Hostname: page-component-848d4c4894-jbqgn Total loading time: 0 Render date: 2024-06-19T07:24:04.392Z Has data issue: false hasContentIssue false

Moving conservation agriculture from principles to a performance-based production system

Published online by Cambridge University Press:  15 March 2024

Stéphane Cordeau*
Affiliation:
Agroécologie, INRAE, Institut Agro, Univ. Bourgogne, Univ. Bourgogne Franche-Comté, F-21000 Dijon, France
*
Corresponding author: Stéphane Cordeau; Email: stephane.cordeau@inrae.fr
Rights & Permissions [Opens in a new window]

Abstract

Conservation agriculture (CA) is an approach to farming that is defined by three principles: (1) minimal soil disturbance (no-till), (2) crop diversity in time and space, and (3) soil coverage by crop residues and/or cover crops. These principles provide a roadmap to protect and improve soil. However, the narrow criteria for defining CA may fail to account for tradeoffs between soil health and other ecosystem services. A literature review of meta-analyses dealing with CA and an online survey in France were conducted to explore the implementation and performances of CA. Research on CA systems has focused on crop productivity and soil quality whereas research on other dimensions of cropping system sustainability are lacking. The effects of CA on other aspects of sustainability such as biodiversity and profitability are less prevalent in the literature. The online survey results show that 63% of respondents thought that CA helps reduce pesticide use, 91% that CA improves water use efficiency, and 77% that CA helps to store carbon and achieve the objectives of the 4 per 1000 international initiative. Given the prevalence and widespread support for CA, we advocate for moving CA from its current definition based on the means toward a definition that includes performance-based metrics that address different ecosystem services. CA has potential to help address challenges associated with climate change, biodiversity loss, and water pollution, but opportunities may be missed without developing performance targets that go beyond soil conservation.

Type
Commentary
Creative Commons
Creative Common License - CCCreative Common License - BY
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.
Copyright
Copyright © The Author(s), 2024. Published by Cambridge University Press

Introduction

Although highly productive, intensive agriculture that has been promoted and adopted over the past decades is associated with major environmental problems. Between 1985 and 2005, crop yields increased considerably worldwide: 34% for cereal crops, 57% for oilseeds, and 11% for forage crops (Faostat, Reference Faostat2020). Factors responsible for increasing crop productivity are now being questioned for their environmental impacts (Tilman et al., Reference Tilman, Cassman, Matson, Naylor and Polasky2002; Stoate et al., Reference Stoate, Báldi, Beja, Boatman, Herzon, Van Doorn, De Snoo, Rakosy and Ramwell2009). The leaching, runoff, and volatilization of agricultural inputs (i.e., nitrogen and phosphorus fertilizers, pesticides), for example, have led to water and air pollution in many parts of the world (Stoate et al., Reference Stoate, Boatman, Borralho, Carvalho, Snoo and Eden2001). The recent French INRAE-IFREMER report on the impact of pesticides on biodiversity and ecosystem services confirms that many terrestrial, aquatic, and marine environments—particularly coastal ones—are contaminated by pesticides (Mamy et al., Reference Mamy, Pesce, Sanchez, Amichot, Artigas, Aviron, Barthélémy, Beaudouin, Bedos, Bérard, Berny, Bertrand, Bertrand, Betoulle, Bureau-Point, Charles, Chaumot, Chauvel, Coeurdassier, Corio-Costet, Coutellec, Crouzet, Doussan, Douzals, Fabure, Fritsch, Gallai, Gonzalez, Gouy, Hedde, Langlais, Le Bellec, Leboulanger, Margoum, Martin-Laurent, Mongruel, Morin, Mougin, Munaron, Nelieu, Pélosi, Rault, Ris, Sabater, Stachowski-Haberkorn, Sucré, Thomas, Tournebize, Achard, Le Gall, Le Perchec, Delebarre, Larras and Leenhardt2022). The eutrophication of water bodies due to excessive nitrogen and phosphorus fertilization in Europe has increased purification costs and caused low-oxygen conditions that endanger aquatic biodiversity, fisheries, and recreational sites (Diaz and Rosenberg, Reference Diaz and Rosenberg2008; Canfield, Glazer, and Falkowski, Reference Canfield, Glazer and Falkowski2010). In France, some river basins have already exceeded the maximum concentration of active substances authorized for water purification purposes (Dubois and Lacouture, Reference Dubois and Lacouture2011). Water resources are becoming increasingly scarce. For example, 20% of irrigated land in the United States is fed by groundwater pumped in excess of recharge (Postel, Reference Postel2014). The combined effect of intensive input use (pesticides, fertilizers, irrigation) and landscape simplification has led to a dramatic decline in farmland biodiversity in various parts of the world (Donald, Green, and Heath, Reference Donald, Green and Heath2001; Fried et al., Reference Fried, Petit, Dessaint and Reboud2009; Sánchez-Bayo and Wyckhuys, Reference Sánchez-Bayo and Wyckhuys2019). Reversing these deleterious trends represents a colossal challenge and agriculture is facing one of the greatest challenges of the 21st century: providing enough quality food while reducing environmental impacts and ensuring a decent living for farmers.

Conservation agriculture: principles first and foremost

Initiated in the United States in the 1950s to limit soil erosion in response to the ‘dust bowl’ episodes that destroyed hundreds of thousands of hectares of cultivated soil in the central United States in the 1930s, adopted in Europe in the 1960s and in Latin America in the 1970s (Derpsch, Reference Derpsch1998), soil conservation techniques and efforts have evolved into conservation agriculture (CA). According to the FAO, CA is a farming system or production strategy defined by the simultaneous and permanent implementation of three principles, also called principles (FAO, 2021): (i) no-till (no soil disturbance except by a light tine or disc during sowing); (ii) crop diversity in time (crop sequence, rotation) and space (intercropping, companion plants); and (iii) maximum soil coverage by crop residues or sown cover crops (annual or permanent cover).

