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Bulk density (Db) and subsequent physical properties are determined by the substrate and packing method. Packing method is the way one fills and compresses a substrate within a given volume. Bulk density produced in the laboratory may not align with “expected” published ranges due to variations in packing. Additionally, it is unknown if ranges identified as “typical” using a small volume sample ring reflect Db occurring in larger production size containers packed using commercial potting practices. Therefore, our objectives were to 1) emulate nursery practices and document the Db associated with a potted 2.8-L (#1) container, 2) develop and test the new “shim and compression” method to determine if it consistently packs sample rings to a Db commensurate with that of a 2.8-L nursery container, and 3) demonstrate how static physical properties are affected by the new “shim and compression” sample ring packing method compared with the traditional bench top tap method. When emulating nursery potting practices with 100% pine bark, coir, and peat, and blends of each, Db ranged from 0.08 g.cm-3 (coconut coir) to 0.17 g.cm-3 (pine bark). We used an espresso tamp and shims to pack the aforementioned substrates in sample rings. The Db achieved using a range in number of presses and discs was largely dependent on the substrate, but the desired Db was consistently achieved for each substrate. There was no effect of disc number on Db (P 5 1.000) for any substrate. There was no effect of tamp number (P $ 0.0602) for all substrates except peat-amended, for which five tamps yielded a greater Db than one tamp (P 5 0.0324). In an experiment in which a different technician who was accustomed to the conventional benchtop tap packing method performed both methods, method influenced Db (P < 0.0001), and the conventional method more closely attained the target Db. To our knowledge, this is the only report of Db observed in commercial container production facilities (i.e., “native”). [ABSTRACT FROM AUTHOR]

Bulk density (Db) and subsequent physical properties are determined by the substrate and packing method. Packing method is the way one fills and compresses a substrate within a given volume. Bulk density produced in the laboratory may not align with “expected” published ranges due to variations in packing. Additionally, it is unknown if ranges identified as “typical” using a small volume sample ring reflect Db occurring in larger production size containers packed using commercial potting practices. Therefore, our objectives were to 1) emulate nursery practices and document the Db associated with a potted 2.8-L (#1) container, 2) develop and test the new “shim and compression” method to determine if it consistently packs sample rings to a Db commensurate with that of a 2.8-L nursery container, and 3) demonstrate how static physical properties are affected by the new “shim and compression” sample ring packing method compared with the traditional bench top tap method. When emulating nursery potting practices with 100% pine bark, coir, and peat, and blends of each, Db ranged from 0.08 g⋅cm−3 (coconut coir) to 0.17 g⋅cm−3 (pine bark). We used an espresso tamp and shims to pack the aforementioned substrates in sample rings. The Db achieved using a range in number of presses and discs was largely dependent on the substrate, but the desired Db was consistently achieved for each substrate. There was no effect of disc number on Db (P = 1.000) for any substrate. There was no effect of tamp number (P ≥ 0.0602) for all substrates except peat-amended, for which five tamps yielded a greater Db than one tamp (P = 0.0324). In an experiment in which a different technician who was accustomed to the conventional benchtop tap packing method performed both methods, method influenced Db (P < 0.0001), and the conventional method more closely attained the target Db. To our knowledge, this is the only report of Db observed in commercial container production facilities (i.e., “native”).

Tamarind (Tamarindus indica L.) is a species with promising potential for commercial production; therefore, studies involving practices of conducting culture in the initial stage are essential. The present study aimed to evaluate different shading levels and substrate compositions in the seedling production of tamarind. The experimental design was completely randomized in a 4×4 factorial scheme, four levels of shading (0%, 18%, 30%, and 50%) and four substrates (pine bark-based substrate pure and mixed with 50% vermiculite, and sphagnum peat-based substrate pure and mixed with 50% vermiculite), with four replicates of four seedlings. Growth and biometric relationships were evaluated at 40 and 98 d after transplantation (DAT). The results reported that seedlings formed on the sphagnum peat-based substrate on pure or associated with vermiculite at 98 DAT had a height greater than 35 cm and a total 8.5 g DM. In contrast, seedlings produced in pine bark-based substrate did not reach 20 cm in height and had less than 3 g total DM. The condition of 30% and 50% shading promoted greater growth in height, reaching an average height greater than 40 cm, while in the full sun environment, seedlings showed an average of less than 35 cm; however, for the other variables, full sun environment did not differ from 30% shading, producing good quality seedlings. Thus, the cultivation of seedlings in an environment with 0% or 30% shading, associated with the sphagnum peat-based substrate pure or mixed with 50% vermiculite promoted the production of tamarind seedlings with vigorous growth. In the best environments, the best substrates increased, on average, 41.3% number of leaves, 80.5% shoot dry mass, 56.8% root dry mass, and 71.0% total dry mass. In the best substrates, the best environments increased, on average, 18.0% number of leaves, 20.7% shoot dry mass, 8.7% root dry mass, and 14.3% total dry mass. [ABSTRACT FROM AUTHOR]

