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The economic potential of agroecology: empirical evidence from Europe
No full textInternational audienceThis article discusses the economic dimensions of agroecological farming systems in Europe. It firstly theoretically elaborates the reasons why, and under what conditions, agroecological farming systems have the potential to produce higher incomes than farms that follow the conventional logic. This theoretical exposition is then followed by a presentation of empirical material from a wide range of European countries that shows the extent to which this potential is being realized. The empirical data draw upon different styles of farming that can be described as ‘proto-agroecological’: approaches to farming that are agroecological by nature, but which may not necessarily explicitly define themselves as agroecological. The empirical material that we present shows the huge potential and radical opportunities that Europe's, often silent, ‘agroecological turn’ offers to farmers that could (and should) be the basis for the future transformation of European agricultural policies, since agroecology not only allows for more sustainable production of healthier food but also considerably improves farmers' incomes. It equally carries the promise of re-enlarging productive agricultural (and related) employment and increasing the total income generated by the agricultural sector, at both regional and national levels. While we recognise that agroecology is a worldwide and multidimensional phenomenon we have chosen to limit this analysis to Europe and the economic dimension. This choice is made in order to refute current discourses that represent agroecology as unproductive and unprofitable and an option that would require massive subsidies
Application of analytic hierarchy process to develop a weighting scheme for life cycle assessment of agricultural production
No full textInternational audienceThe Impact Assessment (IA) step in Life Cycle Assessment (LCA) studies is classified into three steps of characterization, normalization and weighting. In this research, various impact categories were weighted using Analytic Hierarchy Process (AHP), as a multi criteria decision making tool. Iranian tobacco production system was the example of agricultural system. The data for LCA analysis were collected from 225 farms. The data for AHP analysis were gathered by surveying 12 LCA experts. The results indicated that on-farm emissions of CO2, CH4, N2O, NH3, NOx and SO2 were accounted for 25, 96, 93, 99, 21 and 2% of the total emissions (cradle to farm gate), respectively. The characterization indices for the impact categories of acidification, terrestrial eutrophication, global warming, phosphate resources depletion, potash resources depletion and fossil resources depletion for one ton tobacco production were calculated to be 13.87 kgSO2eq, 19.69 kgNOxeq, 1883.90 kgCO2eq, 19.69 kgNOxeq, 4.19 kgP2O5, 6.14 kgK2O, and 59,659.23 MJ, respectively. The LCA + AHP showed that the weighted factors of global warming, terrestrial eutrophication, acidification, fossil resources depletion, phosphate resources depletion and potash resources depletion were 1, 0.790, 0.518, 0.681, 0.422, and 0.263, respectively. Many agricultural systems could benefit from using the developed weighting factors for LCA studies in the agricultural sector. Based on the new developed weighted factors, the weighted indices of aforementioned impact categories for Iranian tobacco production were 0.24, 0.41, 0.19, 1.04, 0.23, and 0.20, respectively. This implies that fossil resources depletion impact category was attributed the highest negative environmental impacts of tobacco production followed by terrestrial eutrophication
Motivations et stratégies pour développer les légumineuses : trajectoires d’insertion de légumineuses dans les exploitations agricoles de deux territoires (Bourgogne et Pays de la Loire)
No full textMotivations et stratégies pour développer les légumineuses : trajectoires d’insertion de légumineuses dans les exploitations agricoles de deux territoires (Bourgogne et Pays de la Loire). Séminaire Protéines des programmes de recherche PSDR Bourgogne – Franche-Comté et du Groupe opérationnel PROTEIN
Comparison Between an Animal-Derived Product Medium and a Chemically Defined Medium for Ram Sperm Cryopreservation
No full textInternational audienceAnimal-derived products are widely used in sperm cryopreservation for their cryoprotective properties. These components, however, tend to be replaced because of sanitary risks. STEMALPHA.CRYO3 (Ref. 5617; Stem Alpha, Saint-Genis-l'Argentiere, France), called "CRYO3," is a chemically defined preservation medium currently used for freezing human tissue and adult stem cells. The aim of this study was to evaluate the effect of a CRYO3-based medium on ram sperm freezing regarding in vitro parameters and in vivo fertility. Semen from nine Charolais rams was collected using an artificial vagina, then split and frozen using two media: a CRYO3-based medium or a control medium containing egg yolk (10%) and milk (45%). Sperm membrane integrity (propidium iodide [PI]/SYBR-14 and calcein AM/ethidium homodimer-1), acrosome integrity (FITC-PNA/PI), and mitochondrial membrane potential (JC-1) were assessed using flow cytometry, while functional membrane integrity was assessed using a hypo-osmotic swelling test and motility parameters, evaluated by computer-assisted sperm analysis. Pregnancy rates, prolificacy, and the average daily weight gain (DWG) of lambs were evaluated after performing 195 laparoscopic inseminations. The control medium showed significantly higher results than CRYO-based medium for all in vitro parameters, except for linearity and straightness (motions parameters). Conversely, field trials showed no significant difference between the control medium and the CRYO3-based medium for pregnancy rates (72.2% and 67.9%, respectively), prolificacy (1.8 and 1.6, respectively), and the DWG (0.34 and 0.35 kg/d, respectively). This preliminary study showed that CRYO3 cannot replace egg yolk and milk in freezing extenders for commercial purposes. However, as laparoscopic inseminations allowed a 67% pregnancy rate, CRYO3-based medium remains an option for international transport or long-term storage of genetic diversity
Estimating the contribution of crop residues to soil organic carbon conservation
No full textInternational audienceAbstract Crop residues contribute to the maintenance of soil organic carbon (SOC) stores, a key component of soil fertility and soil-based climate change mitigation strategies, such as the ‘4 per 1000’ initiative. Residues are also in demand in sectors coupled to crop production, such as the supply chain of livestock and bioenergy production. Ongoing debate revolves around balancing these competing uses, but science-based assessments of the long-term sustainability of residue exploitation are rare. This work uses biophysical simulation modelling to explore the likely response of SOC to different management strategies, using the land area of North Rhine-Westphalia (Germany) as a case study. Four strategies are tested: zero, one third and 100% removal of cereal residues, plus an approach proposed by the State farm advisory service. Simulations are carried out for the period 1971–2050 and 19 crop rotations coincident with land use throughout the study area. Uncertainty associated with the modelled SOC changes is explored by sampling values of relevant parameters for SOC turnover and running an ensemble of model configurations. Simulated SOC is used to trace time-dependent response functions following a change in residue management under different soil textures, initial SOC levels and crop rotations. Results highlight a general exponential decrease in SOC, with relative changes in 2050 distributed between +10% and −40% with respect to a reference period. SOC loss can be buffered or offset by returning all crop residues to the soil. Under such management, an SOC increase can be achieved on clayey soils characterized by a low initial SOC. Under moderate crop residue removal, positive SOC trends are limited to a few crop rotations. In this context, 4 per 1000 increase rate in SOC appears largely out of reach through residue management, calling for additional measures to meet the targets of land-based mitigation of anthropogenic emissions
Agroecological practices for climate change adaptation in semiarid and subhumid Africa
No full textInternational audienceClimate change is expected to strongly affect African farming systems. As vast proportions of African countries’ populations rely on agriculture for livelihood and food security, there is a need to adapt current practices and develop new climate-resilient strategies and farming systems. Here, we inventory and review which agroecological practices currently implemented in semiarid and subhumid Africa can promote adaptation to climate change. This work was carried out through extensive literature research, plus interviews with 24 experts from different African and French NGOs active in agricultural development programs in Africa. We found that: (1) some inventoried practices may not specifically be implemented in response to climate change impacts, yet they aid in adapting to reduced or more variable rainfall and increased temperature, and/or enhance carbon sequestration; (2) other practices promote indirect adaptation by increasing resilience of cropping or livestock systems; (3) many farmers use combinations of different practices to increase overall farming system resilience and through this strategy can achieve efficient adaptation to climate changes, as single practices normally are not sufficient. Our review and evaluation show that a broad variety of agroecological practices provides high potential to adapt to climate change effects in semiarid and subhumid African farming systems
Effects of Reduced Tillage on Weed Pressure, Nitrogen Availability and Winter Wheat Yields under Organic Management