This definition emphasizes that CA is defined above all by the technical means implemented (i.e. the three principles), which are described in greater detail in numerous writings and contextualized according to regions of the world (Kassam et al., Reference Kassam, Friedrich, Shaxson and Pretty2009; Kassam and Friedrich, Reference Kassam and Friedrich2011; Friedrich, Derpsch, and Kassam, Reference Friedrich, Derpsch and Kassam2012; Kassam, Friedrich, and Derpsch, Reference Kassam, Friedrich and Derpsch2019). Thus, CA systems are defined as those in which no mechanical disturbance of the soil is carried out except by the seed drill (less than 15 cm wide or 25% of the cultivated area), which grow more than three different crop species pure or in a mixture (of variety or species), and which cover at least 70% of the soil surface with stubble, crop residues or dead or living cover crops at the time of sowing (Kassam, Friedrich, and Derpsch, Reference Kassam, Friedrich and Derpsch2019). CA systems combine a diverse set of agricultural management practices (e.g., rotation, cover, sowing, fertilization, weeding) which may change as the system evolves (Knowler and Bradshaw, Reference Knowler and Bradshaw2007; Vankeerberghen and Stassart, Reference Vankeerberghen and Stassart2016; Derrouch et al., Reference Derrouch, Chauvel, Felten and Dessaint2020). Stopping tillage (such as ploughing, false seeding practices, mechanical weeding) reduces traction time, fuel consumption, labor (West and Marland, Reference West and Marland2002; Kertész and Madarász, Reference Kertész and Madarász2014; Adeux et al., Reference Adeux, Munier-Jolain, Courson, Guinet, Lecaulle and Cordeau2022), and soil compaction (Raper, Reference Raper2005). However, not all crops and not all soil and climate conditions are suitable or optimal for no-till (e.g., industrial crops such as sugar beet or potatoes), and require the maintenance of shallow tillage for their establishment (e.g., ridging), with harvesting also disturbing the soil. The abandonment of these crops on a farm may have economic consequences and/or require the restructuring of farming equipment. For all the reasons outlined above, it remains very difficult to assess on a global scale the areas actually under CA as defined precisely by the FAO (FAO, 2021), despite the existence of surveys in certain countries (Baker, Collins, and Choudhary, Reference Baker, Collins, Choudhary, García-Torres, Benites, Martínez-Vilela and Holgado-Cabrera2003; Knowler and Bradshaw, Reference Knowler and Bradshaw2007; Kassam et al., Reference Kassam, Friedrich, Shaxson and Pretty2009; Lahmar, Reference Lahmar2010; Friedrich, Derpsch, and Kassam, Reference Friedrich, Derpsch and Kassam2012; Kertész and Madarász, Reference Kertész and Madarász2014; Kassam, Friedrich, and Derpsch, Reference Kassam, Friedrich and Derpsch2019).

Other dimensions of cropping system sustainability than crop productivity and soil quality are lacking

A systematic review of all the meta-analyses published on CA worldwide was conducted using the Web of Science and Scopus databases with the adapted keywords and their relatives: conservation agriculture, no-till, crop diversification, soil cover, meta-analysis, systematic review, meta-regression. A total of 31 meta-analyses published from 2015 to 2022 were identified that fit the selection criteria (Table 1). These meta-analyses highlight that the effects of CA systems on crop productivity and soil quality (e.g., carbon sequestration, soil structure, soil biological activity) have largely been studied in isolation without considering other dimensions of cropping system sustainability (Table 1).

Table 1. Indicators identified in the 31 meta-analyses identified in the scientific literature that synthesized the effects of conservation agriculture with total and/or partial but simultaneous application of the three CA principles defined by the FAO (2021)

An in-depth analysis of the modalities compared in the meta-analyses highlighted the diversity of practices described by authors as CA-based practices, and resurrects the confusion between conservation tillage and CA (Reicosky, Reference Reicosky2015). Many authors define CA system as a system that implements only one of the principles defined by the FAO (FAO, 2021) (e.g., no-till), without necessarily specifying whether their implementation is permanent or temporary. It is also generally accepted in most meta-analyses that cropping systems involving the simultaneous but partial application of all the three principles can be qualified as CA (Scopel et al., Reference Scopel, Triomphe, Affholder, Da Silva, Corbeels, Xavier, Lahmar, Recous, Bernoux and Blanchart2013) (e.g., direct seeding on a diversified rotation involving at least three different crops with soil surface coverage of less than 30%, or diversified rotation involving at least three different crops with plant cover and occasional shallow tillage). Therefore, it remains difficult to identify meta-analyses that actually qualify a CA system, as the complete, simultaneous, and permanent application of all three principles, even though such cases do exist (Jat et al., Reference Jat, Chakraborty, Ladha, Rana, Gathala, Mcdonald and Gerard2020; Dong et al., Reference Dong, Si, Li and Zou2021). It also remains difficult in the scientific literature to quantify the effects of CA in general, as their evaluation requires the selection of plots that have already passed the transition phase estimated at 5–6 years (Chabert and Sarthou, Reference Chabert and Sarthou2020; Derrouch et al., Reference Derrouch, Chauvel, Felten and Dessaint2020) during which soil properties and farming practices evolve. In addition, farmers who are starting now to transition to CA are benefiting from the advices and experience of pioneering advisors and farmers. This makes difficult to use space-for-time substitution approach (Pickett, Reference Pickett and Likens1989) to assess long-term benefits of CA, even if this was done in some primary studies (Trichard et al., Reference Trichard, Alignier, Chauvel and Petit2013; Derrouch et al., Reference Derrouch, Chauvel, Felten and Dessaint2020, Reference Derrouch, Chauvel, Cordeau and Dessaint2021a, Reference Derrouch, Dessaint, Fried and Chauvel2021b). Indeed, farmers who now transition to CA know, for example, that time is required to adapt crop rotations (cash crops, companion crops, cover crops, intercrops) and to stop tillage. In addition, it is not unusual for CA farmers to be confronted in certain years with high pest pressure such as slugs (Scaccini et al., Reference Scaccini, Panini, Chiesa, Nicoli Aldini, Tabaglio and Mazzoni2020), voles (Ruscoe et al., Reference Ruscoe, Brown, Henry, Van De Weyer, Robinson, Hinds and Singleton2022) and/or weeds (Chauhan, Singh, and Mahajan, Reference Chauhan, Singh and Mahajan2012; Chauvel et al., Reference Chauvel, Derrouch, Munier-Jolain, Cordeau, Chauvel, Darmency, Munier-Jolain and Rodriguez2018; Derrouch et al., Reference Derrouch, Chauvel, Cordeau and Dessaint2021a) sometimes being resistant to herbicides (Gliessman, Engles, and Krieger, Reference Gliessman, Engles and Krieger1998; Sammons and Gaines, Reference Sammons and Gaines2014; Heap, Reference Heap2021). These high pest pressures can force farmers to contain these problems with occasional and more or less intensive tillage operations.