Growers rely on soilless substrates to provide sufficient water and nutrients to containerized crops. Traditional bark-based substrates are engineered to have relatively low water-holding capabilities, which can lead to nonuniform rewetting patterns and inefficient usage of water resources. Engineering substrates to redistribute water dynamics and maximize aeration within the container may improve water resource efficiencies. The goal of this study was to evaluate whether more efficient irrigation schedules can be used when stratifying unique substrates within a container for added crop water and nutrient efficiency. Loropetalum chinense ‘Ruby’ liners were planted and grown in a conventional pine bark substrate or one of three stratified substrate treatments, including a bark:peat, bark:coir, or fine bark layered on top of a coarse bark. The crops were grown under four different irrigation schedules, including single daily application, single application at deficit levels, cyclic application, or cyclic at deficit schedules. Stratified substrates improved crop growth, quality, and yield when compared with plants grown in conventional bark in the single application irrigation treatment. Measured at final harvest, substrates positively influenced plant growth index (P < 0.0001), whereas irrigation scheduling alone had no effect (P = 0.6321). There was a strong interaction between substrate and irrigation schedules on Δ growth index (P = 0.0141). There were strong substrate effects on shoot dry weight (P = 0.0060), root dry weight (P = 0.0342), and growth index (P = 0.0040). The stratified bark:coir treatment outgrew all other substrate treatments. In addition, within all irrigation treatments, plants grown with the stratified bark:coir substrate had the highest survival ratings among the other substrate treatments, whereas the conventional bark had the lowest survival rates. Substrate and irrigation had an effect on nitrogen and potassium leachate concentrations levels (P = 0.0107 and P = 0.0004, respectively). Evaluation of microbial communities showed that substrate (P = 0.0010) and the stratified layer (P = 0.0010) had strong influences on the type of community present and the relative abundance in the treatments used herein this study. Specifically, within cyclic scheduling, bark:peat actinomycete populations were significantly greater than other substrate treatments. Furthermore, under deficit irrigation, stratified substrate systems were able to mitigate crop water stress. The results indicate that when crops such as the Loropetalum are grown in the stratified system, crop growth can be sustained when drought conditions are present. This is possible by providing adequate water availability even under low water inputs until subsequent irrigations during the fragile establishment period, when compared with using traditional bark-based substrates.

Stability of substrate pH in container-grown crops is important for proper nutrient management. The objective of this research was to determine the pH buffering capacity of pine bark substrates as a function of particle size and compare those results to sphagnum peat. The weight equivalent of 100 cm3 for fine, medium, and coarse pine bark and sphagnum peat, either as a whole or partitioned into several particle size ranges, was placed in a 250-mL glass jar and filled with 100 mL of an acid or base solution ranging from 0 to 50 meq·L−1 in 10 meq·L−1 increments. After 24 hours, pH was measured. An experiment was also conducted in the greenhouse. The weight equivalent of 500 cm3 of sphagnum peat, fine pine bark, or coarse pine bark was filled into 10-cm plastic pots and irrigated with one of the following: tap water or 10 meq·L−1 of HCl, NaOH, H2SO4, or KHCO3 and with or without a water soluble fertilizer. Substrate pH was determined 4 and 8 weeks after potting using the pour-through method. In all experiments, sphagnum peat had less buffering capacity than pine bark against pH changes from acidic solutions, whereas pine bark had less buffering capacity than sphagnum peat to pH changes from basic solutions. Substrate pH buffering in pine bark increased with decreasing particle size, whereas pH buffering in sphagnum peat was less responsive to particle size. These results will help growers and substrate manufacturers understand how substrate components contribute to pH management during crop production.

