Emissions by aerial routes from protected crop systems (greenhouses and crops grown under cover) : a position paper

This report describes the processes that may lead to emission of Plant Protection Products (PPP) from protected cultivation, through aerial routes. The introduction gives the background for this work and the limitations, outlining in particular why receptors other than air are not explicitly addressed here. Chapters 2 discusses the physical background of greenhouse air exchanges and the factors that affect it. Existing models for estimating ventilation of the different types of greenhouses are reviewed there. Chapter 3 gives a scientific argument about the processes and the factors that may affect aerial emissions of PPP from protected cultivations. The parameters that may have an high impact on the emission are identified there as well. A review of the knowledge needed and of the models that may be available for scoring each emission route is given in Chapter 4. In Chapter 5 a strategy is proposed to reduce/group the number of factors that are important (and to score their relevance) through some model calculations. An outline of the calculations that would be needed for ranking and eventually scoring the emissions and, possibly, highlight groupings of combinations that are similar with respect to emissions, is given

Research collaboration between China and Denmark for development of systemic approaches to agro-ecological pest management without pesticides with focus on vegetable, fruit and berry crops. Proceedings and recommendations from two network workshops

This report is the result of a network project which was established to discuss the potential for collaboration on development of systemic approaches to pest management without pesticides between Chinese and Danish researchers. The focus is on systemic approaches rather than input substitution of synthetic chemicals with agents of natural origin, however, the latter is considered as an integrated tool for the development and design of systemic approaches. The discussions were, furthermore, limited to management of invertebrate pests as well as diseases, while other pests such as weeds have not been included in the discussions. The discussions took place at two workshops and were based on presentations of research from the two countries and field visits in China and Denmark. After the first workshop that took place in China, it was agreed that Chinese and Danish researchers in this particular field had mutual interests and priorities and that there was a potential for creating collaboration that could yield results beneficial for the agricultural/horticultural sectors in both countries. It was also agreed that in spite of the many differences between variation in climate and ecosystems, as well as in farming systems and their organization in China and Denmark, there were many similarities in the production of high-value crops in the two countries, such as vegetables, fruit and berries and, therefore, an obvious focus for joint research efforts. It was also agreed that joint research efforts could aim at specific crops as well as aiming at the development of specific research approaches. Based on the observations and the agreements of the first workshop, the second workshop, which took place in Denmark, focused more specifically on the development of a research framework with specified research questions/topics. Two groups were formed – one working with vegetables and one with fruit and berries working in parallel – both looking into what kind of research is needed for development of systemic approaches to pesticide-free pest management should include both well-known practices and new practices. Although the discussions in the two groups took separate routes and unfolded and described the research topics in each their way, there was a clear consistency between the outputs of the work of the two groups. Each had identified three main research themes that more or less followed the same line and has been merged into three specific recommendations on themes for collaboration, namely: 1) ‘Research to provide the biological foundation and understanding of mechanisms and interactions for development of non-chemical solutions and to improve efficiency of new and existing control methods for severe pest problems’. 2) Research in ‘How best to integrate multifunctional plants (and crops) and use diversification to create a more healthy and productive farming system which is resilient to pests?’ 3) Research in ‘How to design and integrate pest management in eco-functional cropping systems at field and farm/landscape level?

Soil Infrastructure, Interfaces & Translocation Processes in Inner Space (“Soil-it-is”): Towards a Road Map for the Constraints and Crossroads of Soil Architecture and Biophysical Processes

