796 research outputs found
Contexte, concepts et définition des cultures intermédiaires multi-services
No full textLa notion de culture intermédiaire a clairement évolué historiquement, en fonction du service recherché,
passant par exemple de la notion d’engrais vert à CIPAN (piège à nitrate) dans les années 1970 à
1990, et aujourd’hui nous proposons d’utiliser l’acronyme de CIMS pour parler de cultures
intermédiaires multi-services). Ces CIMS sont utilisées pour produire des services écosystémiques en
période d’interculture. Ce sont des cultures qui ne sont pas récoltées, elles sont enfouies ou laissées en
surface du sol. Les CIMS permettent de produire simultanément différents services écosystémiques,
avec plus ou moins d’efficacité en fonction des espèces ou du mélange d’espèces semées, de leur
mode de gestion, de la situation pédo-climatique et de la succession de cultures de vente dans laquelle
elles sont insérées. Les services produits concernent i) la gestion de l’azote (effet piège à nitrate), ii) la
protection physique du sol, iii) le stockage de carbone, iv) la réduction des bio-agresseurs (mauvaises
herbes, pathogènes), v) la pollinisation, vi) l’esthétique du paysage. Le bouquet de services qui peut
être produit par la CIMS et l’éventuel compromis recherché entre les services produits doit être défini
explicitement afin de choisir la bonne espèce ou de concevoir l’assemblage d’espèces à implanter. Un
grand nombre de familles botaniques peuvent être utilisées comme CIMS (crucifères, graminées,
légumineuses, composées, autres familles). Toutefois, il convient de choisir des espèces non hôtes des
maladies et ravageurs des cultures principales, ceci pour limiter les éventuels dis-services. De plus,
pour maximiser les services écosystémiques rendus par les mélanges d’espèces, il est nécessaire que
l’association permette une bonne complémentarité de développement et de croissance. Enfin, nous
faisons l’hypothèse que les CIMS, avec des espèces bien choisies et gérés avec des itinéraires
techniques adaptés, peuvent être un levier efficace d’une écologisation des systèmes de culture
français, sans nécessairement avoir besoin de transformer radicalement le système, ni le niveau de
travail du solThe notion of cover crop has clearly evolved historically, in particular in France and Europe, depending
on the service provided, moving from the notion of green manure to catch crop, and today we are
proposing the term of Multi-services cover crops (MSCC). These MSCC are used in agriculture to
produce various ecosystem services during fallow period between two main cash crops. These MSCC
are not harvested and their biomass is returning to the soil (incorporated or at soil surface). The
provision of multi-services depend on the species, the mixtures of species, the management of the
cover crop, the pedo-climat conditions and the cash crop succession in which the MSCC is inserted.
E. Justes et G. The services produced are the following: i) nitrogen management (nitrate catch crop and green
manuring), ii) soil protection, iii) carbon storage in the soil, iv) control and suppression of weeds,
diseases and pests, v) pollinisation of plants and vi) landscape aesthetic. The trade-off between
services produced by the MSCC must be explicitly defined before their setting up in order to correctly
select the right species or the design of species assemblage appropriate to produce the targeted
services and their level of expression. Many botanical families can be used as MSCC (cruciferous,
grass, legume, other families). However, it is advisable to choose non-host species of diseases and
pests of main cash crops, in order to limit the possible dis-services. In addition, to maximize the
ecosystem services provided by species chosen, it is necessary for the association to achieve good
complementarity of development and growth. Finally, we hypothesize that MSCC, with well-chosen
species and well managed, can be an effective lever for an ecologization of French cropping systems,
without necessarily having to radically transform the cropping system, nor the level of soil tillage
Dynamic analysis of competition and complementarity for light and N use to understand the yield and the protein content of a durum wheat-winter pea intercrop
No full textIn a previous paper (Bedoussac and Justes 2009, Plant and Soil DOI: 10.1007/s11104-009-0082-2), we showed that intercropping of durum wheat and winter pea increased the yield and protein concentration of durum wheat when early N availability was less than 120 kg N.ha-1. The aim of the present work was to understand these results by analysing intercrop species dynamics for growth, light and N acquisition. A 2-year field experiment was carried out in SW France with different fertilizer-N levels in order to compare wheat (Triticum turgidum L.) and pea (Pisum sativum L.) grown as sole crops and as an intercrop in a row substitutive design. The advantages of intercropping in low N conditions were mainly due to: i) better light use (up to 10%) thanks to species dynamic complementarity for leaf area index and height, ii) growth complementarity over time (higher growth rate of wheat until pea flowering and then of pea until wheat flowering), and iii) dynamic complementary N acquisition associated with better wheat N status throughout growth. Disadvantages, underlining poorer complementarity within the intercrop stand, were observed with ample available N in early growth. This induced higher cereal growth during winter which led to increase interspecies competition by reducing pea light absorption and consequently its biomass production
