Effect of ground‐cover type on surface runoff and subsequent soil erosion in Champagne vineyards in France

This study was conducted in Champagne vineyards in France, and the objectives were to compare the main cultivation practices in Champagne vineyards and to specify the conditions required for the optimum effect of inter‐row grass cover on runoff and erosion in experimental plots of 0.25 m² under simulated rainfall. Three types of ground cover were studied. In the bark‐and‐vine‐prunings plots, the runoff coefficient (RC) ranged from 1.3 to 4.0% and soil losses were <1 g/m²/h. In the bare soil (BS) plot, the highest RC of the study was found (80.0%) and soil losses reached 7.4 g/m²/h. In the grass cover plots, the RC and amount of eroded soil were highly variable: the RCs ranged from 0.4 to 77.0%, and soil losses were between less than 1 and 13.4 g/m²/h. Soil type, soil moisture, slope and agricultural practices did not account for the variability. In fact, the density of grass cover in the wheel tracks explained a portion of this variability. The lack of grass in the centre of the inter‐row allowed for a preferential flow and created an erosion line in the wheel tracks where the soil was compacted. This study showed that grass cover in a vineyard was not necessarily sufficient to reduce surface runoff and prevent soil erosion. To be effective, the grass cover must be dense enough in the wheel tracks of agricultural machinery to avoid RCs close to the RC achieved with BS.     

Description of risk factors associated with the detection of BVDV antibodies in Brazilian pig herds

Bovine viral diarrhea virus (BVDV) infects ruminants as primary hosts. However, other animals like pigs are susceptible. This study was conducted to investigate seroprevalence and risk factors associated with the detection of BVDV antibodies in pig herds. A total of 1.705 serum samples of 33 finisher herds, from seven Brazilian states, were collected in slaughterhouses. The samples were tested by virus neutralization (VN) test. In total, 5.35% (91/1.705) were positive and 64% (21/33) of the herds had positive animals. A significant association with “trucks are not cleaned and disinfected” and “visitors do not respect 72-h interval between visits to farms” (P?<?0.05) was found in association with detection of BVDV-2 antibodies. This study suggests that important biosecurity gaps are present in Brazilian pig farms, as the presence of BVDV antibodies in pigs suggests (direct or indirect) contact with population(s) of ruminant species. Closing biosecurity gaps prevents spread of BVDV and other pathogens such as foot-and-mouth disease virus (FMDV) between pig and ruminant farms. This data should be taken in account by CSF surveillance programs, once cross-reaction in serologic tests between classical swine fever virus (CSFV) and BVDV antibodies has been shown to occur.     

Appraisal of interpretation criteria for the single intra-dermal comparative cervical tuberculin test for the diagnosis of tuberculosis in dromedary camels in Ethiopia

Tropical Animal Health and Production - Dromedary camels are the main sources of milk, meat and income for the Ethiopian pastoralists as they withstand the harsh environments of the regions of the...     

Potential Dissipation of Atrazine in the Soil Unsaturated Zone: a Comparative Study in Four European Countries

A European-wide project has been undertaken to establish the potential for dissipation of atrazine in the soil subsurface environment. Samples were obtained, avoiding contamination, in four countries (Belgium, Greece, Hungary and UK) and laboratory studies carried out. In order to make comparisons between results from each laboratory, a ring experiment was carried out using common methodology for sampling, extraction and analytical techniques. Subsurface materials from each country were distributed to the other countries. Atrazine dissipation was determined in each country for all materials under the same laboratory conditions. The results of this comparative study showed generally good agreement between all laboratories. Significant potential microbiological dissipation was detected in certain samples. Where differences occurred between laboratories this was attributed to small, spatially heterogeneous microbial populations in the subsurface materials. © 1997 SCI.     

Degradation of atrazine and isoproturon in the unsaturated zone: a study from Southern England

The potential for degradation of atrazine or isoproturon in the unsaturated zone of two boreholes was studied under laboratory conditions. Intact and uncontaminated samples were obtained from regular depths of 0–16.45 m and 0–9 m using a percussion coring technique. The results showed that the deep unsaturated zone contained micro-organisms capable of degrading atrazine or isoproturon. The rate of degradation was much faster in surface soil than in most unsaturated materials of both boreholes. The amount of atrazine remaining six months after incubation also varied between the two boreholes. A relatively small amount of atrazine was lost from sterilised samples, suggesting a significant role for microbial degradation. The addition of nutrient and energy sources into materials of low degradation capacity did not enhance the degradation of atrazine. Degradation rate was more related to the presence of a competent microbial population rather than to the presence of indigenous organic matter. However, the competent micro-organisms are more likely to be present when the organic matter content is high. The type and activity of these micro-organisms and their physical environment may have considerable influence on atrazine degradation and are likely to be responsible for much of the variation in the rate of degradation observed at different depths. © 1999 Society of Chemical Industry     

Prevalence and incidence of bovine trypanosomosis in an agro-pastoral area of southwestern Burkina Faso

The present study was conducted to determine the prevalence and incidence of trypanosomosis and to investigate some factors influencing them in an agro-pastoral area of southwestern Burkina Faso. A total of 363 crossbred cattle (Baoule-zebu peul), which were bred under natural trypanosomosis challenge, were monitored monthly for parasitaemia, packed cell volume (PCV) and serological analyses over 2 years. The parasitological prevalence estimated at the beginning of the survey using the buffy coat technique (BCT) was 7.54%. As much as 66.7% of all trypanosome infections were due to Trypanosoma vivax, 23.8% due to Trypanosoma congolense and 9.5% due to T. vivax/T. congolense mixed infections. The monthly serological incidence varied from 0.29% to 19.29%.The season was the most important factor influencing the serological prevalence and incidence and the animal PCV. The dry hot season is associated with increasing seroprevalences and incidences and consequently a decreasing average of PCV. In addition, an important spatial heterogeneity was observed.     

Phytochemical Constituents and Allelopathic Effects of Some Medicinal Plants Extract on the Soil Algal Diversity

Phytochemical constituents of the shoots and roots extract of chosen eight medicinal plants （Plantago major, Verbesina encelioides, Glinus lotoides, Helotropium supinum, Mentha microphylla, Euphorbia hirta, Juncus subulatus and Convolvulus arvensis） were estimated using standard qualitative analysis. The extract contained alkaloids, glycosides, saponins, phenols, tannins, f[avonoids and terpenoids in some medicinal plants while others contain some only of these phytochemical components. Allelopathic effect of the various concentrations of the extracts on the soil algal diversity was also investigated. Wollea saccata was the only algal species disappeared from all applied investigated plant extracts. Phormidium richardsii, Monoraphidium braunii, Eunotia verneris and Nitzschia bilobata were the highly sensitive algal species to all applied shoot and root extract from all tested plants, they disappeared from most of the studied plants. On the other hand, Phormidium animale and Chlorella neustonice were highly tolerant algal species to all applied extracts. Counts of Cyanophyceae, Chlorophyceae and Bacillariophyceae were decreased by addition of some investigated medicinal plants extracts such as Juncus subulatus, Convolvulus arvensis and Euphorbia hirta. So the authors can use these plants extracts in biocontrol of the nuisance of algal bloom or any other microorganisms. Also, these plants may be useful to recover eutrophic water which needs further investigation.     

Anticoccidial effects of Khaya senegalensis aqueous stem bark extract on broiler chickens experimentally infected with Eimeria species

Tropical Animal Health and Production - Graded concentrations (200, 400 and 800&nbsp;mg/kg) of the aqueous stem bark extract of Khaya senegalensis was evaluated for its therapeutic efficacy...