► Overall assessment of pea–wheat mixtures based on a 16 site-years experimental network. ► Yields and wheat protein concentrations of mixtures are close to conventionally managed wheat. ► Energetic ...cost significantly higher with conventionally managed wheat compared to mixtures. ► Mixtures maintained margin, increased N2 fixation, and reduced pesticide and soil N after harvest. ► Cereal–legume mixture is a promising way to produce biomass in a sustainable way.
Intensive agriculture ensures high yields but can cause serious environmental damages. The optimal use of soil and atmospheric sources of nitrogen in cereal–legume mixtures may allow farmers to maintain high production levels and good quality with low external N inputs, and could potentially decrease environmental impacts, particularly through a more efficient energy use. These potential advantages are presented in an overall assessment of cereal–legume systems, accounting for the agronomic, environmental, energetic, and economic performances. Based on a low-input experimental field network including 16 site-years, we found that yields of pea–wheat intercrops (about 4.5Mgha−1 whatever the amount of applied fertiliser) were higher than sole pea and close to conventionally managed wheat yields (5.4Mgha−1 on average), the intercrop requiring less than half of the nitrogen fertiliser per ton of grain compared to the sole wheat. The land equivalent ratio and a statistical analysis based on the Price's equation showed that the crop mixture was more efficient than sole crops particularly under unfertilised situations. The estimated amount of energy consumed per ton of harvested grains was two to three times higher with conventionally managed wheat than with pea–wheat mixtures (fertilised or not). The intercrops allowed (i) maintaining wheat grain protein concentration and gross margin compared to wheat sole crop and (ii) increased the contribution of N2 fixation to total N accumulation of pea crop in the mixture compared to pea sole crop. They also led to a reduction of (i) pesticide use compared to sole crops and (ii) soil mineral nitrogen after harvest compared to pea sole crop. Our results demonstrate that pea–wheat intercropping is a promising way to produce cereal grains in an efficient, economically sustainable and environmentally friendly way.
Organic agriculture is a production system which relies on ecosystem management and ecological processes rather than on the external flow of agricultural inputs. The development of the organic sector ...has induced a spatial decoupling of livestock and crop production. This has increased the flow of nutrients that occurs between farms compared to what happens within individual farms. Organic systems have replaced synthetic inputs with site-specific management practices to balance input and output nutrients to ensure short-term productivity and long-term sustainability. This paper addresses the nutrient management of mixed and specialized farming systems, with a special emphasis on the reliance on livestock production for the nutrient management of arable farmland. We assessed the nutrient budgets of nitrogen (N), phosphorus (P), and potassium (K) of 28 organic farms selected according to livestock density from three French counties. The farms were classified as stockless, mixed, and cattle farming systems. A soil surface nutrient budget was calculated for each farm based on inputs (N fixation, excreta, and manure) and outputs (grazing offtake, harvests) on annual crops and grasslands. Inputs due to N atmospheric deposition and seeds and losses due to leaching and volatilization were not considered in this study. Nutrient budgets of the 28 farms revealed N, P, and K deficits, although disparities between farming systems and their geographical location were also observed. Stockless farms presented high N deficit whereas mixed and livestock farming systems presented lower deficits (close to equilibrium) or even surpluses in a county with a high density of livestock farms. Differences between farming systems in terms of P and K budgets followed the same trend, but regional specificities appeared significant in stockless and livestock systems (related to the size of farms and the stocking rate). None of the farms purchased off-farm organic fertilizers when exchanges of manures and straw were observed at the regional scale. When livestock is present on the farm, the nutrient resources came mainly from recycling internal resources (manures, excreta, and N fixation), whereas stockless farming systems purchased organic manure from neighboring farms (14 to 58 % of total N inputs, 10 to 100 % of total P and K inputs). The sustainability of stockless organic farming systems is questioned, noticeably those that were located in regions where resources of organic matter are scarce. Only farming systems producing large quantities of manure or which purchased feed showed balanced nutrient budgets.
