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The aim of this research was to analyze greenhouse gas (GHG) emission in paddy rice–based cropping systems of the Middle Indo–Gangetic plains in India. Two paddy rice–based systems, namely paddy rice–wheat (PW) and paddy rice–potato–fallow (PP), were studied for GHG emission, net return (NR) and eco–efficiencies (EE). The PW (3354.9 ​± ​133.7 kgCO2eq ha−1 y−1) and PP (5096.3 ​± ​11.6 kgCO2eq ha−1 y−1) systems were observed to have significantly different GHG emissions. The most significant contributor to the GHG pool was fertilizer production, contributing about 40.3% and 46.1% in the PW and PP systems, respectively. On–farm direct nitrous oxide (N2O) emission was the second largest contributor to the GHG emission pool. Farm sizes significantly affected GHG emissions in the PW system, and medium farms (>3 ​ha) had higher GHG emission compared to other farm sizes. While the NR in the PP system was significantly higher (2504.3 ​± ​65.6 USD ha−1 y−1) compared to the PW system (1687.1 ​± ​90.6 USD ha−1 y−1) owing to better market prices of potato crop, it also performed slightly better on the EE scale (0.52 and 0.50 USD kgCO2 eq−1, respectively). In the PW system, comparatively larger farms were more eco–efficient than the smaller farms. However, the EE values for different farm sizes in the PP system were numerically and statistically similar. The results reported in this study may be beneficial to farmers to make decisions pertinent to sustainable management of agro inputs in paddy–based cropping systems and collective farming. Moreover, these results can even be utilized by governmental and non–governmental organizations for deciding support/subsidies to farmers in the study area.

Prod 2019-15kEASPEGESTADINRAAGROSUPDOCT; Three methods of innovative design for cropping systems were compared for their contribution tosustainable weed management: (i) de novo expert design by multiple stakeholders; co-design by farmers(ii) of one cropping system during workshops; (iii) of cropping systems for each farmer member of aDEPHY network group over several years. The weed simulation model FLORSYS was used to evaluatethese systems with six indicators, describing weed harmfulness for crop production, weed contribution tobiodiversity and herbicide use. A principal component analysis on this dataset illustrated that there is nocorrelation between herbicide use and weed harmfulness for crop production. De novo expert design ledto bigger changes in practices and systems performances, compared to co-design with farmers, especially when innovative systems are designed for each farmer of a group. The evolution of sustainability of thesecropping systems was assessed with the multicriteria assessment model DEXiPM and again morechanges, often positive, were found with the design methods (i) and (ii). However, only a few innovativecropping systems designed with method (iii) were able to reduce weed harmfulness for production whileenhancing sustainability, thanks to major changes planned in crop sequences (winter wheat reductionand sugarbeet removal), after ten years of step-by-step design. These results illustrate differences andcomplementarities of these design methods.; Trois démarches de conception de systèmes de culture ont été comparées sur leur contribution à la gestion durable des adventices : (i) conception par expertise d’acteurs multiples ; co-conception par des agriculteurs (ii) d’un système innovant lors d’ateliers ponctuel ou (iii) de systèmes innovants pour chaque agriculteur d’un groupe sur une démarche de long terme. Les systèmes définis ont été simulés avec le modèle de dynamique de la flore adventice FLORSYS. Une Analyse en Composantes Principales des résultats de six indicateurs décrivant la nuisibilité des adventices pour la production, la diversité des adventices et l’intensité d’usage d’herbicides a été réalisée. Tout d’abord, la nuisibilité des adventices et l’usage d’herbicides ne sont pas corrélés. Ensuite, les systèmes innovants conçus selon la méthode (i) conduisent à des changements plus importants et contrastés, à l’inverse de la co-conception par des agriculteurs, particulièrement avec des systèmes conçus pour chaque agriculteur. Enfin, l’évolution de la durabilité a été évaluée avec le modèle d’évaluation multicritère DEXiPM. La durabilité évolue plus fréquemment, de manière positive pour les méthodes de conception (i) et (ii). Néanmoins, les seuls systèmes innovants combinant réduction significative de la nuisibilité des adventices pour la production et augmentation de la durabilité sont issus du groupe (iii), avec des modifications profondes de la rotation (réduction du blé tendre, abandon de la betterave) envisagées après 10 ans de conception pas-à-pas. Ces résultats illustrent les différences et complémentarités de ces différentes méthodes.Abstract : Comparing methods for designing innovative cropping systems aiming at sustainable weed managementThree methods of innovative design for cropping systems were compared for their contribution to sustainable weed management: (i) de novo expert design by multiple stakeholders; co-design by farmers (ii) of one cropping system during workshops; (iii) of cropping systems for each farmer member of a DEPHY network group over several years. The weed simulation model FLORSYS was used to evaluate these systems with six indicators, describing weed harmfulness for crop production, weed contribution to biodiversity and herbicide use. A principal component analysis on this dataset illustrated that there is no correlation between herbicide use and weed harmfulness for crop production. De novo expert design led to bigger changes in practices and systems performances, compared to co-design with farmers, especiallyCavan N., et al.190 Innovations Agronomiques 81 (2020), 189-200when innovative systems are designed for each farmer of a group. The evolution of sustainability of these cropping systems was assessed with the multicriteria assessment model DEXiPM and again more changes, often positive, were found with the design methods (i) and (ii). However, only a few innovative cropping systems designed with method (iii) were able to reduce weed harmfulness for production while enhancing sustainability, thanks to major changes planned in crop sequences (winter wheat reduction and sugarbeet removal), after ten years of step-by-step design. These results illustrate differences and complementarities of these design methods.

