Why carbon footprinting (and carbon labelling) only tells half the story

The UK is a world leader in the use of carbon footprints. The introduction of PAS2050 has legitimised carbon footprinting and manufacturers and retailers have responded by estimating carbon footprints for selected products. In industrial production, where the relationship between inputs and outputs is constant and the process is tightly controlled, carbon footprints tend to be reproducible. However, agricultural production is different, being influenced by biological, geological and climatic variation. Thus, although the use of a single value to represent the carbon burden of a food product is appealing, in practice it can be misleading. This paper discusses the variability associated with carbon footprints of agricultural products and considers the value of carbon labelling. We suggest that carbon footprinting is a useful approach that will assist in the transition to a low carbon society but that current approaches to carbon labelling may not help consumers understand the carbon burden of agricultural products

Assessing the costs and benefits of agricultural production using an ecosystem approach

Integrated Farm Management (IFM) is seen as one way for agriculture to contribute towards the UKs challenging national targets for climate change, pollution, biodiversity and other environmental factors. Whilst it is clear that IFM and associated assurance schemes have a role in food quality and enhancement of the environment, they fail to address a number of issues. In particular, they fail to take sufficient account of ‘impact’ and ‘outcome’. In contrast, the relatively new concept of an ecosystem approach does consider these and there is extensive synergy between this approach and IFM. This is pertinent because the UK Department for the Environment, Food and Rural Affairs (Defra) is taking steps to embed an ecosystem approach in policy-making and delivery. This paper sets out to explore the links between IFM and an ecosystem approach and introduces a simple matrix to show how an ecosystem approach might be used to assess the outcome of IFM practices. Limited use of an ecosystem approach suggests that this type of methodology could deliver useful results for IFM. However, it should be used as a decision-support tool rather than a decision-maker. The advantage of using an ecosystem approach for assessing the impact of IFM is that it provides a holistic assessment of land management strategies, rather than focusing on either cropping, or environmental management, alone. However, the values assigned to individual parameters are generally based on expert opinion and, as such, are open to interpretation. Indeed, an ecosystem approach should be interdisciplinary, utilising the knowledge and expertise of a range of stakeholders. Whilst the development of an ecosystem approach for use within an agricultural setting shows promise, it is still in its infancy. There is a need for much discussion, between many disciplines, before it becomes accepted practice

Contribution of integrated farm management (IFM) to Defra objectives

A farming system comprises a complex of interrelated and interacting factors. Any study of an isolated part of the system will not provide adequate understanding of the behaviour of the entire system and interactions may be equally or more important than individual components. There is therefore a requirement for the development of integrated approaches and practices to help farming systems adapt to, eliminate or reduce the negative impacts of production on the environment. This must be achieved whilst maintaining the economic viability of the farm enterprise. Our analysis has confirmed that IFM techniques generally have far more beneficial than adverse effects on current Defra policy objectives. However, there are some notable ‘conflicts’ where a technique that has a large beneficial effect in one policy area has a large negative effect in another. Carbon footprinting is used to quantify the impact of some integrated farming practices

Living on the edge : using and improving trap crops for flea beetle management in small-scale cropping systems

The use of trap crops to manage pest insects offers an attractive alternative to synthetic pesticides. Trap crops may work particularly well at smaller production scales, being highly amenable where crop diversification and reduction of synthetic inputs are prioritised over yield alone. This paper describes a series of experiments. The first was to demonstrate the potential of turnip rape (Brassica rapa L., var. Pasja) as a trap crop to arrest flea beetles (Phyllotreta spp.) to protect a main crop of cauliflower (Brassica oleracea L., var. Lateman). The subsequent experiments explored two possible approaches to improve the function of the trap crop—either by separating trap and main crop plants spatially, or by introducing companion plants of tomato (Lycopersicon esculentum Mill., cv Amateur) into the main crop. In caged field experiments, feeding damage by flea beetles to crop border plantings of turnip rape far exceeded damage to cauliflower plants placed in the same position, indicating a “trap crop effect”. Neither turnip rape plants nor cauliflower as a border significantly reduced flea beetle damage to main crop cauliflower plants, although the numbers of feeding holes in these plants were lowest where a turnip rape border was used. In similar cages, leaving gaps of 3–6 m of bare soil between turnip rape and cauliflower plants significantly reduced feeding damage to the latter, as compared to when plants were adjacent. The results of a small-scale open field trial showed that a turnip rape trap crop alone reduced flea beetle damage to cauliflower, significantly so later in the season at higher pest pressures, but that addition of tomato companion plants did not improve pest control potential

Phenology of the Diamondback moth (Plutella xylostella) in the UK and provision of decision support for brassica growers