Organic farming practices are a possible way to reconcile agricultural production and water quality, but the comparative merits of conventional and organic farming practices regarding the nitrogen ...(N) issue are complex and still being debated. This study was designed to investigate the choices governing conversion to organic farming of an experimental mixed dairy farm in Lorraine (eastern France) and to highlight the associated changes in N fluxes. The study was conducted over a suitably long period of time at a farm scale integrating the diversity of practices in one conventional and then two autonomous organic systems (a grazing livestock system and a mixed dairy system). Two indicators were used to draw up the main features. First, the farm-gate N budgets show that the organic farm has a balance twice as low as the conventional system. Second, the soil surface balance exhibited substantial differences between functional zones. Finally, this study shows that an accurate estimation of soil surface balance requires taking into account the spatial distribution within the farm area based on practices and their rationale.
Intensive agriculture ensures high yields but can cause serious environmental damages. The optimal use of soil and atmospheric sources of nitrogen in cerealalegume mixtures may allow farmers to ...maintain high production levels and good quality with low external N inputs, and could potentially decrease environmental impacts, particularly through a more efficient energy use. These potential advantages are presented in an overall assessment of cerealalegume systems, accounting for the agronomic, environmental, energetic, and economic performances. Based on a low-input experimental field network including 16 site-years, we found that yields of peaawheat intercrops (about 4.5 Mg haa1 whatever the amount of applied fertiliser) were higher than sole pea and close to conventionally managed wheat yields (5.4 Mg haa1 on average), the intercrop requiring less than half of the nitrogen fertiliser per ton of grain compared to the sole wheat. The land equivalent ratio and a statistical analysis based on the Price's equation showed that the crop mixture was more efficient than sole crops particularly under unfertilised situations. The estimated amount of energy consumed per ton of harvested grains was two to three times higher with conventionally managed wheat than with peaawheat mixtures (fertilised or not). The intercrops allowed (i) maintaining wheat grain protein concentration and gross margin compared to wheat sole crop and (ii) increased the contribution of N2 fixation to total N accumulation of pea crop in the mixture compared to pea sole crop. They also led to a reduction of (i) pesticide use compared to sole crops and (ii) soil mineral nitrogen after harvest compared to pea sole crop. Our results demonstrate that peaawheat intercropping is a promising way to produce cereal grains in an efficient, economically sustainable and environmentally friendly way.
Face aux enjeux de durabilité agronomique et environnementale, l'unité Inra de Mirecourt, étudie, depuis 2004, deux systèmes de production agricole en polyculture élevage de bovins laitiers au sein ...de son domaine expérimental. Un des objectifs de cette étude, prévue pour une période de 15 ans, est de mesurer l'impact des pratiques agricoles et du milieu sur la biodiversité faunistique en suivant les populations de carabes. Chargé d'élaborer le protocole de recueil de données à mettre en oeuvre sur le terrain, j'ai développé, à l'aide d'un Système d'Informations Géographiques (SIG), une méthode qui permet d'établir toutes les entités "Unités de Sols/Pratiques culturales (USP)" existantes sur les parcelles du Domaine. L'échantillonnage a été réalisé à partir de critères tels que la taille des entités, le comportement des carabes, la distance aux bordures des parcelles et les moyens humains. Finalement, le piégeage a été réalisé au sein de sept types de sol et huit groupes de pratiques. L'utilisation de l'outil SIG a permis de représenter et d'analyser les données à l'échelle de la parcelle et de limiter le temps passé sur le terrain. La méthode d'échantillonnage a été utilisée pour la mise en place d'autres suivis tels que les évolutions de fertilité des sols et de flore.