The use of appropriate techniques to optimize water availability in substrates is essential for the formation of quality seedlings. Therefore, the objective was to evaluate the influence of substrate physical conditioning through the use of hydrogel. The treatments consisted of the control treatment (without the addition of hydrogel) and three doses of hydrogel (2, 4 and 6 g L-1 of substrate) added to components carbonized rice husk, average regular sand and Sphagnum peat isolated, and in a mixture composed of 50% of carbonized rice husk and 50% of peat (volumetric proportions). A completely randomized design was used, and the substrates were subjected to physical characterization at 0, 10, 50 and 100 hPa, using tension funnels, determining total porosity, aeration space, available water, remaining water and water holding capacity. The results showed that the use of this conditioner up to 4 g L-1, generally, increased total porosity and decreased air space. There was an increase in available water and remaining water, especially for substrates with low water holding capacity (carbonized rice husk and sand). Thus, the use of hydrogel makes it possible to increase the period between irrigations, resulting in significant improvements in the production system. [ABSTRACT FROM AUTHOR]

ABSTRACT: The characterization of substrate properties supports the correct choice of components and directs management decisions in container cultivation. There are several systems of analysis, however, the routine procedures to determine the water retention curve (WRC) are time consuming and inaccurate. This study proposed a reproducible, less time-consuming, and easy to perform method for physical characterization of substrates. We used Sphagnum peat, coconut powder, carbonized rice husk, expanded vermiculite, and expanded clay in isolation. The WRC was obtained at tensions 0, 10, 50, and 100 hPa using the method of Büchner funnel, the European standard (CEN-EN13041), and by the centrifugation method of samples. In centrifugation, tensions were simulated by combining the angular velocity, sample height, and radius measured from the sample outermost point to the central point of the centrifuge. Three rotations were applied (230; 520 and 730 rpm), testing the centrifugation time for each tension and then the volumetric water content was compared between the methods. The results showed a positive correlation (p < 0.001) between the centrifugation and standard methods, considering that the centrifugation time required for moisture stabilization varied according to the material analyzed and the tension applied. However, the time required to obtain a report was reduced by half. Sample centrifugation is a promising method, ensuring that the tensile force actually acts on the entire sample to determine the water retention curve of the substrate also reducing the duration of the analyses.

Toxicity effect of Chlorpyrifos 50% + Cypermethrin 5% EC to terrestrial invertebrate Eisenia fetida in two different sphagnum peat substituted soil was assessed. Artificial soil substrate for earthworm toxicity test comprises of 70% sand, 20% clay and 10% sphagnum peat. In this study, coco peat was used as an alternative substitute for sphagnum peat. The LC50 was 83.7 mg/kg for coco peat and 76.3 mg/ kg for sphagnum peat soil. No significant difference was observed in mortality and biomass between the two soil substrates, but a significant difference was observed in the reproduction. Based on the observations, it is concluded that coco peat can also be used as an alternative to sphagnum peat in toxicity studies. [ABSTRACT FROM AUTHOR]

Untreated stormwater is a major source of microplastics, organic pollutants, metals, and nutrients in urban water courses. The aim of this study was to improve the knowledge about the start-up periods of bioretention filters. A rain garden pilot facility with 13 bioretention filters was constructed and stormwater from a highway and adjacent impervious surfaces was used for irrigation for ∼12 weeks. Selected plants (Armeria maritima, Hippophae rhamnoides, Juncus effusus, and Festuca rubra) was planted in ten filters. Stormwater percolated through the filters containing waste-to-energy bottom ash, biochar, or Sphagnum peat, mixed with sandy loam. Influent and effluent samples were taken to evaluate removal of the above-mentioned pollutants. All filters efficiently removed microplastics >10 µm, organic pollutants, and most metals. Copper leached from all filters initially but was significantly reduced in the biochar filters at the end of the period, while the other filters showed a declining trend. All filters leached nutrients initially, but concentrations decreased over time, and the biochar filters had efficiently reduced nitrogen after a few weeks. To conclude, all the filters effectively removed pollutants during the start-up period. Before being recommended for full-scale applications, the functionality of the filters after a longer period of operation should be evaluated., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Stability of substrate pH in container-grown crops is important for proper nutrient management. The objective of this research was to determine the pH buffering capacity of pine bark substrates as a function of particle size and compare those results to sphagnum peat. The weight equivalent of 100 cm3 for fine, medium, and coarse pine bark and sphagnum peat, either as a whole or partitioned into several particle size ranges, was placed in a 250-mL glass jar and filled with 100 mL of an acid or base solution ranging from 0 to 50 meq·LL1 in 10 meq·LL1 increments. After 24 hours, pH was measured. An experiment was also conducted in the greenhouse. The weight equivalent of 500 cm3 of sphagnum peat, fine pine bark, or coarse pine bark was filled into 10-cm plastic pots and irrigated with one of the following: tap water or 10 meq·LL1 of HCl, NaOH, H2SO4, or KHCO3 and with or without a water soluble fertilizer. Substrate pH was determined 4 and 8 weeks after potting using the pour-through method. In all experiments, sphagnum peat had less buffering capacity than pine bark against pH changes from acidic solutions, whereas pine bark had less buffering capacity than sphagnum peat to pH changes from basic solutions. Substrate pH buffering in pine bark increased with decreasing particle size, whereas pH buffering in sphagnum peat was less responsive to particle size. These results will help growers and substrate manufacturers understand how substrate components contribute to pH management during crop production. [ABSTRACT FROM AUTHOR]

