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Compost is widely used to increase soil fertility, usually practiced by incorporating the compost into the upper soil layer. This study questions the rationale behind this practice. Compost was applied as a mulch and compared with compost worked into the soil in a growth experiment with leek (Allium porrum L. Var. ‘Siegfried Frost’). The compost used was made of source separated organic waste from either gardens and parks, or households. Garden-park compost was applied in 2.5 times greater volumes than household compost to compensate for its lower content of nutrients. The soil was either sandy loam or clay loam. Each of the eight combinations of variables (application method, compost type, and soil type) was repeated three times with 20 leeks in each replicate. Significantly higher yields were obtained with compost applied as a mulch. Here, the yield averaged 78 g fresh weight per leek, compared to 59 g per leek from plots with compost incorporated. Compost mulching also resulted in a significantly higher quality leeks, including more first class leeks, longer and thicker shafts, and a generally better appearance. The advantage of placing the compost on the soil surface rather than thoroughly mixing it with the soil can be attributed to a higher availability of plant nutrients. No significant effect of compost type on leek yield was observed, indicating that the 2.5 times higher volumetric dose of garden-park compost provided the same amount of available nutrients as a single dose of household compost. The soil type did not significantly influence the yields either, which is attributable to both soils being well structured prior to compost amendment. 相似文献
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This study suggests that Iceland may be able to produce sufficient liquid hydrocarbon fuels from biological sources in the future to substitute the Icelandic 2016 consumption of fossil fuels, by using forest products. The authors evaluate a strategy to put forest on up to 35,000 km2 in Iceland to 2050. The preliminary study shows that Iceland could reach climate neutrality around 2050 and be a significant net carbon sequester for the next 250 years. Approximate estimates suggest that the total forest biomass production could reach about 10 million m3yr?1, comprising 3.1 million m3yr?1 of roundwood, 3.1 million m3yr?1 for generic biomass, and about 4.2 million m3yr?1 woody material for biofuel use. This could result in a net annual carbon dioxide sequestration of 2–2.5 mill ton CO2 yr?1 by 2100. The calculations suggest that such an afforestation and land restoration undertaking would be long term profitable in economic terms and that the payback time would be about 2050. The method applied in this study is that of a static mass balance calculations at different time points into the future. Parallel to this work, a full integrated regional forest production model is being developed and will be applied to this issue. 相似文献
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Sundekilde UK Barile D Meyrand M Poulsen NA Larsen LB Lebrilla CB German JB Bertram HC 《Journal of agricultural and food chemistry》2012,60(24):6188-6196
Free oligosaccharides are key components of human milk and play multiple roles in the health of the neonate, by stimulating growth of selected beneficial bacteria in the gut, participating in development of the brain, and exerting antipathogenic activity. However, the concentration of oligosaccharides is low in mature bovine milk, normally used for infant formula, compared with both human colostrum and mature human milk. Characterization of bovine milk oligosaccharides in different breeds is crucial for the identification of viable sources for oligosaccharide purification. An improved source of oligosaccharides can lead to infant formula with improved oligosaccharide functionality. In the present study we have analyzed milk oligosaccharides by high-performance liquid chromatography chip quadrupole time-of-flight mass spectrometry and performed a detailed data analysis using both univariate and multivariate methods. Both statistical tools revealed several differences in oligosaccharide profiles between milk samples from the two Danish breeds, Jersey and Holstein-Friesians. Jersey milk contained higher relative amounts of both sialylated and the more complex neutral fucosylated oligosaccharides, while the Holstein-Friesian milk had higher abundance of smaller and simpler neutral oligosaccharides. The statistical analyses revealed that Jersey milk contains levels of fucosylated oligosaccharides significantly higher than that of Holstein-Friesian milk. Jersey milk also possesses oligosaccharides with a higher degree of complexity and functional residues (fucose and sialic acid), suggesting it may therefore offer advantages in term of a wider array of bioactivities. 相似文献