Face aux enjeux de durabilité agronomique et environnementale, l'unité Inra de Mirecourt, étudie, depuis 2004, deux systèmes de production agricole en polyculture élevage de bovins laitiers au sein ...de son domaine expérimental. Un des objectifs de cette étude, prévue pour une période de 15 ans, est de mesurer l'impact des pratiques agricoles et du milieu sur la biodiversité faunistique en suivant les populations de carabes. Chargé d'élaborer le protocole de recueil de données à mettre en oeuvre sur le terrain, j'ai développé, à l'aide d'un Système d'Informations Géographiques (SIG), une méthode qui permet d'établir toutes les entités "Unités de Sols/Pratiques culturales (USP)" existantes sur les parcelles du Domaine. L'échantillonnage a été réalisé à partir de critères tels que la taille des entités, le comportement des carabes, la distance aux bordures des parcelles et les moyens humains. Finalement, le piégeage a été réalisé au sein de sept types de sol et huit groupes de pratiques. L'utilisation de l'outil SIG a permis de représenter et d'analyser les données à l'échelle de la parcelle et de limiter le temps passé sur le terrain. La méthode d'échantillonnage a été utilisée pour la mise en place d'autres suivis tels que les évolutions de fertilité des sols et de flore.
Face aux enjeux de durabilité agronomique et environnementale, l'unité Inra de Mirecourt, étudie, depuis 2004, deux systèmes de production agricole en polyculture élevage de bovins laitiers au sein ...de son domaine expérimental. Un des objectifs de cette étude, prévue pour une période de 15 ans, est de mesurer l'impact des pratiques agricoles et du milieu sur la biodiversité faunistique en suivant les populations de carabes. Chargé d'élaborer le protocole de recueil de données à mettre en oeuvre sur le terrain, j'ai développé, à l'aide d'un Système d'Informations Géographiques (SIG), une méthode qui permet d'établir toutes les entités "Unités de Sols/Pratiques culturales (USP)" existantes sur les parcelles du Domaine. L'échantillonnage a été réalisé à partir de critères tels que la taille des entités, le comportement des carabes, la distance aux bordures des parcelles et les moyens humains. Finalement, le piégeage a été réalisé au sein de sept types de sol et huit groupes de pratiques. L'utilisation de l'outil SIG a permis de représenter et d'analyser les données à l'échelle de la parcelle et de limiter le temps passé sur le terrain. La méthode d'échantillonnage a été utilisée pour la mise en place d'autres suivis tels que les évolutions de fertilité des sols et de flore.
L'évaluation de l'autonomie alimentaire d'un système d'élevage est à situer au niveau de l'ensemble du système de production quand elle concerne une exploitation prise isolément. A ce niveau ...d'organisation, les marges de progrès en matière d'autonomie relèvent selon nous d'abord d'une recontextualisation des choix de stratégie d'alimentation au regard du milieu "naturel" et des potentialités parcellaires de l'exploitation agricole, qui conditionnent la production végétale et sa valorisation. Cette posture a présidé à la conduite des systèmes laitiers en AB de Mirecourt depuis le début de leur conception pas à pas et leur conversion à l'Agriculture Biologique. Dans cette perpective, une quantification de l'autonomie des deux élevages laitiers considérés (herbager spécialisé sur prairies permanentes d'une part, et combiné à la production de céréales avec des prairies temporaires d'autre part) a été réalisée pour 3 années consécutives (2010, 2011 et 2012) au moyen des composantes de l'indicateur de durabilité PAEP proposé par Delaby et al (2013). Il en résulte la confirmation chiffrée que le fort degré d'autonomie visé est atteint par ces deux systèmes, dans des proportions très voisines, à la fois au plan énergétique et au plan de l'azote. Si l'efficacité productive est particulièrement élevée au regard des intrants mobilisés en très faible quantité, il reste que la production végétale valorisée est de fait relativement limitée...et probablement améliorable.
The assessment of the food self-sufficiency in a livestock farming system is more relevant at the farm level. Scope for progress relies on the forage and feed strategy in regard with land capabilities which determine primary plant procution then its valorization. This idea prevailed with the management of the two organic dairy systems in Mirecourt (France) since the start of the step-by-step design and the turning to organic farming. A quantification of self-sufficiency of two dairy farming systems was made for 3 consecutive years (2010, 2011 and 2012) using the components of the global sustainability indicator PAEP (Delaby et al, 2013). The intended strong degree of self-sufficiency is reached in two systems both with regard to the energy consumption and to the nitrogen use. The procutive efficiency is high considering the inputs used but the valorized plant production remains rather limited and certainly improvable.
