Browsing by Author "Burgess, Paul J."
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Item Open Access Advances in European agroforestry: results from the AGFORWARD project(Springer, 2018-06-09) Burgess, Paul J.; Rosati, AdolfoIn global terms, European farms produce high yields of safe and high quality food but this depends on the use of many off-farm inputs and the associated greenhouse gas emissions, loss of soil nutrients and other negative environmental impacts incur substantial societal costs. Farmers in the European Union receive support through a Common Agricultural Policy (CAP) that comprises direct payments to farmers (Pillar I) and payments related to rural development measures (Pillar II). This paper examines the ways in which agroforestry can support European agriculture and rural development drawing on the conclusions of 23 papers presented in this Special Issue of Agroforestry Systems which have been produced during a 4-year research project called AGFORWARD. The project had the goal of promoting agroforestry in Europe and focused on four types of agroforestry: (1) existing systems of high nature and cultural value, and agroforestry for (2) high value tree, (3) arable, and (4) livestock systems. The project has advanced our understanding of the extent of agroforestry in Europe and of farmers’ perceptions of agroforestry, including the reasons for adoption or non-adoption. A participatory approach was used with over 40 stakeholder groups across Europe to test selected agroforestry innovations through field trials and experiments. Innovations included improved grazing management in agroforestry systems of high nature and cultural value and the introduction of nitrogen fixing plants in high value timber plantations and olive groves. Other innovations included shelter benefits for arable crops, and disease-control, nutrient-retention, and food diversification benefits from integrating trees in livestock enterprises. Biophysical and economic models have also been developed to predict the effect of different agroforestry designs on crop and tree production, and on carbon sequestration, nutrient loss and ecosystems services in general. These models help us to quantify the potential environmental benefits of agroforestry, relative to agriculture without trees. In view of the substantial area of European agroforestry and its wider societal and environmental benefits, the final policy papers in this Special Issue argue that agroforestry should play a more significant role in future versions of the CAP than it does at present.Item Open Access Agricultural technology and land use futures: The UK case(Elsevier Science B.V., Amsterdam., 2009-12-31T00:00:00Z) Burgess, Paul J.; Morris, JoeThis paper explores how agricultural technology has interacted with recent land use in the UK and how it might do so in the next 50 years. From 1960 to 1985, farmers successfully used technology to increase the output of crop and animal products per unit of land and particularly of labour. This reduced the number of people employed in agriculture, and promoted larger and more specialised farm enterprises. Between 1985 and 2006, food prices were relatively low, and although labour productivity continued to increase, land productivity remained relatively static. However during this period, farmers started to address the effects of agriculture on reduced water quality and habitat loss. For established agricultural products, technological innovation tends to have an incremental effect, working through genetic improvement, the removal of abiotic and biotic stress (e.g. crop nutrition and protection, irrigation and drainage, and animal nutrition, health and housing) and the substitution of labour. Whereas the first two processes tend to be scale-neutral, the substitution of labour is usually easiest to achieve on larger farms. Other key areas for technological innovation include addressing air, soil and water quality, biodiversity, waste reduction, and information management. Over the next 50 years, large step-changes in land use arising from agricultural technology are predicted to arise from the development of new markets for agricultural products. A strong bioenergy sector will strengthen the links between crop commodity and energy prices and will have a major effect on future land use. Climate change and the regulation of greenhouse gas emissions will alter the relative profitability of crop and animal production systems. Lastly, increased public awareness of the links between food, health and the environment could substantially shift the demand for specific agricultural products. Continual improvements in agricultural technology are pivotal to providing society with the flexibility to balance the challenges of improving human well-being with the management of the planet’s ecosystem. Increased technological innovation increases the probability that agricultural land can be used for other purposes, but the exact relationship is dependent on trade and environmental policies. The large external effects of agriculture mean that decisions regarding the adoption of future technologies