The development of the organic vegetable market and supply in the UK

The vegetable market is one of the largest sectors within the UK organic food market. This market has grown by 30% p.a. over the last 5 years, although it is now slowing down to a rate of 10-15% p.a. The production of UK organic vegetables increased rapidly from 1999 -2001, as growers responded to economic and policy incentives, and now the UK is 57% self sufficient in organic vegetables. Many new UK farmers have converted to organic production, although this process has involved high costs, largely due to having to take land out of production in the conversion period. However, once converted, farmers have in many cases, experienced overall financial returns that have been comparable or higher than conventional returns, although these good returns are highly dependent on high prices for organic vegetables. In comparison with conventional systems costs of organic vegetable production can be high, especially for organic seeds and for increased casual labour required for hand weeding. The resulting larger workforce, often required for organic vegetable production, can pose new management challenges. In the future, market growth and the numbers of farmers converting, will be slower and any market growth will depend on broadening the customer base, expanding different market channels and increasing home production especially at the beginning and the end of the season, thus enabling a substitution of imports

National-scale modelling of N leaching in organic and conventional horticultural crop rotations - policy implications

A method is presented to model N leaching in crop rotations on a national scale. Representative crop rotations for different regions and soil types are used in the cross-disciplinary, plant, soil, environment & economics model EU-Rotate_N. By comparing contrasting farming systems (organic and conventional) in the UK, their strengths and weaknesses in delivering environmental and economic sustainability can be assessed. Modelling results show that the annual leaching in different horticultural rotations and UK regions, using median weather, is within the range of 13-88 kg N/ha/year for organic and 54-130 kg N /ha/year for conventional. The weighted annual average figures are 39 kg N/ha/year for organic and 81 kg N/ha/year for conventional, respectively. It is concluded that organic horticultural rotations, with a current share of 6.1% already contribute to lower overall N losses from agriculture. However, on a UK national scale, only a large share of organic land use (e.g. >50%) has a large effect on reducing N losses. Similar reductions are also predicted by substantial cuts in conventional N inputs, giving a policy choice if pollution from agriculture steps up further on the political agenda

Environmental and economic modelling of organic, stockless, horticultural crop rotations

Selected results from the ongoing “EU-Rotate_N” research project are presented. This EU 5th-framework project is developing a model-based decision support system to optimise nitrogen use in horticultural crop rotations across Europe. This paper introduces the economic and the fertility-building crops sub-models, and shows data from model validation and first model runs on an organic farm in central England. Preliminary results show that the model has the potential to be a powerful support tool for farmers and advisors, making decisions on rotational plan-ning. The economic, agronomic and environmental consequences of different rotational designs can be projected and assessed in detail

The ecological footprint method on a farm level – a case study on a UK organic farm with parallel cropping

There is increasing interest in the farming community to understand and improve their ecological footprint and reduce CO2-carbon emissions. This case study compares the ecological footprint of organic and conventional cabbage, celeriac, sugar beet and winter wheat crops on a UK commercial, parallel cropping, farm. Results show lower ecological footprints and energy ratios in all organic crops. However, CO2-emissions per unit yield are only lower if the fertility building is not considered. Including energy use for fertility building and reducing yields in proportion to the fertility area brings CO2-emissions per unit yield level with conventional. It is concluded that in order to improve their ecological footprint organic farming needs to improve yield levels and make better use of the fertility area by using it as biogas for energy production, growing main crop legumes or using only short-term fertility building

The Footprint of Genome Architecture in the Largest Genome Expansion in RNA Viruses

The small size of RNA virus genomes (2-to-32 kb) has been attributed to high mutation rates during replication, which is thought to lack proof-reading. This paradigm is being revisited owing to the discovery of a 3′-to-5′ exoribonuclease (ExoN) in nidoviruses, a monophyletic group of positive-stranded RNA viruses with a conserved genome architecture. ExoN, a homolog of canonical DNA proof-reading enzymes, is exclusively encoded by nidoviruses with genomes larger than 20 kb. All other known non-segmented RNA viruses have smaller genomes. Here we use evolutionary analyses to show that the two- to three-fold expansion of the nidovirus genome was accompanied by a large number of replacements in conserved proteins at a scale comparable to that in the Tree of Life. To unravel common evolutionary patterns in such genetically diverse viruses, we established the relation between genomic regions in nidoviruses in a sequence alignment-free manner. We exploited the conservation of the genome architecture to partition each genome into five non-overlapping regions: 5′ untranslated region (UTR), open reading frame (ORF) 1a, ORF1b, 3′ORFs (encompassing the 3′-proximal ORFs), and 3′ UTR. Each region was analyzed for its contribution to genome size change under different models. The non-linear model statistically outperformed the linear one and captured >92% of data variation. Accordingly, nidovirus genomes were concluded to have reached different points on an expansion trajectory dominated by consecutive increases of ORF1b, ORF1a, and 3′ORFs. Our findings indicate a unidirectional hierarchical relation between these genome regions, which are distinguished by their expression mechanism. In contrast, these regions cooperate bi-directionally on a functional level in the virus life cycle, in which they predominantly control genome replication, genome expression, and virus dissemination, respectively. Collectively, our findings suggest that genome architecture and the associated region-specific division of labor leave a footprint on genome expansion and may limit RNA genome size