Multiple functions of buffer strips in farming areas

Buffer strips (BSs) are strips interposed between fields and streams that intercept and treat the waters leaving cropland, and so are a useful tool for reducing agricultural diffuse pollution in lowland areas. If properly vegetated and managed, they can also produce wood for burning, act as sinks for atmospheric CO₂ and enhance the landscape beauty.The paper presents an analysis of the different functions of BS and reviews the more important data from research programmes conducted over the last decade in Veneto Region (North-East Italy). Over a period of 3–5 years, in two experimental sites, young BS reduced total runoff by 33%, losses of N by 44% and P by 50% compared to no-BS. A mature BS was able to abate both NO₃–N and dissolved phosphorus concentrations by almost 100%, in most cases having exiting water that satisfied the limit for avoiding eutrophication. The BS also proved to be a useful barrier for herbicides, with concentrations abated by 60% and 90%, depending on the chemical and the time elapsed since application. Considering the CO₂ immobilized in the wood and soil together, the different BS monitored stored up to 80 t ha^?1 year^?1.The BS caused negligible disturbance to maize, soybean and sugarbeet yields. The hedgerows, particularly if composed of trees taller than 6 m, positively influenced the aesthetic value of the territory, improving its perceived naturalness and screening the man-made elements.Lastly, through a multi-objective analysis, opportunity costs were estimated to support the public decision-maker in determining the subsidies to be paid to encourage farmers to plant BS.     

Possibilities of increasing the residual water‐soluble carbohydrate concentration and aerobic stability of low dry‐matter perennial ryegrass silage through additive and cultivar use

Increasing the residual water‐soluble carbohydrate (WSC) concentration in silage may improve the nutritional value but impair aerobic stability. Our aim was to determine whether the residual WSC concentration and aerobic stability of low dry‐matter (<135 g kg^?1) perennial ryegrass silage could be manipulated through the judicious use of additive and cultivar. Seven additive treatments, including three innovative treatments, were compared across four consecutive harvests of the cultivars AberDart (bred to accumulate high concentrations of herbage WSC) and Fennema (control). The standard of fermentation of silage ensiled without additive (untreated) ranged from very bad to excellent. Application of ammonium tetraformate, at 3 and 6 L t^?1, or homofermentative lactic acid bacteria (LAB) alone had an inconsistent effect on the fermentation and aerobic stability, and negligible effect on residual WSC concentration. A mixture of Lactobacillus buchneri and homofermentative LAB was not an effective silage additive, producing generally poorly fermented silage. An antimicrobial mixture of sodium benzoate, sodium propionate, sodium nitrite and hexamethylenetetramine, applied at 2·5 and 5 L t^?1, frequently improved the standard of fermentation, but the effects were subject to the application rate. The high application rate was the most effective additive evaluated at improving the fermentation and increasing residual WSC concentration and consistently produced silage of excellent standard of fermentation. However, the antimicrobial mixture was not effective at protecting against aerobic instability. The effects of additive treatment were largely inconsistent across cultivars. Overall, AberDart had a negligible effect on the silage fermentation, residual WSC concentration and aerobic stability compared with Fennema.     

Factors associated with infection by Neospora caninum in dogs in Brazil

From August 2006 to 2008, 411 dogs in northeastern Brazil were evaluated for seropositivity to Neospora caninum. The dogs were clinically examined, and their owners were interviewed about the conditions in which the animals were maintained in order to assess the factors associated with infection by this parasite. A serum sample was taken from each dog for serological examination in an indirect fluorescent antibody test for N. caninum. The Yates' Chi-square test or Fisher's exact test was used to select the variables for the multivariate logistic regression model. Seropositivity was detected in 9.26% of dogs. The seropositivity rates of dogs from different environments were 2.6% (4/156) in urban areas, 13.1% (28/214) in peri-urban areas, and 14.6% (6/41) in rural areas. Factors associated with seropositivity for N. caninum were the following: contact with other dogs, access to food outside the home and residing in the peri-urban or rural environments (p<0.05). Results of this study confirm that dogs in urban, rural and peri-urban areas of northeastern Brazil are exposed to N. caninum. Control measures to prevent infection of dogs in the studied region should be focused primarily on preventing access to potential sources of infection, which include environments with other dogs, bovines, and other small intermediate hosts, such as birds and rodents.     

