Browsing by Subject "peat"

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  • Rinne, J.; Tuovinen, J. -P.; Klemedtsson, L.; Aurela, M.; Holst, J.; Lohila, A.; Weslien, P.; Vestin, P.; Łakomiec, P.; Peichl, M.; Peichl, M.; Tuittila, E. -S.; Heiskanen, L.; Laurila, T.; Li, Xuefei; Alekseychik, P.; Mammarella, I.; Ström, L.; Crill, P.; Nilsson, M. B. (2020)
    We analysed the effect of the 2018 European drought on greenhouse gas (GHG) exchange of five North European mire ecosystems. The low precipitation and high summer temperatures in Fennoscandia led to a lowered water table in the majority of these mires. This lowered both carbon dioxide (CO2) uptake and methane (CH4) emission during 2018, turning three out of the five mires from CO(2)sinks to sources. The calculated radiative forcing showed that the drought-induced changes in GHG fluxes first resulted in a cooling effect lasting 15-50 years, due to the lowered CH(4)emission, which was followed by warming due to the lower CO(2)uptake. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.
  • Kaukonen, Eija; Norring, Marianna; Valros, Anna (2017)
    1. Experiment 1, comparing wood shavings and ground straw bedding with peat, was performed on 7 broiler farms over two consecutive batches during the winter season. Experiment 2, assessing the effect of elevated (30 cm) platforms, was conducted in three farms replicated with 6 consecutive batches. 2. Footpad lesions were inspected at slaughter following the Welfare Quality® (WQ) assessment and official programme. Hock lesions, plumage cleanliness and litter condition were assessed using the WQ assessment. Litter height, pH, moisture and ammonia were determined. 3. Footpad condition on wood shavings appeared to be worse compared with peat using both methods of assessment and was accompanied by inferior hock skin health. WQ assessment resulted in poorer footpad and hock skin condition on ground straw compared with peat. Farms differed in footpad and hock skin condition. Footpad and hock lesions were not affected by platform treatment. Peat appeared more friable than ground straw. The initial pH of wood shavings was higher and moisture was lower than in peat, but at the end of production period there were no differences. Ground straw exhibited higher initial and lower end pH, and was drier in the beginning than peat. Litter condition and quality were not affected by platform treatment. 4. This study provides new knowledge about the applicability of peat as broiler bedding and shows no negative effects of elevated platforms on litter condition or the occurrence of contact dermatitis in commercial environments. The results suggest a complicated relationship between litter condition, moisture and contact dermatitis. Furthermore, it is concluded that the farmer’s ability to manage litter conditions is important, regardless of the chosen litter material. Peat bedding was beneficial for footpad and hock skin health compared with wood shavings and ground straw.
  • Westman, Carl Johan (Suomen metsätieteellinen seura, 1981)
  • Heikurainen, Leo; Päivänen, Juhani; Sarasto, Juhani (Suomen metsätieteellinen seura, 1964)
  • Päivänen, Juhani (Suomen metsätieteellinen seura, 1973)
  • Kuisma, Eero (Helsingfors universitet, 2013)
    The use of peat as a growing-medium has raised concerns globally, because it is not ecologically sustainable. Coir is an ecologically friendly alternative, but it is transported very long way to Finland. Therefore, a substitute for peat and coir as a growing-medium in soilless culture is needed. The aim of this research was to find out, whether Finnish plant fibre medium can replace peat or coir in greenhouse production of strawberry. In the experiments four substrates were compared: coir, peat, plant fibre and peat/plant fibre mix. Water holding capacity, pH-buffer capacity and mineralisation of nitrogen were determined, and vegetative and generative growth of strawberries on different substrates were measured. In strawberry cultivation experiment the pH of plant fibre (6,5-7,7) was very close to that of peat (6,4-7,6). Coir and plant fibre had considerably lower pH-buffer capacity than the media that contained peat. The water holding capacity (613 % per dw) of plant fibre was considerably lower than in other media. Plant fibre medium´s water content (32-42 % v/v) was however closest to strawberry´s optimum (25-34 % v/v) during almost the whole experiment. Plant fibre (23:1) and peat/plant fibre mix (29:1) had optimal C/N- ratios in this experiment. The amount of soluble nitrogen was highest in plant fibre medium in the beginning of the experiment. The EC of plant fibre medium was very low in the beginning (0,5 mS/cm), but it increased quickly being 1,2-2,1 mS/cm, so it was second closest to the optimum during the rest of the experiment. The vegetative growth of strawberry plants was more vigorous in peat compared to other substrates. The growth of the root system was weakest in peat. Medium had no significant influence on the amount of yield, and had only minor influence on the quality of the yield. In conclusion, the plant fibre medium could replace peat or coir in the soilless cultivation of strawberry.