Given that the strict implementation of the principles is a difficult task, the entire agricultural community of stakeholders (e.g., farmers, advisors, scientists) maintains a vagueness and a gap between the official FAO definition (FAO, 2021) and the reality of its implementation, which makes difficult the assessment of benefits of CA, whether these benefits are quantified through scientific studies or survey.

Perception of conservation agriculture and its benefits/issues

Agriculture and the farmer are at the heart of many high-profile issues, both positive and negative, such as the use of pesticides and water/air pollution, the preservation of water resources, the emission of greenhouse gas, the need to supply food in quantity and quality, the limitation of soil erosion, the preservation of biodiversity, and the shaping of landscapes. In the media-saturated context, opinions on all these subjects are rife, and it is sometimes difficult to discern what we know or not, and to give credence to this or that statement, either read or heard. Yet scientific activity is not simply a matter of opinions that clash without ever converging. The body of knowledge we have on a subject is obviously evolving, it is not set in stone, but it is the result of a debate based on results we obtained using a scientific approach. Research results must therefore be debated before they become knowledge. But what does this have to do with CA?

CA was not initiated and promoted based on research work and scientific knowledge that would have postulated and converged to affirm that the joint implementation of the three principles (no tillage, plant cover, diversity of cultivated species) would have virtues, even if they pose difficulties. CA has been developed and implemented all over the world by farmers, practitioners, and pioneers, who have rethought farming systems beyond what was known and taught, or at least beyond what was being practiced. Through observation, they deduced empirical knowledge. These CA stakeholders grouped and exchanged as a community and play a very active role, either by increasing the amount of knowledge we have on CA, by circulating them, or simply by circulating ideas and opinions of others. Over the past decades, these observations have often collided with the boundaries of acquired scientific knowledge.

By building on a new and more holistic way of visualizing the agroecosystem, and by re-questioning each agricultural practice implemented and its underlying effects on the components of the agroecosystem (e.g., weeds, earthworms, micro-organisms, carbon and nitrogen cycles), CA has given rise to the expression of several well-known cognitive biases in the community of CA stakeholders (Klein, Reference Klein2020):

  • the tendency to give more credence to ideas/results we like than to ideas/results we do not like; a bias that manifests itself in the community of CA stakeholders when a research result—refuted by some or endorsed by others—comes to fuel scientific debates on CA, its virtues, and its shortcomings;

  • ipsedixitism (‘as soon as the master himself has said it, then there is no more discussion’), which means that a statement can no longer be questioned or debated as long as a person, who is recognized by some CA stakeholders as an expert has affirmed it, a bias also known as the ‘guru effect’ (Sperber, Reference Sperber2010);

  • utracrepidarianism, the tendency to speak confidently about subjects that one does not master completely and thoroughly, which is growing in the community of CA stakeholders as statements are repeated by word of mouth, losing along the way the elements of proof, explanation, or contextualization of the initial statement; and

  • trusting apparent evidence and personal intuition.

In order to compare the opinions of people related to agriculture to those not related to agriculture, we asked ten questions that come up frequently in discussions, field visits, conferences, and meetings with CA stakeholders to a random, non-representative panel of people in France, through the distribution of an anonymous online questionnaire on social networks, via various media, and mailing-lists, from 02/15/2023 to 03/24/2023. After indicating whether or not he/she works in the agricultural sector (farmers, engineers, advisors, technicians, or any activity related to agriculture), the respondent was asked to answer each question with the following choice: ‘I don't know’, ‘YES’, ‘Not so simple—rather YES’, ‘Not so simple—rather NO’, or ‘NO’.

The survey received 2739 responses, of which 2181 and 558 were related and non-related to agriculture, respectively, covering almost the whole territory of France (Fig. 1).

Figure 1. Distribution across France of the 2739 people who answered the online questionnaire about conservation agriculture.

