Characterization of the Wetting Properties of Air-Dried Peats and Composts

Valat, Beatrice; Jouany, Claire; Rivière, L.M.

doi:10.1097/00010694-199108000-00006

Cited by 97 publications

(78 citation statements)

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“…This alkalinization could be attributed to the elevated calcium of composts; liming of sludge from sewage treatment before their composting is actually a method frequently adopted for hygièniser sludge and increase their pH (Guénon, 2010). The incorporation of different types of sewage sludge increased retention in soil (Valat et al, 1991) and the amount of water available for plants (Khaleel et al, 1981). Our study to shown that retention capacity increased under the action of the sludge.…”

Section: Effects Of Composts On the Physical Properties Of Degraded Ssupporting

confidence: 53%

Ecological Restoration of Forest Soils Case of the Forest “Aioun Branise” Saida Algeria

Habib¹,

Zohra²

2014

OJF

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In order to preserve the environment, various treatment processes of wastewater discharges are used. Anaerobic digestion is part and allows among other things the production of sludge. The use of sewage sludge in semi arid, characterized by a binding climate, anthropozoogenic pressure and erosion, more increasingly important, is a solution for the restoration of degraded forest lands. In this study, the effect of an intake of composts from urban sewage sludge on soil quality has been studied in-situ soils degraded in semi arid area. The research followed in this work methodology is the first to evaluate the effectiveness of contribution of compost over time on the restoration of the physico-chemical quality of forest soils, then to evaluate the effectiveness of compost quality depending on the state of disturbance of the ecosystem to restore the chemical quality of these soils. Our results show a significant effect of sewage sludge on soil's physical and chemical characters that have been processed. This effect was delivered by the holding capacity increase, ammonium ions, inorganic phosphorus, total nitrogen, the carbon and the organic matter in these soils. This research is to show that sewage sludge are rich in easily mineralizable organic matter and are supposed to be the most suitable for the restoration of soil most impacted by the antropozoogene action. These contributions would quickly revitalize these soils by labile resource inputs.

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Section: Effects Of Composts On the Physical Properties Of Degraded Ssupporting

confidence: 53%

Ecological Restoration of Forest Soils Case of the Forest “Aioun Branise” Saida Algeria

Habib¹,

Zohra²

2014

OJF

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“…A b of 408 was used in Eq. 3 because it is representative of both the range of contact angles of organic soils, ranging from close to zero for Sphagnum plants (Valat et al 1991) to between 73 and 888 for peat (Waniek et al 2000), and the range of b for moderately hydrophobic soils under a range of u conditions (Bachmann et al 2002(Bachmann et al , 2003. Furthermore, changes in b have minimal effect on the pore size diameter compared with other parameters and therefore the choice of its value does not affect the conclusions of this study.…”

Section: Peat Parameterizationmentioning

confidence: 95%

Role of morphological structure and layering ofSphagnumandTomenthypnummosses on moss productivity and evaporation rates

Goetz

PriceJonathan

2015

Can. J. Soil. Sci.