No full textInternational audienceReduced tillage reduces soil erosion and increases topsoil organic matter compared with conventional tillage. However, yields are often reported to be lower, presumably, due to increased weed pressure and a slower N mineralization under organic farming conditions. The effects of reduced tillage compared with ploughing on weed infestation and winter wheat performance at four different crop stages, i.e., tillering, stem elongation, flowering, and harvest, was monitored for a single season in an eleven-year-old organic long-term tillage trial. To disentangle the effects of weed presence on crop yield and potential crop performance, subplots were cleaned from weeds during the whole cropping season. Weed biomass was consistently higher under reduced tillage. Soil mineral nitrogen contents under reduced tillage management were higher, which could be explained by the earlier ley termination in autumn compared with the conventional tillage system. Nitrogen status of wheat assessed with SPAD measurements was consequently higher under reduced tillage throughout the season. At harvest, wheat biomass and grain yield were similar in both tillage systems in the presence of weeds, but 15–18% higher in the reduced tillage system when weeds were removed. The negative impact of weeds on yields were not found with conventional tillage with a low weed infestation. Results suggest that reduced tillage can provide equivalent and even higher yields to conventional tillage in organically managed winter wheat if weed management is improved and good nutrient supply is assured
Perspectives on Perennial Grain Crop Production among Organic and Conventional Farmers in France and the United States
No full textInternational audiencePerennial grain crops are currently being developed, yet little is known about farmer interest in these new crops. We conducted an online survey in France and the United States to evaluate interest in perennial grains. Results show that 57% of the farmers who responded reported they were “interested” or “very interested” in growing perennial grains, whereas 41% reported they needed more information. Respondents consistently ranked “to increase or maintain farm profitability” and “to improve soil health” among the top reasons why they were interested in growing perennial grains. Reasons why farmers were interested, as well as their concerns about growing perennial grains, differed by country and farm type (i.e., conventional vs. organic). More farmers in France than in the United States ranked “to reduce labor requirements”, and more conventional farmers than organic farmers ranked “to reduce inputs” among their top reasons for their interest. Farmers were also asked about integration strategies and management. More farmers in the United States than in France and more conventional farmers than organic farmers reported that they were interested in dual-purpose perennial crops that can be harvested for both grain and forage. Results from this survey can guide future perennial grain research and development
Integrating multipurpose perennial grains crops in Western European farming systems
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Using mulch from cover crops to facilitate organic no-till soybean and maize production. A review
No full textInternational audienceSustainable cropping systems that balance agricultural productivity and ecological integrity are urgently needed. Overreliance on soil tillage and herbicides to manage weeds has resulted in a number of major environmental problems including soil erosion and degradation, biodiversity loss, and water quality impairment. Combining organic farming and conservation agriculture is a viable alternative to address these challenges. In particular, mulch-based no tillage systems can be used to reduce tillage in organic production, improving soil quality while decreasing labor and fuel requirements. This technique involves planting cash crops directly into terminated cover crops that remain on soil surface and serve as mulch to prevent weeds establishment and protect soil from erosion. Despite potential benefits, adoption of organic mulch-based no tillage is limited due to challenges with cover crop termination, weed suppression, and yields. Here, we (i) review international research on organic mulch-based no tillage systems (soybean and maize), (ii) identify production issues that limit the success of this technique, and (iii) outline research priorities. As result, organic mulch-based no tillage is knowledge intensive and requires advanced planning and careful management of the cover crop. Primary challenges include timely cover crop establishment and termination, nutrient management, reduced soil temperature and moisture at planting, and achieving adequate seed-to-soil contact when planting into thick mulch on soil surface. Long-term research is needed to better understand the effects of this technique production on soil health and on the broader environmental and economic impacts. To increase adoption of organic mulch-based no tillage, future research should focus on (i) screening species and cultivars to identify cover crop and crop combinations that optimize cropping system performance and (ii) developing equipment for improving cover crop termination and seed placement. Research conducted in partnership with farmers will be valuable for developing guidelines and increasing adoption of this technique