should be taken by farmers working with other stakeholders. © 2009 Queen’s Printer and Controller of HMSO. Published by Elsevier Ltd. All rigItem Open Access Agroforestry creates carbon sinks whilst enhancing the environment in agricultural landscapes in Europe(Elsevier, 2019-03-06) Sonja, Kay; Rega, Carlo; Moreno, Gerardo; den Herder, Michael; Palma, João H. N.; Borek, Robert; Crous-Duran, Josep; Freese, Dirk; Giannitsopoulos, Michail; Graves, Anil; Jäger, Mareike; Lamersdorf, Norbert; Memedemin, Daniyar; Mosquera-Losada, Rosa; Pantera, Anastasia; Paracchini, Maria Luisa; Paris, Pierluigi; Roces-Díaz, José V.; Rolo, Victor; Rosati, Adolfo; Sandor, Mignon; Smith, Jo; Szerencsits, Erich; Varga, Anna; Viaud, Valérie; Wawer, Rafal; Burgess, Paul J.; Herzog, FelixAgroforestry, relative to conventional agriculture, contributes significantly to carbon sequestration, increases a range of regulating ecosystem services, and enhances biodiversity. Using a transdisciplinary approach, we combined scientific and technical knowledge to evaluate nine environmental pressures in terms of ecosystem services in European farmland and assessed the carbon storage potential of suitable agroforestry systems, proposed by regional experts. First, regions with potential environmental pressures were identified with respect to soil health (soil erosion by water and wind, low soil organic carbon), water quality (water pollution by nitrates, salinization by irrigation), areas affected by climate change (rising temperature), and by underprovision in biodiversity (pollination and pest control pressures, loss of soil biodiversity). The maps were overlaid to identify areas where several pressures accumulate. In total, 94.4% of farmlands suffer from at least one environmental pressure, pastures being less affected than arable lands. Regional hotspots were located in north-western France, Denmark, Central Spain, north and south-western Italy, Greece, and eastern Romania. The 10% of the area with the highest number of accumulated pressures were defined as Priority Areas, where the implementation of agroforestry could be particularly effective. In a second step, European agroforestry experts were asked to propose agroforestry practices suitable for the Priority Areas they were familiar with, and identified 64 different systems covering a wide range of practices. These ranged from hedgerows on field boundaries to fast growing coppices or scattered single tree systems. Third, for each proposed system, the carbon storage potential was assessed based on data from the literature and the results were scaled-up to the Priority Areas. As expected, given the wide range of agroforestry practices identified, the carbon sequestration potentials ranged between 0.09 and 7.29 t C ha−1 a−1. Implementing agroforestry on the Priority Areas could lead to a sequestration of 2.1 to 63.9 million t C a−1 (7.78 and 234.85Item Open Access Agroforestry for healthy ecosystems: constraints, improvement strategies and extension in Pakistan(Springer Verlag, 2020-01-01) Baig, Mirza B.; Burgess, Paul J.; Fike, John H.Globally, forest ecosystems are shrinking and their health is declining due to a range of biotic and abiotic factors. Forest ecosystems in Pakistan are no exception and the country faces a crisis as its growing population (> 208 million) places increasing pressure on the country’s food production systems and forest resources. Effective food systems that enhance productivity, increase economic outputs, improve ecological outcomes and maintain social acceptance are needed. Agroforestry, a traditional land management system in Pakistan, offers the opportunity to meet these goals. Planting trees on private farmland provides clear ownership of any timber resource and well managed systems have great potential both to boost agriculture and reduce wood shortages. Concerted extension efforts have been made to introduce and promote innovative agroforestry practices in Pakistan, but the success of these efforts depends on many factors. This paper reviews some of the current constraints to agroforestry promotion in Pakistan, including attitudes of the extension staff, poor or weak research-extension coordination, lack of trained personnel, lack of farmer response to advice, tree species limitations, and market mechanism as well as wood price challenges. Establishing model agroforestry farms at the village level can be a productive extension approach, but successful extension programming requires partners to share both an appreciation of the problem and a vision of successful outcomes. Successful promotion also requires appropriate choice of message, messenger, target audience and effective use of appropriate communication tools. Remedial measures to streamline the existing systems and devise future sustainable strategies and approaches are suggested to promote agroforestry in Pakistan.Item Open Access Agroforestry for high value tree systems in Europe(2018-01-06) Pantera, A.; Burgess, Paul J.; Mosquera-Losada, María Rosa; Moreno, G.; López-Díaz, M. L.; Corroyer, N.; McAdam, Jim; Rosati, A.; Papadopoulos, A. M.; Graves, Anil; Rigueiro-Rodríguez, A.; Ferreiro-Domínguez, N.; Fernández-Lorenzo, J. L.; González-Hernández, M. P.; Papanastasis, Vasilios