Extraction of Heavy Metals from Manure and their Bioavailability to Spinach (Spinacia Oleracea L.) after Composting

An investigation was carried out on the extractability of heavy metals (HM) from livestock manure during composting and their uptake by spinach (Spinacia oleracea L.) from compost-amended soil. Significant temporal changes were recorded for elements during composting of manure. Higher concentrations of metals were observed during the early stages of composting. Conversely, later stages of composting produced higher amounts of calcium (Ca), magnesium (Mg) and sodium (Na) in the water extract. Total carbon (C) in the samples was inversely related to the length of composting. The application of composted manure increased spinach growth as compared to the fresh manure. Concentrations of HM in spinach varied in the order iron (Fe) > zinc (Zn) > manganese (Mn) > cadmium (Cd) > lead (Pb) > copper (Cu) and their release from post-harvest soil was identical to that in manure samples. The low extractability of HM may suggest that the use of composted manures would lessen environmental pollution problem in the fields.     

Predicting optimal combinations of by‐catch reduction devices in trawl gears: A meta‐analytical approach

Global efforts to reduce unwanted catches have led to the development of a vast array of by‐catch reduction devices (BRDs), in particular for mixed trawl fisheries. Some of these BRDs could likely benefit from being combined. However, the number of possible combinations would be prohibitive to be tested experimentally. Therefore, in this study we propose a meta‐analytical approach that combines the data available on BRDs tested independently in a fishery and predict the theoretical selectivity of all possible combinations of those devices. This allows to identify promising BRD combinations, worth experimental investigation and flexible trawl configurations, where the selectivity can be substantially modified by adding or removing one BRD, thus aiding fishermen in adapting to high variability in catch composition and quota availability. To illustrate the approach, we used BRDs developed for the well‐studied Nephrops (Nephrops norvegicus, Nephropidae) directed mixed trawl fishery in the Skagerrak and Kattegat seas. We predicted the selectivity of 100 BRD combinations for Nephrops, cod (Gadus morhua, Gadidae) and haddock (Melanogrammus aeglefinus, Gadidae), compared them in terms of absolute selectivity and performance under realistic catch scenarios, from both single‐ and multispecies perspectives, and identified 15 BRD combinations that could be worth future experimental investigation. The meta‐analytical approach makes best use of existing knowledge and leads to new insights about the potential for improvement and flexibility in trawl selectivity. This could benefit a variety of mixed trawl fisheries and help developing a new generation of more flexible gears, with multiple BRDs integrated in their structure.     

Effects of uniconazole with or without micronutrient on the lignin biosynthesis,lodging resistance,and winter wheat production in semiarid regions

Lodging stress results in grain yield and quality reduction in wheat. Uniconazole, a potential plant growth regulator significantly enhances lignin biosynthesis and thus provides mechanical strength to plants in order to cope with lodging stress. A field study was conducted during the 2015–2016 and 2016–2017 growing seasons, to investigate the effects of uniconazole sole application or with micronutrient on the lignin biosynthesis, lodging resistance, and production of winter wheat. In the first experiment, uniconazole at concentrations of 0(CK), 15(US1), 30(US2), and 45(US3) mg L~(-1)was applied as sole seed soaking, while in the second experiment with manganese(Mn) at concentration of 0.06 g L~(-1)Mn, 0.06 g L~(-1)Mn+ 15 mg L~(-1)uniconazole(UMS1), 0.06 g L~(-1)Mn+30 mg L~(-1)uniconazole(UMS2), and 0.06 g L~(-1)Mn+45 mg L~(-1)uniconazole(UMS3), respectively. Uniconazole sole application or with micronutrient significantly increased the lignin content by improving the lignin-related enzyme activities of phenylalanine ammonia-lyase, cinnamyl alcohol dehydrogenase, tyrosine ammonialyase, and peroxidase, ameliorating basal internode characteristics, and breaking strength. The spike length, spike diameter, spikes/plant, weight/spike, yield/spike, and grain yield increased and then decreased with uniconazole application at a higher concentration, where their maximum values were recorded with UMS2 and US2 treatments. The lignin accumulation was positively correlated with lignin-related enzyme activities and breaking strength while, negatively correlated with lodging rate. Uniconazole significantly improved the lignin biosynthesis, lodging resistance, and grain yield of winter wheat and the treatments which showed the greatest effects were uniconazole seed soaking with micronutrient at a concentration of 30 mg L~(-1)and 0.06 g L~(-1), and uniconazole sole seed soaking at a concentration of 30 mg L~(-1).