Chicken-manure-derived biochar reduced bioavailability of copper in a contaminated soil

Purpose

Copper (Cu) contamination has been increasing in land ecosystems due to economic development activities. Excessive amount of Cu in soils is toxic to both plants and microorganisms. Biochar (BC) is known to immobilize soil Cu. The objectives of this research were to investigate the effects of chicken-manure-derived BC (CMB) on Cu immobilization, and growth of native metallophyte Oenothera picensis in a Cu-contaminated soil.

Materials and methods

A Cu-contaminated sandy soil (338 mg Cu kg^?1) was spiked and equilibrated with additional Cu (0, 100, and 500 mg Cu kg^?1). The spiked soil was then amended with CMB (0, 5, and 10 % w/w) and incubated for 2 weeks. The metallophyte was grown on these treatments under greenhouse conditions for 3 months. Pore water solutions were collected from the plant pots every 30 days. After the harvest, soil and pore water pH, soil Cu fractions, pore water Cu concentration, soil microbial activity, plant biomass weight, and Cu concentration in plant parts were determined.

Results and discussion

The CMB increased the pH of soils and soil pore water, and probably also soil major nutrients. It reduced the exchangeable fraction of Cu but increased its organic matter and residual fractions. At the same time, it decreased the Cu concentration in the soil pore water. The CMB increased basal respiration and dehydrogenase activity. The CMB application produced up to three and seven times more root and shoot biomass, respectively. In addition, shoots accumulated lesser Cu than control but roots did more. Plants survived in soil that was spiked with 500 mg Cu kg^?1, only when CMB dose was 10 %.

Conclusions

The CMB affected the Cu uptake in plant by altering the mobility, bioavailability, and spatial distribution of Cu in soils. The increase in available nutrients and decrease in Cu toxicity facilitated plant growth. The increased microbial activity probably also promoted the plant growth and reduced the Cu bioavailability. Therefore, CMB can be used to remediate Cu-contaminated soils.

     

Fall rate of burnt pines across an elevational gradient in a Mediterranean mountain

Burnt wood remaining after a wildfire is a biological legacy with important implications for habitat structure, ecosystem regeneration, and post-fire management. Knowledge of the time required for snags to fall is thus a key aspect for planning forest restoration. In this study, we analyze the fall rate of burnt trees in a Mediterranean pine reforestation. Three plots of 18–32 ha were established after a fire across an elevational gradient spanning from 1400 to 2100 m a.s.l., and snag fall rate was measured on a yearly basis using an experimental setup that considered two levels of a thinning treatment: unthinned (where no post-fire management was conducted and all the snags were left standing after the fire) and thinned (where 90% of the trees were cut after the fire and left on the ground). All the snags remained standing during the first and second winter, and thereafter, they collapsed quickly until reaching 100% after 5.5 years. Snags in low-density stands resulting from thinning fell faster than in unthinned stands, but the differences were minor. There was a negative effect of tree diameter on the rate of collapse, especially in the unthinned treatment, but the effect of diameter was minor too. There was no effect of the elevational gradient on fall rate despite patent differences in climatic conditions and pine species across plots. The results support the contention that post-fire fall rate in dense pine plantations in Mediterranean mountains can occur quickly after the second winter and may show little variation across environmental gradients.     

COMPUTED TOMOGRAPHIC FEATURES OF INCISOR PSEUDO‐ODONTOMAS IN PRAIRIE DOGS (CYNOMYS LUDOVICIANUS)

Maxillary incisor pseudo‐odontomas are common in pet prairie dogs and can cause progressive respiratory obstruction, while mandibular pseudo‐odontomas are rarely clinically significant. The aim of this retrospective cross‐sectional study was to describe CT features of maxillary and mandibular incisor pseudo‐odontomas vs. normal incisors in a group of pet prairie dogs. All pet prairie dogs with head CT scans acquired during the period of 2013–2015 were included. A veterinary radiologist who was aware of final diagnosis reviewed CT scans and recorded qualitative features of affected and normal incisors. Mean density values for the pulp cavity and palatal and buccal dentin were also recorded. A total of 16 prairie dogs were sampled (12 normal maxillary incisors, 20 confirmed maxillary incisor pseudo‐odontomas, 20 normal mandibular incisors, 12 presumed mandibular incisor pseudo‐odontomas). Maxillary incisors with confirmed pseudo‐odontomas had a significantly hyperattenuating pulp and dentin in the reserve crown and apical zone, when compared to normal maxillary incisors. Pseudo‐odontomas appeared as enlargements of the apical zone with a globular/multilobular hyperattenuating mass formation haphazardly arranged, encroaching on midline and growing caudally and ventrally. Presumed mandibular incisor pseudo‐odontomas had similar CT characteristics. In 60% of prairie dogs with maxillary incisor pseudo‐odontomas, the hard palate was deformed and the mass bulged into the oral cavity causing loss of the palatine bone. The common nasal meatus was partially or totally obliterated in 81.8% of prairie dogs with maxillary pseudo‐odontomas. Findings supported the use of CT for characterizing extent of involvement and surgical planning in prairie dogs with pseudo‐odontomas.     