The analysis of the responses provides a number of insights (Fig. 2). The proportion of people answering ‘I don't know’ to a question is higher among people non related to agriculture, for all questions. Sixty-two percent of respondents related to agriculture believe that occasional tillage in CA is not or rather not harmful to soil diversity (yes and rather yes answers). Fifty percent of respondents related to agriculture believe that CA is not impossible without glyphosate (answer no and rather no), and 45% of respondents related to agriculture believe that CA is impossible without glyphosate (answer yes and rather yes). Sixty-six percent of respondents related to agriculture believe that CA is possible under organic principles (yes and rather yes answers). Thirty-five percent of respondents related to agriculture do not know whether pesticides degrade more in CA fields, and 50% think that they do or rather do degrade more. Seventy-seven percent of respondents related to agriculture believe that CA helps to store carbon and achieve the objectives of the 4 per 1000 international initiative (yes and rather yes answers); 7% believe the opposite; 16% are undecided. Sixty-three percent of respondents related to agriculture believe that CA helps reduce pesticide use (yes and rather yes answers); 30% believe the opposite. Ninety-one percent of respondents related to agriculture believe that CA improves water use efficiency and saves water (yes and somewhat yes answers). Fifty-three percent and 69% of agricultural and non-agricultural respondents, respectively, believe that CA helps to provide better quality food (yes and rather yes answers); 21 and 22% of agricultural and non-agricultural respondents, respectively, are undecided. Eighty-three percent of respondents related to agriculture believe that CA helps maintain pollinators in agricultural landscapes (yes and somewhat yes answers). Eighty-seven percent of respondents related to agriculture believe that CA enhances biological regulation (yes and rather yes answers).

Figure 2. Proportion of respondents (N = 2739, expressed as % of 2181 or 558 respondents related and non-related to agricultural, respectively) to the ten questions asked about conservation agriculture (CA). Respondents were asked first whether they were related or not related to work in the agricultural sector (farmers, engineers, advisors, technicians, or any full or partial activity related to agriculture). The values in the bars correspond to percentage of respondents.

This survey shows clear-cut answers on certain aspects, surely reflecting field observations in some cases, or expectations in others. It also reveals gaps in knowledge, either due to a real lack of knowledge on the subject, or a failure to disseminate the knowledge acquired.

Toward conservation agriculture defined by objectives rather than means

According to Kassam, Friedrich, and Derpsch (Reference Kassam, Friedrich and Derpsch2019) the adoption of CA has increased because farmers are looking for a new paradigm to sustainably intensify crop production. They also report that the main factors behind the adoption of CA are very diverse. Although farmers adopting CA target some ecosystem services, many remain to be assessed and quantified (Craheix et al., Reference Craheix, Angevin, Doré and De Tourdonnet2016; Chabert and Sarthou, Reference Chabert and Sarthou2020; Adeux et al., Reference Adeux, Munier-Jolain, Courson, Guinet, Lecaulle and Cordeau2022). As seen earlier in the review of the meta-analyses, it is generally accepted in most meta-analyses that cropping systems involving the simultaneous but partial application of all the three principles can be qualified as CA. In practice, the strict implementation of the principles is a difficult task and the entire agricultural community of stakeholders maintains a vagueness and a gap between the official FAO definition (FAO, 2021) and the reality of its implementation, which makes difficult the assessment of benefits of CA.

It is probably not easy but necessary to define CA by the ecosystem services targeted rather than by the farming practices and the principles. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) designed the Ecosystem Service Assessment Support Tool (ESAST). It has been designed to provide guidance to users who are new to ecosystem services and need assistance in designing an effective assessment process. Five main steps can be carried out to (i) set the scene, (ii) identify the ecosystem services, (iii) the biophysical assessment, (iv) the valuation, and finally (v) put into practice (https://www.guidetoes.eu/index.html).

CA must be defined by assigned objectives and ecosystem services. The review of the meta-analyses (see above) provides an extended list ecosystem services and indicators to assess them (Table 1). Kassam, Friedrich, and Derpsch (Reference Kassam, Friedrich and Derpsch2019) mentioned a list of objectives that CA farmers are targeting when transitioning to CA. This may represent a starting list of ecosystem services targeted and assessed at the cropping system, farm, or landscape level:

  • − increase input factor productivity

  • − yield and total farm output

  • − improved sustainability of production and farm land

  • − better incomes

  • − timeliness of cropping practices

  • − ease of farming and reduction in drudgery

  • − clean water and atmosphere

  • − control of erosion and land degradation

  • − carbon sequestration

  • − rehabilitation of degraded agricultural lands

Indicators should be listed for each of these ecosystem services targeted as Palm et al. (Reference Palm, Blanco-Canqui, Declerck, Gatere and Grace2014) did on ecosystem services related to climate regulation, through carbon sequestration and greenhouse gas emissions, and regulation and provision of water through soil physical, chemical, and biological properties. These indicators would help to monitor the outcomes of CA.

The change proposed in the definition and the way to assess CA has major technical and financial barriers. However, this paradigm shift would allow us to glimpse the diversity of virtuous ways of producing, rather than continuing to try to fit systems (and the farmers who implement them) behind a strict definition that reality, pragmatism, and common sense constantly challenge.

Conclusion

The definition of CA given by the FAO (2021) provides a vision for the implementation of soil conservation practices into a system (Reicosky, Reference Reicosky2015) and defines CA by principles and not by the ecosystem services CA intend to deliver. Despite the clear definition provided by the FAO (Kassam, Friedrich, and Derpsch, Reference Kassam, Friedrich and Derpsch2019; FAO, 2021), CA remains difficult to characterize when we look at systems in their agricultural, climatic, and economic reality. Given the prevalence and widespread support for CA, we advocate for moving CA from its current definition based on the means toward a definition that includes performance-based metrics that address different ecosystem services (Palm et al., Reference Palm, Blanco-Canqui, Declerck, Gatere and Grace2014; Jayaraman et al., Reference Jayaraman, Dang, Naorem, Page and Dalal2021; Kassam and Kassam, Reference Kassam, Kassam, Kassam and Kassam2021). CA has potential to help address challenges associated with climate change, biodiversity loss, and water pollution, but opportunities may be missed without developing performance targets that go beyond soil conservation.