Nurseries rely on soilless substrates to provide suitable growing media for container grown crops. These soilless substrates have been developed to readily drain water to prevent issues with waterlogging and associated soil-borne disease. A negative consequence of high porosity and subsequent drainage throughout the container profile is the required high or frequent irrigation rates with poor retention of applied nutrients. Substrates with relatively high levels of moisture and nutrient retention placed on top of a coarse and freely draining substrate could further optimize water and nutrient retention, while allowing for needed gas exchange for plant establishment and growth. Containerized Red Drift® rose (Rosa ‘Meigalpio’ PP17877) plants were grown under 16 mm or 12 mm daily irrigation, utilizing a traditional pine bark substrate or stratified substrates with either a conventional bark, bark fines, or a bark–peat mixture on top of a coarse bark within a container. The stratified substrates received 20% less controlled-release fertilizer; however, the fertilizer in the stratified treatments was concentrated in the upper strata only. During the first growing phase or season, plants grown in stratified substrates outperformed those grown in conventional, non-stratified bark substrates under normal irrigation. The stratified substrates did not reduce growth under reduced irrigation regimes. Overall, crop growth was equal or superior for stratified substrates when compared to the non-stratified controls, even with a 20% reduction of fertilizer. This research suggests that stratified substrate systems can be used to reduce fertilizer and irrigation rates while producing crops of similar or superior quality to conventionally grown containerized crops.

The uptake of nickel [Ni(II)] by Paenibacillus sp., Methylobacterium sp., Paraburkholderia sp., and Pseudomonas sp. strains isolated from a boreal bog was studied using batch experiments. All strains removed Ni(II) from the solution and the uptake efficiency was affected by the nutrient source, incubation temperature, time, and pH. As highest Ni uptake (with a maximum Kd of 1890 L/kg DW) was recorded for the Pseudomonas sp. strains, these bacteria were used in the following protein expression (SDS-PAGE and MALDI-TOFF), transmission electron microscopy (TEM) and EDS experiments. In addition, Freundlich and Langmuir sorption isotherms were determined. In the Ni(II) treated cells, dense crystalline intra-cellular accumulations were observed in TEM examinations, which were identified as Ni accumulations using EDS. SDS-PAGE and MALDI-TOFF spectra of Ni(II) treated cells showed several changes in the protein profiles, which can indicate active accumulation of Ni in these bacteria. Concurrently, we observed Ni(II) uptake to follow Freundlich and Langmuir isotherms, suggesting straight cellular biosorption in addition to the intra-cellular accumulation. The role of cellular (cell membrane and cell wall) functional groups involved in Ni(II) binding were therefore studied using Fourier transformation infrared spectroscopy. These analyses supported the potential role of the alcoholic hydroxyl, carboxyl and amine groups in Ni(II) binding in these bacteria, therefore suggesting two different Ni(II) uptake mechanisms; (i) intra-cellular accumulation [possibly connected to detoxification of Ni(II)], and (ii) straight biosorption on cell membrane/wall functional groups.

