Browsing by Subject "soil"

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Now showing items 21-31 of 31
  • Koutaniemi, Leo; Koponen, Raimo; Rajanen, Kyösti (Suomen metsätieteellinen seura, 1988)
  • Mäkelä, Jaakko Johannes; Ketoja, Elise; Kuisma, Miia T; Salo, Tapio; Yli-Halla, Markku Juhani; Kahiluoto, Helena (2019)
    Processing of organic residues may affect plant-availability of phosphorus (P) and thus the potential to recycle the nutrient, i.e., recyclability, but empirical evidence in the field is lacking. In field experiments in clay and silt loam soils with low available P, impact on P recyclability by cattle manure and sewage sludge processing methods (composting, anaerobic digestion, lime-stabilization, acid-oxidizer) and three application rates were assessed. Synthetic nitrogen (N) and potassium (K) fertilizers were supplied in surplus and NPK served as a reference. The differences in plant response were small at relevant application rates and not consistently explained by solubility of fertilizer P. Least P was required in composted manure for the same P uptake in silt loam, and composting was beneficial to plant response in clay as well. Lime-stabilization of sewage sludge had an adverse effect on P uptake in silt loam. Increasing application rates of sewage sludge hardly enhanced but did not lower P uptake or yield even at an excessive rate. Soil water-extractable P in the autumn liable to leaching was increased by NPK only. In clay soil, sewage sludges performed better than manures obviously due to anaerobic conditions caused by high precipitation, but in silt loam the contrary was the case. In conclusion, the availability of P in processed residues is more susceptible to weather and soil variables than in synthetic fertilizer. P fertilization benefits in cereal cropping in current north European conditions appear to be generally small.
  • Nylund, Liisa; Nylund, Markku; Kellomäki, Seppo; Haapanen, Antti (Suomen metsätieteellinen seura, 1980)
  • Verheijen, Frank G. A.; Mankasingh, Utra; Penizek, Vit; Panzacchi, Pietro; Glaser, Bruno; Jeffery, Simon; Bastos, Ana Catarina; Tammeorg, Priit; Kern, Juergen; Zavalloni, Costanza; Zanchettin, Giulia; Sakrabani, Ruben (2017)
    A representativeness survey of existing European Biochar field experiments within the Biochar COST Action TD1107 was conducted to gather key information for setting up future experiments and collaborations, and to minimise duplication of efforts amongst European researchers. Woody feedstock biochar, applied without organic or inorganic fertiliser appears over-represented compared to other categories, especially considering the availability of crop residues, manures, and other organic waste streams and the efforts towards achieving a zero waste economy. Fertile arable soils were also over-represented while shallow unfertile soils were under-represented. Many of the latter are likely in agroforestry or forest plantation land use. The most studied theme was crop production. However, other themes that can provide evidence of mechanisms, as well as potential undesired side-effects, were relatively well represented. Biochar use for soil contamination remediation was the least represented theme; further work is needed to identify which specific contaminants, or mixtures of contaminants, have the potential for remediation by different biochars.
  • Sakrabani, Ruben; Kern, Juergen; Mankasingh, Utra; Zavalloni, Costanza; Zanchettin, Giulia; Bastos, Ana Catarina; Tammeorg, Priit; Jeffery, Simon; Glaser, Bruno; Verheijen, Frank G. A. (2017)
    Biochar research is extensive and there are many pot and laboratory studies carried out in Europe to investigate the mechanistic understanding that govern its impact on soil processes. A survey was conducted in order to find out how representative these studies under controlled experimental conditions are of actual environmental conditions in Europe and biomass availability and conversion technologies. The survey consisted of various key questions related to types of soil and biochar used, experimental conditions and effects of biochar additions on soil chemical, biological and physical properties. This representativeness study showed that soil texture and soil organic carbon contents used by researchers are well reflected in the current biochar research in Europe (through comparison with published literature), but less so for soil pH and soil type. This study provides scope for future work to complement existing research findings, avoiding unnecessary repetitions and highlighting existing research gaps.
