Search results for "Soil"
showing 10 items of 3493 documents
Soil microbiome of primeval forest ecosystems in Transkarpathia
2018
The aim of this study was to investigate the soil microbiome of primeval forest ecosystems, namely the structure of microbial communities,the number of major ecological-functional groups, functional parameters such as: soil toxicity, as well as enzymatic activity of the soil by the level of catalase and invertase. To analyze the successional processes in the soil microbiocenosis due to the influence of endogenous and exogenous factors. To estimate the integrity of microbial communities in different edaphotopes of primeval forest ecosystems. Methods. Microbiological studies of soil were carried out according to generally accepted methods in soil microbiology. Enzymatic activity of the soil: …
Hop stunt viroid: A polyphagous pathogenic RNA that has shed light on viroid–host interactions
2021
[Taxonomy]: Hop stunt viroid (HSVd) is the type species of the genus Hostuviroid (family Pospiviroidae). The other species of this genus is Dahlia latent viroid, which presents an identical central conserved region (CCR) but lacks other structural hallmarks present in Hop stunt viroid. HSVd replication occurs in the nucleus through an asymmetric rolling-circle model as in the other members of the family Pospiviroidae, which also includes the genera Pospiviroid, Cocadviroid, Apscaviroid, and Coleoviroid.
Methanotrophs are core members of the diazotroph community in decaying Norway spruce logs
2018
Dead wood is initially a nitrogen (N) poor substrate, where the N content increases with decay, partly due to biological N2 fixation, but the drivers of the N accumulation are poorly known. We quantified the rate of N2 fixation in decaying Norway spruce logs of different decay stages and studied the potential regulators of the N2-fixation activity. The average rate for acetylene reduction in the decaying wood was 7.5 nmol ethylene g−1d−1, which corresponds to 52.9 μg N kg−1d−1. The number of nifH copies (g−1 dry matter) was higher at the later decay stages, but no correlation between the copy number and the in vitro N2 fixation rate was found. All recovered nifH sequences were assigned to t…
Long-term effects of no tillage treatment on soil N availability, N uptake, and 15N-fertilizer recovery of durum wheat differ in relation to crop seq…
2016
Abstract No tillage (NT) soil management has largely been promoted because of its potential to generate both economic and environmental benefits. However, it often leads to reductions in crop yield and quality, which in many cases have been attributed to the effects this technique has on the nitrogen (N) dynamics in the soil–plant system. This 2-year study, performed within a long-term experiment in which NT was continuously applied for over 15 years, aimed to verify whether and to what extent the use of NT affects soil N availability, recovery of 15 N-labeled fertilizer, and N use efficiency (NUE) and its components (N uptake efficiency, NUpE; N utilization efficiency, NUtE). Durum wheat w…
Plant Growth Along the Altitudinal Gradient — Role of Plant Nutritional Status, Fine Root Activity, and Soil Properties
2008
In tropical montane forests, aboveground net primary productivity (ANPP ) usually decreases with increasing altitude. Besides low photosynthesis (Kitayama and Aiba 2002) and direct impact of low temperatures on plant growth (Hoch and Korner 2003), low ANPP at high altitudes has often been attributed to nutrient limitation (Bruijnzeel et al. 1993; Bruijnzeel and Veneklaas 1998; Tanner et al. 1998). Plant growth is often correlated with nutrient availability in tropical montane forests. For example, the exceptionally high tree stature in a montane forest stand in Papua New Guinea was attributed to its nutrient rich soil parent material (Edwards and Grubb 1977). In montane forests of Jamaica (…
History of land-use intensity can modify the relationship between functional complexity of the soil fauna and soil ecosystem services - A microcosm s…
2012
Abstract Agricultural intensification generally results in the loss of soil organic matter, a decline in soil biodiversity, and the reduced ability of soils to retain nutrients. Intensified land-use can bring about legacy effects in soil ecosystem services that may last for hundreds of years after the cessation of agricultural practises. We studied, in a laboratory pot experiment, whether legacy effects due to intensive land/soil management (intensively managed wheat field) can be alleviated by restoring the disturbed soil with soil fauna typical of less managed soils (grassland soil). We also compared the effects of functional complexity of the soil fauna (microfauna, microfauna + mesofaun…
Variable impacts of enchytraeid worms and ectomycorrhizal fungi on plant growth in raw humus soil treated with wood ash
2007
Abstract An increasing amount of evidence shows the context dependent nature of various biotic interactions across terrestrial and aquatic ecosystems. We established a laboratory experiment to study whether the effects of Cognettia sphagnetorum (Enchytraeidae) and ectomycorrhizal fungi on Scots pine (Pinus sylvestris) seedling growth are influenced by wood ash application. Acidic coniferous forest soil was treated with wood ash at 5000 kg ha−1 or left as ash-free control and inoculated with soil saprotrophic microbes and nematodes. The microcosms were destructively sampled 26 and 51 weeks after initiation of the experiment. We measured enchytraeid and pine seedling biomass, abundance of nem…
Absorption, translocation and metabolism of pyridate in a tolerant crop (Zea mays) and two susceptible weeds (Polygonum lapathifolium L. and Chenopod…
1988
Summary Absorption, translocation and metabolism of 14C-pyridate were compared in tolerant maize. moderately susceptible Polygonum lapathifolium and susceptible Chenopodium album. Foliar absorption was limited in all species, but comparatively higher penetration levels were observed in younger leaves of dicotyledonous species. The absorbed radioactivity was not very mobile and translocation appeared mainly sym-plastic. Herbicide selectivity could not be explained on the basis of absorption and transport. Chenopodium and P. lapathifolium degraded pyridate and formed unstable water-soluble conjugates that easily released a phytotoxic metabolite. By contrast, more stable unidentified water-sol…
Prevention of Fusarium head blight infection and mycotoxins in wheat with cut-and-carry biofumigation and botanicals
2020
Fusarium head blight (FHB) is a devastating fungal disease of wheat worldwide causing yield losses and grain contamination with mycotoxins that jeopardise food and feed safety. Field experiments using mulch layers or botanicals were conducted in two consecutive years to investigate prevention measures with the potential to suppress FHB and reduce mycotoxins in wheat. We simulated a system with high disease pressure, i.e. maize-wheat rotation under no-tillage, by applying maize residues artificially inoculated with Fusarium graminearum in field plots after wheat sowing. For mulch layers, a novel cut-and-carry biofumigation approach was employed. Cover crops grown in separate fields were harv…
Net ammonification as influenced by plant diversity in experimental grasslands
2012
Abstract Previous plant diversity experiments have mainly reported positive correlations between diversity and N mineralization. We tested whether this relationship can be explained by plant diversity-induced changes i) in the quantity or quality of organic matter or ii) in microclimatic conditions of central European grassland mixtures. We measured ex-situ net ammonification in a laboratory incubation of aboveground plant material and soil sampled in differently diverse plant mixtures. Secondly, in-situ net ammonification was assessed in a field incubation with mineralization cores containing standardized material in four treatments: soil only (control), and soil mixed with field-fresh pla…