Predicting soil water and mineral nitrogen contents with the STICS model for estimating nitrate leaching under agricultural fields
No full textThe performance of the STICS soil-crop model for the dynamic prediction of soil water content (SWC) and soil mineral nitrogen (SMN) in the root zone (120 cm) of seven agricultural fields was evaluated using field measurements in a coarse-grained alluvial aquifer of the Garonne River floodplain (southwestern France) from 2005 to 2007. The STICS model was used to simulate drainage and nitrate concentration in drainage water in all the agricultural fields of the study area, in order to quantify and assess the temporal and spatial variability of nitrate leaching into groundwater. Simulations of SWC and SMN in the seven monitored fields were found to be satisfactory as indicated by root mean square error (RMSE) and model efficiency being 6.8 and 0.84% for SWC and 22.8 and 0.92% for SMN, respectively. On average, SWC was slightly overestimated by a mean difference of 10 mm (3%) and there was almost no bias in SMN estimations (<0.5%). These satisfactory results demonstrate the potential for using the STICS model to accurately simulate nitrate leaching. Across the study area, simulated drainage and nitrate concentration were extremely variable from one field to another. For some fields, simulated mean annual nitrate concentration in drainage water exceeded 300 mg NO3 − L−1 and predicted nitrate leaching was close to 100 kg N ha−1, while other fields had very low nitrate losses. About 15% of the farmers’ fields were responsible for 60–70% of nitrate leaching. The SMN in late autumn, before winter drainage, was found the main determining factor explaining this variability. This situation may be attributed to unsatisfactory cumulative nitrogen management over the medium term. Ineffective nitrogen management was found to be more detrimental than a single annual incident of overfertilization, particularly in situations of deep soils and in cases of low or highly variable drainage between years
The FACCE-ERA-NET+ project Climate - CAFÉ: climate change adaptability of cropping and farming systems for Europe
No full textEric, Justes et al.-- Trabajo presentado en el Climate-smart Agriculture 2015 (Global Science Conference), celebrado en Montpellier del 16 al 18 de marzo de 2015.Climate-CAFE aims to improve the “adaptive capacity” of arable and forage based farming systems to climate
change (CC)
through ecologically intensive adaptation strategies. Strategies will be evaluated at cropping and
farming systems as well as regional levels for “Adaptation Pilots” along a North-South climate gradient in the
EU. Three categories of strategies will be evaluated: i) Resistance strategies that seek to maintain the status
quo through management actions that reduce perturbations due to CC; ii) Resilience strategies requiring
systemic adaptation at field and farm level for increasing the adaptive capacity after a climate disturbance; iii)
Transformative strategies addressing needs and possibilities for re-configuration of cropping and farming
systems. Strategy evaluation will reveal synergies and trade-offs among objectives and their indicators at
different scales under 2050-2100 IPCC scenarios. The proposed adaptation strategies will include improved
soil and water management via ecological intensification, including new cultivars and cultivar mixtures, novel
rotations, alternative tillage options, and the inclusion of legumes cover-and intercrops. Since adaptation is
context-specific, the project will work in “Adaptation Pilots” and local networks of researchers, advisors and
farmers, representative of regional cropping and farming systems. Experimental data (SE, FI, UK, CH, FR and
SP), expert technical and farmer knowledge, and simulation models at the scales of crops (STICS, DAYCENT),
farms and landscapes (MODAM, FarmDESIGN) will be used to characterise adaptation strategies and foster
learning in participatory co-design workshops. The expected result of the Climate-CAFE project is an overview
of potential CC adaptation measures at the three considered levels for selected sites across the EU, along with
mutual learning experiences for improved understanding and acceptability of CC adaptation strategies among
farmers and other stakeholders.N
Evaluation of the impact of various agricultural practices on nitrate leaching under the root zone of potato and sugar beet using the STICS soil–crop model