Soil functions and their impact on health, economy, and the environment are evident at the macro scale but determined at the micro scale, based on interactions between soil micro-architecture and the transport and transformation processes occurring in the soil infrastructure comprising pore and particle networks and at their interfaces. Soil structure formation and its resilience to disturbance are highly dynamic features affected by management (energy input), moisture (matric potential), and solids composition and complexation (organic matter and clay interactions). In this paper we review and put into perspective preliminary results of the newly started research program “Soil-it-is” on functional soil architecture. To identify and quantify biophysical constraints on soil structure changes and resilience, we claim that new approaches are needed to better interpret processes and parameters measured at the bulk soil scale and their links to the seemingly chaotic soil inner space behavior at the micro scale. As a first step, we revisit the soil matrix (solids phase) and pore system (water and air phases), constituting the complementary and interactive networks of soil infrastructure. For a field-pair with contrasting soil management, we suggest new ways of data analysis on measured soil-gas transport parameters at different moisture conditions to evaluate controls of soil matrix and pore network formation. Results imply that some soils form sponge-like pore networks (mostly healthy soils in terms of agricultural and environmental functions), while other soils form pipe-like structures (agriculturally poorly functioning soils), with the difference related to both complexation of organic matter and degradation of soil structure. The recently presented Dexter et al. (2008) threshold (ratio of clay to organic carbon of 10 kg kg-1) is found to be a promising constraint for a soil’s ability to maintain or regenerate functional structure. Next, we show the Dexter et al. (2008) threshold may also apply to hydrological and physical-chemical interface phenomena including soil-water repellency and sorption of volatile organic vapors (gas-water-solids interfaces) as well as polycyclic aromatic hydrocarbons (water-solids interfaces). However, data for differently-managed soils imply that energy input, soil-moisture status, and vegetation (quality of eluded organic matter) may be equally important constraints together with the complexation and degradation of organic carbon in deciding functional soil architecture and interface processes. Finally, we envision a road map to soil inner space where we search for the main controls of particle and pore network changes and structure build-up and resilience at each crossroad of biophysical parameters, where, for example, complexation between organic matter and clay, and moisture-induced changes from hydrophilic to hydrophobic surface conditions can play a role. We hypothesize that each crossroad (e.g. between organic carbon/clay ratio and matric potential) may control how soil self-organization will manifest itself at a given time as affected by gradients in energy and moisture from soil use and climate. The road map may serve as inspiration for renewed and multi-disciplinary focus on functional soil architecture

Long-term fate of sewage-sludge derived cadmium in arable soils

The focus of this work was to improve knowledge of the long-term fate of cadmium supplied to arable soils by sewage sludge. Emphasis was placed on measured and modelled changes in the solubility and mobility of cadmium, resulting from long-term turnover of both sludge-derived and inherent organic matter of the soil. Measurements were conducted in a long-term sludge supplied field experiment, situated at Ultuna (60°N, 17°E), started in 1956. Furthermore, batch studies on soil samples and modelling exercises in WHAM were performed in order to study the speciation of cadmium in the soil-solution system. A comprehensive model -the SLAM model- was developed to increase the understanding of the influence of soil and sludge adsorption characteristics on cadmium solubility and bioavailability, and the migration rate of cadmium in soil profiles. The long-term sludge supplies had increased the solubility of cadmium, measured in crop cadmium concentration, as an effect of enhanced acidification and increased Cd concentration in the soil. A low Cd migration was measured, attributed to non-equilibrium Cd concentration in percolating water, a high cadmium sorption capacity in the subsoil and root driven Cd circulation in the soil profile. No increased Cd sorption capacity was measured in the sludge supplied soil, despite the almost doubled soil organic matter content. This might be partly attributed to the higher iron oxide and hydroxide concentration measured in the sludge, forming more stable complexes with soil humic compounds compared to cadmium complexes with soil humic compounds. A Monte-Carlo analysis of the SLAM model suggested that the major parameters affecting leaching and crop uptake of cadmium were the cadmium loading and the partitioning coefficient for sludge-derived inorganic material and parameters controlling the effect of pH on sorption. Long-term scenario simulations in SLAM identified critical factors influencing plant cadmium uptake: the cadmium concentration in the sludge, the adsorption capacity of the sludge in relation to the adsorption capacity of native soil and the proportion of the sludge adsorption capacity contributed by the inorganic fraction

Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions

Background Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity because of the combined effects of surface chemistry and roughness. The physical and chemical complexity of the plant cuticle limits the development of models that explain its internal structure and interactions with surface-applied agrochemicals. In this article we introduce a thermodynamic method for estimating the solubilities of model plant surface constituents and relating them to the effects of agrochemicals. Results Following the van Krevelen and Hoftyzer method, we calculated the solubility parameters of three model plant species and eight compounds that differ in hydrophobicity and polarity. In addition, intact tissues were examined by scanning electron microscopy and the surface free energy, polarity, solubility parameter and work of adhesion of each were calculated from contact angle measurements of three liquids with different polarities. By comparing the affinities between plant surface constituents and agrochemicals derived from (a) theoretical calculations and (b) contact angle measurements we were able to distinguish the physical effect of surface roughness from the effect of the chemical nature of the epicuticular waxes. A solubility parameter model for plant surfaces is proposed on the basis of an increasing gradient from the cuticular surface towards the underlying cell wall. Conclusions The procedure enabled us to predict the interactions among agrochemicals, plant surfaces, and cuticular and cell wall components, and promises to be a useful tool for improving our understanding of biological surface interactions

Integrated grain storage - technology transfer for organic farming

The attached document is the final report of the Defra Project OF0176. Demand for organic grain continues to grow and currently in the UK much has to be imported to satisfy the market. Expansion of UK production, together with continued imports, will see an increase in the need for effective grain storage using organic methods to preserve the quality of this valuable commodity. The objectives of this project were to conduct a desk study review to: 1) Highlight the main grain storage problems experienced by organic growers in the UK. 2) Bring together in a more convenient form technical information already available that will enable growers to tackle these problems more successfully. 3) Identify areas of current storage technology requiring a minimum of modification to ensure a smooth transfer from the conventional to the organic sector. 4) Identify areas where appropriate organic alternatives to conventional storage procedures do not exist that will require further research and development to find replacements. The following have been identified as areas requiring further research and development that are likely to provide important opportunities for improving the storage of organic grain: • Store structure cleaning, including the effectiveness of vacuum cleaning and steam treatments, and the feasibility of using diatomaceous earths to control invertebrate pests. • Energy efficient drying and cooling systems, and consider the use of renewable energy sources including solar and wind power or the processing of waste products and energy crops. • More effective invertebrate pest monitoring through improvements in sampling strategies, together with enhanced trap design and the incorporation of lures. • Disinfestation using grain cleaners and hot air driers. • Biological control for store structure treatments. This will require work to assess the effectiveness of naturally occurring biological control agents to treat residual infestations hidden in empty grain store structures. Strategies will need to be developed to encourage the development and conservation of beneficial invertebrates in stores, including the possible use of natural semiochemicals to manipulate their behaviour. • Biological control for surface infestations of grain. As well as looking at the practicality of using top-dressing or bait trap application techniques to control grain surface infestations in cooled bins, there is a need to develop effective methods for the removal of beneficial invertebrates from the grain immediately before it is marketed. A more detailed Executive Summary can be found at the top of the main report