  • Huhta, Veikko; Hyvönen, Riitta; Koskenniemi, Antti; Vilkamaa, Pekka; Kaasalainen, Paula; Sulander, Minna (Suomen metsätieteellinen seura, 1986)
  • Palonen, Vesa; Pumpanen, Jukka; Kulmala, Liisa-Maija; Levin, Ingeborg; Heinonsalo, Jussi; Vesala, Timo (2018)
    We present a radiocarbon (C-14) dataset of tropospheric air CO2 forest soil air CO2, and soil CO2 emissions over the course of one growing season in a Scots pine forest in southern Finland. The CO2 collection for C-14 accelerator mass spectrometry (AMS) analysis was done with a portable, suitcase-sized system, using molecular sieve cartridges to selectively trap CO2 The piloting measurements aimed to quantify the spatial, seasonal and diurnal changes in the C-14 content of CO2 in a northern forest site. The atmospheric samples collected above the canopy showed a large seasonal variation and an 11 parts per thousand difference between day and nighttime profiles in August. The higher Delta C-14 values during night are partly explained by a higher contribution of C-14-elevated soil CO2, accumulating in the nocturnal boundary layer when vertical mixing is weak. We observed significant seasonal trends in Delta C-14-CO2 at different soil depths that reflected changes in the shares of autotrophic and heterotrophic respiration. Also the observed diurnal variation in the Delta C-14 values in soil CO2 highlighted the changes in the origin of CO2, with root activity decreasing more for the night than decomposition.
  • Grandell, Laura (Helsingfors universitet, 2010)
    Suomenlinna is one of the most popular tourist and cultural attractions in Helsinki. Kustaanmiekka, as well as the whole of Suomenlinna, nature has become a traditional Finnish archipelago nature and over the centuries, the place of the duties of the fortress of flora. Because of the island's varied habitats of the region, the vegetation is very rich. Fortress of many plant species have become invasive plant across Europe and Russia. Most of the Suomenlinna Area is rock dry meadow and also fortress dry meadow, both of which belong to protected areas. Kustaanmiekka pastures grow dry meadow and heat species, such as rare Botrychium lunaria and Dianthus deltoides. This study was primarily designed to identify the region Kustaanmiekka dry meadow flora 2009 summer season, and different vascular plant species richness. The study also examined the factors of soil and the treatment history of the possible impact of dry meadow species. The study surveyed ten different wild dry meadows in Finland Kustaanmiekka castle fortress in the region. Dry meadows were located in different parts of Kustaanmiekka in such places, which was the highest in dry meadow vegetation. Field works were carried out in June and July, calculated for each squares Vascular Plants coverage, and also by listing up the squares outside the spring and late summer bloomers in May and August. To determine the properties of soil were taken from each dry meadow topsoil sample in August. The other investigated variables were slope geomorphology and moss, litter, bare land, vegetation and rocks coverages in squares. Dry meadow average vegetation height was measured in June and July. There were clear differences in flora between dry meadows. Plant species ranged dry meadows the total number of species of 40-60 species of plants. 120 different species of vascular plants were found, most of which bloom in June and July. Dry meadows plant species ranged from 6.3 to 13.6 in one plant species per square meters, in addition to the Shannon-Wiener diversity index ranged from 1.4 to 2.3 value. The most common species, which the meadows were, were, inter alia, Achillea millefolium, Dactylis glomerata, Elymus repens and Potentilla argentea. The region also grew a few alien species such as Berteroa incana, Bunias orientalis and Epilobium hirsutum. Soil factors such as high phosphorus content had no effect on the number of plant species in the meadows. Only the pH and conductivity were positively correlated with the height of the vegetation in dry meadows. Although the results of the dry meadows treatment had no effect on dry meadow amount of vegetation, can be expected right kind of treatment will improve the competitiveness of other typical meadow plants in point.