No full textThe quaternary aquifer of Vitoria-Gasteiz (Basque Country, Northern Spain) is characterised by a shallow water table mainly fed by drainage water, and thus constitutes a vulnerable zone in regards to nitrate pollution. Field studies were performed with a potato crop in 1993 and a sugar beet crop in 2002 to evaluate their impact on nitrate leaching. The overall predictive quality of the STICS soil–crop model was first evaluated using field data and then the model was used to analyze dynamically the impacts of different crop management practices on nitrate leaching. The model was evaluated (i) on soil nitrate concentrations at different depths and (ii) on crop yields. The simulated values proved to be in satisfactory agreement with measured values. Nitrate leaching was more pronounced with the potato crop thanwith the sugar beet experiment due to i) greater precipitation, ii) lower N uptake of the potato crop due to shallow root depth, and iii) a shorter period of growth. The potato experiment showed that excessive irrigation could significantly increase nitrate leaching by increasing both drainage and nitrate concentrations. The different levels of N-fertilization examined in the sugar beet study had no notable effects on nitrate leaching due to its high N uptake capacity. Complementary virtual experiments were carried out using the STICS model. Our study confirmed that in vulnerable zones agricultural practices must be adjusted, that is to say: 1) N-fertilizer should not be applied in autumn before winter crops; 2) crops with low N uptake capacity (e.g. potatoes) should be avoided or should be preceded and followed by nitrogen catch crops or cover crops; 3) the nitrate concentration of irrigation water should be taken into account in calculation of the N-fertilization rate, and 4) Nfertilization must be precisely adjusted in particular for potato crops
Nutrition azotée et fonctionnement agrophysiologique spécifique des légumineuses
No full textAvec la contribution de : Guénaëlle Corre-Hellou, Jean-Jacques Drevon, Gérard Duc, Pierre Jouffret, Eric Justes, Bernadette Julier, Christophe Naudin, Anne Schneider, Pascal Thiébeau, Françoise Vertès.absen
Nouveau regard sur la genèse du Dernier des Justes
No full textLe premier roman d’André Schwarz-Bart (1928-2006), Le Dernier des Justes, paru au Seuil en septembre 1959 connut un succès considérable dès avant l’attribution du Prix Goncourt en décembre de la même année et fut aussitôt traduit dans une trentaine de langues. Répondant à la nécessité intérieure de rendre hommage aux membres de sa famille assassinée à Auschwitz, de célébrer la mémoire du peuple juif massacré par les nazis, ce roman conçu comme un petit caillou déposé sur une tombe de nuages se présente comme une « saga identitaire » (F. Kaufmann),un récit mythico-historique Après plusieurs expériences d’écriture entre 1945 et 1953, le noyau initial du roman apparaît en 1953 autour du personnage contemporain d’Ernie Lévy puis remonte le temps pour inscrire Auschwitz dans neuf siècles d’antisémitisme européen. Il n’aboutit que six ans plus tard, au bout de cinq versions aux approches et tons différents, passant du lyrisme à l’ironie, de la distance narrative à celle des légendes juives et des chroniques médiévales. L’étude génétique de ce roman foisonnant se fonde sur une thèse universitaire et cinquante ans de recherches. Elle s’appuie sur l’analyse de notes et de brouillons confiés par l’auteur dans les années 70, ou consultés après sa mort dans sa maison de Goyave (Guadeloupe). Le processus de création de l’œuvre est également éclairé par des échanges avec l’auteur (correspondance, notes prises lors de rencontres et d’entretiens téléphoniques), ainsi que par des interviews et des analyses littéraires contenues dans les trois imposants dossiers de presse réunis par les éditions du Seuil à la suite de la publication du Dernier des Justes, et dépouillés en 1972. La correspondance entre l’auteur et le Seuil a été consultée dans les archives de l’IMEC en août 2019. La correspondance privée d’André Schwarz-Bart avec Robert Kocioleck, un ami d’après-guerre, a été consultée et étudiée à Jérusalem.André Schwarz-Bart’s (1928-2006) first novel, Le Dernier des Justes, published by Le Seuil in September 1959, was already a great success before being awarded the Prix Goncourt in December of that year and was immediately translated into some thirty languages. Responding to the inner need to pay homage to the members of his family murdered in Auschwitz, to celebrate the memory of the Jewish people massacred by the Nazis, this novel, conceived as a small pebble placed on a grave of clouds, is presented as an “identity Saga” (F. Kaufmann), a mythico-historical narrative. After several writing experiments between 1945 and 1953, the initial core of the novel appeared in 1953 around the contemporary character of Ernie Lévy, and then went back in time to inscribe Auschwitz in nine centuries of European anti-Semitism. It was completed six years later, after five versions, each one with different approaches and tones, moving from lyricism to irony, from narrative distance to that of Jewish legends and medieval chronicles. The genetic story of this ample novel is based on a university thesis and fifty years of research. It is grounded on the analysis of notes and drafts entrusted by the author in the 1970s, or consulted after his death in his house in Goyave (Guadeloupe). The creative process of the novel is also fueled by exchanges with the author (correspondence, notes taken during meetings and telephone conversations), as well as by interviews and literary analyses contained in the three imposing press files gathered by the Seuil publishing house following the publication of The Last of the Just, and studied in 1972. The correspondence between the author and Le Seuil was consulted in the IMEC archives in August 2019. André Schwarz-Bart’s private correspondence with Robert Kocioleck, a post-war friend, was consulted and studied in Jerusalem. Translated by www.DeepL.com/Translator (free version) and reviewed
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