The uptake of nickel [Ni(II)] by Paenibacillus sp., Methylobacterium sp., Paraburkholderia sp., and Pseudomonas sp. strains isolated from a boreal bog was studied using batch experiments. All strains removed Ni(II) from the solution and the uptake efficiency was affected by the nutrient source, incubation temperature, time, and pH. As highest Ni uptake (with a maximum Kd of 1890 L/kg DW) was recorded for the Pseudomonas sp. strains, these bacteria were used in the following protein expression (SDS-PAGE and MALDI-TOFF), transmission electron microscopy (TEM) and EDS experiments. In addition, Freundlich and Langmuir sorption isotherms were determined. In the Ni(II) treated cells, dense crystalline intra-cellular accumulations were observed in TEM examinations, which were identified as Ni accumulations using EDS. SDS-PAGE and MALDI-TOFF spectra of Ni(II) treated cells showed several changes in the protein profiles, which can indicate active accumulation of Ni in these bacteria. Concurrently, we observed Ni(II) uptake to follow Freundlich and Langmuir isotherms, suggesting straight cellular biosorption in addition to the intra-cellular accumulation. The role of cellular (cell membrane and cell wall) functional groups involved in Ni(II) binding were therefore studied using Fourier transformation infrared spectroscopy. These analyses supported the potential role of the alcoholic hydroxyl, carboxyl and amine groups in Ni(II) binding in these bacteria, therefore suggesting two different Ni(II) uptake mechanisms; (i) intra-cellular accumulation [possibly connected to detoxification of Ni(II)], and (ii) straight biosorption on cell membrane/wall functional groups. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess usability of composts made of sewage sludge and either straw or leaves used as substrates for growing zonal pelargoniums. The study plants ‘Hot Pink’ cv. of Survivor group and ‘Fire’ cv. of Graffiti group were grown in 5 different substrates. The control substrate was high peat (100%) deacidified with chalk and dolomite up to pH 5.8–6.0 and supplemented with 2.5 g·dm-3 of Azofoska multicomponent fertilizer. The other four substrates contained two types of composts: SSRS – sewage sludge, straw (1:1, v/v) and SSL – sewage sludge, leaves (1:1, v/v), mixed with high peat at two different proportions, 1:3 (v/v) and 1:7 (v/v). Chemical composition of the substrates was investigated and they were supplemented with nitrogen and potassium as recommended for pelargoniums. Plant morphological parameters were evaluated during flowering. They included plant height and diameter, number of shoots and leaves, leaf assimilation area and leaf weight. Leaf chlorophyll and carotenoid content was also estimated. Inflorescence related parameters included inflorescence diameter and inflorescence stem length, number of flowers per inflorescence and flower diameter. All inflorescences formed over 10 weeks of flowering were counted. Plant ornamental value was assessed using a five-score bonitation scale. The investigated composts were found to be useful components of the substrates for zonal pelargonium production. Irrespective of the compost share, the tested substrates significantly affected most of the evaluated morphological traits. The substrate containing the compost made of sewage sludge and straw (SSRS) and peat (1:3, v/v) was found the most beneficial for pelargonium foliage, i.e. the number of leaves, their fresh weight and assimilation area. Leaf chlorophyll and carotenoid content in the pelargoniums grown in the substrates containing either dose of SSRS compost did not differ from the control plants. Substrate type did not affect bonitation score of ‘Survivor Hot Pink’ cultivar. The bonitation score of ‘Graffiti Fire’ cultivar was the highest for plants growing in the substrates with either SSRS or SSL compost plus peat in 1:3 ratio (v/v).

In this study, continuous biosorption-desorption cycles in a fixed-bed column were performed to evaluate the extended use of sphagnum peat as biosorbent material to remove Zn(II) ions from aqueous solutions. Biosorption-desorption studies revealed that the sphagnum peat as biosorbent could be regenerated using 0.1M HCl as eluting agent with more than 70% recovery in four successive biosorption-desorption cycles. The results showed that the sphagnum peat should be used as an alternative, effective and low-cost biosorbent for Zn(II) ions removal from polluted aqueous solution. [ABSTRACT FROM AUTHOR]

With the aims of investigating the causes of environmental changes in high mountain ecosystems during the Holocene in relation to climate forcings and identifying thresholds for vegetation community shifts, we performed a multi-proxy palaeoecological reconstruction based on two sediment cores from Bassa Nera, a lentic system located close to the montane–subalpine ecotone in the Central Pyrenees. Using pollen, plant macroremains, charcoal, chemical elements and loss-on-ignition at centennial to decadal resolution, we reconstructed the vegetation and lacustrine dynamics during the last 10,000 years. A montane pollen ratio was used as a palaeoecological indicator to track altitudinal shifts in high mountain vegetation, which was compared to the ice-rafted debris index (IRD) as a proxy for summarizing the climatic influence of the North Atlantic Circulation. Our results show upward shifts of deciduous forest and its presence in Bassa Nera from the onset of the Holocene until 4200 cal yr BP, when it was replaced by coniferous taxa. The montane ratio showed a link between vegetation and North Atlantic influence, while changes in Sphagnum macroremains and aquatic taxa allowed description of local ontogenic changes from the initial pond to the present peatland. The loss-on-ignition record showed some flood events at Bassa Nera between 4500 and 3900 cal yr BP. The studied proxies allowed inferences concerning anthropic pressure in the catchment through grazing activities by 7300 cal yr BP and the appearance of cereal agriculture around 5190 cal yr BP. The highest human pressure occurred in the late Bronze Age, Roman Period and Middle Ages. [ABSTRACT FROM AUTHOR]

