Farmers’ management of functional biodiversity goes beyond pest management in organic European apple orchards

Supporting functional biodiversity (FB), which provides natural pest regulation, is an environmentally sound and promising approach to reduce pesticide use in perennial cultures such as apple, especially in organic farming. However, little is known about farmers’ practices and motivations to implement techniques that favor FB, especially whether or not they really expect anything from FB in terms of pest regulation. In fact, FB-supporting techniques (FB-techniques) are massively questioned by practitioners due to inadequate information about their effectiveness. An interview survey was performed in eight European countries(i) to describe farmers’ practices and identify promising FB-techniques: (ii) to better understand their perceptions of and values associated with FB; and (iii) to identify potential drivers of (non-)adoption. Fifty-five advisors and 125 orchard managers with various degrees of experience and convictions about FB were interviewed and a total of 24 different FB-techniques which can be assigned to three different categories (ecological infrastructures, farming practices and redesign techniques) were described. Some were well-established measures (e.g., hedges and bird houses), while others were more marginal and more recent (e.g., animal introduction and compost). On average, farmers combined more than four techniques that had been implemented over a period of 13 years, especially during their establishment or conversion period. In general, it was difficult for farmers to evaluate the effectiveness of individual FB-techniques on pest regulation. They considered FB-techniques as a whole, targeting multiple species, and valued multiple ecosystem services in addition to pest regulation. The techniques implemented and their associated values differed among farmers who adopted various approaches towards FB. Three different approaches were defined: passive, active and integrated. Their appraisal of FB is even more complex because it may change with time and experience. These findings provide empirical evidence that the practical implementation of promising techniques remains a challenge, considering the diversity of situations and evaluation criteria. Increased cooperation between researchers, farmers and advisors should more effectively target research, advisory support and communication to meet farmers’ needs and perceptions

An additive manufactured CubeSat mirror incorporating a novel circular lattice

Additive Manufacturing (AM; 3D printing) for mirror fabrication allows for intricate designs that can combine lightweight structures and integrated mounting. Conventional lightweight structures utilise cubic or prismatic unit cells, which do not provide uniform support at the edge of curved mirrors. We present a new circular lattice based upon cylindrical coordinates and how this lattice has been incorporated within an 80 mm diameter mirror intended for use in a 3U CubeSat telescope. Several design iterations are explored, which include prototype mirrors produced in a titanium alloy and a finite element analysis of the one of the design iterations

Monitoring functional agrobiodiversity in orchards : Going to Assessment !

This video presents three monitoring methods (threshing, trap strip and predation plate) that can be used in orchards to monitor functional biodiversity and assess the presence or activity of useful beneficials to control certain pests. The advantage of these simplified methods is that fruit farmers can use them independently to assess the effect of their agro-ecological practices or infrastructures on functional biodiversity

Observer la biodiversité fonctionnelle en arboriculture : aller jusqu'à l'évaluation

This video presents three monitoring methods (threshing, trap strip and predation plate) that can be used in orchards to monitor functional biodiversity and assess the presence or activity of useful beneficials to control certain pests. The advantage of these simplified methods is that fruit farmers can use them independently to assess the effect of their agro-ecological practices or infrastructures on functional biodiversity

Origin of dielectric polarization suppression in confined water from first principles

It has long been known that the dielectric constant of confined water should be different from that in bulk. Recent experiments have shown that it is vanishingly small, however the origin of the phenomenon remains unclear. Here we used ab initio molecular dynamics simulations (AIMD) and AIMD-trained machine-learning potentials to understand water's structure and electronic properties underpinning this effect. For the graphene and hexagonal boron-nitride substrates considered, we find that it originates in the spontaneous anti-parallel alignment of the water dipoles in the first two water layers near the solid interface. The interfacial layers exhibit net ferroelectric ordering, resulting in an overall anti-ferroelectric arrangement of confined water. Together with constrained hydrogen-bonding orientations, this leads to much reduced out-of-plane polarization. Furthermore, we directly contrast AIMD and simple classical force-field simulations, revealing important differences. This work offers insight into a property of water that is critical in modulating surface forces, the electric-double-layer formation and molecular solvation, and shows a way to compute it.<br/

Origin of dielectric polarization suppression in confined water from first principles.