To evaluate the resilience of innovative weed management strategies, the impact of climate change wasinvestigated with a regionalized simulation approach. First, we checked that the protocol for dynamicregionalisation correctly mimicked the climate observed over 1980-2016. Then, the protocol was appliedto two periods (2010-2040 and 2069-2099). Finally, we compared existing and prospective croppingsystems in terms of weed management and impacts on crop production and biodiversity, with these twoclimate trajectories. To do so, 44 cropping systems from 5 regions were simulated with the weed dynamicsmodel FlorSys. Our results show that surface temperature will increase in average by approx. 4°C at theend of the century with the RCP8.5 trajectory. Three cropping system types were identified in responseto these climate changes, those whose weed harmfulness for crop production (1) decreased,(2) increased, particularly with trajectory RCP8.5 from 2069-2099, (3) was average but whose weedcontribution to biodiversity increased. The study allowed identifying the management levers essential forinnovative cropping systems that are robust relatively to climate change.; Pour tester la robustesse des stratégies innovantes de gestion des adventices, le changement climatique a été abordé par une approche de simulations climatiques régionalisées. D'abord, nous avons vérifié que le protocole de régionalisation dynamique mimait correctement le climat observé sur la période 1980-2016. Ensuite, ce protocole a été appliqué à deux trajectoires de forçage radiatif (RCP4.5 et RCP8.5) définies pour l'exercice d'intercomparaison des modèles climatiques globaux (CMIP5) afin d'évaluer l'incertitude associée aux émissions de gaz à effet de serre attendue sur la deuxième moitié du 21 e siècle. Enfin, nous avons comparé des systèmes de culture existants et prospectifs, en terme de gestion de la flore adventice et de son impact sur la production agricole et la biodiversité, avec ces trajectoires climatiques. Pour cela, 44 systèmes de 5 régions ont été simulés avec le modèle de dynamique de la flore adventice FLORSYS. Nos résultats montrent que les températures de surface augmentent en moyenne de ~4 °C en fin de siècle pour la trajectoire RCP8.5. Face à ces changements climatiques, trois types de systèmes de culture ont été identifiés : ceux dont la nuisibilité des adventices pour la production (1) diminue ; (2) augmente, particulièrement avec la trajectoire RCP8.5 sur la période 2069-2099 ; (3) est moyenne mais dont la contribution des adventices à la biodiversité augmente. Ces travaux identifient les leviers à prioriser pour définir des systèmes de culture innovants et robustes face au changement climatique.

In the Northern mountainous region of Vietnam, cassava–cowpea intercropping system has been widely promoted with support from the local agricultural department. However, cowpea yield is often limited because of a low Biological Nitrogen Fixation (BNF) activity due to its low natural nodulation and lack of available effective Rhizobium products. The aim of this study was to identify the most effective native rhizobia isolate nodulating cowpea with the potential to increase BNF and yield of cowpea. A greenhouse experiment was initially conducted with five treatments: three native rhizobia isolates (CMBP037, CMBP054, and CMBP065); a control (no inoculation and no N application); and N+ (no inoculation, application of N as KNO3). Field inoculations were carried out and the treatments were as follows: a control (no inoculation); CMBP (037+054) – a mixture of strains from Mau Dong; CMBP065 strain from Cat Thinh. CMBP054 and CMBP065 had the highest nodulation in the greenhouse (46.4 and 60.7 nodules plant−1, respectively) and were rated as effective with symbiotic efficiency (SEF) of 54.56 and 55.73%, respectively. In the field, CMBP (037+054) recorded significantly higher nodulation (19.4 nodules plant−1) than the control (11.7 nodules plant−1). CMBP (037+054) also increased cowpea shoot dry weight, shoot N, and yield by 28.6, 4.9, and 10.5%, respectively, compared to the uninoculated control. This effect was slope dependent (statistically significant in moderate and steep slope, not with gentle slope). Besides, the high expansion rate of intercropping with cowpea showed the high adoption level of these agroecological practices by local farmers. This study reveals the potential of native rhizobia inoculation to enhance soil fertility and sustainable agriculture in the Northern mountainous region of Vietnam and proposes enhanced efforts to promote the availability and utilization of effective inoculants for cowpea.

International audience; In the irrigated plains of North Africa, the sustainability of productive resources is subject to multiple threats linked to the prevailing productivist model of irrigated agriculture. These threats, such as soil degradation and unequal access to resources, markets, and information, prompt farmers to mobilize depleting natural resources, including soil and water, in an often environmentally unsustainable way. In order to sustain their farming systems and consequent incomes, farmers sometimes update their strategies by setting-up alternative farming practices. This study aims at mapping and analyzing such existing local farming practices with agroecological potentials. Our approach is based on direct observations combined with 150 interviews of farmers in three major irrigated plains in North Africa, namely, the Merguellil, Upper Cheliff, and Saiss plains, respectively, in Tunisia, Algeria, and Morocco. This study shows that a wide range of alternative practices with agroecological potential are emerging (or exist) locally, against the flow of the dominant agricultural model which is rather in favor of intensive practices. The most common practices are developed to improve soil fertility management (production of manure tea, integration of legumes in crop successions), increase per surface agricultural production (relay intercropping, intercropping, agroforestry), or provide multiple ecosystem services (diversification, livestock integration). These practices are jointly used, mostly to (i) increase land-use efficiency, and hence face land fragmentation; (ii) diversify their cropping strategy, and spread out market-related risks; and (iii) reduce expensive production costs related to irrigation and chemical fertilization. The gradient of adoption observed according to national contexts suggests a strong influence of contrasting socio-political and historical factors at the regional to national levels. The analysis of logics in implementing such practices by farmers indicates that economic reasons take precedence over environmental concerns. As such, these practices can be seen as (i) an access to low-cost strategies for small farmers or (ii) a pathway to international markets for agribusiness farmers. Taming the extensive local knowledge related to ecological intensification strategies, as identified in this study, can help to pave the way for a more sustainable agriculture, in this intensively cultivated region of the world.

