The environmental implications of manure use in organic farming systems (OF0161)

This is the final report of Defra project OF0161. A desk study was undertaken (a) to identify the important N flows in three types of organic farming systems (extensive upland, intensive lowland mixed and stockless vegetable systems) in relation to manure use and (b) to determine the effects of changed management practice on these flows. A study of the published literature has highlighted the key stages for nutrient management prior to land spreading. Dietary inputs - amounts of N excreted and the partitioning between urine and faeces is important in determining the fate of N through the farming system. Diet affects this partition, but we were unable to find evidence of differences between organic and non-organic rations. Clearly, a crude N balance (N in feed - N in milk) provides a good guide to risk. Because N removal in milk is a small component, the more intensive systems are likely to generate more N as excreta. Housing - it is estimated that, in the UK, NH3 losses from housing constitute c. 35% of the total NH3 emissions from cattle production systems (compared with 14% from manure storage) and about 20% of total N2O emissions. The limited available information suggests that losses by NH3 emission during housing are larger from slurry based systems than from cattle housed on straw. The converse is true of N2O losses. Solid manure storage - composting offers advantages (namely sterilisation) but also can exacerbate loss of nitrogen as NH3. Losses of up to almost 80% of the total N have been reported. Our analysis of the numerous experiments suggests that the C:N ratio should be >30 at the start of composting to retain N (i.e. to reduce losses to <10%). Loose covering had little effect on retaining nitrogen. NPK are lost in leachate during manure storage (but only represent a true loss if the leachate is not collected for recycling). Slurry storage - losses are predominantly as NH3 and typically 0.05% (winter) - 0.1% (summer) of the total N content per day. A crust would approximately halve losses. Stirring increases volatilisation. Aeration would have similar effects, but may also increase N2O emissions if it produces intermittent aerobic and anaerobic conditions. Covering stores would substantially decrease losses and options range from straw to concrete structures. Effectiveness increases with cost! A simple N model was constructed to calculate the integrated effects of management practices during housing and storage. Our calculations suggested that an all-slurry system (though not permitted under organic regulations) would retain more N than a straw-based system: losses from slurry are greater during housing, less during storage (assuming the slurry lagoon is covered or has a crust and is not regularly stirred), and greater in the field (as ammonia and nitrate in particular): N losses from FYM after spreading are less, especially if composted. The question that inevitably will be asked is ‘do conventionally managed systems provide more of a risk than organic systems?’ There is no straightforward answer. Many of the loss processes from manure will be the same between systems but they will be modified by management and by the intensity of the enterprise. It is this latter point - i.e. the nutrient balance - that will have most impact on any comparison; farms with a large nutrient excess will be more prone to large losses. Thus, generally, organic farms provide less emissions than conventional farming systems involving livestock. The move to more solid-based systems should result in smaller losses of N during housing, but practical measures to reduce losses during storage need to be investigated. The outcome of all management processes is the production of manures that vary widely in composition between farms and often within farms. Our analyses of 14 cattle slurries and 45 cattle manures confirm the wide variations in nutrient contents as affected by many management factors. Generally, NPK values were c. 20-40% less than published values for ‘conventionally’ produced manures (although these mean values were also associated with a wide range of values). This probably reflects the lower intensity of organic production systems

Understanding soil fertility in organically farmed systems (OF0164)

This is the final report of the Defra project OF0164. Organic farming aims to create an economically and environmentally sustainable agriculture, with the emphasis placed on self-sustaining biological systems rather than external inputs. Building soil fertility is central to this ethos. ‘Soil fertility’ can be considered as a measure of the soil’s ability to sustain satisfactory crop growth, both in the short- and longer-term. It is determined by a set of interactions between the soil’s physical environment, chemical environment and biological activity. The aim of this project was, therefore, to provide a better scientific understanding of soil fertility under organic farming. The approach was to undertake a comprehensive literature review at the start of the project to assess and synthesise available information. Studies were then designed to address specific questions identified from the literature review. The literature review was written during the first year of the project. In addition to submitting written copies to DEFRA, the chapters were posted on a project website: www.adas.co.uk/soilfertility. The Review was based around key questions: • What are the soil organic matter characteristics and the roles of different fractions of the soil organic matter? • Do organically managed soils have higher levels of organic matter (SOM), with a resultant improvement in soil properties? • Is the soil biology different in organically managed soils, in terms of size, biodiversity and activity? • Do organically managed soils have a greater inherent capacity to supply plant nutrients? • What are the nutrient pools and their sizes? • What are the processes and rates of nutrient transfer in relation to nutrient demand? • What are the environmental consequences of organic management? The project also included a large amount of practical work. This necessarily covered a wide range of topics, which were examined in a series of separate studies: • Soil microbiology: a series of measurements focusing on two sites, undertaken by University of Wales Bangor (UWB) • Field campaigns in autumn 1999 and spring/summer 2000: separate field sampling campaigns focusing especially on nutrient pools, undertaken by HDRA, ADAS and IGER • Incubation studies: a series of three separate experiments to look in more detail at N dynamics, managed by ADAS, with support from IGER and HDRA From the literature review and the practical work, the following was concluded: Organic matter is linked intrinsically to soil fertility, because it is important in maintaining good soil physical conditions (e.g. soil structure, aeration and water holding capacity), which contribute to soil fertility. Organic matter also contains most of the soil reserve of N and large proportions of other nutrients such as P and sulphur. Field management data gathered from farmers showed, however, that organic matter returns are not necessarily larger in organic systems. Many non-organically farmed soils receive regular manure applications and the generally higher yielding crops on conventional farms may return larger crop residues. Conversely, many organic fields receive little or no manure, relying on the fertility building ley phase for organic matter input. This observation is important. Management practices within organic and non-organic systems are diverse, and all have consequences for soil fertility. The Executive Summary at the start of the main attached report has additional sections on Soil Structure, Soil Biology, and Nutrient Cycling with some greater detail on comparisons of organic and conventional management and the consequences for soil fertility

