The long‐term fertilization experiments in Halle (Saale), Germany — Introduction and survey

Six of originally eight long‐term trials in Halle (Saale), Germany, are still continuing. Five are situated at Julius‐Kühn‐Feld, an experimental station launched by Julius Kühn in Halle in 1866. Apart from the Eternal Rye trial established in 1878, those are phosphorus, potassium, lime, and organic fertilization long‐term trials, all being launched by Karl Schmalfuß in 1949. Other long‐term trials have been terminated, but data are available on the effects of nitrogen fertilization and the physiological reaction of fertilizers. Another long‐term trial in Halle (Adam‐Kuckhoff‐Straße 17b) investigates the influence of fertilization on soil formation from loess. Up to now, the major results are as follows: 1. Changes in soil‐ecological properties due to fertilization and rotation were only evident after 30 years, and new steady states sometimes took 70 years to occur. 2. In the long term, the C‐ and N‐contents of the soil largely depend on the amount of hardly decomposable organic matter applied with organic fertilization. High mineral‐N doses, with consequent high crop and root residues, increased the humus content of the soil. 3. Mineral fertilization can replace organic fertilization in terms of sustainable yield capacity provided equal nutrient amounts were applied. 4. The high P‐supply ability of the soil in Halle could not be explained by traditional soil analysis methods of calculating plant‐available P. With some restrictions, the same is valid for K. 5. At the experimental site, soluble salts (nitrate, sulphate) accumulated in the subsoil. 6. A regular lime demand of central German chernozems could be proved, especially in case of low soil organic matter (SOM) and physiologically acid fertilization.     

Environmental threats and conservation implications for Atlantic salmon and brown trout during their critical freshwater phases of spawning,egg development and juvenile emergence

Atlantic salmon Salmo salar L. and brown trout Salmo trutta fario L. are species of high socio-economic and ecological value. Declining populations make them target species of fisheries management. This paper reviews the direct effects of deficient longitudinal connectivity, changes in discharge, high water temperatures, oxygen depletion, changes in water chemistry and increasing loads of fine sediment on the critical life stages of spawning, egg incubation and emergence. It further provides an overview about the basic autecological requirements of Atlantic salmon and brown trout and summarises important thresholds of physico-chemical tolerances. This collection of information provides important baselines for assessing historical, ongoing and new threats relevant for the management of both species in fresh waters. Critical early-life stages of both species are almost identical, creating synergies in conservation and restoration. Seaward-migrating forms are exposed to further stressors, but improving starting conditions can also greatly improve their resilience.     

Soil‐ and plant‐based nitrogen‐fertilizer recommendations in arable farming

Under‐ as well as overfertilization with nitrogen (N) will result in economic loss for the farmer due to reduced yields and quality of the products. Also from an ecological perspective, it is important that the grower makes the correct decision on how much and when to apply N for a certain crop to minimize impacts on the environment. To aggravate the situation, N is a substance that is present in many compartments in different forms (nitrate, ammonium, organic N, etc.) in the soil‐plant environment and takes part in various processes (e.g., mineralization, immobilization, leaching, denitrification, etc.). Today, many N‐recommendation systems are mainly based on yield expectation. However, yields are not stable from year to year for a given field. Also the processes that determine the N supply from other sources than fertilizer are not predictable at the start of the growing season. Different methodological approaches are reviewed that have been introduced to improve N‐fertilizer recommendations for arable crops. Many soil‐based methods have been developed to measure soil mineral N (SMN) that is available for plants at a given sampling date. Soil sampling at the start of the growing period and analyzing for the amount of NO ‐N (and NH ‐N) is a widespread approach in Europe and North America. Based on data from field calibrations, the SMN pool is filled up with fertilizer N to a recommended amount. Depending on pre‐crop, use of organic manure, or soil characteristics, the recommendation might be modified (±10–50 kg N ha^–1). Another set of soil methods has been established to estimate the amount of N that is mineralized from soil organic matter, plant residues, and/or organic manure. From the huge range of methods proposed so far, simple mild extraction procedures have gained most interest, but introduction into practical recommendation schemes has been rather limited. Plant‐analytical procedures cover the whole range from quantitative laboratory analysis to semiquantitative “quick” tests carried out in the field. The main idea is that the plant itself is the best indicator for the N supply from any source within the growth period. In‐field methods like the nitrate plant sap/petiole test and chlorophyll measurements with hand‐held devices or via remote sensing are regarded as most promising, because with these methods an adequate adjustment of the N‐fertilizer application strategy within the season is feasible. Prerequisite is a fertilization strategy that is based on several N applications and not on a one‐go approach.     