Weeds and D. stramonium management is a major challenge for farmers and human food chain as popcorn. Before redesigning cropping systems (CS) for an ecological intensive weed management, CS need to be characterized and their weeds management efficiency assessed. This is the aim of this study conducted in a network of 16 popcorn farmers in the South-West of France. From farmers surveys, CS were mainly characterized by the diversity of the crop rotation and the weed management. Two soil types were identified influencing the type of CS. Abundance, composition and diversity of weed communities were measured in one field of each farmer after weeding. A strong distinction between fields managed in organic agriculture and in conservation agriculture was observed. In these fields, weed communities had a greater abundance than in those managed in conventional agriculture. Weed biomass was about 192 ± 188, 40 ± 22 et 1 ± 3 g MS.m-2 respectively in these different types of management. The orientation of CS provided a better explanation of the differences seen in the characteristic of weed communities than our typology due to a very low weed abundance in conventional. Fields managed in organic agriculture were more vulnerable to D. stramonium infestation as in those where the seed spacing was 80 cm. In these fields, D. stramonium was more abundant. Based both on the literature and our results, a redesign framework of CS was proposed to modify the CS in function of the presence or not of D. stramonium in the field.; La gestion des adventices et de D. stramonium est un enjeu majeur des agriculteurs et des filières dédiées à l’alimentation humaine comme le popcorn. Avant de repenser les systèmes de culture (SDC) pour une gestion écologiquement intensive des adventices, ils doivent être caractérisés et leur efficacité de gestion des adventices évaluée, objets de notre étude menée dans un réseau de 16 agriculteurs produisant du maïs popcorn dans le Sud-Ouest de la France. À partir d’enquêtes réalisées auprès des agriculteurs, les SDC ont été caractérisés selon la diversité de la rotation et la gestion des adventices. Deux types de sol ont été identifiés impactant le SDC mis en place. Les mesures des caractéristiques des communautés adventices présentes dans les parcelles suivies après désherbage, montre notamment une plus forte abondance des communautés adventices entre les parcelles en agriculture biologique (AB) et en agriculture de conservation, que celle en agriculture « conventionnelle ». Les biomasses étaient respectivement de 192 ± 188, 40 ± 22 et 1 ± 3 g MS.m-2 à floraison du maïs. L’orientation des SDC explique mieux les différences observées sur les communautés adventices que notre typologie due à une très faible abondance des adventices en « conventionnelle ». Les parcelles en AB et celles où l’écartement de semis est de 80 cm sont plus à risque pour D. stramonium étant plus abondant sur ces parcelles. À partir de la littérature et de nos résultats, un cadre de reconception des SDC est proposé orientant cette étape selon la présence ou non de D. stramonium dans la parcelle.

Les sols d'altitude du sud de la Basse-Terre (andosols) sont caractérisés par des stocks de matière organique très élevés qui peuvent être particulièrement sensibles à l'intensification du travail du sol et au réchauffement climatique. Cette sensibilité est déterminée par la vitesse de décomposition de la matière organique. Dans cette étude nous avons estimé pour la première fois le gradient altitudinal du taux de décomposition in-situ de la matière organique du sol, et observé qu'il diminue dans les sols de haute altitude, ce qui explique leurs plus grands stocks en matière organique.Le rendement de la banane, la quantité de résidus de récolte et le carbone apporté au sol par ces résidus diminuent avec l'altitude, mais ils ne déterminent pas le gradient de matière organique. D'ailleurs, les gradients altitudinaux de température et de pluviométrie, ainsi que la disponibilité de nutriments, ne peuvent pas expliquer la forte réduction du taux de décomposition en altitude. Ce dernier est surtout contrôlé par la minéralogie des sols, laquelle détermine l'accroissement en altitude de la protection physique de la matière organique vis-à-vis de la dégradation provoquée par l'activité microbienne du sol.Ce phénomène a d'importantes conséquences sur la résilience des sols aux impacts agro-environnementaux, laquelle augmente fortement dans les sols de haute altitude. Les résultats obtenus apportent des pistes intéressantes aussi bien pour la recherche agronomique que pour la gestion de pratiques culturales dans le gradient altitudinal du sud de la Basse-Terre.

National audience; The data presented in this article describe 21 species that can be found in banana cropping systems: 17 cover crops species, 2 spontaneous species and 2 cultivars of banana. The cover crop species belongs mainly to Fabaceae family, but also to Poaceae, Euphorbiacea and Asteraceae. Four repetition of each species were cultivated individually, in the field, under non-limiting conditions. 40 variables were measured on whole plant, leaves and roots, at flowering or after six months of growth for longer cycle species. This dataset is made available to provide data on these species, enable comparisons between datasets and meta-analysis on cover crop or on species presented in arable fields. The data presented in this article were used in the research articles entitled “Trait-based characterisation of cover plants' light competition strategies for weed control in banana cropping systems in the French West Indies” (Tardy et al. 2015) and “Trait-based characterization of soil exploitation strategies of banana, weeds and cover plant species” (Tardy et al. 2017).

Master; Mon stage a été effectué à l’INRAE de Colmar au sein de l’équipe AGISEM (Agriculture, Biodiversité, Services écosystémiques et évaluation Multicritères) de l’UMR LAE (Laboratoire Agronomie et Environnement). Il a pour objectifs la caractérisation de la flore du vignoble et sa mise en relation avec les pollinisateurs qui y sont observés. L’érosion de la biodiversité au sein des paysages agricoles en générale et dans le vignoble en particulier est une réalité inquiétante en raison d’une agriculture devenue intensive et nécessitant une utilisation importante de produits phytopharmaceutiques. Il est donc important de favoriser la biodiversité dans les paysages agricoles car elle permet d’équilibrer les écosystèmes et de rendre de nombreux services écosystémiques aux cultures. Cette étude a été réalisée sur un « essai Système » en viticulture à Wintzenheim dans le cadre du projet SALSA (Systèmes viticoles agroécologiques mobilisant la résistance variétale et les régulations naturelles). L’étude a pour but de voir l’importance de la caractérisation de la flore en milieu viticole pour la prédiction de la pollinisation, l’importance de l’implantation de couverts végétaux sur les interrangs et l’impact de l’itinéraire technique sur l’installation d’une flore diversifiée. Pour ce faire, nous avons en premier lieu comparé la biodiversité floristique au sein des différentes méthodes de productions et les types d’agricultures mis en place sur l’essai Système. Ensuite nous avons comparé la biodiversité floristique au sein des interrangs enherbés avec celle des interrangs travaillés et cavaillons. Les résultats obtenus démontrent qu’un système de culture dont l’itinéraire technique induit une faible pression sur la végétation, ainsi que la mise en place de couverts végétaux présentent un intérêt en termes d’attraction des pollinisateurs. Les résultats indiquent également que l’itinéraire technique joue un rôle important sur la richesse spécifique, les espèces rencontrées et leur répartition.

International audience; Sustainable intensification (SI) of farming systems aims to increase food production from existing farmland in ways that have a lower environmental impact and maintain the food production capacity over time. SI embraces a set of diverse agricultural technologies that share a common feature: their adoption is dependent on the interactions between farmers’ decision-making processes, locally specific agro-ecological conditions, and the traits of the technology itself. There are concerns about the sustainability of the maize mono-cropping systems that are in use in Laosc today. Therefore, we used discrete choice experiments (DCE) to explore the potential adoption or alternative agricultural systems. We analyse the heterogeneity of farmers’ preferences and willingness to pay for different cropping system attributes using a mixed logit model, and we discuss the possible drivers and barriers to the adoption of these more sustainable options. The results suggest the existence of four types of farmers: “fertility-minded”, “factor-constrained”, “maximisers”, and “risk-averse”. Each type of farmers was likely to react differently to the proposed sustainable intensification techniques. Overall, the DCE appeared to be an efficient tool to elicit the diversity of farmer preferences in an agricultural region and for fine-tuning strategies for successful research and development of sustainable intensification.