P.; Mantzanas, K.; van Lerberghe, Philippe; Malignier, N.Most farm-based agroforestry projects focus on the integration of trees on arable or livestock enterprises. This paper focuses on the integration of understorey crops and/or livestock within high value tree systems (e.g., apple orchards, olive groves, chestnut woodlands, and walnut plantations), and describes the components, structure, ecosystem services and economic value of ten case studies of this type of agroforestry across Europe. Although their ecological and socio-economic contexts vary, the systems share some common characteristics. The primary objective of the farmer is likely to remain the value of tree products like apples, olives, oranges, or nuts, or particularly high value timber. However there can still be production, environmental or economic benefits of integrating agricultural crops such as chickpeas and barley, or grazing an understorey grass crop with livestock. Three of the systems focused on the grazing of apple orchards with sheep in the UK and France. The introduction of sheep to apple orchards can minimise the need for mowing and provide an additional source of revenue. Throughout the Mediterranean, there is a need to improve the financial viability of olive groves. The case studies illustrate the possibility of intercropping traditional olive stands with chickpea in Greece, or the intercropping of wild asparagus in high density olive groves in Italy. Another system studied in Greece involves orange trees intercropped with chickpeas. Stands of chestnut trees in North-west Spain can provide feed for pigs when the fruit falls in November, and provide an excellent habitat for the commercial production of edible mushrooms. In Spain, in the production of high quality walnut trees using rotations of up to 50–60 years, there are options to establish a legume-based mixed pasture understorey and to introduce sheep to provide financial and environmental benefits.Item Open Access Agroforestry in the UK(The Royal Forestry Society, 2017-04-30) Burgess, Paul J.The Royal Forestry Society, the Woodland Trust and the Soil Association are hosting a one-day conference on ‘Agroforestry: Improving Productivity for Farmers and Foresters’ at Cranfield University, Bedfordshire on 22 June 2017. This will be followed by a one-day Farm Woodland Forum workshop, including a field visit to the apple and cereal agroforestry system of Stephen Briggs. To set these events in context, this article explains why UK agroforestry is important, topical, how it is being used to market food products, improve productivity, address climate-change and flood management, and how it depends on dynamic farmers and foresters.Item Open Access Agroforestry systems of high nature and cultural value in Europe: provision of commercial goods and other ecosystem services(2017-09-30) Moreno, G.; Aviron, S.; Berg, S.; Crous-Duran, Josep; Franca, A.; García de Jalón, S.; Hartel, T.; Mirck, J.; Pantera, A.; Palma, João H. N.; Paulo, J. A.; Re, G. A.; Sanna, F.; Thenail, Claudine; Varga, Anna; Viaud, V.; Burgess, Paul J.Land use systems that integrate woody vegetation with livestock and/or crops and are recognised for their biodiversity and cultural importance can be termed high nature and cultural value (HNCV) agroforestry. In this review, based on the literature and stakeholder knowledge, we describe the structure, components and management practices of ten contrasting HNCV agroforestry systems distributed across five European bioclimatic regions. We also compile and categorize the ecosystem services provided by these agroforestry systems, following the Common International Classification of Ecosystem Services. HNCV agroforestry in Europe generally enhances biodiversity and regulating ecosystem services relative to conventional agriculture and forestry. These systems can reduce fire risk, compared to conventional forestry, and can increase carbon sequestration, moderate the microclimate, and reduce soil erosion and nutrient leaching compared to conventional agriculture. However, some of the evidence is location specific and a better geographical coverage is needed to generalize patterns at broader scales. Although some traditional practices and products have been abandoned, many of the studied systems continue to provide multiple woody and non-woody plant products and high-quality food from livestock and game. Some of the cultural value of these systems can also be captured through tourism and local events. However there remains a continual challenge for farmers, landowners and society to fully translate the positive social and environmental impacts of HNCV agroforestry into market prices for the products and services.Item Open Access Agronomy and economics of two novel energy crops: Sida Hermaphrodita (L.) Rusby and Silphium Perfoilatum L.