Acknowledgements: The authors thank D. V. Matyushov for fruitful discussions. T. D. and L. F. were supported by the European Research Council (grant 819417) under the European Union Horizon 2020 Research and Innovation Programme. A. M. acknowledges support from the European Union under the “n-aqua” European Research Council project (grant 101071937). C. S. acknowledges partial financial support from the Alexander von Humboldt-Stiftung and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) project number 500244608. J. C. and A. M. thank Beijing Municipal Natural Science Foundation (no. JQ22001) for support. We are grateful to the UK Materials and Molecular Modelling Hub for computational resources, which is partially funded by EPSRC (EP/P020194/1 and EP/T022213/1), and computational support from the UK national high performance computing service, ARCHER, for which access was obtained via the UKCP consortium, funded by EPSRC grant ref. EP/P022561/1. We are also grateful to the Research IT and the use of the High Performance Computing (HPC) Pool funded by the Research Lifecycle Programme at the University of Manchester.It has long been known that the dielectric constant of confined water should be different from that in bulk. Recent experiments have shown that it is vanishingly small, however the origin of the phenomenon remains unclear. Here we used ab initio molecular dynamics simulations (AIMD) and AIMD-trained machine-learning potentials to understand water's structure and electronic properties underpinning this effect. For the graphene and hexagonal boron-nitride substrates considered, we find that it originates in the spontaneous anti-parallel alignment of the water dipoles in the first two water layers near the solid interface. The interfacial layers exhibit net ferroelectric ordering, resulting in an overall anti-ferroelectric arrangement of confined water. Together with constrained hydrogen-bonding orientations, this leads to much reduced out-of-plane polarization. Furthermore, we directly contrast AIMD and simple classical force-field simulations, revealing important differences. This work offers insight into a property of water that is critical in modulating surface forces, the electric-double-layer formation and molecular solvation, and shows a way to compute it

Co-design of agroecological temperate fruit tree systems in France: the ALTO project

International audienceCrop diversification and agroecological practices preserving biodiversity are a way to foster ecosystem services. The ALTO project is a multi-actor research project based on new fruit production concepts. Three diversified orchards in three sites of Southern France were designed following the same objectives of ecological intensification and production in very low or pesticide-free systems. Agronomic, ecological and organizational aspects were involved in the co-design approach. The first system is a newly planted circular orchard with a pest suppressive design. The second is an orchard, with previous agroecological infrastructures and fruit trees, that has evolved “step by step” into a diversified production area. The third site investigates the effects of spatial arrangement of an agroforestry apple agrosystem on tree architecture and functioning. The design and the evaluation of these experimental systems address three main questions, shared by one, two or all sites: 1) Can crop and non-crop diversification, as well as spatial arrangement, limit fruit damage caused by pests? 2) Can crop design, more specifically agroforestry, impacts abiotic resource sharing between crops? 3) How growing fruit-trees in these diversified systems impact workload and organization? Although this research is in progress and requires multi-year data, the first results provide feedback on the effectiveness of pest suppressive strategies (trap plants and low-susceptibility cultivars, barrier effects, flower strips and diversified surrounding landscape to favor natural enemies of pests, etc.), as well as on resource sharing for light, and on flowering. Tradeoffs between agronomic, ecological and organizational aspects are also investigated. Besides, the experimental prototypes are likely to evolve with time integrating further exchanges with stakeholders and lessons from on-going management. Multicriteria evaluation of these experimented multi-production prototypes is still in progress but the present analysis opens avenues for agroecological design in perennial crops

Varietal and technical innovations for the sustainable and integrated management of root-knot nematodes

International audienceThe current restrictions on the use of chemical nematicides have contributed to increased root-knot nematodes (Meloidogyne spp.) problems in horticultural crops. In this context, plant resistance (R) appears as the most effective method of control, but the restricted number of cultivated vegetable species with root-knot nematode R-genes available (tomato, pepper), and the possible occurrence of virulent nematodes able to reproduce on R-plants may constitute a severe threat to this control strategy. To increase the sustainability of the protection, a scientific challenge exists in building cropping strategies based on the combination of genetic resistance with cultivation practices. Our projects aimed at assessing such innovative strategies in a multi-site device in research stations and commercial farms. First, we looked at three components of crop protection, i.e., R-efficiency, R-durability, and sustainability of rotating cultivation. Overall, a constant hierarchy of management strategies was observed, with Pyramyding > Alternating > Mixture of R-genes > Sequential use of a single R-gene introgressed in a susceptible background. We are currently analysing (1) the impact of agronomic practices on the parasite pressure in the soil and on ecological diversity including other nematode species, (2) the linkage between reduction of Meloidogyne populations in the soil and increase of R-genes durability, and (3) the sustainability assessment of such varietal and technical innovations. Multidisciplinary approaches were combined to foster synergistic and long-term goals. The diversity of partners and associated forces brought all the complementary expertise needed for answering specific short-term questions as well as generic mid- to long-term expectations