International audience

Trois sites représentatifs de trois régions d’agriculture essentiellement pluviale, mais où la petite irrigation s’avère aussi essentielle, ont été étudiés dans le cadre de cet ouvrage. Deux d’entre eux sont situés en Zambie : le site de Katongo Kapala dans le district de Mpika (1 500 m d’altitude) et celui de Miloso dans le district de Mkushi (1 400 m) . Le troisième site est localisé non loin d’Iringa, sur les hauts plateaux du Sud...

Les chapitres précédents ont permis de mettre en avant certaines pistes en matière de résilience et d’adaptation. Ils prolongent ou renouvellent les travaux portant sur la vulnérabilité qui mettent en évidence les liens entre pauvreté, vulnérabilité et exposition au risque. Ces chapitres décrivent les processus, les mécanismes et les trajectoires qui expliquent la forte exposition aux aléas de certains groupes d’agriculteurs et de ru...

Le bassin versant du Mékong : enjeux des changements climatiques et globaux Géographie du Mékong : enjeux environnementaux, sociaux et économiques Dixième fleuve le plus long du monde (4 900 km), le Mékong draine un bassin versant de 810 000 km² où vivent 70 millions de personnes dans six pays (Chine, Birmanie, Laos, Thaïlande, Cambodge et Vietnam). Son débit est régi par l’alternance des moussons,...

À partir de l’étude détaillée d’un petit nombre de situations très contrastées, nos travaux ont permis de mettre en évidence les processus et les trajectoires expliquant la forte exposition aux aléas de certains groupes d’agriculteurs, ainsi que le maintien ou l’accroissement de cette exposition. Ces travaux permettent d’expliquer, à l’échelle du système agraire et à celle des systèmes de production, les ressorts de cette vulnérabili...

La question de l’adaptation des agricultures du Sud au changement climatique se pose-t-elle différemment en région de montagne ? En montagne, les agriculteurs doivent composer avec l’altitude, la pente et les phénomènes érosifs qu’elle facilite, l’étagement. À cela s’ajoutent parfois les difficultés de communication. De par le monde, de telles situations sont trop nombreuses, trop variées et trop dissemblables pour espére...

Si le Sahel avait déjà connu des épisodes de sécheresse sévère dans son histoire (1880, 1912-1914, 1940-1944 ; Jouve, 1991), celle qui a sévi à partir de la fin des années 1960 constitue un phénomène exceptionnel par sa persistance, son intensité et son déploiement à l’échelle de l’ensemble de l’Afrique au sud du Sahara. De 1968 à 1984, l’isohyète 100 mm est ainsi descendu de 250 à 300 km au sud et l’isohyète 500 mm de ...

Les études et publications sur les risques associés au changement climatique pour l’agriculture sont extrêmement nombreuses. Une rapide revue de cette abondante littérature permet d’identifier les aléas et les risques naturels liés au changement climatique qui affectent le plus — en fréquence et en intensité — les pratiques et les productions des agriculteurs dans le monde : la sécheresse, aléa ponctuel, et l’aridification, péjoration par ...

À partir de l’étude détaillée et de la comparaison d’une douzaine de situations locales contrastées en Afrique sub-saharienne et en Asie du Sud-Est, les auteurs mettent en évidence les processus et les trajectoires qui expliquent la forte exposition aux aléas des différents groupes d’agriculteurs, ainsi que leur inégale capacité d’adaptation. Ils expliquent les ressorts de cette vulnérabilité et illustrent le poids des choix passés et actuels en matière de politiques agricole, environnementale et commerciale. Enfin, ils présentent les modalités d’ajustement et les transformations passées et en cours des pratiques paysannes allant dans le sens d’une réduction de l’exposition à l’aléa, d’une atténuation de la vulnérabilité, et d’une meilleure adaptation aux changements globaux : dérèglement climatique bien sûr, mais aussi accroissement démographique, compétition accrue pour l’accès aux ressources, évolution des prix relatifs et fluctuations des marchés, dérégulation et baisse des soutiens publics, etc. Ils esquissent en conclusion les chemins possibles en matière d’adaptation et des propositions de mesures politiques pour accompagner les producteurs. Pour des raisons de différences de fabrication, les figures et photos en couleurs de la présente version sont disséminées au sein des différents chapitres, mais sont réunies à la fin du chapitre 4 de la version PDF.

Les différents cas concrets présentés dans les chapitres 1 à 6 illustrent des contextes géographiques et des degrés d’exposition contrastés au changement climatique et à l’accroissement des aléas climatiques (pluviométrie et crue). Ils offrent ainsi une palette de situations riche d’enseignements et invitent à une comparaison des modalités concrètes d’adaptation des exploitations agricoles aux changements et aléas climati...

Deux régions ont été identifiées pour étudier le cas des zones inondables à vocation rizicole, mais à faible niveau d’aménagement : la basse vallée du fleuve Rufiji dans le Sud de la Tanzanie et la région d’Ifakara sur le Kilombero, affluent du fleuve Rufiji (figure 3.1). Ces deux petites régions offrent un terrain de choix pour réfléchir aux modalités de prise en compte, par les agriculteurs, des risques liés aux aléas c...

La région du delta du fleuve Sénégal (figure 5.1) connaissait déjà, avant l’épisode de sécheresse des années 1970-1980 qui a marqué l’ensemble du Sahel, de faibles totaux pluviométriques. Elle était aussi particulièrement sujette aux variations interannuelles de la pluviométrie et de la crue du fleuve, rendant l’agriculture pluviale hasardeuse (Lericollais, 1975). L’adaptation ancienne et systémique des agriculteurs et éleveurs à des...