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Price, J. S. 2015. Role of morphological structure and layering of Sphagnum and Tomenthypnum mosses on moss productivity and evaporation rates. Can. J. Soil Sci. 95: 109Á124. Morphological structures of peatland mosses control moss water relations and the rate of water loss by drainage and evaporation, thus influencing their physiological functions. While many of these mechanisms are understood for Sphagnum mosses, there is a limited understanding of how these processes operate in Tomenthypnum nitens, a dominant brown moss species in northern rich fens. This study contrasts how different hydrophysical characteristics of Tomenthypnum and Sphagnum species affect capillary water flow that supports evaporation and productivity. Laboratory investigations indicate that volumetric water content (u), gross ecosystem productivity, and evaporation decreased with water ). Despite lower u and a smaller fraction of pores between 66 and 661 mm to retain water within the Tomenthypnum structure (10%) compared with Sphagnum (27%), both mosses had similar fractions of water conducting pore spaces and were able to maintain capillary rise throughout the experiment. While there was a larger difference in the bulk density and porosity of the Tomenthypnum moss compared with its underlying peat than there was in the Sphagnum profile, a layer of partially decomposed moss of intermediate properties was sufficient to provide a connection between the moss and peat under low water table conditions. In trying to characterize the soil-water pressure (c) in near-surface mosses of Tomenthypnum based on measurements of vapour pressure, we found disequilibrium conditions that severely underestimated c (i.e., very large negative pressures). It is this disequilibrium that drives evaporation and draws up capillary water to the moss surface for peatlandÁatmosphere carbon and water transfers.Key words: Peatlands, bryophytes, water retention, hydraulic conductivity, theoretical pore-size distribution, water vapour Goetz, J. D. et Price, J. S. 2015. Influence de la morphologie et de la superposition des couches de mousses de type Sphagnum et Tomenthypnum sur la productivite´de la plante et le taux d'e´vaporation. Can. J. Soil Sci. 95: 109Á124. Dans les tourbie`res, la morphologie des mousses controˆle les relations entre l'eau et la plante, ainsi que la vitesse a`laquelle l'eau disparaıˆt par drainage et e´vaporation, ce qui exerce une influence sur les fonctions physiologiques de la mousse. Quoique beaucoup de ces me´canismes soient bien connus chez les mousses du genre Sphagnum, nos connaissances sont plus limite´es sur ces processus chez Tomenthypnum nitens, une mousse brune qui domine dans les riches marais du nord. Cette e´tude illustre combien les caracte´ristiques hydrophysiques diffe´rentes des espe`ces des genres Tomenthypnum et Sphagnum modifient l'e´coulement capillaire de l'eau, dont de´pendent l'e´vaporation et la productivite´. Les e´tudes en laboratoire indiquent que la masse volumique de l'eau (u), la productivite´brute de l'e´cosyste`me...

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“…For living Sphagnum plants, Valat et al (1991) found the contact angle between tissues and water to be close to zero, therefore cos Â D cos 0 D 1. Using Equation (3), the capillary height in living Sphagnum at equilibrium is approximated by:…”

Section: Theory Of Pressure and Capillaritymentioning

confidence: 98%

“…Thus, there is a five-fold difference in capillary height between living mosses and peat because of contact angles. Other studies examining the contact angle of peat give values ranging between 15 and 60°for intact 'high bog' peat (Burghardt, 1985), and 110°, for hydrophobic, air-dried Sphagnum peat (Valat et al, 1991).…”

Section: Theory Of Pressure and Capillaritymentioning

confidence: 99%

Sphagnum under pressure: towards an ecohydrological approach to examining Sphagnum productivity

Thompson

Waddington

2008

Ecohydrology

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The genus Sphagnum is the key peat-forming bryophyte in boreal ecosystems. Relying entirely on passive capillary action for water transport, soil moisture is often the limiting factor in Sphagnum production, and hence peat accumulation. While several hydrological models of peat physics and peatland water movement exist, these models do not readily interface with observations and models of peatland carbon accumulation. A conflict of approaches exists, where hydrological studies primarily utilize variables such as hydraulic head, while ecological models of Sphagnum growth adopt the coarse hydrological variables of water table (WT), volumetric water content (VWC) or gravimetric water content (WC). This review examines the potential of soil pressure head as a measurement to link the hydrological and ecological functioning of Sphagnum in peatlands. The nonvascular structure of Sphagnum mosses and the reliance on external capillary transport of water in the mosses make them an ideal candidate for this approach. The main advantage of pressure head is the ability to mechanistically link plot-scale hydrology to cellular-scale water requirements and carbon exchange. Measurement of pressure head may improve photosynthetic process representation in the next generation of peatland models.

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Characterization of the Wetting Properties of Air-Dried Peats and Composts

Cited by 97 publications

References 0 publications

Ecological Restoration of Forest Soils Case of the Forest “Aioun Branise” Saida Algeria

Ecological Restoration of Forest Soils Case of the Forest “Aioun Branise” Saida Algeria

Role of morphological structure and layering ofSphagnumandTomenthypnummosses on moss productivity and evaporation rates

Sphagnum under pressure: towards an ecohydrological approach to examining Sphagnum productivity

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