In the UK, severe infestations by Plutella xylostella occur sporadically and are due mainly to the immigration of moths. The aim of this study was to develop a more detailed understanding of the phenology of P. xylostella in the UK and investigate methods of monitoring moth activity, with the aim of providing warnings to growers. Plutella xylostella was monitored using pheromone traps, by counting immature stages on plants, and by accessing citizen science data (records of sightings of moths) from websites and Twitter. The likely origin of migrant moths was investigated by analysing historical weather data. The study confirmed that P. xylostella is a sporadic but important pest, and that very large numbers of moths can arrive suddenly, most often in early summer. Their immediate sources are countries in the western part of continental Europe. A network of pheromone traps, each containing a small camera sending images to a website, to monitor P. xylostella remotely provided accessible and timely information, but the particular system tested did not appear to catch many moths. In another approach, sightings by citizen scientists were summarised on a web page. These were accessed regularly by growers and, at present, this approach appears to be the most effective way of providing timely warnings

Effects of landscape and region on pests and pathogens in Brassica vegetables and oilseed rape.

Abstract: Pests and pathogens of Brassica vegetables and oilseed rape are mainly managed at a field level. Management of pest insects at a farm level is only suitable for farmers owning compact areas of land, which is not the case in many central European areas. This paper discusses the effects of landscape and region on pests and pathogens in Brassica crops. Topics covered include pest and disease dispersal and persistence, regional races or biotypes, new pests and pathogens, insecticide resistance, conservation biocontrol and monitoring and forecasting

Evaluation of module-sown companion plants as a method of controlling cabbage root fly

A novel technique for controlling cabbage root fly was tested. Companion plants of either birdsfoot trefoil (Lotus corniculatus), red clover (Trifolium pratense) or yellow trefoil (Medicago lupulina) were sown into modules together with calabrese (Brassica oleracea var Italica). The presence of companion plants subsequently reduced cabbage root fly egg-laying by up to 48% and reduced root damage considerably. Companion plant species did not affect egg-laying in this trial. Although, financially, this technique compares very favourably with an alternative strategy of applying fleece, further refinement is needed to improve the survival of companion plants on a commercial field scale as they were particularly vulnerable to damage by steerage hoes, which are used commonly in organic systems

Identification of Novel Pesticides for Use against Glasshouse Invertebrate Pests in UK Tomatoes and Peppers

To inform current and future pesticide availability to glasshouse vegetable growers, the current project trialled more than twenty products, including existing industry standards, against four key pests of glasshouse tomatoes and bell peppers. These included experimental conventional chemical pesticides as well as alternative biopesticide and biorational products based on phytochemicals, microbials and physically-acting substances. The results suggest that certain biopesticide products, particularly botanicals, provide good levels of pest control, with the same being true of experimental conventional chemical pesticides not yet recommended for use against these pests on these crops. Efforts are on-going to ensure that results of the current project translate to industry benefit via new pesticide approvals

Ecological selectivity of pesticides and application methods

According to David Pimentel, 20 years ago, less than 0.1% of the pesticides applied reached their target pests (Pimentel, 1995). This was partly due to ‘poor’ application methods and partly because of the minuscule amount of pesticide either picked up or consumed by the pest. At the time, Pimentel was describing the application of pesticides mainly by sprays, including aerial spraying, and both pesticide chemistry and application technology have improved since then. However, a considerable proportion of pesticides are still applied as sprays, either to crop foliage or to the soil, and this continues to be a relatively untargeted method of application

Vulnerability of horticultural crop production to extreme weather events

The potential impact of future extreme weather events on horticultural crops was evaluated. A review was carried out of the sensitivities of a representative set of crops to environmental challenges. It confirmed that a range of environmental factors are capable of causing a significant impact on production, either as yield or quality loss. The most important of these were un-seasonal temperature, water shortage or excess,and storms. Future scenarios were produced by the LARS-WG1, a stochastic weather generator linked with UKCIP02 projections of future climate. For the analyses, 150 years of synthetic weather data were generated for baseline, 2020HI and 2050HI scenarios at defined locations. The output from the weather generator was used in case studies, either to estimate the frequency of a defined set of circumstances known to have impact on cropping, or as inputs to models of crop scheduling or pest phenology or survival. The analyses indicated that episodes of summer drought severe enough to interrupt the continuity of supply of salads and other vegetables will increase while the frequency of autumns with sufficient rainfall to restrict potato lifting will decrease. They also indicated that the scheduling of winter cauliflowers for continuity of supply will require the deployment of varieties with different temperature sensitivities from those in use currently. In the pest insect studies, the number of batches of Agrotis segetum (cutworm) larvae surviving to third instar increased with time, as did the potential number of generations of Plutella xylostella (diamond-back moth) in the growing season, across a range of locations. The study demonstrated the utility of high resolution scenarios in predicting the likelihood of specific weather patterns and their potential effect on horticultural production. Several limitations of the current scenarios and biological models were also identified