National audience; Is it possible to use nitrogen fertilization for weed control? Use of herbicides and mineral fertilizers must be reduced to make cropping systems more sustainable. These changes could lead to the development of a residual weed flora and an increased competition for resources, including nitrogen, between weeds and crops. This project aims at identifying which fertilization techniques and cultivar traits contribute to the biological regulation of weeds by modulating plant‐plant competition for nitrogen and thus help to reduce herbicide use, using a modelling approach (FLORSYS). The first step of the PhD project aimed at introducing plant‐plant competition for nitrogen into the FLORSYS model. FLORSYS already simulates competition for light and its role in crop growth and weed dynamics depending on cropping system, pedoclimate and species traits. In particular, an original function was proposed based on greenhouse experiments to estimate the nitrogen demand of individual plants from their leaf biomass irrespective of shading conditions. Then, virtual experiments were performed in a case study with maize monoculture, to identify the nitrogen fertilization techniques and the cultivar traits linked to nitrogen nutrition that impacted weed dynamics the most. Finally, innovative cropping systems will be proposed for this case study to promote biological weed regulation via nitrogen competition to reconcile weed control, crop production and biodiversity.; Est-il possible d'utiliser la fertilisation azotée pour lutter contre les mauvaises herbes ? L'utilisation d'herbicides et d'engrais minéraux doit être réduite pour rendre les systèmes de culture plus durables. Ces changements pourraient entraîner le développement d'une flore résiduelle de mauvaises herbes et une concurrence accrue pour les ressources, notamment l'azote, entre les mauvaises herbes et les cultures. Ce projet vise à identifier les techniques de fertilisation et les caractéristiques des cultivars qui contribuent à la régulation biologique des mauvaises herbes en modulant la concurrence entre les plantes pour l'azote et qui permettent ainsi de réduire l'utilisation d'herbicides, en utilisant une approche de modélisation (FLORSYS). La première étape du projet de doctorat visait à introduire la compétition plante-plante pour l'azote dans le modèle FLORSYS. FLORSYS simule déjà la compétition pour la lumière et son rôle dans la croissance des cultures et la dynamique des mauvaises herbes en fonction du système de culture, du pédoclimat et des caractéristiques des espèces. En particulier, une fonction originale a été proposée sur la base d'expériences en serre pour estimer la demande en azote de chaque plante à partir de sa biomasse foliaire, indépendamment des conditions d'ombrage. Ensuite, des expériences virtuelles ont été réalisées dans une étude de cas avec la monoculture du maïs, afin d'identifier les techniques de fertilisation azotée et les caractères des cultivars liés à la nutrition azotée qui avaient le plus d'impact sur la dynamique des mauvaises herbes. Enfin, des systèmes de culture innovants seront proposés pour cette étude de cas afin de promouvoir la régulation biologique des mauvaises herbes par la concurrence de l'azote pour concilier la lutte contre les mauvaises herbes, la production végétale et la biodiversité.

The conversion of native vegetation (NV) into agricultural land by clearing and tillage disrupts the soil structure, and depletes soil organic carbon (SOC) pool. Data on changes in SOC pools are needed to enhance scientific knowledge regarding the effects of land use and Conservation Agriculture (CA) on soil fertility, agronomic productivity, and soil C sink capacity. The objective of this study was to quantify changes in SOC fractions due to conversion of NV to agricultural land, and to assess the rate of recovery of SOC fractions and the resilience index of CA cropping systems under sub-tropical (Ponta Grossa/PR — PG) and tropical (Lucas do Rio Verde/MT — LRV) regions of Brazil.

L'agriculture de décrue est un mode de production ancestral qui a permis aux populations des plaines inondables africaines de survivre, et même de développer des sociétés avancées comme l'Égypte pharaonique, le Tekrour, le Ghana, les empires malien ou songhaï. Elle a l'avantage de fournir une production appréciable en saison sèche, et nécessite très peu d'intrants et un travail limité. Si les rendements à l'hectare sont faibles, la productivité du travail est appréciable et explique l'engouement des riverains à son endroit, malgré la fréquente possibilité de la remplacer par une agriculture irriguée moderne. L'importance de cette pratique dans la sous-région ouest-africaine reste peu connue, car les services statistiques nationaux ont tendance à la négliger. Dans ce chapitre, nous passons en revue la littérature existante pour l'Afrique de l'Ouest et centrale, c'est-à-dire du Sénégal jusqu'au Tchad. L'objectif est de mieux appréhender les perspectives de cette agriculture, qui avait presque disparu pendant les grandes sécheresses des années 1980 et qui était censée disparaître définitivement avec la construction de plusieurs dizaines de barrages régulateurs sur les grands fleuves de la sous-région. Depuis, les plans de barrages ont été suspendus à cause de l'endettement des États et du rapport alarmant rendu par la Commission mondiale des barrages (WCD, 2000). Par ailleurs, les pluies sont en partie revenues, permettant aux riverains de certaines plaines inondables de relancer cette production, notamment dans plusieurs plaines du bassin du lac Tchad. Depuis quelque temps, les plans de barrages sont réapparus sur l'agenda des États et des agences de bassin. Si les bailleurs traditionnels sont toujours réticents, la Chine se montre déterminée à financer et réaliser ces projets de barrages qui avaient été enterrés dans les années 1990. Dans ce chapitre, les auteurs font un bilan zone par zone, en comparant les surfaces potentiellement inondables, les surfaces cultivées, les cultures pratiquées et les techniques de production spécifiques à ces zones.

International audience; Background and aims: Agroforestry systems combining trees with crops or pastures have been widely used to reduce water, soil, and nutrient losses and associated water pollution from agricultural lands in both temperate and tropical regions. However, reviews on improvement/efficiency and the scope of such reductions by soil, management, climate, and hydrological processes are limited.Methods: This paper synthesized the available evidence on the reduction in surface runoff, soil erosion, nutrient, and pollutant losses (e.g., herbicides, pesticides, and antibiotics) to quantify the effectiveness of agroforestry systems on water quality improvement based on published studies.Results: On average, agroforestry systems reduced surface runoff, soil, organic carbon, and related nutrient losses by 1–100%, 0–97%, –175–92%, and –265–100%, respectively, with average values of 58%, 65%, 9%, and 50%, respectively. They also lowered herbicide, pesticide, and other pollutant losses by –55–100% (49% on average).Conclusions: Reduction efficiency of agroforestry systems is site-dependent and varies widely depending on different biophysical factors. A comprehensive science-based review is needed to generalize agroforestry design and site adaptability for water and soil conservation where climatic, geographical, ecological, and socio-economic conditions are relatively similar in the world.