The role of the exit in the initial screening of investment opportunities: The case of business angel syndicate gatekeepers

The exit process has been largely ignored in business angel research.. The practitioner community identifies the difficulty in achieving exits as the most pressing problem for investors. This has been attributed to the failure of investors to adopt an exit-centric approach to investing. The validity of this claim is examined via a study of the investment approach of 21 ‘gatekeepers’ (managers) of angel groups in Scotland and Northern Ireland. Most gatekeepers say that they do consider the exit when they invest. However, this is contradicted by a verbal protocol analysis which indicates that the exit is not a significant consideration in their initial screening process. The small number of exits achieved by the groups is consistent with the general lack of an exit-centric approach to investing. Only three groups exhibit evidence of a strong exit-centric approach to investing. The lack of exits may have a negative impact on the level of future angel investment activity

Shigella sonnei genome sequencing and phylogenetic analysis indicate recent global dissemination from Europe

Shigella are human-adapted Escherichia coli that have gained the ability to invade the human gut mucosa and cause dysentery1,2, spreading efficiently via low-dose fecal-oral transmission3,4. Historically, S. sonnei has been predominantly responsible for dysentery in developed countries, but is now emerging as a problem in the developing world, apparently replacing the more diverse S. flexneri in areas undergoing economic development and improvements in water quality4-6. Classical approaches have shown S. sonnei is genetically conserved and clonal7. We report here whole-genome sequencing of 132 globally-distributed isolates. Our phylogenetic analysis shows that the current S. sonnei population descends from a common ancestor that existed less than 500 years ago and has diversified into several distinct lineages with unique characteristics. Our analysis suggests the majority of this diversification occurred in Europe, followed by more recent establishment of local pathogen populations in other continents predominantly due to the pandemic spread of a single, rapidly-evolving, multidrug resistant lineage

A randomised phase II trial of docetaxel vs docetaxel and irinotecan in patients with stage IIIb–IV non-small-cell lung cancer who failed first-line treatment

Response rate and toxicity of second-line therapy with docetaxel (75 mg m−2) or docetaxel, irinotecan, and lenogastrim (60 mg m−2, 200 mg m−2, and 150 μg m−2 day−1, respectively) were compared in 108 patients with stage IIIb–IV non-small-cell lung cancer. Addition of irinotecan to docetaxel does not improve response rate, and increases gastrointestinal toxicity

Belowground DNA-based techniques: untangling the network of plant root interactions

Contains fulltext : 91591.pdf (publisher's version ) (Closed access)7 p

The Relationship Between Low Family Income and Psychological Disturbance in Young Children: An Australian Longitudinal Study

Objective This study examines the relationship between low family income (LFI) experienced at different points in time, chronic low income status and its impact on child behaviour measured at 5 years of age. Method Longitudinal data from the Mater University Study of Pregnancy were used to measure LFI in families at three points in time (the antenatal period, 6 months post birth and at 5 years of age). Outcome variables were three independent groups of behaviour problems labelled as externalising, social, attentional and thought (SAT) problems, and internalising problems. These groups were developed from the Child Behaviour Checklist. An analysis based on logistic regression modelling was carried out examining the relationship between LFI and a range of intermediate variables known to be associated with child behaviour problems. Results The more often families experienced low income, the higher the rate of child behaviour problems at age 5. Low family income was still independently associated with SAT behaviour problems after controlling for smoking in the first trimester, parenting styles, maternal depression and marital disharmony at age 5. The association between LFI and internalising and externalising behaviour problems was largely mediated by maternal depression. Conclusion Low family income is a significant factor in the aetiology of a variety of child behaviour problems. The mechanisms involved in the link between LFI and childhood internalising and externalising behaviours involve the exposure of the children to maternal depression. However, the relationship between LFI and SAT behaviour problems remains to be elucidated

Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy

A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.Comment: Published in Physical Review Letter

Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.Comment: Replaced with published version. Added journal reference and DO