Batch Chromium(VI), Cadmium(II) and Lead(II) Removal from Aqueous Solutions by Horticultural Peat

The selectivity and uptake capacity of horticultural peat available in Romania was evaluated with respect to the removal of Cd(II), Cr(VI) and Pb(II) ions from aqueous solution. The kinetics, sorption capacities, selectivity and pH dependence of sorption were determined. The influence of metal concentration in solution is discussed in the terms of Langmuir and Freundlich isotherm and constants. Sorption capacities increased with increasing metal concentration in solution. For solutions containing 300 mg/l of metal, the observed uptake capacities were 20 mg Cd(II)/g peat, 15 mg Cr(VI)/g peat and 30 mg Pb(II)/g peat. The study proved that horticultural peat is a suitable material for the removal of the studied heavy metal ions from aqueous solutions, achieving removal efficiencies higher than 90%, and could be considered as a potential material for treating effluent polluted with Cd(II), Cr(VI) and Pb(II) ions.     

Transmission and control implications of seroconversion to Maedi-Visna virus in Basque dairy-sheep flocks

A retrospective analysis of seroconversion to Maedi-Visna virus (MVV) was carried out for 10 infected semi-intensively reared dairy-sheep flocks that were tested annually between 1994 and 1999. Four of the flocks raised replacement lambs artificially with bovine colostrum and milk replacement to avoid lactogenic MVV infection but did not prevent aerosol contact between replacements and other sheep in the flock. Flock culling percentages ranged between 14 and 25% and in eight flocks the number of sheep that seroconverted was similar to or lower than the number of sheep culled—suggesting that incidence could be reduced by culling seropositive sheep without increasing average culling percentages. Random-effects logistic regression indicated that seroconversion was associated positively with increasing contact with infected sheep and with lifetime MV-serological status of the dam (used as a proxy measure of genetic susceptibility), but not with mode of rearing pre-weaning (artificially or with a seropositive or seronegative dam). Our results indicate that when conditions allow efficient horizontal transmission, there is no evidence that lactogenic infection increases the risk of MV infection and that there is an important inheritable component of disease resistance or susceptibility.     

Seroprevalence and associated risk factors of neosporosis in beef and dairy cattle in Italy

A cross-sectional serological survey for Neospora caninum was carried out on beef and dairy cattle in southern and northern Italy. A total of 111 herds and 1140 animals were tested using an ELISA assay (CHEKIT-Neospora) to detect anti-N. caninum antibodies. Management and individual data were collected and analysed both by linear and logistic multiple-regression models in order to find good predictors of the cattle seroprevalence and anti-N. caninum antibody level. At least one seropositive animal was found in 49 herds (44.1%), of which 31 (39.7%) from southern Italy and 18 (54.5%) from northern Italy. A total of 126 head of cattle (11%) were found to be seropositive and the seroprevalence was lower in southern (8.7%) than in northern Italy (16%). One of the best predictors of neosporosis seroprevalence in this study was the practice of self-rearing replacement heifers. Further risk factors were linked to higher stocking density, i.e. animals farmed in large herds and with no summer or permanent grazing practices were more likely to be seropositive than others. Farms with two or more dogs had higher herd seropositivity than farms with one or no dogs and this factor interacted significantly with the farm size and presence of poultry. Among individual characteristics, seropositivity was higher in animals sampled in mid- or late-pregnancy compared to animals either in early pregnancy or not pregnant. There was a significant interaction between the factors for pregnancy status and grazing practices. None of the epidemiological data recorded was a good predictor of the anti-N. caninum antibody level.