En Tunisie, la culture de blé dur en irrigué est pratiquée sur une superficie moyenne annuelle de 48 700 ha, soit environ les deux tiers des superficies céréalières conduites en irrigué. Elle produit en moyenne 180 000 t, soit 20 % de la production nationale de blé dur. Cependant, les rendements réalisés restent toujours en dessous des attentes avec une faible productivité, particulièrement celle de la ressource en eau. Dans ce contexte, l’objectif de ce travail est d’élaborer un diagnostic opérationnel de fonctionnement des exploitations céréalières irriguées et de mettre en exergue les principaux leviers d’amélioration des performances de la culture du blé dur. Pour ce faire, des enquêtes de terrain ont été menées auprès d’un échantillon de 698 céréaliculteurs. Les données recueillies ont permis d’élaborer une typologie de fonctionnement et d’analyser les performances de la culture du blé dur. Trois systèmes de production types ont été identifiés : un système monocultural basé sur la culture du blé dur, un système diversifié à orientation céréalière et un système diversifié à orientation maraîchère. L’analyse des performances a révélé une disparité nette entre deux niveaux de performance distincts pour chaque système de production. In Tunisia, irrigated durum wheat is grown on an average annual area of 48 700 ha, which represents two-thirds of the irrigated cereal area. It produces an average of 180 000 t, or 20% of national durum wheat production. However, the yields achieved are still below expectations with low productivity, particularly of water resources. In this context, this work aims to draw up an operational diagnosis of the irrigated cereal farms and to highlight the main levers for improving the performance of the durum wheat crop. To this end, field surveys were conducted with a sample of 698 grain farmers. The data collected made it possible to develop a typology of farming systems and to analyze the performance of the durum wheat cultivation activity. Three types of farming systems were identified: A monocultural system based on durum wheat cropping, a diversified cereal-oriented system and a diversified horticulture-oriented system. Performance analysis revealed a clear disparity between two distinct performance levels for each farming system.

The adoption of Conservation Agriculture (CA) and the maintenance of crop residues on the soil surface result in the long-term increase of carbon (C) in the system, promoting C sequestration and reducing C-CO2 emissions to the atmosphere. The present study conducted in subtropical and tropical regions in Brazil aimed to assess the impact of the continuous plow-based conventional tillage (CT) on soil organic carbon (SOC) stock vis-a-vis native vegetation (NV) as baseline, compare SOC balance among CT, CA cropping systems, and NV; and evaluate the redistribution of SOC stock in soil profile in relation to soil resilience.

International audience; The promotion of optimum rotations and agricultural management of winter wheat-based cropping systems is very critical, as wheat is considered an essential component in the Mediterranean diet. Considering the delicate economic situation of farmers in the Mediterranean area, recommending a low risk, sustainable farming system is desirable. In this study, an innovative application of a multi-criteria field-level approach is presented, targeting food security, farmer profitability and environmental sustainability. The CropSyst biophysical simulation model was calibrated and implemented for the study site. It was chosen for its agro-environmental robustness to simulate four rotations (wheat-wheat, wheat-fallow, wheat-potato, and wheat-fava bean). Four types of wheat agricultural management systems (full fertilization and full irrigation, full fertilization and zero irrigation, zero fertilization and full irrigation, and zero fertilization and irrigation) were tested in low and high soil water holding capacity (WHC) types. The effects of soil conditions, management practices and rotation type on wheat grain yields were assessed. Furthermore, the performance of each winter wheat-based cropping system was evaluated in terms of productivity (protein production and profitability) and the efficient use of resources (nitrogen and water), as well as the economic risk of low relative productivity each one engenders. The results show that there is no particular optimal scenario that can simultaneously ensure high productivity, reduce economic risk of low relative productivity, and achieve high wheat- water- and nitrogen-use efficiency. However, the wheat-fava bean rotation cultivated with no wheat fertilization appeared to be a better substitute to the wheat-wheat rotation in terms of protein production (0.93 t/ha versus 0.8 t/ha in low WHC soil and 1.34 t/ha versus 1.17 t/ha in high WHC). This cropping system achieved a higher net profit (2111 US$/ha versus 1222US$/ha in low WHC and 3550 US$/ha versus 2450 US$/ha in high WHC), showing high resource-use efficiency and was less risky for farmers. Moreover, a very high profit could only be attained with the wheat-potato rotation (8640 US$/ha and 12,170 US$/ha in low and high WHC, respectively), yet with low input-efficiency and high economic risk of low relative productivity.

Conservation agriculture (CA) is recognized as a promising crop management strategy for sustainable agricultural intensification. The objective of this study was to evaluate CA cropping systems for rainfed maize as an alternative to the traditional tillage-based cropping systems (CT) in the context of family farms, using a multi-criteria model that represents the point of view of farmers. Farmers considered several aspects for evaluating the cropping systems, thatwere systematized in the model through five criteria (with sub-criteria): (a) costs; (b) yield; (c) labour; (d) human health and environment; and (e) production risks. CA did not differ from CT for the 'costs' criterion but was superior for the 'yield' and 'labour' criteria. In contrast, CT obtained better ratings for the criteria 'human health and environment' and 'production risks'. Considering all criteria, CA was better appraised than CT. However, a new local policy measure that subsidizes the hiring of mechanized tillage services overturns this outcome, indicating the importance of exogenous factors. Overall, the participatory processes in building the model allowed us to better understand the reasons of adoption or non-adoption of CA by small-scale farmers in the tropics.

International audience; The adoption of new cropping practices such as integrated Crop-Livestock systems (iCL) aims at improving the land use sustainability of the agricultural sector in the Brazilian Amazon. The emergence of such integrated systems, based on crop and pasture rotations over and within years, challenges the remote sensing community who needs to implement accurate and efficient methods to process satellite image time series (SITS) in order to come up with a monitoring protocol. These methods generally include a SITS preprocessing step which can be time consuming. The aim of this study is to assess the importance of preprocessing operations such as temporal smoothing and computation of phenological metrics on the mapping of main cropping systems (i.e. pasture, single cropping, double cropping and iCL), with a special emphasis on the iCL class. The study area is located in the state of Mato Grosso, an important producer of agriculture commodities located in the Southern Brazilian Amazon. SITS were composed of a set of 16-day composites of MODIS Vegetation Indices (MOD13Q1 product) covering a one year period between 2014 and 2015. Two widely used classifiers, i.e. Random Forest (RF) and Support Vector Machine (SVM), were tested using five data sets issued from a same SITS but with different preprocessing levels: (i) raw NDVI; (ii) raw NDVI + raw EVI; (iii) smoothed NDVI; (iv) NDVI-derived phenometrics; (v) raw NDVI + phenometrics. Both RF and SVM classification results showed that the "raw NDVI + raw EVI" data set achieved the highest performance (RF OA = 0.96, RF Kappa = 0.94, SVM OA = 0.95, SVM Kappa = 0.93), followed closely by the "raw NDVI" and the "raw NDVI + phenometrics" datasets. The "NDVIderived phenometrics" alone achieved the lowest accuracies (RF OA = 0.58 and SVM OA = 0.66). Considering that the implementation of preprocessing steps is computationally expensive and does not provide significant gains in terms of classification accuracy, we recommend to use raw vegetation indices for mapping cropping practices in Mato Grosso, including the integrated Crop-Livestock systems.