(2021-05) Cumplido-Marin, Laura; Graves, Anil R.; Burgess, Paul J.The PhD project of title “Agronomy and Economics of two novel energy crops: Sida hermaphrodita (L.) Rusby and Silphium perfoliatum L.” was first conceptualised within the international project SidaTim. The main aim of the PhD was to reduce the uncertainty associated with the adoption of Sida hermaphrodita (L.) Rusby and Silphium perfoliatum L., through data gathering and evaluating their agronomic, economic and environmental performance. The main objectives of the PhD were: to review all available information and publications regarding the cultivation and energy production of the two species; to assess their agronomic performance in the UK; to examine the impact of their establishment on soil carbon; to determine their profitability against other potential crops across a European gradient; and to evaluate the greenhouse gas emissions associated with their cultivation. The novelty of the research lies on the establishment and assessment of two novel bioenergy crops in the UK compared across a range of climatic conditions, addressing the knowledge gaps regarding reliability and availability of information and assessment of their agronomic, economic and environmental performance. The first year of the project was dedicated to background research, collecting and processing the first set of soil analyses, producing all Silphium perfoliatum (L.) seedlings from seed, importing Sida hermaphrodita (L.) Rusby seeds from Germany, and in 2017 establishing an experimental site in Silsoe, Bedfordshire, UK. During the first three years,the mean maximum height of Sida hermaphrodita (L.) Rusby originated from seedlings was 198 cm and the maximum stem diameters were 14-18 mm. The mean maximum height of Silphium perfoliatum (L.) was 158 cm over three years and the maximum stem diameters were 14-16 mm. As opposed to the expected increase in maximum heights and diameters with time until plantation maturity, an overall reduction in maximum heights and diameters was recorded with time for Sida hermaphrodita (L.) Rusby, whilst only maximum diameters of Silphium perfoliatum (L.) decreased with time. Each year from February 2018, a winter harvest to measure the solid biomass production of Sida hermaphrodita (L.) Rusby and a summer harvest to measure the green biomass production of both Sida hermaphrodita (L.) Rusby and Silphium perfoliatum L. were carried out until September 2020. Mean dry biomass yields of Sida hermaphrodita (L.) Rusby plants grown from transplants for solid fuel for combustion were 1.7, 5.4, and 3.7 t DM ha⁻¹ in 2018, 2019, and 2020 respectively. Green biomass yields of Sida hermaphrodita (L.) Rusby for anaerobic digestion were on average 10.8, 8.1, 6.0 t DM ha⁻¹ in 2018, 2019, and 2020 respectively. The recorded declines in harvested biomass from Sida hermaphrodita (L.) Rusby are attributed to the combined effect of plant mortality, management and fertilisation practices. The corresponding mean green biomass yields of Silphium perfoliatum L. for anaerobic digestion were 4.6, 6.7, 8.9 t DM ha⁻¹ in 2018, 2019, and 2020. The second and third year focussed on objectives three and four, as well as collecting and processing the second set of soil analyses, data analysis, and writing up. The bulk density of the soil across 0-5 cm and 10-15 cm changed from 1.4-1.7 g cm³ prior to cultivation in 2017, to a uniform 1.4 g cm³ in 2020. The concentration of soil organic carbon at 0-5 cm decreased from 2.58% in 2017 to 1.85% in 2020, whereas at 10-15 cm, it increased from 1.86% to 2.12% over the three years. Overall, the mean soil organic carbon stocks (0-15 cm) declined from 65.0-67.6 t C ha⁻¹ in 2017 in 55.2-58.3 t C ha⁻¹ in 2020. The profitability of Sida hermaphrodita (L.) Rusby and Silphium perfoliatum (L.) was predicted over a rotation of 16 years and compared to that of an arable rotation and two other energy crops for the particular case of the UK and three other European countries. The calculated net present value (NPV) of Sida hermaphrodita (L.) Rusby was -1,591 £ ha⁻¹ without subsidies and 1,075 £ ha⁻¹ with subsidies; the corresponding net present values for Silphium perfoliatum (L.) were 3,031 £ ha⁻¹ and 5,607 £ ha⁻¹ . The study also calculated how much prices and costs would need to change for the NPV of the two crops to match the NPV of the most profitable energy crop or the arable rotation. Using an Excel model developed based on the IPCC guidelines, the greenhouse gas emissions for Sida hermaphrodita (L.) Rusby and Silphium perfoliatum (L.) production were calculated for a 16-year period. On a per annum basis, overall greenhouse gas emissions were estimated respectively at 4.2, 0.3, 2.2, -4.0 and -0.6 t CO2 eq ha⁻¹ for the arable rotation, short rotation coppice, Miscanthus, Sida hermaphrodita (L.) Rusby and Silphium perfoliatum (L.) systems. The environmental assessment demonstrated that cultivating Sida hermaphrodita (L.) Rusby and Silphium perfoliatum (L.) could potentially contribute to reducing greenhouse gas emissions.Item Open Access Application of an ecosystem function framework to perceptions of community woodlands(Elsevier Science B.V., Amsterdam., 2009-07-01T00:00:00Z) Agbenyega, Olivia; Burgess, Paul J.; Cook, Matthew; Morris, JoeOwners, local residents, government, and conservation