Precision farming uses typology in arable crop-oriented farms in northern France

The adoption of precision farming techniques (PFTs) has been widely studied targeting specific PFT or farming systems along with the potential benefits of these PFTs in terms of yield or input use. However, few studies have examined how PFTs are adopted and used at the farm level. In this study a preliminary investigation was made of on-farm PFT uses in the Oise region (northern France). Three main PFTs were identified in the area: Global Navigation Satellite Systems (GNSS) guidance, section control, and variable rate (VR) application. For each farm, the use of every PFT was defined by the technical characteristics of the equipment, the field operation(s) concerned, the targeted crop(s), the aim of the use, the PFT adoption drivers, and the perceived impacts by the farmers. These different variables were combined into a typology of PFT uses. The results show that most of the farms combined GNSS guidance for all technical operations and section control, whereas VR application was less common. Section control was largely used by farmers for liquid fertilizers and phytochemical spraying. The typology shows three to five types of use for each PFT, which differ in terms of technique adoption drivers, e.g. reducing on-farm work or adaptation to field morphology. According to literature, economic impacts were found to be the most frequent, however farmers seemed unable to quantify them. Social impacts such as reduced work time and fatigue were also frequent and are becoming the main motivation for using PFT on farms studied. Further research is needed to assess the use trajectories of PFT along with the motivations of each PFT use.

     

The future demographic niche of a declining grassland bird fails to shift poleward in response to climate change

Context

Temperate grasslands and their dependent species are exposed to high variability in weather and climate due to the lack of natural buffers such as forests. Grassland birds are particularly vulnerable to this variability, yet have failed to shift poleward in response to recent climate change like other bird species in North America. However, there have been few studies examining the effect of weather on grassland bird demography and consequent influence of climate change on population persistence and distributional shifts.

Objectives

The goal of this study was to estimate the vulnerability of Henslow’s Sparrow (Ammodramus henslowii), an obligate grassland bird that has been declining throughout much of its range, to past and future climatic variability.

Methods

We conducted a demographic meta-analysis from published studies and quantified the relationship between nest success rates and variability in breeding season climate. We projected the climate-demography relationships spatially, throughout the breeding range, and temporally, from 1981 to 2050. These projections were used to evaluate population dynamics by implementing a spatially explicit population model.

Results

We uncovered a climate-demography linkage for Henslow’s Sparrow with summer precipitation, and to a lesser degree, temperature positively affecting nest success. We found that future climatic conditions—primarily changes in precipitation—will likely contribute to reduced population persistence and a southwestward range contraction.

Conclusions

Future distributional shifts in response to climate change may not always be poleward and assessing projected changes in precipitation is critical for grassland bird conservation and climate change adaptation.

     

ENABLING CROP DIVERSIFICATION TO SUPPORT TRANSITIONS TOWARD MORE SUSTAINABLE EUROPEAN AGRIFOOD SYSTEMS

• Crop diversification is a dynamic pathway towards sustainable agrifood systems.• Technological and institutional barriers restrict uptake of crop diversification.• More coordination and cooperation among agrifood system stakeholders is required.• The European Crop Diversification Cluster calls for multiactor networks.European cropping systems are often characterized by short rotations or even monocropping, leading to environmental issues such as soil degradation, water eutrophication, and air pollution including greenhouse gas emissions, that contribute to climate change and biodiversity loss. The use of diversification practices (i.e., intercropping, multiple cropping including cover cropping and rotation extension), may help enhance agrobiodiversity and deliver ecosystem services while developing new value chains. Despite its benefits, crop diversification is hindered by various technical, organizational, and institutional barriers along value chains (input industries, farms, trading and processing industries, retailers, and consumers) and within sociotechnical systems (policy, research, education, regulation and advisory). Six EU-funded research projects have joined forces to boost crop diversification by creating the European Crop Diversification Cluster (CDC). This Cluster aggregates research, innovation, commercial and citizen-focused partnerships to identify and remove barriers across the agrifood system and thus enables the uptake of diversification measures by all European value-chain stakeholders. The CDC will produce a typology of barriers, develop tools to accompany actors in their transition, harmonize the use of multicriteria assessment indicators, prepare policy recommendations and pave the way for a long-term network on crop diversification.     

Seaweed Extracts: A Promising Source of Antibiofilm Agents with Distinct Mechanisms of Action against Pseudomonas aeruginosa

The organization of bacteria in biofilms is one of the adaptive resistance mechanisms providing increased protection against conventional treatments. Thus, the search for new antibiofilm agents for medical purposes, especially of natural origin, is currently the object of much attention. The objective of the study presented here was to explore the potential of extracts derived from three seaweeds: the green Ulva lactuca, the brown Stypocaulon scoparium, and the red Pterocladiella capillacea, in terms of their antibiofilm activity against P. aeruginosa. After preparation of extracts by successive maceration in various solvents, their antibiofilm activity was evaluated on biofilm formation and on mature biofilms. Their inhibition and eradication abilities were determined using two complementary methods: crystal violet staining and quantification of adherent bacteria. The effect of active extracts on biofilm morphology was also investigated by epifluorescence microscopy. Results revealed a promising antibiofilm activity of two extracts (cyclohexane and ethyl acetate) derived from the green alga by exhibiting a distinct mechanism of action, which was supported by microscopic analyses. The ethyl acetate extract was further explored for its interaction with tobramycin and colistin. Interestingly, this extract showed a promising synergistic effect with tobramycin. First analyses of the chemical composition of extracts by GC–MS allowed for the identification of several molecules. Their implication in the interesting antibiofilm activity is discussed. These findings suggest the ability of the green alga U. lactuca to offer a promising source of bioactive candidates that could have both a preventive and a curative effect in the treatment of biofilms.     