Dossier Captages : Favoriser l'autoépuration; National audience

International audience; Cloudy conditions reduce the utility of optical imagery for crop monitoring. New constellations of satellites – including the RADARSAT Constellation Mission (RCM) and Sentinel-1A/B, both available under free and open data policies – can be used to create stacks of dense seasonal C-band Synthetic Aperture Radar (SAR) data. Yet to date, the contribution of SAR imagery to operational crop mapping is often limited to that of a gap-filler, compensating for optical data obscured by clouds. The Joint Experiment for Crop Assessment and Monitoring (JECAM) SAR Inter-Comparison Experiment is a multi-year, multi-partner project focused on evaluating methods for SAR-based crop classification. Stacks of dense time-series SAR imagery, from RADARSAT-2 and Sentinel-1 satellites, were acquired for 10 sites located in six countries. Decision Tree (DT) and Random Forest (RF) classification methodologies were applied to these SAR data-stacks, as well as to data-stacks of optical only, and optimized SAR/optical data combinations. For the dense time-series SAR stacks, overall classification accuracies above 85% and 80% were obtained for 6 of 10 and 8 of 10 sites, respectively. For maize, the SAR-only data delivered user’s and producer’s accuracies greater than 90% for half the sites. For soya bean, accuracies greater than 80% were reported for 5 of 9 sites and classification accuracies were greater than 80% for wheat on half the sites. Classification results were influenced by the mix and number of agriculture classes present at each site, the available SAR imagery, as well as the training and validation data sets for individual crop types. These results have important operational implications for regions of the world dominated by cloudy conditions and the lack of adequate amounts of optical imagery to support satellite-based crop monitoring.

International audience; Tropical cropping systems are highly dependent on synthetic insecticides, which generates sustainability issues. We performed a bibliometric analysis of the current insecticide literature (2017-2019) and used the Sustainable Development Goals roadmap to identify research topics in insecticide research that should be promoted to attain sustainable cropping systems. Bioinsecticides and integrated pest management were identified as potential substitutes for synthetic insecticides while insecticide contamination, degradation and impacts on non-target organisms were pinpointed as topics with the potential to lessen detrimental effects of synthetic insecticides. We also highlighted how peculiarities specific to the tropics (tropical climate, high biodiversity, strong traditional knowledge, insecticide regulations, lack of local scientific data, and farmer training through extension services) affect the identified research topics and why they should be taken into account. We finally suggest to combine the identified research topics in order to promote research synergies across disciplines.

The cultivation of vegetables under tunnels is considered a promising alternative to the use of chemicals to manage insect pests. However, higher temperatures under covers hinder their use in warm regions. We investigated the effect of high tunnels covered with plastic film or small or large mesh insect-nets on the performances of tomato plants in Tanzania over two years. Control plants were grown in open field plots. The temperature during the day was 4°C and 15°C higher under the nets and under the plastic than in the open. The total number of insect pests per plant over the season was generally lower under the nets than in open, with the small mesh better than the large mesh. The nets promoted plant growth compared with the open plots, with higher leaf area, plant dry weight, and plant height. Marketable yields were lower in open (2.7 and 10.8 t.ha−1), intermediate under the large mesh (7.9 and 38.4 t.ha−1), and high under the small mesh (16.8 and 50.1 t.ha−1). Higher productivity under the nets was associated with better plant growth and fewer insects than in the open. Contrasting results could be obtained in warmer climates because of the increase in temperatures recorded under tunnels.

International audience; Cover crops are a potential component of agroecological cropping systems, since they may render crop rotations more sustainable. They simultaneously provide multiple ecosystem services, such as decreasing nitrate leaching, decreasing erosion, and increasing soil organic matter. However, cover crops increase evapotranspiration and reduce drainage, which results in a potential disservice for groundwater recharge. Little attention has focused on management of cover crop residues after destruction or their influence on water flux dynamics, particularly in dry and temperate climates. The objective of our study was to analyze and quantify the impact of cover crop management on soil water content and water flux dynamics to understand the main mechanisms of system functioning. We combined a two-year field experiment with crop-model simulations. We performed the field experiment in southwestern France that compared three cover crop treatments, with bare soil as the control. The treatments included (1) living cover crops lasting ca. 9 months from August-April, (2) crushing cover crops in November and leaving them as mulch on the soil, and (3) plowing up cover crops in November to promote residue decomposition and the green manure effect. The STICS soil-crop model was used to predict water fluxes that were not measured and to perform a 20-year independent simulation study based on recent climate series for the experimental site. Our main results indicated that cover crops (1) always reduce water drainage by 20-60 mm compared to that under bare soil; and (2) could significantly reduce soil water content (0-120 cm deep) for the next cash crop by a mean of 20-50 mm, and up to 80 mm in dry spring conditions, but early destruction could decrease this negative impact. The simulations clearly showed that the interaction between climate variability, i.e., rainfall distribution during the fallow period, and cover crop management should be considered to explain the impact of inter-annual variability on the water balance. Thus, destroying cover crops mechanically in late autumn and retaining the residues as mulch could be a good compromise between the multiple services the cover crop provides during the fallow period and avoiding the negative impact on soil water availability for the next cash crop.

Dossier Captage : Favoriser l'autoépuration; National audience

Pests, diseases and weeds are major constraints to cropping system intensification in sub-Saharan Africa. Four major intensification systems to achieve sustainable agriculture have been identified: conventional with high input, organic, agroecological and eco-technical 'sustainable intensive'. Those systems display advanced crop protection. Here we review the performance of those systems in the context of sub-Saharan Africa. The major points are: (1) Unlike economies of Europe and North America following World War 2, and of Asia and Latin America following the Green Revolution, sub-Saharan Africa rural economies were not transformed by conventional intensification involving cultivation of cash crops for export and over-reliance on pesticides. Genetically modified crops were used only to a limited extent at the regional level. (2) Most staple food-based cropping systems are de facto organic due to the unavailability of synthetic inputs. Organic systems are thus developing for some export cash crop sectors, with synthetic pesticides are being substituted by non-chemical pesticides. (3) Agroecological crop protection focuses on biological pest regulations such as the replacement of chemical inputs, thus implying the re-design of cropping systems. (4) For crop protection, the eco-technical pathway, which is based on principles of integrated pest management and ecological intensification, is more flexible and pragmatic than the other systems. In this review we compare the different systems, notably their contribution to six ecosystem services connected with crop protection issues: biomass production, pest and disease regulation, maintenance of water quality, biodiversity conservation, pollination and climate change mitigation. We then identify research needs in the context of food security, urbanization, trade globalization and climate change.