Effect of mineral nitrogen fertilizer forms on N2O emissions from arable soils in winter wheat production

Nitrogen fertilizers are supposed to be a major source of nitrous oxide (N₂O) emissions from arable soils. The objective of this study was to compare the effect of N forms on N₂O emissions from arable fields cropped with winter wheat (Triticum aestivum L.). In three field trials in North‐West Germany (two trials in 2011/2012, one trial in 2012/2013), direct N₂O emissions during a one‐year measurement period, starting after application of either urea, ammonium sulfate (AS) or calcium ammonium nitrate (CAN), were compared at an application rate of 220 kg N ha^?1. During the growth season (March to August) of winter wheat, N₂O emission rates were significantly higher in all three field experiments and in all treatments receiving N fertilizer than from the non‐fertilized treatments (control). At two of the three sites, cumulative N₂O emissions from N fertilizer decreased in the order of urea > AS > CAN, with emissions ranging from 522–617 g N ha^?1 (0.24–0.28% of applied fertilizer) for urea, 368–554 g N ha^?1 (0.17–0.25%) for AS, and 242–264 g N ha^?1 (0.11–0.12%) for CAN during March to August. These results suggest that mineral nitrogen forms can differ in N₂O emissions during the growth period of winter wheat. Strong variations in the seasonal dynamics of N₂O emissions between sites were observed which could partly be related to weather events (e.g., precipitation). Between harvest and the following spring (post‐harvest period) no significant differences in N₂O emissions between fertilized and non‐fertilized treatments were detected on two of three fields. Only on one site post‐harvest emissions from the AS treatment were significantly higher than all other fertilizer forms as well as compared to the control treatment. The cumulative one‐year emissions varied depending on fertilizer form across the three field sites from 0.05% to 0.51% with one exception at one field site (AS: 0.94%). The calculated overall fertilizer induced emission averaged for the three fields was 0.38% which was only about 1/3 of the IPCC default value of 1.0%.     

The herbicide binding niche of photosystem II-a model

The Q_B binding niche of photosystem II is also the binding site for many different herbicides. In order to understand the mode of binding of the herbicides, a 3-dimensional model of the binding niche was constructed. The model was based upon a comparison of the known structure of the Q_B binding niche in purple bacteria with sequence and mutant data of the D-1 protein of photosystem II. Plastoquinone builds up hydrogen bonds to phenylalanine 265 backbone amide nitrogen, to serine 264 hydroxyl, and to histidine 215 delta-1 nitrogen. In addition to these hydrogen bond donors and acceptors, herbicides can build up hydrogen bonds to backbone carbonyl of alamine 263 and to serine 268 hydroxyl. This is supported by binding data of inhibitors in Chlamydomonas reinhardtii chloroplasts of wild type and of five D-1 protein mutants (Ser264 Ala, Ala251 Val, Phe255Tyr, Val2191le, Leu275Phe).     

A classification scheme for earthworm populations (Lumbricidae) in cultivated agricultural soils in Brandenburg,Germany

Earthworm activity is observed at long‐term monitoring sites as an indicator of soil function to assess changes resulting from environmental and management conditions. In order to assess changes, characteristic values of earthworm populations under different site conditions have to be known. Therefore, a classification scheme for site‐specific earthworm populations was developed for soil in agricultural use, taking interactions between earthworm populations and soil properties into account. Characteristics of sites grouped by means of a cluster analysis after principal‐component analysis served as a basis for the derivation of the classification scheme. Soil variables found to characterize site differences with respect to earthworm populations were the texture of the topsoil, the texture of the subsoil, and the soil organic‐matter (SOM) content. The textural classes of the topsoil were divided into five groups comprising sandy soils (Ss), silty sand soils (Su), slightly loamy sand soils (Sl2), medium to strongly loamy sand soils (Sl3/Sl4), and loam and clay soils. Soil organic matter was divided into grades of equal size in a range from <1%, 1%–2% up to >6%. The variables “earthworm abundance” and “earthworm species” were selected to represent earthworm populations and were divided into six groups ranging from very low to extremely high. Defined groups of earthworm populations showed a clear structure in relation to soil textural groups and the content of SOM. From this distribution, a classification scheme was derived as basis for prognostic values of site‐specific earthworm populations, thus enabling the interpretation of changes over time. For some soil textural groups, selected variables appeared to enable the derivations of expected earthworm densities and species composition outside the range of the given database, but for some soil textural groups, broader databases will be needed to specify these derivations.     