  • Harju, A. Vilhelmiina; Narhi, Ilkka; Mattsson, Marja; Kerminen, Kaisa; Kontro, Merja H. (2021)
    Views on the entry of organic pollutants into the organic matter (OM) decaying process are divergent, and in part poorly understood. To clarify these interactions, pesticide dissipation was monitored in organic and mineral soils not adapted to contaminants for 241 days; in groundwater sediment slurries adapted to pesticides for 399 days; and in their sterilized counterparts with and without peat (5%) or compost-peat-sand (CPS, 15%) mixture addition. The results showed that simazine, atrazine and terbuthylazine (not sediment slurries) were chemically dissipated in the organic soil, and peat or CPS-amended soils and sediment slurries, but not in the mineral soil or sediment slurries. Hexazinone was chemically dissipated best in the peat amended mineral soil and sediment slurries. In contrast, dichlobenil chemically dissipated in the mineral soil and sediment slurries. The dissipation product 2,6-dichlorobenzamide (BAM) concentrations were lowest in the mineral soil, while dissipation was generally poor regardless of plant-derived OM, only algal agar enhanced its chemical dissipation. Based on sterilized counterparts, only terbutryn appeared to be microbially degraded in the organic soil, i.e., chemical dissipation of pesticides would appear to be utmost important, and could be the first response in the natural cleansing capacity of the environment, during which microbial degradation evolves. Consistent with compound-specific dissipation in the mineral or organic environments, long-term concentrations of pentachloroaniline and hexachlorobenzene were lowest in the mineral-rich soils, while concentrations of dichlorodiphenyltrichloroethane (DTT) and metabolites were lowest in the organic soils of old market gardens. OM amendments changed pesticide dissipation in the mineral soil towards that observed in the organic soil; that is OM accelerated, slowed down or stopped dissipation.
  • Päivänen, Juhani (Suomen metsätieteellinen seura, 1982)
  • Rainio, Pauli (Helsingfors universitet, 2013)
    In Norway spruce (Picea abies) dominated mineral soil sites, the polypore Heterobasidion parviporum often causes severe decay problems (butt rot, root rot). Not much is however known on the ability of H. parviporum to cause decay losses in peatland. The purpose of this study was to answer some fundamental question: 1) Is H. parviporum able to cause decay losses in drained mires? 2) Is there an effect of other soil microbes during saprotrophic growth of Heterobasidion on peat soil? 3) What are the potential inhibitory effects of microbes inhabiting peat soil on growth of Heterobasidion? For the decay study, wood discs (P. abies) in mesh bags were buried at the different forest sites; mineral soil and peatlands (including drained mire and undrained mire). The amount of weight loss was documented after four months. The study was repeated in vitro by autoclaving soil samples from these sites together with wood discs followed by inoculation with H. parviporum. On mineral soil, H. parviporum decayed spruce (P. abies) wood disc much more than on non-drained pristine mire. On drained (ditched) mire, no significant difference in the weight loss was observed. H. parviporum grew significantly more on the sterilized soil and decayed more wood, compared to non-sterilized soil. The results suggested that secreted metabolites in the unsterilized soil may be able to significantly suppress saprotrophic growth of H. parviporum. In the fungal growth inhibition experiment, water- and acetone-soluble substances were extracted from the soil with acetone and water. No fungal growth inhibiting substances were detected from the various peat soils or mineral soils.