Competing interests

None.

References

Adeux, G., Munier-Jolain, N., Courson, E., Guinet, M., Lecaulle, S. and Cordeau, S. (2022) ‘Multicriteria assessment of conservation agriculture systems’, Frontiers in Agronomy, 4, p. 999960.CrossRefGoogle Scholar
Adil, M., Zhang, S., Wang, J., Shah, A.N., Tanveer, M. and Fiaz, S. (2022) ‘Effects of fallow management practices on soil water, crop yield and water use efficiency in winter wheat monoculture system: a meta-analysis’, Frontiers in Plant Science, 13, pp. 113.CrossRefGoogle ScholarPubMed
Baker, C.J., Collins, R.M. and Choudhary, M.A. (2003). ‘Factors affecting the uptake of no-tillage in Australia, Asia and New Zealand' in García-Torres, L., Benites, J., Martínez-Vilela, A. and Holgado-Cabrera, A. (eds) Conservation agriculture. Dordrecht: Springer, pp. 1320. https://doi.org/10.1007/978-94-017-1143-2_2CrossRefGoogle Scholar
Basche, A.D. and Delonge, M.S. (2019) ‘Comparing infiltration rates in soils managed with conventional and alternative farming methods: a meta-analysis’, PLoS ONE, 14, pp. 122.CrossRefGoogle ScholarPubMed
Bohoussou, Y.N.D., Kou, Y.H., Yu, W.B., Lin, B.J., Virk, A.L., Zhao, X., Dang, Y.P. and Zhang, H.L. (2022) ‘Impacts of the components of conservation agriculture on soil organic carbon and total nitrogen storage: a global meta-analysis’, Science of the Total Environment, 842, p. 156822.CrossRefGoogle ScholarPubMed
Bowles, T.M., Jackson, L.E., Loeher, M. and Cavagnaro, T.R. (2017) ‘Ecological intensification and arbuscular mycorrhizas: a meta-analysis of tillage and cover crop effects’, Journal of Applied Ecology, 54, pp. 1785–93.CrossRefGoogle Scholar
Canfield, D.E., Glazer, A.N. and Falkowski, P.G. (2010) ‘The evolution and future of Earth's nitrogen cycle’, Science, 330, pp. 192–6.CrossRefGoogle ScholarPubMed
Chabert, A. and Sarthou, J.-P. (2020) ‘Conservation agriculture as a promising trade-off between conventional and organic agriculture in bundling ecosystem services’, Agriculture, Ecosystems & Environment, 292, p. 106815.CrossRefGoogle Scholar
Chauhan, B.S., Singh, R.G. and Mahajan, G. (2012) ‘Ecology and management of weeds under conservation agriculture: a review’, Crop Protection, 38, pp. 5765.CrossRefGoogle Scholar
Chauvel, B., Derrouch, D., Munier-Jolain, N. and Cordeau, S. (2018). ‘Gestion de la flore adventice en semis direct sous couvert’ in Chauvel, B., Darmency, H., Munier-Jolain, N. and Rodriguez, A. (eds) (Coord.) Gestion durable de la flore adventice des cultures. Versailles, France: Éditions Quæ, pp. 207–20.Google Scholar
Cooper, J., Baranski, M., Stewart, G., Nobel-De Lange, M., Bàrberi, P., Fließbach, A., Peigné, J., Berner, A., Brock, C., Casagrande, M., Crowley, O., David, C., De Vliegher, A., Döring, T.F., Dupont, A., Entz, M., Grosse, M., Haase, T., Halde, C., Hammerl, V., Huiting, H., Leithold, G., Messmer, M., Schloter, M., Sukkel, W., Van Der Heijden, M.G.A., Willekens, K., Wittwer, R. and Mäder, P. (2016) ‘Shallow non-inversion tillage in organic farming maintains crop yields and increases soil C stocks: a meta-analysis’, Agronomy for Sustainable Development, 36, p. 22. https://doi.org/10.1007/s13593-016-0354-1CrossRefGoogle Scholar
Corbeels, M., Naudin, K., Whitbread, A.M., Kühne, R. and Letourmy, P. (2020) ‘Limits of conservation agriculture to overcome low crop yields in sub-Saharan Africa’, Nature Food, 1, pp. 447–54.CrossRefGoogle Scholar
Craheix, D., Angevin, F., Doré, T. and De Tourdonnet, S. (2016) ‘Using a multicriteria assessment model to evaluate the sustainability of conservation agriculture at the cropping system level in France’, European Journal of Agronomy, 76, pp. 7586.CrossRefGoogle Scholar
Derpsch, R. (1998). ‘Historical review of no-tillage cultivation of crops’ in: Conservation Tillage for Sustainable Agriculture. Proceedings from an International Workshop, Harare, pp. 22–7.Google Scholar
Derrouch, D., Chauvel, B., Cordeau, S. and Dessaint, F. (2021a) ‘Functional shifts in weed community composition following adoption of conservation agriculture’, Weed Research, 62, pp. 103–12.CrossRefGoogle Scholar
Derrouch, D., Chauvel, B., Felten, E. and Dessaint, F. (2020) ‘Weed management in the transition to conservation agriculture: farmers’ response’, Agronomy, 10, p. 843.CrossRefGoogle Scholar
Derrouch, D., Dessaint, F., Fried, G. and Chauvel, B. (2021b) ‘Weed community diversity in conservation agriculture: post-adoption changes’, Agriculture, Ecosystems & Environment, 312, p. 107351.CrossRefGoogle Scholar
Diaz, R.J. and Rosenberg, R. (2008) ‘Spreading dead zones and consequences for marine ecosystems’, Science, 321, pp. 926–9.CrossRefGoogle ScholarPubMed
Donald, P.F., Green, R. and Heath, M. (2001) ‘Agricultural intensification and the collapse of Europe's farmland bird populations’, Proceedings of the Royal Society of London. Series B: Biological Sciences, 268, pp. 25–9.CrossRefGoogle Scholar
