Time filter

Source Type

Wolfarth F.,Johann Heinrich Von Thunen Institute | Schrader S.,Johann Heinrich Von Thunen Institute | Oldenburg E.,Julius Kuhn Institute | Weinert J.,Chamber of Agriculture Lower Saxony
Soil Biology and Biochemistry

Despite well-known positive aspects of conservation tillage combined with mulching on arable fields, one drawback may be the survival of phytopathogenic fungi on plant residues. Therefore, plant pathogen repression is an important ecosystem service to prevent cultivated plants from fungal diseases and mycotoxin contamination. A microcosm-study was conducted under constant laboratory conditions to assess the impact of soil microfauna (Aphelenchoides saprophilus, Nematoda) and soil mesofauna (Folsomia candida, Collembola) on soil-borne phytopathogenic fungi (Fusarium culmorum) and its mycotoxin deoxynivalenol (DON). Our hypotheses were: (1) nematodes and collembolans reduce the biomass of F. culmorum and the content of DON in infected wheat straw; (2) the species interaction of A. saprophilus and F. candida enhances the degradation of Fusarium biomass and DON concentration in wheat straw; (3) the degradation efficiency of nematodes and collembolans is affected by soil texture. Therefore, microcosms were filled with soil of different texture and finely chopped wheat straw (Fusarium-infected vs. non-infected). The microcosms were inoculated with the two species in different combinations (single and mixed species, non-faunal control). After 2 and 4 weeks of incubation, the individual densities in all soil faunal treatments increased with highest individual numbers in the non-infected treatments in case of collembolans and in the infected treatments in case of nematodes. The Fusarium biomass (Fusarium protein equivalents = FPE) of all infected treatments decreased by at least one order of magnitude after 2 weeks. At the end of 4 weeks Fusarium-biomass was reduced by 93% in sandy and silt loam and 89% in clay loam mostly in mixed species treatments. Also DON concentrations were reduced significantly compared to the initial concentration in all treatments after 4 weeks. The highest reduction was found in mixed species treatments, where DON was degraded by 92%, 95% and 39% for sandy loam, silt loam and clay loam, respectively. We concluded that particularly interacting collembolans and nematodes play an important role in plant pathogen repression and mycotoxin degradation. In any case, soil texture matters in the provision of these ecosystem services by collembolans and nematodes. © 2012 Elsevier Ltd. Source

Kromker V.,Hanover University of Applied Sciences | Pfannenschmidt F.,Chamber of Agriculture Lower Saxony | Helmke K.,Osnabruck University of Applied Sciences | Andersson R.,Osnabruck University of Applied Sciences | Grabowski N.T.,University of Veterinary Medicine Hannover
Journal of Dairy Research

The prevalence of intramammary infections (IMI) and subclinical mastitis (SCM) in 436 German Holstein heifers was put in relation with clinical findings of the udder and data regarding individual rearing and housing conditions of the animals. The clinical examination took place on the day of the livestock auction (at approximately 41 d in milk, DIM). On that day, 31% of the heifers had IMI in at least one quarter, and 18% of all quarters were infected. Coagulase-negative staphylococci were the most prevalent bacteria isolated, accounting for 68% of the positive samples. Data were analysed by logistic regression. Criteria such as 'juvenile intersucking', 'teats shorter than 35 mm', 'teats with a diameter <18 mm' and 'udder oedema at the day of the auction' were associated with IMI in heifers during the first 41 DIM. Loose-housing systems during pregnancy (as opposed to tie-stalls), juvenile intersucking, clinical mastitis during the first week after calving, teat diameters <18 mm, and employing organic bedding material in the stables before calving were associated with subclinical mastitis. © Proprietors of Journal of Dairy Research 2012. Source

Piechotta M.,University of Veterinary Medicine Hannover | Bollwein J.,University of Veterinary Medicine Hannover | Friedrich M.,University of Gottingen | Heilkenbrinker T.,Chamber of Agriculture Lower Saxony | And 5 more authors.
Journal of Reproduction and Development

The objective of the present study was to compare two commercially available blood-based pregnancy tests, namely BioPRYN, an ELISA for pregnancy-specific protein B (PSPB), and an ELISA for pregnancy-associated glycoprotein (PAG), for early pregnancy diagnosis in dairy cattle using transrectal ultrasonography as a gold standard. Transrectal ultrasonography was conducted 26-58 days after artificial insemination (AI) in 197 cattle from 19 farms. Concurrently, a blood sample was collected for determination of serum PSPB and PAG. Transrectal palpation was performed approximately 120 days after AI to verify that pregnancy was maintained. For PSPB and PAG, there were no significant differences (P>0.05) in sensitivity (98.0 and 97.8%), specificity (97.1 and 91.2%), positive predictive values (99.3 and 97.8%), negative predictive values (91.9 and 91.2%) and accuracy (97.8 and 96.4%). In conclusion, the two blood pregnancy assays were equally efficacious and were highly accurate (based on transrectal ultrasonography as the gold standard). © 2011 by the Society for Reproduction and Development. Source

Kayser M.,University of Gottingen | Benke M.,Chamber of Agriculture Lower Saxony | Isselstein J.,University of Gottingen
Agronomy for Sustainable Development

Information on the environmental impact of maize production is actually inconsistent. Indeed some experiments report good nitrogen (N) efficiencies and small residual N. Other experiments show large leaching losses, while in practice maize production is often coupled with an intensive production and large N surpluses. Here, we present data from a 4-year experiment with silage maize on a sandy soil of high mineralization potential. The experimental set-up included three N input forms, mineral, cattle and pig slurry and four rates of total N, of 0, 80, 160 and 240 kg N ha-1 year-1 and the use of suction cups. Results show that dry matter and N yields for N0-N240 were relatively high and consistent (158-192 kg N ha-1). Further findings show large residual soil mineral nitrogen, of 138-237 kg Nha-1, and high nitrate concentrations in leaching water during winter, of 39-73 mg NO 3-N L-1, corresponding to leaching losses of 86-152 kg N ha-1. Response to N input was small with apparent N recoveries of 14-22% for manures and mineral fertilizers. We conclude that caution is needed when maize production is extended to fields with an apparently high potential for mineralization and that use as grassland would be a better alternative with regard to N leaching losses. © INRA and Springer Science+Business Media B.V. 2011. Source

Feller C.,Leibniz Institute of Vegetable and Ornamental Crops | Richter E.,Julius Kuhn Institute | Smolders T.,Limseeds BV | Wichura A.,Chamber of Agriculture Lower Saxony
Annals of Applied Biology

BBCH [Biologische Bundesanstalt (Julius Kühn-Institut), Bundessortenamt, CHemische Industrie] scales are used in applied natural sciences for the description of phenological growth stages of plants and are available for many crops today. Currently, a specific BBCH scale for Asparagus officinalis, a perennial vegetable plant of worldwide interest, does not exist. In this study, an extended BBCH scale was developed, describing precisely the growth stages of A. officinalis. Nine principal growth stages were defined and subdivided into several secondary growth stages resulting in a two-digit decimal code. Detailed descriptions of the particular stages and illustrations were included to clarify the application of the code system. The scale is proposed to specify and harmonise research activities as well as to enhance comparability of crop management practices for growers of asparagus. © 2012 Association of Applied Biologists. Source

Discover hidden collaborations