Phosphate Leaching from Intact Soil Column in Response to Reducing Conditions

Iron(III)(hydr)oxides can dissolve under reducing soil conditions. Simultaneously, oxide-associated inorganic phosphate is released to the soil solution. In this study, the effect of reducing soil conditions on phosphate leaching from transient waterlogging clayey soil is evaluated. We applied glucose solutions (either 100 or 1000 mg glucose-C L^-1) at a steady flow rate of 0.63 mm h^-1 to a saturated intact column of structured Alfisol (diam. 0.5 m, height 1.0 m). Effluent concentrations of iron(II) and reactive orthophosphate (P_i) increased slightly during 5 d of low glucose application, reaching values of 2.5 mg Fe L^-1, and 0.02 mg PO₄-P L^-1, respectively. During 10 d of high glucose application, the iron(II) concentration increased to 14 mg Fe L^-1 and fluctuations in the P_i-concentration between 0.002 and 0.1 mg PO₄-P L^-1 were observed. The fluctuations in P_i-concentration are ascribed to interactions between progression of the glucose front, and P_i-mobilization/resorption processes at the walls of macropores. The daily P-losses during low and high glucose applications averaged 0.3 mg PO₄-P m^-2 d^-1, and 0.5 mg PO₄-P m^-2 d^-1, respectively. Comparisons with a parallel topsoil study suggest that subsoil exerts a strong control on leaching – probably via resorption – of P_i mobilized in the topsoil.     

Organic sulfur forms in mineral top soils of the Marsh in Schleswig‐Holstein,Northern Germany

Little is known about the nature of organic sulfur (S) in soils of the Marsh in Schleswig‐Holstein, Northern Germany. In addition to total and inorganic S, we determined two organic S fractions (ester sulfate‐sulfur and carbon‐bonded sulfur) in 14 aerated mineral top horizons of two salt marshes and ten dyked polder soils of different age. All soils developed from marine sediments. Total S concen‐trations ranged from 153 to 950 mg kg^—1. Organic S was the main S constituent (range from 53 to 99% with a median of 97%). Higher inorganic S levels were found only in the salt marshes due to soluble sulfate (15 to 47%). The younger marsh soils (salt marshes and soils of a polder dyked in 1978) had unique high S contents of 0.9 to 2.4% in their organic matter, whereas the S contents of the organic matter in older marsh soils were at only 0.6%. This S‐rich organic matter is a heritage of a former anoxic marine environment. In most horizons the carbon‐bonded S was the dominant sulfur form. However, both carbon‐bonded S and ester sulfate‐S did not relate to soil age. This limits the benefit of the wet chemical fractionation procedure used for studying the fate of organic S in marsh soils.     

Purification and characterization of an alpha-mannosidase from the tropical fruit babaco ( Vasconcellea x heilbornii Cv. babaco)

An alpha-mannosidase (EC 3.2.1.24) present in the lyophilized latex of babaco ( Vasconcellea heilbornii ) has been purified to apparent homogeneity by native PAGE. The purification involves a three-step procedure with successive anion exchange with Q Sepharose HP, lectin affinity chromatography using ConA Sepharose 4B, and gel filtration using Superdex 200 prep grade. The molecular mass was determined to be in the range of 260-280 kDa by Superdex 200 prep grade gel filtration, and isoelectric focusing showed a pI range between 5.85 and 6.55, suggesting different glycosylated isoforms. The optimal temperature for the alpha-mannosidase was determined to lie between 50 and 60 degrees C, and the optimal pH was 4.5 at 50 degrees C. The K(m) value for p-nitrophenyl alpha-mannopyranoside (pNPM) was found to be 1.25 mM and the V(max), 2.4 microkat mg(-1) at 50 degrees C and 1.94 microkat mg(-1) at 40 degrees C. The pure alpha-mannosidase was specific for mannose and did not display activity for any other tested synthetic substrates.     

Criteria and standards for sustainable agriculture

This paper presents an assessment system which on the basis of quantifiable criteria and appropriate orientation values describes the risk potentials of farming as far as environmental protection and sustainability is concerned. The procedure addresses the most significant risks and suggests ranges for their tolerability. By this way farmers can recognize principal shortcomings of their management and look for appropriate countermeasures to cope with them. The guiding principle is a way of farming which uses the available resources and the production potential as efficiently as possible, while keeping the unfavorable impacts on soils, water, air and biota within acceptable limits. Several years of investigations in about 125 different farms have shown that non‐tolerable impacts of farming on the environment are predominantly due to avoidable managerial mistakes. The suggested assessment system provides criteria for the actual magnitude and the tolerability of the different risk potentials and may thus help to substantiate the compliance with such general principles as ”︁good farming practice”.     