organisations can express divergent preferences in the development and management of local woodlands. The perceptions of these four groups were examined, in the context of three community woodlands in Eastern England, using an ecosystem function framework. In a pilot study, residents were able to allocate a relative importance to woodland ecosystem services which were then related to “regulation”, “habitat”, and “production” or “information” functions. However residents also placed importance on negative services or “dis-services” associated with the woodland ecosystem. Therefore a fifth category of “dis-services” was included in the main survey which included 84 local residents, three woodland owners, three government institutions, and six representatives from conservation groups. Each of the four groups placed greatest importance on services associated with habitat (16–39% of the total importance) and information (30–50%) functions suggesting, in this example, mutual interest in the use of woodlands as a habitat or recreational resource. By contrast a potential area of difference was the particularly high importance placed by one owner on dis-services such as fly tipping. In addition the woodland owners placed higher importance (10–20%), than local residents and conservation groups (7–9%), on the productive services of the wood. This suggests a need for communication when production-related operations affect recreation. The ecosystem function framework appears to be a useful approach for highlighting potential tensions and areas of mutual interest in the manageItem Open Access Application of the ecosystem functions framework to community woodlands(Cranfield University, 2007-02) Agbenyega, Olivia; Burgess, Paul J.; Cook, M. V.The UK government provides financial incentives to land owners who promote community use of newly-planted woodlands. De Groot et al. (2002) have developed a framework for classifying ecosystem functions. This research applies this framework to identify and describe perceptions of the function, use and value of community woodlands in order to inform local management and government policy. The research was an exploratory and descriptive case study with an initial flexible and final fixed stage. A poplar wood (Pegnut Wood) and two mixed-broadleaf woodlands(Clapham Park Wood and Reynolds Wood), all planted in Bedfordshire between 1993 and 1998, provided the case studies. Data collection methods included semi-structured interviews, self-administered structured questionnaires, direct observation, modelling of tree data and review of secondary documents. In total 172 out of 400 local residents, 20 on-site visitors, and 8 other stakeholders (owners, government institutions and conservation groups) gave responses. The primary motivations of the owners for establishing the woods were production, information and habitat functions. However financial cost-benefit analyses indicated negative returns to owners without government grants. In the first set of interviews 43- 58% of the local respondents at each site described the selected woods and community woods as “very important”. There was a significant positive association between nearness to the woods and level of importance. Those who visited the woods placed greatest emphasis on the use of the woods for exercise and recreation (48-64%), and as a wildlife habitat (50-52%). Using the ecosystem function framework, local respondents at Pegnut Wood and Clapham Park Wood placed greatest value on habitat (29-39%) and information functions (33-38%) and lowest value on regulation (14-19%), production (5-8%) and negative functions (7-8%). Respondents at Reynolds Wood placed the greatest relative importance on negative functions (36%). Across the three sites, local respondents placed the greatest relative value on the use of the woodlands as a habitat for wild plants and animals (14%) and to provide landscape beauty (12%). A second set of interviews, focussed on the recreational use of the woodlands, showed that the main purpose for visiting the woods was walking (median frequency of once a month and duration of between 31-60 minutes). Fifteen out of 88 respondents indicated that they were willing to contribute to support the woods. Many of those not in favour felt such support was a government responsibility. Overall, owners, local residents, government and local conservation groups showed similar relative valuations of the different functions and uses of community woodlands, indicating that there was substantial scope for working together. The research showed that it was useful to apply the ecosystem functions framework to community woodlands. It provided a structure for analysing planting objectives and it encouraged a focus on indirect uses. Stakeholders recognised potential negative functions of the woodland, and it proved useful to include these in the framework. We note the challenges in recognising and placing a high value on the regulation function amongst the range of stakeholders. The framework also helped to identify synergies and tensions between stakeholders without the need for monetising values.Item