  • Hall, James P. J.; Harrison, Ellie; Parnanen, Katariina; Virta, Marko; Brockhurst, Michael A. (2020)
    Carriage of resistance genes can underpin bacterial survival, and by spreading these genes between species, mobile genetic elements (MGEs) can potentially protect diversity within microbial communities. The spread of MGEs could be affected by environmental factors such as selection for resistance, and biological factors such as plasmid host range, with consequences for individual species and for community structure. Here we cultured a focal bacterial strain,Pseudomonas fluorescensSBW25, embedded within a soil microbial community, with and without mercury selection, and with and without mercury resistance plasmids (pQBR57 or pQBR103), to investigate the effects of selection and resistance gene introduction on (1) the focal species; (2) the community as a whole; (3) the spread of the introducedmerresistance operon. We found thatP. fluorescensSBW25 only escaped competitive exclusion by other members of community under mercury selection, even when it did not begin with a mercury resistance plasmid, due to its propensity to acquire resistance from the community by horizontal gene transfer. Mercury pollution had a significant effect on community structure, decreasing alpha diversity within communities while increasing beta diversity between communities, a pattern that was not affected by the introduction of mercury resistance plasmids byP. fluorescensSBW25. Nevertheless, the introducedmerAgene spread to a phylogenetically diverse set of recipients over the 5 weeks of the experiment, as assessed by epicPCR. Our data demonstrates how the effects of MGEs can be experimentally assessed for individual lineages, the wider community, and for the spread of adaptive traits.
  • Yan, Lijuan (Helsingfors universitet, 2012)
    Soil contamination can result in soil degradation, bring great loss to agricultural production and pose threat to human health. Many of the soil contaminants are petroleum hydrocarbons (PHCs) derived from crude oil or refined petroleum products. Phytoremediation which relies on plants and their associated microorganisms to remove contaminants is cost-effective and applicable to treat a wide variety of soil contaminants. Besides trees, herbaceous plants are widely and effectively used in the remediation of PHC contaminated soils. Greenhouse studies have found that Galega orientalis co-inoculated with Rhizobium galegae and plant growth promoting bacteria (PGPB) benefiting soil with nitrogen fixation is able to remediate PHC contaminated soils. The FP7 ‘‘Legume-Futures’’ remediation field experiment was established at Viikki experimental farm, University of Helsinki in 2009 in order to test the practical applicability of the greenhouse results in a field scale. In a split-plot design, crop (Galega orientalis, Bromus inermis, Galega orientalis + Bromus inermis, bare soil control) treatments were designated the main factor, oil (±) and PGPB (±) the sub-factors in factorial combination with four replicates. Soil samples were taken at four time points from July 2009 to May 2011. Soil total solvent extractable material (TSEM) was extracted and measured by the gravimetrical method as a direct indicator of oil content. Physiochemical properties (pH, EC, total C and N and C/N ratio) of soil samples (taken in July 2009 and Nov. 2010) were determined. The losses of total C and TSEM between July 2009 and Nov. 2010 were calculated to estimate the differences crops and PGPB brought in oil treated plots. Crop dry matter yields were determined. The changes of soil microbial population, bacterial diversity and community structures were studied by the 16S rRNA gene based community fingerprinting method LH-PCR. Bioremediation and physical removal were the main processes of oil removal in our experiment. Climate factors (e.g. temperature and precipitation) had an overriding influence on the removal of oil in our study. Soil condition with a neutral pH and C/N ratio in our field was optimal for biodegradation of hydrocarbons. The changes in soil microbial total DNA, diversity and community structure were sensitive indicators of soil contamination and recovery. Crop (Galega orientalis and Bromus inermis) and PGPB treatment had no significant effect on soil physiochemical and microbiological properties nor on the removal of oil in our experiment, which largely differed from our hypothesis. Resource competition between crops and microorganisms might have resulted in the better oil remediation in bare soils than in vegetated soils. Nevertheless, crops were found to have a high tolerance to oil contamination and surprisingly, the oil contamination seemed to increase the growth of both crop species. Bromus in mixture plots (without commercial nitrogen fertilization) had better yield than in pure plots (with commercial nitrogen fertilization) as a result of biological nitrogen fixation of Galega orientalis and Rhizobium galegae. Therefore the mixture of galega and bromus can be suggested to be applied in future phytoremediation projects.
  • Wilde, S. A. (Suomen metsätieteellinen seura, 1965)