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Sundekilde UK Frederiksen PD Clausen MR Larsen LB Bertram HC 《Journal of agricultural and food chemistry》2011,59(13):7360-7367
The aim of the present study was to investigate the relationship between the metabolite profile of milk and important technological properties by using nuclear magnetic resonance (NMR)-based metabolomics. The metabolomics approach was introduced for the metabolic profiling of a set of milk samples from two dairy breeds representing a wide span in coagulation properties. The milk metabolite profiles obtained by proton and carbon NMR spectroscopy could be correlated to breed and, more interestingly, also with the coagulation profile, as established by traditional methods by using principal component analysis (PCA). The metabolites responsible for the separation into breed could mainly be ascribed to carnitine and lactose, whereas the metabolites varying in the samples with respect to coagulation properties included citrate, choline, carnitine, and lactose. The results found in the present study demonstrated a promising potential of NMR-based metabolomics for a rapid analysis and classification of milk samples, both of which are useful for the dairy industry. 相似文献
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Rasmussen Hanne N. Jensen Martin Frampton John Hansen-Møller Jens Nielsen Ulrik Bräuner 《New Forests》2020,51(5):781-800
New Forests - Conifer tree species belonging to Abies are notoriously difficult to propagate vegetatively due to aging of material, slow rooting, and persistent plagiotropism in rooted cuttings. We... 相似文献
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Mahsa Haei Johannes Rousk Ulrik Ilstedt Erland Bååth 《Soil biology & biochemistry》2011,43(10):2069-2077
Most climate change scenarios predict that the variability of weather conditions will increase in coming decades. Hence, the frequency and intensity of freeze-thaw cycles in high-latitude regions are likely to increase, with concomitant effect on soil carbon biogeochemistry and associated microbial processes. To address this issue we sampled riparian soil from a Swedish boreal forest and applied treatments with variations in four factors related to soil freezing (temperature, treatment duration, soil water content and frequency of freeze-thaw cycles), at three levels in a laboratory experiment, using a Central Composite Face-centred (CCF) experimental design. We then measured bacterial (leucine incorporation) and fungal (acetate in ergosterol incorporation) growth, basal respiration, soil microbial phospholipid fatty acid (PLFA) composition, and concentration of dissolved organic carbon (DOC). Fungal growth was higher in soil exposed to freeze-thawing perturbations and freezing temperatures of −6 °C and −12 °C, than under more constant conditions (steady 0 °C). The opposite pattern was found for bacteria, resulting in an increasing fungal-to-bacterial growth ratio following more intensive winter conditions. Soil respiration increased with water content, decreased with treatment duration and appeared to mainly be driven by treatment-induced changes in the DOC concentration. There was a clear shift in the PLFA composition at 0 °C, compared with the two lower temperatures, with PLFA markers associated with fungi as well as a number of unsaturated PLFAs being relatively more common at 0 °C. Shifts in the PLFA pattern were consistent with those expected for phenotypic plasticity of the cell membrane to low temperatures. There were small declines in PLFA concentrations after freeze-thawing and with longer durations. However, the number of freeze-thaw events had no effect on the microbiological variables. The findings suggest that the higher frequency of freeze-thaw events predicted to follow the global warming will likely have a limited impact on soil microorganisms. 相似文献
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Bertelsen MF Steele SL Gr?ndahl C Baandrup U 《Journal of zoo and wildlife medicine》2011,42(3):521-523
A 46-yr-old male white rhinoceros (Ceratotherium simum) died during anesthesia following agonal excitation. On postmortem, a well-demarcated 2.5-cm tan mass was identified in the right adrenal gland. Histopathology confirmed the presence of a pheochromocytoma, and elevated levels of epinephrine in serum collected shortly prior to the animal's death, as compared with sera from healthy controls, demonstrated the functional nature of the tumor. Although rare, pheochromocytoma should be considered as a differential diagnosis in cases of suspected hypertension and acute death in rhinos. 相似文献
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