L'évaluation de l'autonomie alimentaire d'un système d'élevage est à situer au niveau de l'ensemble du système de production quand elle concerne une exploitation prise isolément. A ce niveau ...d'organisation, les marges de progrès en matière d'autonomie relèvent selon nous d'abord d'une recontextualisation des choix de stratégie d'alimentation au regard du milieu "naturel" et des potentialités parcellaires de l'exploitation agricole, qui conditionnent la production végétale et sa valorisation. Cette posture a présidé à la conduite des systèmes laitiers en AB de Mirecourt depuis le début de leur conception pas à pas et leur conversion à l'Agriculture Biologique. Dans cette perpective, une quantification de l'autonomie des deux élevages laitiers considérés (herbager spécialisé sur prairies permanentes d'une part, et combiné à la production de céréales avec des prairies temporaires d'autre part) a été réalisée pour 3 années consécutives (2010, 2011 et 2012) au moyen des composantes de l'indicateur de durabilité PAEP proposé par Delaby et al (2013). Il en résulte la confirmation chiffrée que le fort degré d'autonomie visé est atteint par ces deux systèmes, dans des proportions très voisines, à la fois au plan énergétique et au plan de l'azote. Si l'efficacité productive est particulièrement élevée au regard des intrants mobilisés en très faible quantité, il reste que la production végétale valorisée est de fait relativement limitée...et probablement améliorable.
The assessment of the food self-sufficiency in a livestock farming system is more relevant at the farm level. Scope for progress relies on the forage and feed strategy in regard with land capabilities which determine primary plant procution then its valorization. This idea prevailed with the management of the two organic dairy systems in Mirecourt (France) since the start of the step-by-step design and the turning to organic farming. A quantification of self-sufficiency of two dairy farming systems was made for 3 consecutive years (2010, 2011 and 2012) using the components of the global sustainability indicator PAEP (Delaby et al, 2013). The intended strong degree of self-sufficiency is reached in two systems both with regard to the energy consumption and to the nitrogen use. The procutive efficiency is high considering the inputs used but the valorized plant production remains rather limited and certainly improvable.
Organic agriculture is a production system which relies on ecosystem management and ecological processes rather than on the external flow of agricultural inputs. The development of the organic sector ...has incluced a spatial decoupling of livestock and crop production. This has increased the flow of nutrients that occurs between farms compared to what happens within individual farms. Organic systems have replaced synthetic inputs with site-specific management practices to balance input and output nutrients to ensure short-term productivity and long-term sustainability. This paper addresses the nutrient management of mixed and specialized farming systems, with a special emphasis on the reliance on livestock production for the nutrient management of arable farmland. We assessed the nutrient budgets of nitrogen (N), phosphorus (P), and potassium (K) of 28 organic farms selected according to livestock density from three French countries. The farms were classified as stockless, mixed, and cattle farming systems. A soil surface nutrient budget was calculated for each farm based on inputs (N fixation, excreta, and manure) and outputs (grazing, offtake, harvests) on annual crops and grasslands. Inputs due to N atmospheric deposition and seeds and losses due to leaching and volatization were not considered in this study. Nutrient budgets of the 28 farms revealed N, P and K deficits, although disparities between farming systems and their geographical location were also observed. Stockless farms presented high N deficit whereas mixed and livestock farming systems presented lower deficits (close to equilibrium) or even surpluses in a county with a high density of livestock farms. Differences between farming systems in terms of P and K budgets followed the same trend, but regional specificities appreared significant in stockless and livestock systems (related to the size of farms and the stocking rate). None of the farms purchased off-farm organic fertilizers when exchanges of manures and straw were observed at the regional scale. When livestock is present on the farm, the nutrient resources came mainly from recycling internal resources (manures, excreta, and N fixation), whereas stockless farming systems purchased organic manure from neighboring farms ( 14 to 58 % of total N inputs, 10 to 100 % of total P and K inputs). The sustainability of stockless organic farming systems is questioned, noticeably those that were located in regions where resources of organic matter are scarce. Only farming systems producing large quantities of manure or which purchased feed showed balanced nutrient budgets.
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