Open Access Assessing climate change causes, risks and opportunities in forestry(Ip Publishing, 2011-01-27T00:00:00Z) Burgess, Paul J.; Moffat, Andy J.; Matthews, Robin B.Forests play an important role in regulating the global climate through storing carbon that would otherwise be released as CO 2 to the atmosphere, and affecting the global energy balance through absorption of solar radiation. Forests are also affected directly by the impact of increased CO 2 levels and temperatures on ecosystem processes, and indirectly by human responses seeking to mitigate the net emissions of greenhouse gases (GHGs) or adapt to new climates. This paper attempts to assess the significance of these different aspects, within the context of poverty reduction. It provides a brief assessment of the global role of deforestation on net global GHG emissions; assesses the positive and negative direct effects of climate change on forest productivity, forest disturbance, carbon sequestration, water and air quality, biodiversity and cultural services; and discusses the indirect effects on forestry of human responses to minimise net GHG emissions, through new markets, other land use change, and global, national and local initiatives.Item Open Access Assessing the carbon capture potential of a reforestation project(Nature Publishing Group, 2021-10-07) Lefebvre, David; Williams, Adrian G.; Kirk, Guy J. D.; Burgess, Paul J.; Meersmans, Jeroen; Silman, Miles R.; Román-Dañobeytia, Francisco; Farfan, Jhon; Smith, PeteThe number of reforestation projects worldwide is increasing. In many cases funding is obtained through the claimed carbon capture of the trees, presented as immediate and durable, whereas reforested plots need time and maintenance to realise their carbon capture potential. Further, claims usually overlook the environmental costs of natural or anthropogenic disturbances during the forest’s lifetime, and greenhouse gas (GHG) emissions associated with the reforestation are not allowed for. This study uses life cycle assessment to quantify the carbon footprint of setting up a reforestation plot in the Peruvian Amazon. In parallel, we combine a soil carbon model with an above- and below-ground plant carbon model to predict the increase in carbon stocks after planting. We compare our results with the carbon capture claims made by a reforestation platform. Our results show major errors in carbon accounting in reforestation projects if they (1) ignore the time needed for trees to reach their carbon capture potential; (2) ignore the GHG emissions involved in setting up a plot; (3) report the carbon capture potential per tree planted, thereby ignoring limitations at the forest ecosystem level; or (4) under-estimate tree losses due to inevitable human and climatic disturbances. Further, we show that applications of biochar during reforestation can partially compensate for project emissions.Item Open Access Barriers and enablers to uptake of agroecological and regenerative farming practices, and stakeholder views about ‘living labs’(DEFRA, 2023-02-20) Hurley, Paul D.; Rose, David Christian; Burgess, Paul J.; Staley, Joanna T.This report forms the second component of a Defra-sponsored research project entitled “Evaluating the productivity, environmental sustainability and wider impacts of agroecological compared to conventional farming systems”. The first component comprised a rapid evidence review of regenerative/agroecological farming systems. This second component describes and discusses the results of a survey to explore i) farmer and stakeholder definitions of agroecological and regenerative farming, ii) the barriers to the adoption of agroecological and regenerative farming, and iii) farmer and stakeholder views towards the concept of ‘living labs’ as a way to share research and learnings about agroecological/regenerative farming (Figure 1).Item Open Access The carbon storage benefits of agroforestry and farm woodlands(Cranfield University, 2014-07) Upson, Matthew A.; Burgess, Paul J.Planting trees on agricultural land either as farm woodlands or agroforestry (trees integrated with farming) is one option for reducing the level of atmospheric carbon dioxide. Trees store carbon as biomass, and may increase carbon storage in the ground. A review of the literature outlined uncertainty relating to changes in carbon storage after planting trees on agricultural land. The aim of this thesis is to deter¬mine the impact of tree planting on arable and pasture land in terms of above and belowground carbon storage and thereby address these uncertainties, and assess the implications for the Woodland Carbon Code: a voluntary standard for carbon storage in UK woodlands. Measurements of soil organic carbon to a depth of 1.5 m were taken at two field sites in Bedfordshire in the UK: a 19 year old silvoarable trial, and a 14 year old silvopasture and farm woodland. On average 60% and 40% of the soil carbon (rel¬ative to 1.5 m) was found beneath 0.2 and 0.4 m in depth respectively. Whilst tree planting in the arable system showed gains in soil organic carbon (12.4 t C ha−1 at 0–40 cm), tree planting in