Breeding of Persian melon: Purpose to increase volatile compounds in melon (Cucumis melo) intergroup F1 cross population

Understanding the volatile profile of melon is an ever increasingly important task for breeders for enhancing their flavour component. For this purpose, F1 progeny and parental lines were analysed using headspace-solid phase microextraction gas chromatography–mass spectrometry-based analysis. Diallel analysis showed that most of the investigated compounds were controlled via non-additive genetic effects with general combining ability to specific combining ability ratios of less than 0.4. High heterosis results were observed in alcohols such as ethanol and octanol in both rind and mesocarp samples and benzylalcohol in the rind. It was also noted that the ester-based compounds with high heterosis values in mesocarp samples differed from those with heterosis in rind samples. These observations further emphasize the non-additive control of these compounds. It can be concluded that non-additive genetic control is strongly governing the genetic profile within the studied progeny. This finding indicated that dudaim lines as a valuable genetic material enhanced the volatile profile of odourless commercial types of ameri and inodorus melon.     

Functional and antigenic properties of GlpO from Mycoplasma mycoides subsp. mycoides SC: characterization of a flavin adenine dinucleotide-binding site deletion mutant

L-α-glycerophosphate oxidase (GlpO) plays a central role in virulence of Mycoplasma mycoides subsp. mycoides SC, a severe bacterial pathogen causing contagious bovine pleuropneumonia (CBPP). It is involved in production and translocation of toxic H₂O₂ into the host cell, causing inflammation and cell death. The binding site on GlpO for the cofactor flavin adenine dinucleotide (FAD) has been identified as Gly ₁₂−Gly₁₃−Gly ₁₄−Ile₁₅−Ile₁₆−Gly ₁₇. Recombinant GlpO lacking these six amino acids (GlpOΔFAD) was unable to bind FAD and was also devoid of glycerophosphate oxidase activity, in contrast to non-modified recombinant GlpO that binds FAD and is enzymatically active. Polyclonal monospecific antibodies directed against GlpOΔFAD, similarly to anti-GlpO antibodies, neutralised H₂O₂ production of M. mycoides subsp. mycoides SC grown in the presence of glycerol, as well as cytotoxicity towards embryonic calf nasal epithelial (ECaNEp) cells. The FAD-binding site of GlpO is therefore suggested as a valuable target site for the future construction of deletion mutants to yield attenuated live vaccines of M. mycoides subsp. mycoides SC necessary to efficiently combat CBPP.     

Communication in production animal medicine: modelling a complex interaction with the example of dairy herd health medicine

Background

The importance of communication skills in veterinary medicine is increasingly recognised. Appropriate communication skills towards the client are of utmost importance in both companion animal practice and production animal field and consultancy work. The need for building a relationship with the client, alongside developing a structure for the consultation is widely recognised and applies to both types of veterinary practice.

Results

Veterinary advisory practice in production animal medicine is, however, characterised by a more complex communication on different levels. While the person-orientated communication is a permanent process between veterinarian and client with a rather personal perspective and defines the roles of interaction, the problem-orientated communication deals with emerging difficulties; the objective is to solve an acute health problem. The solution - orientated communication is a form of communication in which both veterinarian and client address longstanding situations or problems with the objective to improve herd health and subsequently productivity performance. All three forms of communication overlap.

Conclusions

Based on this model, it appears useful for a veterinary practice to offer both a curative and an advisory service, but to keep these two separated when deemed appropriate. In veterinary education, the strategies and techniques necessary for solution orientated communication should be included in the teaching of communication skills.     

Retention of Ni,Zn and Cd by Si-associated goethite

Synthetic goethite used to study the effects of reaction time and temperature on the pH-dependent sorption of Ni, Zn and Cd was associated with amorphous silica. Ni interacted with dissolved Si and formed a Ni/Si precipitate on the goethite surface. Individual metals added at a concentration of 0.5 μmol g^?1 and sorbed during a reaction period of 504 hours (21 days) at 35°C were extracted by 0.7 M HNO₃ for 14 days. At the end of this period 11,28 and 40 percent of Ni, Cd and Zn, respectively, were not extracted whereas 20 percent of the total Fe content of the goethite and 39 percent of the associated Si were dissolved. During the sorption process metals became immobilized in the goethite particles. This effect can be related to a diffusion of metal ions into micropores. A total mobilization of sorbed metals can only be achieved by a complete dissolution of the goethite. The strong fixation of Ni, Zn and Cd by goethite suggests that additions of this Fe oxide could be used to ameliorate highly contaminated sludges or soils.