Diversified rotations in protected vegetable production systems (DiverIMPACTS Practice Abstract)

By relying on these principles, it is possible to design rotations that are more favourable to the preservation of soil health while taking into account the organisational constraints of a farm and economic opportunities

Challenges of complying with both food value chain specifications and agroecology principles in vegetable crop protection

To meet the challenges of sustainability in agricultural system design, reducing the dependency on synthetic plant protection products has become a core issue. There are currently two major reasons for farmers' decision to reduce their use of synthetic products: public policies, and the extralegal requirements of food supply chains. To reduce or eliminate synthetic plant protection products, agroecological crop protection (ACP) relying on the development of agroecology science and practices is a promising holistic approach focused on crop health overall. ACP requires a consistent combination of various agronomic practices at different spatiotemporal and trophic levels. Vegetable crops are minor crops facing the major challenges of producing high-quality produce and of controlling sanitary pressure on yields. Thus, agroecological vegetable systems must not only be adapted to official regulations and environmental parameters but must also comply with the specifications of the targeted food value chains (FVC), which are variable: marketing standards regarding cosmetic issues are very strict in long value chains, whereas they are more flexible in local short chains. Whereas fresh vegetable production is strongly challenged by the reduction of synthetic plant protection products, there are few studies that show how to design, manage and assess agroecological crop protection strategies for such systems, considering the main specifications and criteria of the FVC as a whole. This article reports on the challenges of complying with both FVC specifications and agroecology principles in protected vegetable crop protection. This study relies on four cropping systems implemented in an experimental station for 4.5 years, each of which had a specific strategy of crop protection management and was devoted to a particular FVC. The four FVCs are "local direct sale in lowpesticide farming", "local direct sale in organic farming", "super- and hypermarket value chain in low-pesticide farming" and "super- and hypermarkets value chain in organic farming". Results consist in the description of combination of agronomic practices used, as well as the corresponding decision-making processes. They then present the performance of the four systems tested, showing that agroecological crop protection strategies are successful in reducing or eliminating synthetic plant protection products. We then discuss failure and success factors highlighted by this multi-year experiment. It illustrates that agroecological crop protection and compliance with the FVC's expectations can be compatible but involve specific trade-offs, depending on the targeted food value chain. We finally stress key areas to investigate further in order to achieve still challenging objectives in vegetable systems

Design, experimentation and assessment of four protected vegetable cropping systems adapted to different food systems

Design, experimentation and assessment of four protected vegetable cropping systems adapted to different food systems. 5. International Symposium for Farming Systems Design (AGRO2015

Participatory design of innovative intercropping systems in protected market gardening production

Participatory design of innovative intercropping systems in protected market gardening production. Innovation in Integrated & Organic Horticulture, INNOHORT 201

Analysis of young Miscanthus x giganteus yield variability: a survey of farmers' fields in east central France

Miscanthus x giganteus is often regarded as one of the most promising crops to produce bioenergy because it is renowned for its high biomass yields, combined with low input requirements. However, its productivity has been mainly studied in experimental conditions. Our study aimed at characterizing and explaining young M.giganteus yield variability on a farmers' field network located in the supply area of a cooperative society in east central France. It included the first three growth years of the crop. We defined and calculated a set of indicators of limiting factors that could be involved in yield variations and used the mixed-model method to identify those explaining most of the yield variation. Commercial yields averaged 8.1 and 12.8 t DM ha(-1) for the second and third growth year, respectively. However, these mean results concealed a high variability, ranging from 3 to 19 t DM ha(-1). Commercial yields, measured on whole fields, were on average 20% lower than plot yields, measured on a small area (two plots of 25 m(2)). Yields were found to be much more related to shoot density than to shoot mass, and particularly to the shoot density established at the end of the planting year. We highlighted that planting success was decisive and was built during the whole plantation year. Fields with the lowest yields also had the highest weed cover, which was influenced by the distance between the field and the farmhouse, the preceding crop and the soil type. Our findings show that growing young M.giganteus on farmers' fields involves limiting factors different from those commonly reported in the literature for experimental conditions and they could be useful to assess the economic and environmental impacts of growing M.giganteus on farmers' fields. They could also stimulate the discussion about growing bioenergy crops on marginal lands

Design and assessment of protected market gardening cropping systems suited to contrasted food systems

Design and assessment of protected market gardening cropping systems suited to contrasted food systems. Innovation in Integrated & Organic Horticulture, INNOHORT 201

Lower average yields but similar yield variability in organic versus conventional horticulture: A meta-analysis

Organic agriculture prohibits the use of almost all synthetic inputs and it is expected to have lower impacts on natural resources than conventional agriculture. However, previous meta-analyses have shown that yields in organic systems are in average 8 to 25% lower compared with conventional systems. Here, we focus on horticulture (fruits and vegetables) and we refine our knowledge by characterising the distributions of organic and conventional yields both in terms of average yield loss and in terms of variability across experiments and across years. We built a new dataset including 636 ratios of organic versus conventional yields covering 37 horticultural species and 17 countries and estimated (i) mean yield ratios, (ii) yield ratio probability distribution across experiments and (iii) interannual yield variances in organic and conventional systems. Our results show that yields in organic horticulture are indeed on average 10 to 32% lower than those in conventional horticulture but they exhibit large variation across experiments. An analysis of yield ratio probability distribution shows that yield loss in organic horticulture has about 10% chances to exceed 50% compared to conventional systems. The analysis gives also around 20% chances to get higher yields in organic horticulture compared to conventional systems. None of the tested covariates (e.g. crop type, climate zone) was able to explain a significant part of the yield ratio variability. We find no evidence of a larger interannual variability (i.e. lower yield stability) in organic versus conventional horticulture. Longer-term trials could nonetheless help substantiate this result. Our results support also the needs to conduct new experiments in countries from the Southern Hemisphere and to collect standard data on crop management and environmental characteristics