Sunflower expellers have greater ileal digestibility of amino acids than sunflower meal,but there are only minor variations among different sources of sunflower meal when fed to growing pigs

The objective was to test the hypothesis that there is no effect of origin or processing procedure on the standardized ileal digestibility (SID) of amino acids (AA) and crude protein (CP) in sunflower coproducts. Six sources of sunflower meal (SFM) and one source of sunflower expellers (SFE) were obtained from Ukraine, Italy, Hungary, and the United States. Each source of SFM or SFE was the only source of CP and AA in one diet, and an N-free diet was also used for a total of eight diets. Eight barrows (body weight: 28.5 ± 2.4 kg) had a T-cannula installed in the distal ileum and were allotted to one of the eight diets using an 8 × 8 Latin square design with eight periods. The Lys:CP ratio in the six sources of SFM ranged from 3.10% to 3.96% with CP concentrations ranging from 27.34% to 36.75%. CP in SFE was 26.87% and the Lys:CP ratio was 3.51%. Concentrations of acid-hydrolyzed ether extract in the six sources of SFM ranged from 0.60% to 3.11%, but SFE contained 8.77%. Results indicated that the SID of CP was lower (P < 0.05) in SFM from Hungary compared with all other sources of SFM except for one of the sources from Ukraine. There were no differences in the SID of Lys, Met, and Trp among sources of SFM, but for most of the remaining indispensable AA, the SFM from Hungary had less (P < 0.05) SID than the other sources. However, only a few differences in the SID of indispensable AA were observed among the other sources of SFM, but the SID of CP and all AA except Trp was greater (P < 0.05) in SFE compared with SFM. In conclusion, there were only a few differences in the SID of the first-limiting AA among SFM obtained from Ukraine, Hungary, Italy, and the United States, but the SID of CP and AA was greater in SFE than in SFM indicating that processing of sunflower seeds influence the nutritional value.     

Using a telemetry study to assess the boundary net efficiency of an enclosure system used for yellow eel density monitoring

To assess yellow eel (Anguilla anguilla L.) densities in non‐tidal waters, 1‐ha enclosure approach was developed. For unbiased density and biomass calculations, the catchability of the system needs to be evaluated. A telemetry study with 49 tagged eels was conducted in 2015 and 2016 to verify the effectiveness of the 1.8‐m high boundary net. Excluding recaptured eels (N = 10), 42.8% of the released eels (N = 15) escaped the enclosure within 48 hr. Regarding the movement frequency, similar movement patterns were observed for enclosed and escaped eels within 48 hr after release. Based on the telemetry study, it is concluded that the boundary net is recognised as an obstacle by yellow eels, and reduces the escapement of enclosed eels.     

Population‐level consequences of seismic surveys on fishes: An interdisciplinary challenge

Offshore activities elevate ambient sound levels at sea, which may affect marine fauna. We reviewed the literature about impact of airgun acoustic exposure on fish in terms of damage, disturbance and detection and explored the nature of impact assessment at population level. We provided a conceptual framework for how to address this interdisciplinary challenge, and we listed potential tools for investigation. We focused on limitations in data currently available, and we stressed the potential benefits from cross‐species comparisons. Well‐replicated and controlled studies do not exist for hearing thresholds and dose–response curves for airgun acoustic exposure. We especially lack insight into behavioural changes for free‐ranging fish to actual seismic surveys and on lasting effects of behavioural changes in terms of time and energy budgets, missed feeding or mating opportunities, decreased performance in predator‐prey interactions, and chronic stress effects on growth, development and reproduction. We also lack insight into whether any of these effects could have population‐level consequences. General “population consequences of acoustic disturbance” (PCAD) models have been developed for marine mammals, but there has been little progress so far in other taxa. The acoustic world of fishes is quite different from human perception and imagination as fish perceive particle motion and sound pressure. Progress is therefore also required in understanding the nature and extent to which fishes extract acoustic information from their environment. We addressed the challenges and opportunities for upscaling individual impact to the population, community and ecosystem level and provided a guide to critical gaps in our knowledge.     

Anaesthetic properties of Propiscin (Etomidaat) and 2-phenoxyethanol in the common carp (Cyprinus carpio L.), neural and behavioural measures

The objective of the study was to evaluate the anaesthetic effects of Propiscin (2% etomidate) and 2-phenoxyethanol on common carp ( Cyprinus carpio L.) by observing neural and behavioural measures. When exposed to the anaesthetic agent, the carp lost equilibrium after approximately 90 s of exposure. They did not breathe and the controls did not respond to tail pinch or prick or 6 V at the skin of the upper jaw. A shift to lower frequencies on the electroencephalogram (EEG) and computing fast Fourier transformation was observed when exposed to water containing Propiscin or 2-phenoxyethanol. Heart rate was reduced after placement in the water containing an anaesthetic agent. It may be concluded from our results that common carp were immobilized and sedated, when exposed to water containing 2 mL L⁻¹ Propiscin and immobilized and anaesthetized in water containing 0.5 mL L⁻¹ 2-phenoxyethanol. In addition, the use of EEG provides for a sound assessment of exposure of carp to these anaesthetics.     

Effort rights‐based management

Effort rights‐based fisheries management (RBM) is less widely used than catch rights, whether for groups or individuals. Because RBM on catch or effort necessarily requires a total allowable catch (TAC) or total allowable effort (TAE), RBM is discussed in conjunction with issues in assessing fish populations and providing TACs or TAEs. Both approaches have advantages and disadvantages, and there are trade‐offs between the two approaches. In a narrow economic sense, catch rights are superior because of the type of incentives created, but once the costs of research to improve stock assessments and the associated risks of determining the TAC and costs of monitoring, control, surveillance and enforcement are taken into consideration, the choice between catch or effort RBM becomes more complex and less clear. The results will be case specific. Hybrid systems based on both catch and effort are increasingly employed to manage marine fisheries to capture the advantages of both approaches. In hybrid systems, catch or effort RBM dominates and controls on the other supplements. RBM using either catch or effort by itself addresses only the target species stock externality and not the remaining externalities associated with by‐catch and the ecosystem.