Search results for "fertilization"
showing 10 items of 326 documents
Macro Element Content in Fertilized Forest Soils in Spruce (Picea Abies (L.) H. Karst.) Stands in Latvia
2012
The present paper provides an overview of analysis conducted with soil samples from depths up to 80 cm, obtained in the Klive area from a spruce stand owned by JSC “Latvijas Valsts meži”. Also test fertilization attempts were made with the use of ash- and potassium-based artificial fertilizers (K2SO4). The content of macro elements (K, Ca, N, and C) was determined in the soil samples in the course of the analysis. The obtained results indicate that the content of K and Ca decreases at greater horizontal depths of the soil. Nutrients are subsequently being leached away from the soil. A higher C/N ratio at the horizontal depth of up to 10 cm in the soil means a higher content of organic subst…
Nutrient impoverishment and limitation of productivity after 20 years of conservation management in wet grasslands of north-western Germany
2009
Abstract European wet grasslands are characterized by high diversity of plant and animal species but are threatened by intensive land use. Although preservation or restoration of species-rich wet grasslands requires low nutrient availability that could be achieved by long-term management, studies monitoring nutrient removal are lacking. Our objective was to assess the long-term effect of management (mowing twice a year without or with PK fertilization for 20 years) on (i) productivity and nutrient removal with the harvest, (ii) the type of nutrient limitation, and (iii) plant species richness in wet grasslands in north-western Germany considering the differences between organic and mineral …
Short-term impact of biogas digestates on soils microbial communities
2022
International audience; Anaerobic digestion of organic waste is considered a key process to produce renewable energy to meet the growing sustainable energy demand. Digestates can be used in agriculture as soil amendments and improve crop yields. However, their use at large scale in agricultural fields still requires to prove their innocuity on soil biota, especially on microorganisms that play important roles in soil ecosystem. Here, we designed a microcosm experiment to compare the short-term (42-days) effects of four different digestates (derived from cattle manure, energy crop, food residues or slurry with bio-waste) on the soil microbial communities. Each digestate was applied on three …
Water-use efficiency and transpiration across European forests during the Anthropocene
2015
Considering the combined effects of CO2 fertilization and climate change drivers on plant physiology leads to a modest increase in simulated European forest transpiration in spite of the effects of CO2-induced stomatal closure. The Earth’s carbon and hydrologic cycles are intimately coupled by gas exchange through plant stomata1,2,3. However, uncertainties in the magnitude4,5,6 and consequences7,8 of the physiological responses9,10 of plants to elevated CO2 in natural environments hinders modelling of terrestrial water cycling and carbon storage11. Here we use annually resolved long-term δ13C tree-ring measurements across a European forest network to reconstruct the physiologically driven r…
Short-term effects of potassium fertilization on the hydraulic conductance of Laurus nobilis L.
2011
This study reports experimental evidence on the effect of short term potassium fertilization on potassium uptake, tissue concentration and hydraulic conductance of pot-grown laurel plants. Potassium uptake and loading into the xylem of laurel seedlings increased within 24 h from fertilization. Potassium was not accumulated in roots and leaves, but the [K+] of xylem sap was 80% higher in fertilized plants (+K) than in potassium starved plants (-K), likely as a result of recirculation between xylem and phloem. This increase in xylem sap [K+] resulted in a 45% increase in transpiration rate, a 30% increase in plant hydraulic conductance (Kplant) and a 120% increase in leaf specific conductivit…
Asistētas reproduktīvas tehnoloģijas grūtniecība, tās iznākums mātēm un jaundzimušajiem
2019
Ievads. Pēc PVO datiem, neauglība skar katru 4 pāri reproduktīvā vecumā, līdz ar to asistētās reproduktīvās tehnoloģijas paliek arvien populārākas. Neskatoties uz mākslīgās apaugļošanas iespēju neauglīgam pārim tikt pie bērna, zinātniskajā literatūrā aprakstīta negatīva superovulācijas ietekme uz sievietes organismu, palielinot komplikāciju attistīšanās risku, kas varētu ietekmēt sievietes un jaundzimušā veselības stāvokli. Darba mērķis. Izpētīt grūtniecības un perinatālo komplikāciju iestāšanās biežumu, superovulācijas ietekmi uz grūtniecības iznākumu, kā arī salīdzināt jaundzimušā parametrus mākslīgās apaugļošanas un spontānas grūtniecības grupās. Materiāli un metodes. Prospektīvs, salīdz…
Size-selective harvesting fosters adaptations in mating behavior and reproductive allocation, affecting sexual selection in fish
2019
The role of sexual selection in the context of harvest‐induced evolution is poorly understood. However, elevated and trait‐selective harvesting of wild populations may change sexually selected traits, which in turn can affect mate choice and reproduction. We experimentally evaluated the potential for fisheries‐induced evolution of mating behaviour and reproductive allocation in fish. We used an experimental system of zebrafish (Danio rerio) lines exposed to large, small or random (i.e. control) size‐selective mortality. The large‐harvested line represented a treatment simulating the typical case in fisheries where the largest individuals are preferentially harvested. We used a full factoria…
Data from: Sperm competition accentuates selection on ejaculate attributes
2019
Ejaculate attributes are important factors driving the probability of fertilizing eggs. When females mate with several males, competition between sperm to fertilize eggs should accentuate selection on ejaculate attributes. We tested this hypothesis in the North African houbara bustard (Chlamydotis undulata undulata) by comparing the strength of selection acting on two ejaculate attributes when sperm from single males or sperm from different males were used for insemination. In agreement with the prediction, we found that selection on ejaculate attributes was stronger when sperm of different males competed for egg fertilization. These findings provide the first direct comparison of the stren…
Dithiothreitol prevents age-associated decrease in oocyte/conceptus viability in vitro.
1998
The present study was designed to ascertain whether the negative effects on reproductive potential of post-ovulatory ageing in vitro of oocytes can be prevented by antioxidant therapy. Mouse metaphase II (MII) oocytes were aged in vitro for 12 h prior to insemination in the presence of varying concentrations of L-ascorbic acid, 6-methoxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), L-cystine dihydrochloride, ethylenediaminetetraacetic acid (EDTA), beta-mercaptoethanol and DL-dithiothreitol (DTT). In-vitro ageing of oocytes was associated with lower fertilization rate, higher proportion of concepti exhibiting cellular fragmentation at 24 h post-insemination and lower percentage of…