Dong, L., Si, T., Li, Y.E. and Zou, X.X. (2021) ‘The effect of conservation tillage in managing climate change in arid and semiarid areas—a case study in Northwest China’, Mitigation and Adaptation Strategies for Global Change, 26, pp. 119.CrossRefGoogle Scholar
Dubois, A. and Lacouture, L. (2011) Bilan de présence des micropolluants dans les milieux aquatiques continentaux Période 2007–2009. Commissariat général au développement durable–Service de l'observation et des statistiques.Google Scholar
Fao (2021). Conservation agriculture principles. Available at: https://www.fao.org/conservation-agriculture/overview/principles-of-ca/en/ (Accessed: 13 December 2021) [Online].Google Scholar
Faostat, F. (2020). Statistical databases. Food and Agriculture Organization of the United Nations. Available at: https://www.fao.org/faostat/en/Google Scholar
Fried, G., Petit, S., Dessaint, F. and Reboud, X. (2009) ‘Arable weed decline in Northern France: crop edges as refugia for weed conservation?’, Biological Conservation, 142, pp. 238–43.CrossRefGoogle Scholar
Friedrich, T., Derpsch, R. and Kassam, A. (2012) ‘Overview of the global spread of conservation agriculture’, Field Actions Science Reports, 6, pp. 17.Google Scholar
Gliessman, S.R., Engles, E. and Krieger, R. (1998) Agroecology: ecological processes in sustainable agriculture. Boca Raton, Florida, USA: CRC Press.Google Scholar
Hallama, M., Pekrun, C., Lambers, H. and Kandeler, E. (2019) ‘Hidden miners—the roles of cover crops and soil microorganisms in phosphorus cycling through agroecosystems’, Plant and Soil, 434, pp. 745.CrossRefGoogle Scholar
Heap, I. (2021). The International Herbicide-Resistant Weed Database. Online. Available at: http://www.weedscience.org/Home.aspx [Online]. Available at: www.weedscience.org (Accessed: 19 March 2020).Google Scholar
Jat, M.L., Chakraborty, D., Ladha, J.K., Rana, D.S., Gathala, M.K., Mcdonald, A. and Gerard, B. (2020) ‘Conservation agriculture for sustainable intensification in South Asia’, Nature Sustainability, 3, pp. 336–43.CrossRefGoogle Scholar
Jayaraman, S., Dang, Y.P., Naorem, A., Page, K.L. and Dalal, R.C. (2021) ‘Conservation agriculture as a system to enhance ecosystem services’, Agriculture, 11, p. 718.CrossRefGoogle Scholar
Kassam, A. and Friedrich, T. (2011). ‘Conservation agriculture: principles, sustainable land management and ecosystem services’, in: Proceedings of the 40th National Convention of the Italian Agronomy Society, pp. 79.Google Scholar
Kassam, A., Friedrich, T. and Derpsch, R. (2019) ‘Global spread of conservation agriculture’, International Journal of Environmental Studies, 76, pp. 2951.CrossRefGoogle Scholar
Kassam, A., Friedrich, T., Shaxson, F. and Pretty, J. (2009) ‘The spread of conservation agriculture: justification, sustainability and uptake’, International Journal of Agricultural Sustainability, 7, pp. 292320.CrossRefGoogle Scholar
Kassam, A. and Kassam, L. (2021). ‘10 - Paradigms of agriculture’ in Kassam, A. and Kassam, L. (eds) Rethinking food and agriculture. Sawston, UK: Woodhead Publishing, pp. 181218.CrossRefGoogle Scholar
Kertész, Á and Madarász, B. (2014) ‘Conservation agriculture in Europe’, International Soil and Water Conservation Research, 2, pp. 91–6.CrossRefGoogle Scholar
Kim, N., Zabaloy, M.C., Guan, K. and Villamil, M.B. (2020) ‘Do cover crops benefit soil microbiome? A meta-analysis of current research’, Soil Biology and Biochemistry, 142, p. 107701.CrossRefGoogle Scholar
Klein, É. (2020) Le goût du vrai. Paris, France: Gallimard.Google Scholar
Knapp, S. and Van Der Heijden, M.G.A. (2018) ‘A global meta-analysis of yield stability in organic and conservation agriculture’, Nature Communications, 9, pp. 19.CrossRefGoogle ScholarPubMed
Knowler, D. and Bradshaw, B. (2007) ‘Farmers’ adoption of conservation agriculture: a review and synthesis of recent research’, Food Policy, 32, pp. 2548.CrossRefGoogle Scholar
Kumara, T.M.K., Kandpal, A. and Pal, S. (2020) ‘A meta-analysis of economic and environmental benefits of conservation agriculture in South Asia’, Journal of Environmental Management, 269, p. 110773.CrossRefGoogle Scholar
Lahmar, R. (2010) ‘Adoption of conservation agriculture in Europe: lessons of the KASSA project’, Land Use Policy, 27, pp. 410.CrossRefGoogle Scholar
