Stocktake study of current fertilisation recommendations across Europe and discussion towards a more harmonised approach

The European Commission has set targets for a reduction in nutrient losses by at least 50% and a reduction in fertiliser use by at least 20% by 2030 while ensuring no deterioration in soil fertility. Within the mandate of the European Joint Programme EJP Soil ‘Towards climate-smart sustainable management of agricultural soils’, the objective of this study was to assess current fertilisation practices across Europe and discuss the potential for harmonisation of fertilisation methodologies as a strategy to reduce nutrient loss and overall fertiliser use. A stocktake study of current methods of delivering fertilisation advice took place across 23 European countries. The stocktake was in the form of a questionnaire, comprising 46 questions. Information was gathered on a large range of factors, including soil analysis methods, along with soil, crop and climatic factors taken into consideration within fertilisation calculations. The questionnaire was completed by experts, who are involved in compiling fertilisation recommendations within their country. Substantial differences exist in the content, format and delivery of fertilisation guidelines across Europe. The barriers, constraints and potential benefits of a harmonised approach to fertilisation across Europe are discussed. The general consensus from all participating countries was that harmonisation of fertilisation guidelines should be increased, but it was unclear in what format this could be achieved. Shared learning in the delivery and format of fertilisation guidelines and mechanisms to adhere to environmental legislation were viewed as being beneficial. However, it would be very difficult, if not impossible, to harmonise all soil test data and fertilisation methodologies at EU level due to diverse soil types and agro-ecosystem influences. Nevertheless, increased future collaboration, especially between neighbouring countries within the same environmental zone, was seen as potentially very beneficial. This study is unique in providing current detail on fertilisation practices across European countries in a side-by-side comparison. The gathered data can provide a baseline for the development of scientifically based EU policy targets for nutrient loss and soil fertility evaluation.     

Microwave heating remediation of soils contaminated with diesel fuel

Purpose

Diesel fuel represents a permanent source of soil pollution, and its removal is a key factor for human health. To address the limitations of conventional remediation techniques, microwave (MW) heating could be employed due to its great potentiality. This work presents the lab-scale experiments performed to study the potential of MW processing for diesel-polluted soils treatment and related modeling for the optimization of MW systems operating conditions.

Materials and methods

A sandy soil was artificially contaminated with diesel fuel, moisturized with different amounts of water content, and thermally treated by MW radiation using a lab-scale apparatus to investigate the effect of soil moisture on soil temperature profiles and contaminant removal kinetics. An operating power, ranging from 100 to 1,000 W, and treatment times of 5, 10, 18, 30, and 60 min were investigated. Contaminant residual concentration values were fitted using the first order kinetic model, and desorption parameters were calculated for each soil at different operating powers.

Results and discussion

Main results show that the operating power applied significantly influences the contaminant removal kinetics, and the moisture content in soil has a major effect on the final temperature reachable during MW heating. Minimal contaminant concentrations were achievable by applying powers higher than 600 W for a treatment time longer than 60 min. For remediation times shorter than 10 min, which result in a soil temperature of about 100 °C, the effect of the distillation process increases the contaminant removal, whereas for longer times, soil temperature is the main key factor in the remedial treatment.

Conclusions

MW thermal desorption of diesel-polluted soil was shown to be governed by pseudo-first-order kinetics, and it could be a better choice for remediation of diesel-polluted soils, compared to several biological, chemical–physical, or conventional thermal treatments, due to its excellent removal efficiency. The results obtained are of scientific and practical interest and represent a suitable tool to optimize the treatment operating conditions and to guide the design and the scale-up of MW treatments for full-scale remediation activities of diesel-polluted soils.     

Simulation of peak-demand hydrographs in pressurized irrigation delivery systems using a deterministic–stochastic combined model. Part I: model development

This study describes a model named HydroGEN that was conceived for simulating hydrographs of daily volumes and hourly flow rates during peak-demand periods in pressurized irrigation delivery networks with on-demand operation. The model is based on a methodology consisting of deterministic and stochastic components and is composed of a set of input parameters to reproduce the crop irrigation management practices followed by farmers and of computational procedures enabling to simulate the soil water balance and the irrigation events for all cropped fields supplied by each delivery hydrant in a distribution network. The input data include values of weather, crop, and soil parameters, as well as information on irrigation practices followed by local farmers. The resulting model outputs are generated flow hydrographs during the peak-demand period, which allow the subsequent analysis of performance achievable under different delivery scenarios. The model can be applied either for system design or re-design, as well as for analysis of operation and evaluation of performance achievements of on-demand pressurized irrigation delivery networks. Results from application of HydroGEN to a real pressurized irrigation system at different scales are presented in a companion paper (Part II: model applications).     

Polymerase exchange during Okazaki fragment synthesis observed in living cells

DNA replication machineries have been studied extensively, but the kinetics of action of their components remains largely unknown. We report a study of DNA synthesis during replication in living Escherichia coli cells. Using single-molecule microscopy, we observed repetitive fluorescence bursts of single polymerase IIIs (Pol IIIs), indicating polymerase exchange at the replication fork. Fluctuations in the amount of DNA-bound single-stranded DNA-binding protein (SSB) reflect different speeds for the leading- and lagging-strand DNA polymerases. Coincidence analyses of Pol III and SSB fluctuations show that they correspond to the lagging-strand synthesis and suggest the use of a new Pol III for each Okazaki fragment. Based on exchanges involving two Pol IIIs, we propose that the third polymerase in the replisome is involved in lagging-strand synthesis.     