  • Lounela, Anu K. (2021)
    This article explores how changing environmental conditions and practices connect with shifting forms and valuations of sociality in a Ngaju Dayak village in the radically transformed peatlands of southern Borneo. It proposes that the production of values and social relations is indivisible from the production of a livelihood through material means and dwelling in the local environment. The article describes how changing Ngaju orientations to social life and the riverscape have been interlinked with fluctuations in the local valuescape. The focus is on two distinct but overlapping forms of organising sociality and labour in the riverine environment, and how they have influenced and been influenced by the dialectically conjoined Ngaju values of solidarity and autonomy, and, more recently, by emerging economic value. It is argued that the valuation of sociality crucially reflects the changing valuation of land and nature and related politics of value within the local riverscape. Finally, the article shows that the radically transformed riverine environment sets limits on (imagining) environmental practices, forms of sociality, and how they are valued.
  • Hooijer, A.; Page, S.; Jauhiainen, Jyrki; Lee, W.A.; Lu, X.X.; Idris, A.; Anshari, G. (2012)
    Abstract. Conversion of tropical peatlands to agriculture leads to a release of carbon from previously stable, long-term storage, resulting in land subsidence that can be a surrogate measure of CO2 emissions to the atmosphere. We present an analysis of recent large-scale subsidence monitoring studies in Acacia and oil palm plantations on peatland in SE Asia, and compare the findings with previous studies. Subsidence in the first 5 yr after drainage was found to be 142 cm, of which 75 cm occurred in the first year. After 5 yr, the subsidence rate in both plantation types, at average water table depths of 0.7 m, remained constant at around 5 cm yr−1. The results confirm that primary consolidation contributed substantially to total subsidence only in the first year after drainage, that secondary consolidation was negligible, and that the amount of compaction was also much reduced within 5 yr. Over 5 yr after drainage, 75 % of cumulative subsidence was caused by peat oxidation, and after 18 yr this was 92 %. The average rate of carbon loss over the first 5 yr was 178 t CO2eq ha−1 yr−1, which reduced to 73 t CO2eq ha−1 yr−1 over subsequent years, potentially resulting in an average loss of 100 t CO2eq ha−1 yr−1 over 25 yr. Part of the observed range in subsidence and carbon loss values is explained by differences in water table depth, but vegetation cover and other factors such as addition of fertilizers also influence peat oxidation. A relationship with groundwater table depth shows that subsidence and carbon loss are still considerable even at the highest water levels theoretically possible in plantations. This implies that improved plantation water management will reduce these impacts by 20 % at most, relative to current conditions, and that high rates of carbon loss and land subsidence are inevitable consequences of conversion of forested tropical peatlands to other land uses.
  • Binte Mostafiz, Suraiya (Helsingfors universitet, 2014)
    Plant production in soilless systems is attracting increased interest day by day. The major reason for these interest is the fact that soilless medium can help to eliminate soil-borne diseases and give an understanding of plant nutritional requirements. The aim of this thesis is to evaluate the suitability of chemically and physically modified wood shavings as growing media for horticultural crop production. Five different wood shavings derived from Scots pine trees, namely untreated wood, heat treated wood, organic acid treated wood, Q-Treat, Q-Treat and organic acid treated wood, along with mixtures of peat and Q-Treat as 50/50 v/v (P50Q50), 25/75 (v/v) (P25Q75) and peat (control ) were used. In order to assess the characteristics of the growing media phytotoxicity, pH, water holding capacity, N immobilization, EC, water content of the substrates were analysed. Plant performances on the substrates was evaluated by observing the vegetative and generative growth of Hosta ‘Golden Tiara’ and strawberry ‘Elsanta’ plants. Q-Treat, organic acid treated wood and P50Q50 showed a high water holding capacity. No nitrogen immobilization was observed in Q-Treat. At the same time, EC and water content of the substrates were favourable for both Hosta ‘Golden Tiara’ and strawberry production. Hosta ‘Golden Tiara’ plants grew satisfactorily on all the substrates but the visual quality of the plants was unacceptable on untreated wood. For strawberry, vegetative growth was strong on peat and P50Q50. Least runners were formed on P25Q75 and all of the wood substrates. However, the yield from strawberries was highest on peat and P25Q75. The quality of strawberry fruits on wood substrates was equal to that on peat. In conclusion, based on the results obtained in this experiment, 50% of peat may be replaced by 50% Q-Treat in soilless cultivation for Hosta ‘Golden Tiara’ and 75% of peat may be replaced by Q-Treat in soilless strawberry production.