Mamy, L., Pesce, S., Sanchez, W., Amichot, M., Artigas, J., Aviron, S., Barthélémy, C., Beaudouin, R., Bedos, C., Bérard, A., Berny, P., Bertrand, C., Bertrand, C., Betoulle, S., Bureau-Point, È, Charles, S., Chaumot, A., Chauvel, B., Coeurdassier, M., Corio-Costet, M.-F., Coutellec, M.-A., Crouzet, O., Doussan, I., Douzals, J.P., Fabure, J., Fritsch, C., Gallai, N., Gonzalez, P., Gouy, V., Hedde, M., Langlais, A., Le Bellec, F., Leboulanger, C., Margoum, C., Martin-Laurent, F., Mongruel, R., Morin, S., Mougin, C., Munaron, D., Nelieu, S., Pélosi, C., Rault, M., Ris, N., Sabater, S., Stachowski-Haberkorn, S., Sucré, E., Thomas, M., Tournebize, J., Achard, A.L., Le Gall, M., Le Perchec, S., Delebarre, E., Larras, F. and Leenhardt, S. (2022) ‘Impacts des produits phytopharmaceutiques sur la biodiversité et les services écosystémiques. Rapport de l'expertise scientifique collective’. INRAE—IFREMER).Google Scholar
Marcillo, G.S. and Miguez, F.E. (2017) ‘Corn yield response to winter cover crops: an updated meta-analysis’, Journal of Soil and Water Conservation, 72, pp. 226–39.CrossRefGoogle Scholar
Mondal, S., Chakraborty, D., Bandyopadhyay, K., Aggarwal, P. and Rana, D.S. (2020) ‘A global analysis of the impact of zero-tillage on soil physical condition, organic carbon content, and plant root response’, Land Degradation and Development, 31, pp. 557–67.CrossRefGoogle Scholar
Nicoloso, R.S. and Rice, C.W. (2021) ‘Intensification of no-till agricultural systems: an opportunity for carbon sequestration’, Soil Science Society of America Journal, 85, pp. 1395–409.CrossRefGoogle Scholar
Nouri, A., Lukas, S., Singh, S., Singh, S. and Machado, S. (2022) ‘When do cover crops reduce nitrate leaching? A global meta-analysis’, Global Change Biology, 28, pp. 4736–49.CrossRefGoogle ScholarPubMed
Nunes, M.R., Karlen, D.L., Moorman, T.B. and Cambardella, C.A. (2020a) ‘How does tillage intensity affect chemical soil health indicators? A United States meta-analysis’, Agrosystems, Geosciences and Environment, 3, pp. 115.CrossRefGoogle Scholar
Nunes, M.R., Karlen, D.L., Veum, K.S., Moorman, T.B. and Cambardella, C.A. (2020b) ‘Biological soil health indicators respond to tillage intensity: a US meta-analysis’, Geoderma, 369, p. 114335.CrossRefGoogle Scholar
Osipitan, O.A., Dille, J.A., Assefa, Y., Radicetti, E., Ayeni, A. and Knezevic, S.Z. (2019) ‘Impact of cover crop management on level of weed suppression: a meta-analysis’, Crop Science, 59, pp. 833–42.CrossRefGoogle Scholar
Palm, C., Blanco-Canqui, H., Declerck, F., Gatere, L. and Grace, P. (2014) ‘Conservation agriculture and ecosystem services: an overview’, Agriculture, Ecosystems & Environment, 187, pp. 87105.CrossRefGoogle Scholar
Payen, F.T., Sykes, A., Aitkenhead, M., Alexander, P., Moran, D. and Macleod, M. (2021) ‘Soil organic carbon sequestration rates in vineyard agroecosystems under different soil management practices: a meta-analysis’, Journal of Cleaner Production, 290, p. 125736.CrossRefGoogle Scholar
Pickett, S.T.A. (1989). ‘Space-for-time substitution as an alternative to long-term studies’ in Likens, G.E. (ed.) Long-term studies in ecology: approaches and alternatives. New York, NY: Springer New York, pp. 110–35.CrossRefGoogle Scholar
Pittelkow, C.M., Liang, X., Linquist, B.A., Van Groenigen, K.J., Lee, J., Lundy, M.E., Van Gestel, N., Six, J., Venterea, R.T. and Van Kessel, C. (2015a) ‘Productivity limits and potentials of the principles of conservation agriculture’, Nature, 517, pp. 365–68.CrossRefGoogle ScholarPubMed
Pittelkow, C.M., Linquist, B.A., Lundy, M.E., Liang, X., Van Groenigen, K.J., Lee, J., Van Gestel, N., Six, J., Venterea, R.T. and Van Kessel, C. (2015b) ‘When does no-till yield more? A global meta-analysis’, Field Crops Research, 183, pp. 156–68.CrossRefGoogle Scholar
Postel, S. (2014) The last oasis: facing water scarcity. London, UK: Routledge.CrossRefGoogle Scholar
Powlson, D.S., Stirling, C.M., Thierfelder, C., White, R.P. and Jat, M.L. (2016) ‘Does conservation agriculture deliver climate change mitigation through soil carbon sequestration in tropical agro-ecosystems?’, Agriculture, Ecosystems and Environment, 220, pp. 164–74.CrossRefGoogle Scholar
Raper, R. (2005) ‘Agricultural traffic impacts on soil’, Journal of Terramechanics, 42, pp. 259–80.CrossRefGoogle Scholar
Reich, J., Paul, S.S. and Snapp, S.S. (2021) ‘Highly variable performance of sustainable intensification on smallholder farms: a systematic review’, Global Food Security, 30, p. 100553.CrossRefGoogle Scholar
Reicosky, D.C. (2015) ‘Conservation tillage is not conservation agriculture’, Journal of Soil and Water Conservation, 70, pp. 103–8.CrossRefGoogle Scholar
Ruscoe, W.A., Brown, P.R., Henry, S., Van De Weyer, N., Robinson, F., Hinds, L.A. and Singleton, G.R. (2022) ‘Conservation agriculture practices have changed habitat use by rodent pests: implications for management of feral house mice’, Journal of Pest Science, 95, pp. 493503.CrossRefGoogle Scholar
Rusinamhodzi, L. (2015). ‘Crop rotations and residue management in conservation agriculture’ in Farooq, M. and Siddique, K. (eds) Conservation agriculture. Cham: Springer, pp. 2137. https://doi.org/10.1007/978-3-319-11620-4_2CrossRefGoogle Scholar
