data and agronomic management, while biodiversity (SDG15) is primarily based on ecological input. Soil health contributes separately to SDG15 and certainly plays an important role when assessing the other SDGs. But farmers will, and rightly so, receive financial support for achieving ecosystem services rather than for achieving soil health. The soil science profession (and this applies to other scientific disciplines as well) would be well advised to, rather than pontificate about the importance of their own profession, clearly focus on strengthening and documenting their contributions to interdisciplinary programs assessing ecosystem services in line with the SDGs.

4. Conclusions

• Providing a focus on ecosystems in line with the SDGs provides clarity to farmers and allows a direct connection with the international policy arena beyond professional bubbles. Defining relatively simple, but scientifically sound, indicators and thresholds for ecosystem services can be the basis for a transparent regulatory system and can justify subsidies that act as payment for provided societal services.
• Realization in practice of whatever science-derived scheme is being adopted by the policy arena depends on whether or not it is being accepted and applied by farmers when dealing with agriculture. There is now a serious lack of trust between the policy and practice arenas that can be diminished by scientists and practitioners working jointly in living labs.
• The ultimate success of the SDG effort in agriculture will depend on realizing a series of “living labs” in a given area with particular soil types focusing on realizing “lighthouses”, thereby creating a crucial feeling of ownership for the farmers.
• The case study showed, on the one hand, that several indicators could be defined using standard methodology and concepts, while innovative cutting-edge methodology added attractive new opportunities for rapid and relatively cheap characterizations. Field work remains essential, however, to check modeling assumptions.
• Soil science plays a key role when contributing to all ecosystem services. Showing this with specific examples in a “living lab/lighthouse” context is the best way to promote the profession, which is needed to justify current major funding of soil science research. Defining threshold values of ecosystem services should have high priority in future soil research. Cutting-edge research is not the only thing that can contribute to defining indicators and thresholds. More than a hundred years of research has produced many valuable insights and methodologies that can be applied as well. The “better” can be the enemy of the “good”. The sustainable development issue is highly urgent; there is no time to lose anymore!