Historically, substrate science has utilized the pressure extraction method to measure soilless substrate moisture characteristic curves, albeit with published discrepancies. Recently, a device utilizing the evaporative method to generate moisture characteristic curves by measuring water potential as volumetric water content decreases via evaporation, known as a Hyprop, has become available. This research compares and contrasts moisture characteristic curves developed over a 2-week period using both the pressure extraction and the evaporative methods for two-component greenhouse ( Sphagnum peat and perlite) and nursery (aged pine bark and sand) soilless substrates. The pressure extraction method was conducted between water potentials of 0 and −300 hPa (10 data points used in conventional methodology for allotted time), while the evaporative method measurements continued until the tensiometers cavitated (≈ −500 to −700 hPa) and provided higher data density (100 data points) within the two week period. The evaporative method was found to produce repeatable results, with subsequent measurements of each substrate providing analogous measurements (P > 0.9000 and P > 0.3700 for the peat and bark substrate, respectively). There was little variation between the two methodologies for the peat substrate (0.004% difference in the area under the curves from 0 to −300 hPa). However, differences were observed between the methodologies for the bark substrate, with the percentage difference increasing with increasing water potential (9.6% at −100 hPa; 23.7% at −300 hPa). Additionally, the evaporative method measured a continued decrease in volumetric water content of the aged pine bark and sand substrate with increasing water potentials throughout the range of measurements, unlike the pressure extraction method, which has documented issues with loss of hydraulic connectivity between the sample and the plate in coarse highly porous organic substrates. Therefore, the pressure extraction method ceases to decrease in volumetric water content (≤ −65 hPa) resulting in a divergence in curves generated by the two methods. Both methods were found to have limitations while measuring substrate water content near saturation, with the pressure plate resistance to free drainage of water influencing measurements and the evaporative method continually underestimating the saturation point. As a result, both methods provided decreased volumetric water content measurements near saturation than when static physical properties were directly measured; therefore, moisture characteristic curves should be used collectively with static properties to correct for underestimation of total porosity and to better yield an understanding of the hydrophysical properties of a soilless substrate. [ABSTRACT FROM AUTHOR]

Effect of potting media on growth and quality of ornamental foliage plant, aglaonema cv. Ernesto's Favourite, was evaluated. Soil, cocopeat and sphagnum peat, in combination with sand, FYM and vermicompost in various proportions, were used as potting media. Maximum plant height (71.36cm), number of leaves (16.00), leaf length (60.39cm), leaf width (10.13cm), leaf area (208.36cm2), plant growth index (63.37cm), fresh weight of root (45.00g), dry weight of root (8.53g), visual plant grade (4.50), colour grade (4.58), root grade (4.45), and, N (3.46 %), P (0.95 %) and K content in leaf (1.91%) were recorded with the medium containing cocopeat + sand + vermicompost in 2:1:1, (v/v) combination at 150 DAP. Medium containing cocopeat + sand + FYM + vermicompost in 2:1:1:0.5 ratio, (v/v) was found to be on par with cocopeat + sand + vermicompost in 2:1:1, (v/v) combination with respect to leaf width, dry weight of root, visual plant grade, colour grade, root grade and K content.