Sammons, R.D. and Gaines, T.A. (2014) ‘Glyphosate resistance: state of knowledge’, Pest Management Science, 70, pp. 1367–77.CrossRefGoogle ScholarPubMed
Sánchez-Bayo, F. and Wyckhuys, K.A.G. (2019) ‘Worldwide decline of the entomofauna: a review of its drivers’, Biological Conservation, 232, pp. 827.CrossRefGoogle Scholar
Scaccini, D., Panini, M., Chiesa, O., Nicoli Aldini, R., Tabaglio, V. and Mazzoni, E. (2020) ‘Slug monitoring and impacts on the ground beetle community in the frame of sustainable pest control in conventional and conservation agroecosystems’, Insects, 11, p. 380.CrossRefGoogle ScholarPubMed
Scopel, E., Triomphe, B., Affholder, F., Da Silva, F.A.M., Corbeels, M., Xavier, J.H.V., Lahmar, R., Recous, S., Bernoux, M. and Blanchart, E. (2013) ‘Conservation agriculture cropping systems in temperate and tropical conditions, performances and impacts. A review’, Agronomy for Sustainable Development, 33, pp. 113–30.CrossRefGoogle Scholar
Shackelford, G.E., Kelsey, R. and Dicks, L.V. (2019) ‘Effects of cover crops on multiple ecosystem services: ten meta-analyses of data from arable farmland in California and the Mediterranean’, Land Use Policy, 88, p. 104204.CrossRefGoogle Scholar
Sperber, D. (2010) ‘The guru effect’, Review of Philosophy and Psychology, 1, pp. 583–92.CrossRefGoogle Scholar
Stoate, C., Báldi, A., Beja, P., Boatman, N.D., Herzon, I., Van Doorn, A., De Snoo, G.R., Rakosy, L. and Ramwell, C. (2009) ‘Ecological impacts of early 21st century agricultural change in Europe—a review’, Journal of Environmental Management, 91, pp. 2246.CrossRefGoogle ScholarPubMed
Stoate, C., Boatman, N.D., Borralho, R.J., Carvalho, C.R., Snoo, G.R.D. and Eden, P. (2001) ‘Ecological impacts of arable intensification in Europe’, Journal of Environmental Management, 63, pp. 337–65.CrossRefGoogle ScholarPubMed
Sun, W., Canadell, J.G., Yu, L., Yu, L., Zhang, W., Smith, P., Fischer, T. and Huang, Y. (2020) ‘Climate drives global soil carbon sequestration and crop yield changes under conservation agriculture’, Global Change Biology, 26, pp. 3325–35.CrossRefGoogle ScholarPubMed
Tilman, D., Cassman, K.G., Matson, P.A., Naylor, R. and Polasky, S. (2002) ‘Agricultural sustainability and intensive production practices’, Nature, 418, pp. 671–77.CrossRefGoogle ScholarPubMed
Toler, H.D., Augé, R.M., Benelli, V., Allen, F.L. and Ashworth, A.J. (2019) ‘Global meta-analysis of cotton yield and weed suppression from cover crops’, Crop Science, 59, pp. 1248–60.CrossRefGoogle Scholar
Trichard, A., Alignier, A., Chauvel, B. and Petit, S. (2013) ‘Identification of weed community traits response to conservation agriculture’, Agriculture, Ecosystems & Environment, 179, pp. 179–86.CrossRefGoogle Scholar
Vankeerberghen, A. and Stassart, P.M. (2016) ‘The transition to conservation agriculture: an insularization process towards sustainability’, International Journal of Agricultural Sustainability, 14, pp. 392407.CrossRefGoogle Scholar
Vicente-Vicente, J.L., García-Ruiz, R., Francaviglia, R., Aguilera, E. and Smith, P. (2016) ‘Soil carbon sequestration rates under Mediterranean woody crops using recommended management practices: a meta-analysis’, Agriculture, Ecosystems and Environment, 235, pp. 204–14.CrossRefGoogle Scholar
West, T. and Marland, G. (2002) ‘Net carbon flux from agricultural ecosystems: methodology for full carbon cycle analyses’, Environmental Pollution, 116, pp. 439–44.CrossRefGoogle ScholarPubMed
Zhao, X., Liu, S.L., Pu, C., Zhang, X.Q., Xue, J.F., Zhang, R., Wang, Y.Q., Lal, R., Zhang, H.L. and Chen, F. (2016) ‘Methane and nitrous oxide emissions under no-till farming in China: a meta-analysis’, Global Change Biology, 22, pp. 1372–84.CrossRefGoogle Scholar
Zuber, S.M. and Villamil, M.B. (2016) ‘Meta-analysis approach to assess effect of tillage on microbial biomass and enzyme activities’, Soil Biology and Biochemistry, 97, pp. 176–87.CrossRefGoogle Scholar
Figure 0

Table 1. Indicators identified in the 31 meta-analyses identified in the scientific literature that synthesized the effects of conservation agriculture with total and/or partial but simultaneous application of the three CA principles defined by the FAO (2021)

Figure 1

Figure 1. Distribution across France of the 2739 people who answered the online questionnaire about conservation agriculture.

Figure 2

Figure 2. Proportion of respondents (N = 2739, expressed as % of 2181 or 558 respondents related and non-related to agricultural, respectively) to the ten questions asked about conservation agriculture (CA). Respondents were asked first whether they were related or not related to work in the agricultural sector (farmers, engineers, advisors, technicians, or any full or partial activity related to agriculture). The values in the bars correspond to percentage of respondents.