Abstract: This study analyzes soil sealing and its repercussions in the loss of fertile soils, which are more appropriate for agriculture use. Also, soil sealing increases flood risk. The main objective is to estimate soil loss by sealing in the Guadarrama River Basin (Madrid, Spain) between 1961 and 2011. The combination of digital processing (Normalized Difference Vegetation Index (NDVI), principal components and convolution filters) of satellite imagery with the digital terrain model helps to detect risk areas and allows quick updating of sealed soil mapping. The supervised classifications of the images were used to estimate the actual soil loss by sealing (9% in 2011) in the Guadarrama River Basin and the types and agrologic classes that have been lost. Soil loss occurs to a greater extent in highly permeable soils (sands) and in the most fertile soils. The main sealed soil associations are luvisols (alfisols), regosols (entisols) and cambisols (inceptisols).
Abstract: Numerous outbreaks of Escherichia coli O157:H7 have been linked to the consumption of leafy vegetables. However, up to the present, little has been known about E. coli O157:H7’s adaptive responses to survival on actively growing (and thus responsive) plants. In this study, whole genome transcriptional profiles were generated from E. coli O157:H7 cells (isolate Sakai, stx-) one hour and two days after inoculation on the leaves of growing butterhead lettuce, and compared with an inoculum control. A total of 273 genes of E. coli O157:H7 Sakai (5.04% of the whole genome) were significantly induced or repressed by at least two-fold (p < 0.01) in at least one of the analyzed time points in comparison with the control. Several E. coli O157:H7 genes associated with oxidative stress and antimicrobial resistance were upregulated, including the iron-sulfur cluster and the multiple antibiotic resistance (mar) operon, whereas the Shiga toxin virulence genes were downregulated. Nearly 40% of the genes with significantly different expression were poorly characterized genes or genes with unknown functions. These genes are of special interest for future research as they may play an important role in the pathogens’ adaptation to a lifestyle on plants. In conclusion, these findings suggest that the pathogen actively interacts with the plant environment by adapting its metabolism and responding to oxidative stress.
Abstract: The paper addresses issues related to the citrus waste valorisation process and its inherent uncertainties from the perspective of a new and innovative firm. Thus, we investigate the relevance/role of a business plan analysis in developing a new business (new biobased value chains) in the case of citrus waste valorisation. We look primarily at the inherent uncertainty associated with the start-up phase of a new business aimed at producing and wholesaling semi-finished products derived from the recovery of citrus waste in southern Italy. In order to do so, we use a qualitative case study approach focusing on a small citrus waste valorisation firm located in Calabria, using Agro Management Development (AMD) as a unit of analysis. The choice of this research setting is not random, given the fact that many companies from the Mediterranean are trying to engage in activities to valorise citrus waste deriving from production value chains. The main findings of our analysis can be summarized as follows: (i) focusing primarily on one area of uncertainty (i.e., market uncertainty) might undermine chances of success, as it could indicate an incomplete business strategy to stakeholders, hence hindering their willingness to commit to a new entrepreneurial initiative; (ii) although a business plan could be an effective way to narrow down uncertainty for a new innovative firm, it should be properly customised in order to address all relevant dimensions of uncertainty. Indeed, an insufficiently developed plan might be counterproductive, revealing (for instance, to possible investors) an inadequate strategy for facing and solving emerging problems, therefore putting the whole business project at risk.
Abstract: The study introduces a prototype multispectral camera system for aerial estimation of above-ground biomass and nitrogen (N) content in winter wheat (Triticum aestivum L.). The system is fully programmable and designed as a lightweight payload for unmanned aircraft systems (UAS). It is based on an industrial multi-sensor camera and a customizable image processing routine. The system was tested in a split fertilized N field trial at different growth stages in between the end of stem elongation and the end of anthesis. The acquired multispectral images were processed to normalized difference vegetation index (NDVI) and red-edge inflection point (REIP) orthoimages for an analysis with simple linear regression models. The best results for the estimation of above-ground biomass were achieved with the NDVI (R 2 = 0.72–0.85, RMSE = 12.3%–17.6%), whereas N content was estimated best with the REIP (R 2 = 0.58–0.89, RMSE = 7.6%–11.7%). Moreover, NDVI and REIP predicted grain yield at a high level of accuracy (R 2 = 0.89–0.94, RMSE = 9.0%–12.1%). Grain protein content could be predicted best with the REIP (R 2 = 0.76–0.86, RMSE = 3.6%–4.7%), with the limitation of prediction inaccuracies for N-deficient canopies.
Abstract: Production of arable crops in Switzerland is subsidized for services performed within the Proof of Ecological Performance (PEP) program, the crop protection part of which is based on IPM principles. Within PEP, chemical insect control must rely on those approved insecticides that are deemed harmless for beneficial arthropods. Approved insecticides potentially impacting beneficial arthropods may also be applied, but only if unavoidable and with an official permit. In order to assess the ecological and economic sustainability of this PEP program, a reference insecticide strategy illustrating the current PEP requirements was compared with other strategies. For this purpose, a sustainability assessment taking account of ecotoxicological risks and economic viability in addition to the preservation of beneficial arthropods was performed according to the SustainOS methodology. The results show that the one-off use of Audienz (spinosad) to control cereal leaf beetle (Oulema melanopus)—a key pest in winter wheat—would significantly improve sustainability vis-à-vis the reference (Nomolt (teflubenzuron) plus Biscaya (thiacloprid)). However, in the case of the Colorado potato beetle (Leptinotarsa decemlineata), in potato crops, where Audienz is considered the reference, no alternative would exhibit better sustainability. Moreover, the study shows that strategies using Novodor (Bacillus thuringiensis) protect beneficial species well but have the drawbacks of increased yield risk and higher costs. The conclusions drawn from these analyses allow recommendations for modifications of the PEP requirements for these two pest insects. The SustainOS methodology, a multi-step process combining expert knowledge with quantitative assessments including a sensitivity analysis of key target parameters and a rule-based aggregation of assessment results, yielded valuable insights into the sustainability of different crop protection strategies.