The aim of this study was to assess usability of composts made of sewage sludge and either straw or leaves used as substrates for growing zonal pelargoniums. The study plants 'Hot Pink' cv. of Survivor group and 'Fire' cv. of Graffiti group were grown in 5 different substrates. The control substrate was high peat (100%) deacidified with chalk and dolomite up to pH 5.8-6.0 and supplemented with 2.5 g·dm-3 of Azofoska multicomponent fertilizer. The other four substrates contained two types of composts: SSRS - sewage sludge, straw (1:1, v/v) and SSL - sewage sludge, leaves (1:1, v/v), mixed with high peat at two different proportions, 1:3 (v/v) and 1:7 (v/v). Chemical composition of the substrates was investigated and they were supplemented with nitrogen and potassium as recommended for pelargoniums. Plant morphological parameters were evaluated during flowering. They included plant height and diameter, number of shoots and leaves, leaf assimilation area and leaf weight. Leaf chlorophyll and carotenoid content was also estimated. Inflorescence related parameters included inflorescence diameter and inflorescence stem length, number of flowers per inflorescence and flower diameter. All inflorescences formed over 10 weeks of flowering were counted. Plant ornamental value was assessed using a five-score bonitation scale. The investigated composts were found to be useful components of the substrates for zonal pelargonium production. Irrespective of the compost share, the tested substrates significantly affected most of the evaluated morphological traits. The substrate containing the compost made of sewage sludge and straw (SSRS) and peat (1:3, v/v) was found the most beneficial for pelargonium foliage, i.e. the number of leaves, their fresh weight and assimilation area. Leaf chlorophyll and carotenoid content in the pelargoniums grown in the substrates containing either dose of SSRS compost did not differ from the control plants. Substrate type did not affect bonitation score of 'Survivor Hot Pink' cultivar. The bonitation score of 'Graffiti Fire' cultivar was the highest for plants growing in the substrates with either SSRS or SSL compost plus peat in 1:3 ratio (v/v). [ABSTRACT FROM AUTHOR]

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Branched glycerol dialkyl glycerol tetraethers (br GDGTs) are membrane lipids produced by unknown Bacteria and are being increasingly used as temperature proxies. Nevertheless, the direct effect of temperature on br GDGT distributions has been rarely evaluated. In this study, the impact of increasing temperature on br GDGT distributions and the speed of adaptation of br GDGT source microorganisms to temperature change were investigated by analysing br GDGTs in Sphagnum peat cores incubated under controlled conditions at two different temperatures - 12 and 15°C - for 1 yr. Br GDGTs present as intact polar lipids (IPLs, presumably derived from recently active microorganims) and core lipids (CLs, derived from dead biomass) were analysed. There were no significant differences in the relative abundances of the most abundant br GDGTs in the CL and IPL pools after 3 months' incubation. In contrast, the distribution of the br GDGT IPLs was significantly affected by temperature after 1 yr, whereas no change was observed in the CL fraction. This suggests that (i) the CL pool of br GDGTs has a turnover of at least 1 yr in peat and (ii) br GDGT source microorganisms rapidly adjust their membrane lipid composition (in > 3 months and < 1 yr, based on IPL analysis). [ABSTRACT FROM AUTHOR]

Sand-based rootzone mixtures used in establishing turfgrass areas have many advantages such as: reduced compaction from traffic and a fast rate of water infiltration. At the same time rapid draining and the lightweight of secondary materials used along with sand, such as peat or composted manure result in an overall lower weight of such rootzones compared to soil. This experiment studied the performance of some species of perennial cool season grasses for turf grown on four different rootzone mixtures in greenhouse conditions. Results demonstrated that a rootzone made by sand and sphagnum peat mixed in a ratio of 2:1 by volume considerations, obtained the highest turf quality in terms of establishment capacity, recovery after cutting, vertical growth, turf density, percent ground cover, thermo-hydric stress tolerance and general ornamental appearance. Compared with the rootzone made from 100% soil, sand + peat mixture offered a better availability of water and nutrients for plants. But using sand as a primary material for growing turf recommends a greater attention for supplying water and nutrients to the plants, imposing an intensive management where irrigation and fertilization should be done with smaller but more frequent doses. [ABSTRACT FROM AUTHOR]

The environment of the northern taiga to tundra transition is highly sensitive to climate fluctuations. In this study from northeastern European Russia, stable carbon and oxygen isotope ratios (δ13C, δ18O) in α-cellulose of Sphagnum fuscum stems subsampled from hummocks and peat plateau profiles have been used as climate proxies. The entire isotope time series, dated by lead (210Pb), caesium (137Cs) and AMS-radiocarbon (14C) dating, spans the past 2500 years. Plant macrofossil analyses were used as an aid in single species selection, but are also helpful in identifying past surface moisture conditions. The most significant relationships were found between the recent δ13C record and summer (July–August) temperatures (R2 = 0.58, p < 0.01), and the recent δ18O record and winter (October–May) precipitation anomalies in the tundra region (R2 = 0.36, p < 0.01). The study demonstrates that stable isotopes preserved in northern peat deposits are useful indicators for summer temperature and winter precipitation at decadal to millennial timescales. [ABSTRACT FROM PUBLISHER]