Age of wheat and barley roots and infection by gaeumannomyces graminis var tritici

Seminal roots of wheat and barley seedlings were inoculated with G. graminis var tritici on regions 0, 5- and 15-days old, and assessed for intensity and extent of infection after standard times. Wheat roots were most heavily infected on young regions, whereas barley roots were most heavily infected on old ones. The effect of root age in wheat was similar in both unsterile and aseptic conditions, so it could not be ascribed to saprophytic rhizosphere micro-organisms interacting with G. graminis.The contrasting results for wheat and barley are explained by a single hypothesis, based on decreasing host-resistance in the root cortex but increasing resistance at or near the endodermis as the roots age. It is suggested that, under some conditions, even small amounts of non-pathogenic root cortex death can enhance infection by G. graiminis. This interpretation may explain several aspects of take-all and its biological control by other dark mycelial parasites.     

Mycoparasitism by Pythium oligandrum and P. acanthicum

Isolates of the reported mycoparasites Pythium oligandrum, P. acanthicum and P. periplocum markedly reduced growth and cellulolysis by Botryotrichum piluliferum, grew rapidly across agar plates precolonized by Phialophora radicicola var radicicola (sensu Deacon) and, where tested (not P. periplocum), were non-pathogenic towards higher plants. Isolates of P. echinulatum, P. mamillatum. P. megalacanthum, P. spinosum, P. ultimum and one isolate of P. acanthicum behaved differently from the mycoparasites and could, themselves, be placed in two groupings in these tests. It is suggested that the ability or otherwise to grow on Phialophora-precolonized agar plates may help to distinguish broad biological groupings within the genus Pythium, but these groupings may cut across conventional taxonomic ones.One isolate of P. acanthicum was tested for its effects on a range of cellulolytic fungi: it reduced their growth to different extents, as did P. oligandrum.Plates of potato-dextrose agar precolonized by Phialophora radicicola were used to isolate selectively P. oligandrum and similar fungi from soils, but the use of hemp seed baits in conjunction with precolonized plates was less selective for these fungi.Straw pieces precolonized by P. oligandrum and buried in soil decomposed at the same rate as virgin straws or those precolonized by P. ultimum or Mucor hiemalis. Subsequently, Stachyholrys atra appeared to colonize straws more frequently from soil, and Fusarium spp. less so, in the presence of P. oligandrum than in its absence. In the laboratory, P. oligandrum was antagonized by Slachyholrys, whereas Fusarium spp. were frequently overgrown by the Pythium.     

Comparison of growth,digestive system maturation and skeletal development in sea bass larvae reared in an intensive or a mesocosm system

The quality of development in intensive or mesocosm hatchery‐reared Dicentrarchus labrax larvae was investigated using physiological indicators assessing ontogeny. Larvae were reared in intensive (120 L tanks) and in mesocosm systems (20 m³ enclosures) with the same feeding sequence, excluding the wild zooplankton naturally available in mesocosms. Faster growth was recorded since early development [16 day after hatching (DAH)] in the mesocosm. Maturation of the digestive system also occurred earlier as indicated by the higher amylase secretion ratios, the intestinal maturation index (alkaline phosphatase/leucine–alanine peptidase and aminopeptidase‐N/leucine–alanine peptidase ratios) and the more developed intestinal epithelium at 23 DAH. Nevertheless, the delay in digestive maturation in the intensive system seemed retrieved within few days. In both the groups, the number of vertebrae ranged between 24 and 26, with the dominant class being 25 vertebrae. However, the distributions differed between treatments for meristic characteristics, ossification stages and incidence of malformation types. Loss of a vertebra was more frequent in the intensive system, while the appearance of an additional vertebra was more frequent in the mesocosm. Ossification at 37 DAH was also more advanced in the mesocosm in addition to a lesser rate and severity of skeletal malformations. It is suggested that the early nutritional contribution of mesocosm wild zooplankton, yet at densities of 0.2–0.7 prey mL^?1, had key effects on larvae development since the early stages.     

Retrospective Study: Cause and clinical characteristics of rib fractures in cats: 33 cases (2000–2009)

Objective – To characterize the clinical features and population differences among cats sustaining traumatic and nontraumatic rib fractures. Design – Retrospective clinical study. Setting – University small animal hospital. Animals – Thirty‐three cats with radiographic evidence of rib fractures. Interventions – None. Measurements and Main Results – Cats with rib fractures were identified by performing a computer search of the radiology database. Thirty‐three cats that sustained rib fractures were identified between January 2000 and September 2009. Seventeen cats had fractures due to trauma and 16 were deemed to occur from nontraumatic causes. A Mann‐Whitney rank‐sum test revealed statistically significant differences in the median ages between the 2 groups. Older cats were more likely to sustain rib fractures as a result of a presumed nontraumatic causes. A Chi‐square analysis showed that nontraumatic fractures occurred significantly more often in the midbody region and involved the 9th–13th ribs. The majority of cats with presumed nontraumatic rib fracture had respiratory disease; the remaining cats had chronic renal disease or neoplasia. Cats with traumatic rib fractures had external signs of trauma. Conclusion – Rib fractures in cats may be clearly associated with trauma, or may be an incidental finding in cats with comorbidities. Cats with diseases that cause prolonged respiratory effort or coughing, metabolic diseases, or certain neoplasms, are at increased risk of spontaneous nontraumatic rib fractures.