the pasture was associated with losses of soil organic carbon (6.1–13.4 t C ha−1 at 0–10 cm). Evidence from a nearby mature grazed woodland indicate that these losses may be recovered. No differences associated with tree planting were found to the full 1.5 m, though this may be due to a lack of statistical power. Measurements of above and belowground biomass, and the root distribution of 19 year old poplar (Populus spp.) trees (at the silvoarable trial) and ash (Fraxinus excelsior) trees ranging from 7 to 21 years (at several field sites across Bedfordshire) were made, involving the destructive harvest of 48 trees. These measurements suggest that Forestry Commission yield tables overestimate yield for poplar trees grown in a silvoarable system. An allometric relationship for determining ash tree biomass from diameter measurements was established. The biophysical model Yield-SAFE was updated to take into account root growth, and was parameterised using field measurements. It was successfully used to describe existing tree growth at two sites, and was then used to predict future biomass carbon storage at the silvoarable trial. Measurements indicate that losses in soil carbon at relatively shallow depths can offset a large proportion of the carbon stored in tree biomass, but assessing changes on a site by site basis may be prohibitively expensive for schemes such as the Woodland Carbon Code.Item Open Access Colour, water and chlorophyll loss in harvested broccoli (Brassica oleracea L. Italica) under ambient conditions in Pakistan(Elsevier, 2018-11-30) Shakeel, Muhammad; Khan, Salik Nawaz; Saleem, Yasar; Burgess, Paul J.; Shafiq, ShaziaBroccoli (Brassica oleracea L. Italica) is a nutritious green vegetable containing desirable phytochemicals that is being more widely consumed in Pakistan. However the florets rapidly discolour and wilt after harvest. This study reports the changes in the colour, turgor, weight, visual quality and chlorophyll of harvested broccoli florets after harvest under ambient temperatures of 18 ± 1 °C and a relative humidity of 45–62%. There were significant declines in colour, turgor, weight and chlorophyll within the first two days, with a change from “good” to “unacceptable” assessments occurring at day 4 or 5. The level of chlorophyll decreased from 13.47 μg/ mg on day 1 to 5.18 μg/ mg on day 4. It is proposed that the green colour and turgor can be retained longer by storing at lower temperatures and higher relative humidities.Item Open Access Comparative economics of Sida hermaphrodita (l.) Rusby and Silphium perfoliatum L. as bioenergy crops in Europe(Elsevier, 2022-05-26) Cumplido-Marin, Laura; Burgess, Paul J.; Facciotto, Gianni; Coaloa, Domenico; Morhart, Christopher; Bury, Marek; Paris, Pierluigi; Nahm, Michael; Graves, Anil R.The purpose of this research was to fill the identified gap on financial data of Sida hermaphrodita (L.) Rusby (Sida) and Silphium perfoliatum L. (Silphium), two perennial bioenergy crops that potentially provide a more sustainable alternative/complement to other bioenergy crops. Using discounted cash flow analysis, the Net Present Values of Sida and Silphium were compared to a rotation of other arable crops including maize, and the two energy crops of short rotation coppice and Miscanthus. The analysis was completed using the SidaTim analysis tool for the UK, Italy, Germany and Poland, producing a total of four independent models. The results showed that with no subsidies, cultivating Sida was unattractive in all four countries relative to other crop options. However, Silphium, was an economically viable option in each country. Both Sida and Silphium can offer greater environmental benefits than other arable crops, and the profitability of each crop would be further enhanced if additional payments for such public services were made to farmers, and if there were secure markets for the sale of the biomass. This study is the first comparative economic analysis in West and Central Europe of the two novel energy crops in comparison to more common energy crops and an arable rotation.Item Open Access A comparison of methods to quantify greenhouse gas emissions of cropping systems in LCA(Elsevier, 2017-03-23) Goglio, Pietro; Smith, Ward N.; Grant, B. B.; Desjardins, R. L.; Gao, X.; Hanis, K.; Tenuta, M.; Campbell, C. A.; McConkey, B. G.; Nemecek, Thomas; Burgess, Paul J.; Williams, Adrian G.Carbon dioxide and nitrous oxide are two important greenhouse gases (GHG) released from cropping systems. Their emissions can vary substantially with climate, soil, and crop management. While different methods are available to account for GHG emissions in life cycle assessments (LCA) of crop production, there are no standard procedures. In this study, the objectives were: (i) to compare several methods of estimating CO2 and N2O emissions for a LCA of cropping systems and (ii) to estimate the relative contribution of soil GHG emissions to the overall global warming potential (GWP) using results from a field experiment located in Manitoba, Canada. The methods were: (A) measurements; (B) Tier I and (C) Tier II IPCC (Intergovernmental panel