Technologies for climate change adaptation: agricultural sector

This Guidebook presents a selection of technologies for climate change adaptation in the agricultural sector. A set of twenty two adaptation technologies are showcased that are primarily based on the principals of agroecology, but also include scientific technologies of climate and biological sciences complemented with important sociological and institutional capacity building processes that are required to make adaptation function. The technologies cover monitoring and forecasting the climate, sustainable water use and management, soil management, sustainable crop management, seed conservation, sustainable forest management and sustainable livestock management. Technologies that tend to homogenize the natural environment and agricultural production have low possibilities of success in conditions of environmental stress that are likely to result from climate change. On the other hand, technologies that allow for, and indeed promote, diversity are more likely to provide a strategy which strengthens agricultural production in the face of uncertain future climate change scenarios. In this sense, the twenty two technologies showcased in this Guidebook have been selected because they facilitate the conservation and restoration of diversity while at the same time providing opportunities for increasing agricultural productivity. Many of these technologies are not new to agricultural production practices, but they are implemented based on assessment of current and possible future impacts of climate change in a particular location. Agro-ecology is an approach that encompasses concepts of sustainable production and biodiversity promotion and therefore provides a useful framework for identifying and selecting appropriate adaptation technologies for the agricultural sector. The Guidebook provides a systematic analysis of the most relevant information available on climate change adaptation technologies in the agriculture sector. It has been compiled based on a literature review of key publications, journal articles, and e-platforms, and by drawing on documented experiences sourced from a range of organizations working on projects and programmes concerned with climate change adaptation technologies in the agricultural sector. Its geographic scope is focused on developing countries where high levels of poverty, agricultural production, climate variability and biological diversity currently intersect. Key concepts around climate change adaptation are not universally agreed. It is therefore important to understand local contexts – especially social and cultural norms - when working with national and sub-national stakeholders to make informed decisions about appropriate technology options. Thus, decision-making processes should be participative, facilitated, and consensus-building oriented and should be based on the following key guiding principles: increasing awareness and knowledge, strengthening institutions, protecting natural resources, providing financial assistance and developing context-specific strategies. For decision-making the Community–Based Adaptation framework is proposed for creating inclusive governance that engages a range of stakeholders directly with local or district government and national coordinating bodies, and facilitates participatory planning, monitoring and implementation of adaptation activities. Seven criteria are suggested for the prioritization of adaptation technologies: (i) The extent to which the technology maintains or strengthens biological diversity and is environmentally sustainable; (ii) The extent to which the technology facilitates access to information systems and awareness of climate change information; (iii) Whether the technology support water, carbon and nutrient cycles and enables stable and/or increased productivity; (iv) Income-generating potential, cost-benefit analysis and contribution to improved equity; (v) Respect for cultural diversity and facilitation of inter-cultural exchange; (vi) Potential for integration into regional and national policies and can be scaled-up; (vii) The extent to which the technology builds formal and information institutions and social networks. Finally, recommendations are set out for practitioners and policy makers: • There is an urgent need for improved climate modelling and forecasting which can provide a basis for informed decision-making and the implementation of adaptation strategies. This should include traditional knowledge. • Information is also required to better understand the behaviour of plants, animals, pests and diseases as they react to climate change. • Potential changes in economic and social systems in the future under different climate scenarios should also be investigated so that the implications of adaptation strategy and planning choices are better understood. • It is important to secure effective flows of information through appropriate dissemination channels. This is vital for building adaptive capacity and decision-making processes. • Improved analysis of adaptation technologies is required to show how they can contribute to building adaptive capacity and resilience in the agricultural sector. This information needs to be compiled and disseminated for a range of stakeholders from local to national level. • Relationships between policy makers, researchers and communities should be built so that technologies and planning processes are developed in partnership, responding to producers’ needs and integrating their knowledge

Mitigating ground effect on mini quadcopters with model reference adaptive control

Mitigating ground effect becomes a big challenge for autonomous aerial vehicles when they are flying in close proximity to the ground. This paper aims to develop a precise model of ground effect on mini quadcopters, provide an advanced control algorithm to counter the model uncertainty and, as a result, improves the command tracking performance when the vehicle is in the ground effect region. The mathematical model of ground effect has been established through a series of experiments and validated by a flight test. The experiments show that the total thrust generated by rotors increases linearly as the vehicle gets closer to the ground, which is different from the commonly-used ground effect model for a single rotor vehicle. In addition, the model switches from a piecewise linear to a quadratic function when the rotor to rotor distance is increased. A control architecture that utilizes the model reference adaptive controller (MRAC) has also been designed, where MRAC is added to the altitude loop. The performance of the proposed control algorithm has been evaluated through a set of flight tests on a mini quadcopter platform and compared with a traditional proportional–integral–derivative (PID) controller. The results demonstrate that MRAC dramatically improves the tracking performance of altitude command and can reduce the rise time by 80 % under the ground effect