The use and cost of energy in agriculture have increased, making it necessary to make current agricultural practices more energy efficient. To do this, the prevailing systems must be thoroughly analysed. Studies have focused on assessing the energy performance of individual crops, but notably few studies have investigated different cropping systems. This paper aims to assess the energy performance of the two most used cropping systems of the Indo-Gangetic plains in India, namely Paddy rice–Wheat (PW) and Paddy rice–Potato (PP). The PW system was more energy efficient with Energy Use Efficiency (EUE) of 6.87 ± 1.7 compared to 3.61 ± 0.58 for the PP system. Higher Energy Efficiency Ratio (EERM) (3.94 ± 1.30) and Specific Energy(4.39 ± 2.06) (SE) were reported for the PW system, compared to 2.62 ± 0.47 and 2.15 ± 0.35 respectively for the PP system. Fertiliser use accounted for the highest input energy consumption in both systems, accounting for 58% and 51% of the energy consumed in PW and PP systems respectively, followed by fuel, seeds and electricity. The net income from the PP system (2295.7 ± 457.4 USD.ha−1.yr−1) was higher than that from the PW system (1555.4 ± 856.6 USD.ha−1.yr−1). The higher return of PP system was attributed to higher yield and better market price for the potato produce. There were no significant differences reported for various energy and economic parameters within different farm sizes in the PP system. However, for PW system, small farms were energy efficient while larger farms were economically efficient. Keywords: Energy input–output analysis, Indo-Gangetic plains, Energy use efficiency, Cropping system, Paddy rice, Wheat and potato

African mountains are characterized by high levels of biodiversity and provide ecosystem services to millions of people. Due to steep environmental gradients, growing human populations and geographical isolation, these coupled socio-ecological systems are highly vulnerable to climate change impacts. The capacity of local stakeholders to anticipate future changes and to assess their potential impacts are paramount for enhancing adaptation and resilience. Here we apply a participatory scenario development framework in two parts of the Eastern Afromontane Biodiversity Hotspot: Taita Hills in Kenya and Jimma rural area in Ethiopia. In each area, we facilitated local stakeholders in envisioning adaptation scenarios under projected climate changes by mid-21st century, and assessed the potential impacts of these pathways on land use and land cover. In the Taita Hills, under a business-as-usual scenario, human population and activities concentrate at high elevation, triggering cascade effects on remnant forest cover, biodiversity and ecosystem services. Alternative adaptation scenarios envisage reforestation associated with either improved agricultural practices or ecosystem restoration. In the Jimma area, rising temperatures are expected to disrupt traditional coffee production under a business-as-usual scenario, resulting in the loss of coffee-forest canopies and reduction of forest-dependent biodiversity. Alternative adaptation scenarios envisage either expansion of commercial coffee plantations or expansion of agroforestry, including traditional coffee farming. In the both Taita and Jimma, adaptation pathways present trade-offs between provisioning, supporting and regulating services, and between livelihoods and biodiversity conservation. Our findings encourage the use of multidisciplinary, bottom-up approaches for developing locally tailored, climate-smart and sustainable adaptation pathways.

Cocoa production in Côte d'Ivoire (40% of the world market) has tripled in the past 35 years even as the country's forests are depleted. The chocolate industry, concerned about production so concentrated in one country and its dependence on the forest, is trying to convince smallholders to obtain 'cocoa certification.' This scheme, while couched in environmental terms, aims to increase cocoa yields and recommends the removal of kola trees from cocoa plots. This advice, ultimately largely ignored by the cocoa farmers, reflects a lack of understanding of farmer practices and kola tree's economic, social, and cultural role. The chocolate industry reveals its vision for agroforestry as limited to production and demonstrates an unwillingness to participate in the smallholder-driven innovation system that is transforming Ivorian cocoa cultivation.

Soil organic carbon (SOC) sequestration was evaluated for several long-term rain-fed cropping systems for conservation agriculture (CA) and conservation tillage (CT) in Cambodia using the Environmental Policy Integrated Climate (EPIC) model. The mean crop yield, biomass and SOC stocks of four treatments and three replication in each primary cropping system (rice, soybean and cassava) were used for calibration and validation during the period 2009–2013. The CT and CA1 treatments were assigned to continuous cropping of primary crops. CA2 and CA3 treatments were assigned to rotated primary crops with maize. In all CA treatments, forage or legume cover crops were prior planted and intercropped with the primary crops to maintain full soil cover. The results show that EPIC successfully simulated crop yields, biomass, and SOC. However, the model tended to underestimate SOC in the CT treatments and overestimate SOC in the CA2 and CA3 treatments. Crop residue was found to highly influence SOC sequestration. Sediment loss in the CT treatments was found to be four times greater than CA treatments due to the CT tillage effects. The 20-year future simulations, using historical weather and automatically generated by EPIC, showed a decrease trend in SOC stocks in all CT treatments and an increase trend in most CA treatments, with the greatest increase for CA2 and CA3 treatments. Thus, the CA treatments in combination with the maize rotation were demonstrated to be more efficient to manage SOC sequestration over CA with one continuous primary crop.

International audience; This Special Issue highlights new contributions on the role of agroforestry systems for climate change mitigation and adaptation in different pedoclimatic contexts. This Special Issue was launched during the 4th World Congress on Agroforestry (https://agroforestry2019.cirad.fr/) held in Montpellier, France, 20–22 May 2019. This event gathered more than 1200 delegates and leading keynote speakers from 97 countries (Dupraz et al., 2019). Of the 82 articles received, 14 were considered for publication in this Special Issue, including several articles not presented during the congress. This Special Issue includes eight articles on climate change mitigation through agroforestry, and 6 articles on climate change adaptation (Table 1). Research results presented in this Special Issue cover 10 different countries (plus two papers with a global perspective) encompassing a broad range of agroforestry systems, including shaded perennial-crop systems, agroforests, silvopastures, parklands, hedgerows, and riparian systems.