Abstract: Stable carbon and oxygen isotope ratios in single plant components in Sphagnum peat have a good potential to reveal environmental changes in peat archives. Two peat profiles, covering the past ∼6000years, and a Sphagnum hummock from a discontinuous permafrost area in west central Canada were studied in order to evaluate the effect of decomposition rate on isotope records and to assess which plant components are most suitable for climate reconstructions. The stable isotope values from the most recently forming Sphagnum tissues were compared with observational climate data to study the impact of variations in temperature and precipitation on the peat isotopes. Our results show that there is high correlation between δ13C values in α-cellulose isolated from Sphagnum fuscum stems and summer temperatures, whereas δ18O in the plant tissues is controlled by several factors, such as summer precipitation, summer temperature and evaporation. According to our results, decomposition as derived from C/N values and colorimetry does not seem to affect the oxygen and carbon isotope values of α-cellulose from Sphagnum fuscum peat significantly. There is, however, a (quasi-) constant offset between the isotope values of branches and stems and between whole plant material and α-cellulose, which makes it crucial to select single moss-fractions when past climate and environmental changes are to be derived from the isotope record. [Copyright &y& Elsevier]

The Dajiuhu Basin at Shennongjia, located within typical East Asian Monsoon region, preserves a sub-alpine sphagnum peat deposition in its central area. The topmost 120 cm of the peat covers the last 4000 years according to AMS 14C dating of pollen concentration. Carbon isotope of a-cellulose, extracted from sphagnum peat, provides a quantitative reconstruction of atmospheric relative humidity, based on transfer functions of C3 plants carbon isotopic fractionation equation and the bryophyte photosynthesis CO2 absorption rate equation. δ13C, TOC and C/N variations reveal that the Dajiuhu area has experienced a long-term tendency to dry during 4000-1000 aBP, with a major transition happening around 3000 aBP. Four relative dry events are identified at 3400-3200, 3000-2600, 2200-2000 and 1600-1400 aBP, respectively, corresponding to those climate events documented in many global records. Three periodicities, 664 a, 302 a and 277 a enclosed in the atmospheric humidity of Dajiuhu are correlated to the cycles of solar activities. The weakening of East Asia summer monsoon during this period registered in the Dajiuhu peat is consistent with the synchronous weakening of Indian Monsoon. This trend may be attributed to gradual decrease of Northern Hemispheric summer solar insolation and the consequently southward migration of Intertropical Convergent Zone (ITCZ). [ABSTRACT FROM AUTHOR]

Sphagnum peat has been found to efficiently remove heavy metals, oil, detergents, dyes, pesticides and nutrients from contaminated waters since its major constituents, i.e., unesterified polyuronic acids, cellulose, and fulvic and humic acids (HA), show functional groups (e.g., alcohols, aldehydes, carboxylic acids, ketones and phenolic hydroxides) which may adsorb pollutant species. The influence of the extractant on the analytical characteristics of HA is an old but still open topic that should be studied in relation to the nature of the matrix from which they originate. While a number of works have been published on the effects of different reagents on the extraction yields and structural properties of HA from soils, relatively little attention has been devoted to peat HA. In this work, the contents of some major and trace elements (As, Ca, Cr, K, Mn, Sr, and Ti) in five Sphagnum-peat samples and in their corresponding HA fractions isolated using three common extractant solutions, i.e., 0.5M NaOH, 0.1M Na4P2O7, and 0.5M NaOH+0.1M Na4P2O7, where investigated by X-ray fluorescence spectroscopy. In general, Cr, Mn, and Ti concentrations of bulk peat samples were higher than those of the corresponding HA fractions regardless of the extractant used. Arsenic, Ca, K, and Sr concentrations in the HA fractions were affected by the extraction procedure, although at different extents depending on the extractant utilized. In particular, compared to both NaOH and NaOH+Na4P2O7, the Na4P2O7 extractant yielded HA generally richer in As, Ca, K, and Sr, and poorer in Ti. These results may be related to both the nature of each HA fraction and the physical and chemical form of each element supplied to the studied bog via atmospheric deposition. [Copyright &y& Elsevier]