on Climate Change) methodology, (D) a simple carbon model combined with Intergovernmental Panel for Climate Change (IPCC) Tier II methodology for soil N2O emissions, and (E) the DNDC (DeNitrification DeComposition) agroecosystem model. The estimated GWPs (−7.2–17 Mg CO2eq ha−1 y−1; −80 to 600 kg CO2eq GJ−1 y−1) were similar to previous results in North America and no statistical difference was found between GWP based on methods D and E and GWP based on observations. The five methods gave estimates of soil CO2 emissions that were not statistically different from each other, whereas for N2O emissions only DNDC estimates were similar to observations. Across crop types, all methods gave comparable CO2 and N2O emission estimates for perennial and legume crops, but only DNDC gave similar results with respect to observations for both annual and cereal crops. Whilst the results should be confirmed for other locations, the agroecosystem model and method D can be used, at certainly one selected site, in place of observations for estimating GHGs in agricultural LCA.Item Open Access A comparison of the responses of mature and young clonal tea to drought.(Cambridge University Press, 2001-01-01T00:00:00Z) Nixon, D. J.; Burgess, Paul J.; Sanga, B. N. K.; Carr, M. K. V.To assist commercial producers with optimising the use of irrigation water, the responses to drought of mature and young tea crops (22 and 5 years after field planting respectively) were compared using data from two adjacent long-term irrigation experiments in Southern Tanzania. Providing the maximum potential soil water deficit was below about 400-500 mm for mature, and 200-250 mm for young plants (clone 6/8), annual yields of dry tea from rainfed or partially irrigated crops were similar to those from the corresponding well-watered crops. At deficits greater than this, annual yields declined rapidly in young tea (up to 22 kg (ha mm)-1) but relatively slowly in mature tea (up to 6.5 kg (ha mm)- 1). This apparent insensitivity of the mature crop to drought was due principally to compensation that occurred during the rains for yield lost in the dry season. Differences in dry matter distribution and shoot to root ratios contributed to these contrasting responses. Thus, the total above ground dry mass of well-irrigated, mature plants was about twice that for young plants. Similarly, the total mass of structural roots (>1 mm diameter), to 3 m depth, was four times greater in the mature crop than in the young crop and, for fine roots (<1 mm diameter), eight times greater. The corresponding shoot to root ratios (dry mass) were about 1:1 and 2:1 respectively. In addition, each unit area of leaf in the canopy of a mature plant had six times more fine roots (by weight) available to extract and supply water than did a young plant. Despite the logistical benefits resulting from more even crop distribution during the year when crops are fully irrigated, producers currently prefer to save water and energy costs by allowing a substantial soil water deficit to develop prior to the start of the rains, up to 250 mm in mature tea, knowing that yield compensation will occur later.Item Open Access Compatible measurements of volumetric soil water content using a neutron probe and Diviner 2000 after field calibration.(Blackwell Publishing Ltd., 2006-12-01T00:00:00Z) Burgess, Paul J.; Reinhard, Berend Richard; Pasturel, P.Field calibrations for a neutron probe and a capacitance sensor (Diviner 2000) for measuring the soil water content of a shrinking–swelling clay soil were substantially different from commonly used default values. Using our field calibrations, the two instruments estimated similar changes in the cumulative water content of a soil profile (0–1 m depth) over one growing seaItem Open Access Contrasting changes in soil carbon under first rotation, secondary and historic woodland in England and Wales(Elsevier, 2021-12-09) Rivas Casado, Monica; Bellamy, Patricia; Leinster, Paul; Burgess, Paul J.This study investigates changes in soil carbon under woodland combining data from the National Soil Inventory of England and Wales with data from the National Inventory of Woodlands and Trees to create a unique dataset with woodland management information at the sites where soil carbon was measured in 1980 and 2003. Three woodland management stages were compared: first rotation (i.e. recently planted on land not previously under woodland and not yet harvested), second rotation (i.e. harvested at least once), and historic woodlands. Woodlands in their first rotation demonstrated a reduction (p < 0.01) in topsoil organic carbon content typically losing over 2% per year, whereas no change (p ≥ 0.10) was observed for the other two woodland types. This large reduction in organic carbon could not be statistically explained by a higher inherent soil carbon, as the mean soil carbon content of the first rotation and second rotation woodlands were not (p ≥ 0.50) different. The average age of the woodlands under first rotation was 42 years, indicating that the period of significant soil carbon loss could go on for about 40 years after planting.