Equine Sarcoid Associated with Cutaneous Habronemosis

Equine sarcoids are benign fibroblastic skin tumors affecting equids worldwide. Infection with bovine papillomavirus types 1 and 2 has been implicated as a major fact in the disease development; however, the cellular mechanisms underlying fibroblast transformation are still largely unknown. In the present study, a diagnosis of sarcoid was histologically assessed along with eosinophilic dermatitis. The sarcoid lesion expressed the viral oncoproteins E5 and E2, suggesting a causative role of the virus and its replication. Ribosomal DNA of the nematode Habronema muscae was also revealed in the lesion. This is the first report to describe and discuss an association of cutaneous habronemosis with equine sarcoid.     

Emmer wheat, a potential new host of Tilletia indica

Two representative Italian emmer wheat (Triticum dicoccum) landraces, two selected lines and three improved emmer wheat cultivars, derived from crosses with durum wheat (Molisano landrace × ‘Simeto’), were tested for their susceptibility to Tilletia indica, the cause of Karnal bunt of wheat. Plants of emmer wheat were inoculated by injecting allantoid sporidial suspensions into the boot cavity of plants, just prior to ear emergence. A highly susceptible Indian spring wheat cultivar (Triticum aestivum) was used as a comparative control. At maturity of the plants, the seeds were harvested and assessed for incidence and severity of disease. All emmer wheat genotypes tested were infected but showed differing levels of susceptibility. The percentage of infected seeds for individual genotypes ranged from 5.4 to 75.0% compared with 99.1% for WL-711. The severity of infection was less in the old landraces, but it was higher in all the improved emmer wheat cultivars. In conclusion, Italian cultivars of emmer wheat were found to be highly susceptible to T. indica, and are potentially able to support the establishment of the pathogen.Authors L. Riccioni and M. Valvassori contributed equally to this work and should both be considered as first author.     

Impact of alfalfa mosaic virus subgroup I and II isolates on terpene secondary metabolism of Lavandula vera D.C., Lavandula×alardii and eight cultivars of L. hybrida Rev.

Lavandula vera D.C., Lavandula×alardii and eight different L. hybrida Rev. cultivars cultivated at the Herb Garden of Casola Valsenio (Italy), found naturally infected by Alfalfa mosaic virus (AMV), have been evaluated for the influence of their pathologic status on essential oil biosynthesis and quality. The viral disease, consisting of a “yellow mosaic” on leaves and stems, was identified by means of electron microscopy, RT-PCR-RFLP and PAS-ELISA assays. Molecular characterization of the coat protein gene of four AMV isolates suggested that three of them belonged to subgroup I (from cvs. Ordinario and Grosso, Lavandula×alardii), while the isolate from cv. Sumiens showed molecular features of subgroup II. The infection of Lavandula plants by AMV (of the two subgroups) was found to decrease essential oil secretion. Changes in the relative composition regarded the linalool-linalyl acetate ratio; the overall increase in terpenic esters and in some cases increased sesquiterpenic abundance. Infection caused by AMV subgroup II isolate influenced negatively the quality of the essential oil much more than AMV isolates belonging to subgroup I. The importance of the phytopathological status of essential oil bearing crops is outlined.     

p53 protein expression in conjunctival squamous cell carcinomas of domestic animals

The expression of p53 protein was investigated in eight formalin-fixed, paraffin-embedded conjunctival squamous cell carcinomas of five horses and one cow, dog and cat each by an immunohistochemical procedure in order to evaluate protein overexpression. Anti-human p53 protein mouse monoclonal antibodies known to be cross-reactive with p53 protein of the animal species examined were used. Positive p53 nuclear immunostaining was detected in five equine, one bovine and one feline cases. Conversely, no p53 immunostaining was found in the only canine case examined. These results demonstrate a frequent p53 overexpression in conjunctival squamous cell carcinoma that could be related to UV-induced mutations of the p53 tumor suppressor gene.     

GIS-models work well, but are not enough: Habitat preferences of Lanius collurio at multiple levels and conservation implications

Species conservation largely depends on knowledge of habitat needs of target species. GIS-models are increasingly used to assess habitat preferences and distribution of target species, but their accuracy is constrained by availability of digital data layers. We developed a two-steps approach aiming at showing pros and cons of landscape (GIS)- and site-level habitat models, identifying key habitat factors for conservation of a threatened bird species, the red-backed shrike Lanius collurio. A spatially explicit GIS-model was generated using landscape variables, and a second model at site level was developed using fine-scale variables measured on the ground. The GIS-based model was then extrapolated to the entire region to obtain a map of distribution of suitable habitats. Positive associations between shrike occurrence and both hedgerow length and partial shrub cover were detected at both scales. Shrikes were also positively associated with grassland cover at landscape level and with partial cover of untilled herbaceous vegetation at the finer scale, and negatively affected by lucerne cover. The GIS-model led to an affordable map of predicted habitat suitability which should help conservationists to focus on different local priorities, but was unable to identify effects of untilled and lucerne cover. Site-level model gave fine details for habitat management, but its application elsewhere requires ground-measurements of factors. Combining the multiscale models could indicate more urgent actions at large scales (e.g. maintaining suitable habitats, or improving connectivity among isolated patches) and draw a detailed figure of the most suitable habitat for the species. Shrike occurrence was associated with a higher number of shrub and tree species: the indicator value of the species should ensure general benefits for biodiversity from dedicated management.