Microbial respiration and biomass in soil of a lodgepole pine stand acidified with elemental sulphur

1989 ◽  
Vol 19 (8) ◽  
pp. 955-961 ◽  
Author(s):  
S. Visser ◽  
D. Parkinson
Keyword(s):  
Microbial Biomass ◽  
Soil Ph ◽  
Glucose Utilization ◽  
Microbial Respiration ◽  
Mineral Soil ◽  
Rocky Mountain ◽  
Dry Weight ◽  
Elemental Sulphur ◽  
Utilization Patterns ◽  
Time Required

A study was conducted to determine the effects of elemental sulphur (So) dust pollution on pH, microbial respiration and biomass, glucose mineralization dynamics, and selected soil chemical characteristics in the organic and mineral soil of a Pinuscontorta Dougl. stand near Rocky Mountain House, Alberta. Six sampling sites were established 50 to 750 m downwind of a So block located at a sour gas processing facility. The sites represented a gradient in sulphur (S) concentrations (1072 to 35 800 μg•(g soil)−1) and pH (4.9 to 1.6). In the organic horizon, So dust significantly reduced the pH from a mean of 4.1 to 2.3 and microbial biomass from 753 to 130 mg C•(100 g dry weight soil)−1. Increasing acidification also reduced total Ca, Mg, K, Mn, and P. A reduction in the cations, P, and microbial biomass was particularly evident at a soil pH below 3.3. Glucose mineralization patterns were altered as a result of acidification. The time required by the soil microbial biomass to attain maximum CO2 efflux following glucose enrichment increased from 11 h in the least acidified soil (pH 4.1) to 38 h in the most acidified soil (pH 2.3). Soil respiration was not significantly affected by soil acidification. Microbial biomass was highly correlated with pH. The mineral soil demonstrated a decreasing trend in pH (5.0 to 3.7) with increasing S levels (79 to 499 μg•(g dry weight soil)−1), but no significant effects on respiration and biomass were detected. However, glucose utilization patterns revealed a tendency towards a slower responding and less efficient biomass with increasing acidity. The time to reach maximum CO2 efflux following glucose enrichment increased from 14 h in the least acidified site (pH 5.0) to 26 h in the most acidified site (pH 3.7). The use of biomass measurements coupled with glucose utilization patterns for providing insight into the effects of pollutant stress on soil microorganisms is discussed.

Effect of timber harvesting on microbial biomass fluxes in a northern Rocky Mountain forest soil

1986 ◽  
Vol 16 (5) ◽  
pp. 1076-1081 ◽  
Author(s):  
James A. Entry ◽  
Nellie M. Stark ◽  
Howard Loewenstein
Keyword(s):  
Microbial Biomass ◽  
Snow Cover ◽  
Forest Soil ◽  
Soil Ph ◽  
Rocky Mountain ◽  
Timber Harvesting ◽  
Soil Microbial Activity ◽  
Mountain Forest ◽  
Clear Cut ◽  
Soil Temperatures

Microbial biomass and relative bacterial and fungal percentages were measured in organic forest soil from a Rocky Mountain site subjected to four harvesting treatments: RL, clear-cut and residue left; RR, clear-cut and residue removed; RB, clear-cut and residue burned; C, uncut control. Microbial biomass peaked in spring and fall regardless of treatment. Biomass in soil from the RB treatment was significantly (p < 0.05) less than that in soil from the other treatments most of the year; biomass did not significantly differ in soil from the RR and C treatments. During summer and winter, microbial biomass in soil from the RL treatment was significantly greater than that in soil from any other treatment, probably because of the large amount of organic residue left after harvest; moreover, this residue insulated the soil, preventing it from drying or freezing. At soil temperatures above 5 °C, microbial biomass correlated positively with soil moisture regardless of treatment; at soil temperatures below 2.5 °C, microbial biomass correlated positively with increasing soil temperature. During periods with snow cover, bacterial and fungal percentages were roughly equal regardless of treatment; during the rest of the year, bacterial percentages were high in the RL and RB treatments and low in the RR and C treatments. During periods without snow cover, bacterial and fungal percentages correlated positively with increasing soil pH; however, at near-freezing temperatures the percentage of bacteria and fungi seemed unaffected by soil pH. These findings suggest that treatments that remove a large portion of available site nutrients while reducing soil microbial activity could limit stand development.

Soil acidity in 1970 and 1989 in a coniferous forest in southwest Finland

1998 ◽  
Vol 78 (3) ◽  
pp. 477-479 ◽  
Author(s):  
C. J. Westman ◽  
S. Jauhiainen
Keyword(s):  
Key Words ◽  
Soil Ph ◽  
Soil Acidity ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Soil Layers ◽  
Water Suspension ◽  
Ph Values ◽  
Humus Layer ◽  
Repeated Sampling

Forest soil pH in southwest Finland was measured with identical sampling and analysing methods in 1970 and 1989. The acidity of the organic humus layer increased significantly as pH values measured on water and on salt suspensions decreased between the two sampling dates. For the mineral soil layers, no unambiguous trend was found. pH values measured on salt suspension tended to be unchanged or lower, while pH on water suspension in some soil layers were even higher in 1989 than in 1970. Key words: pH, repeated sampling

scholarly journals MICROBIAL ACTIVITY AND MYCORRHIZAL POTENTIAL OF FOUR OVERBURDEN TYPES USED IN THE RECLAMATION OF EXTRACTED OIL SANDS

1983 ◽  
Vol 63 (2) ◽  
pp. 363-375 ◽  
Author(s):  
R. M. DANIELSON ◽  
S. VISSER ◽  
D. PARKINSON
Keyword(s):  
Microbial Biomass ◽  
Microbial Activity ◽  
Plant Species ◽  
Oil Sands ◽  
Microbial Respiration ◽  
Bottom Layer ◽  
Jack Pine ◽  
Litter Bags ◽  
Mycorrhizal Development ◽  
Slender Wheatgrass

Slender wheatgrass and jack pine were grown in the greenhouse in cores containing a bottom layer of extracted oil sands with four overburdens individually layered over the sand. The overburdens included a muskeg peat, two shallow mineral overburdens and a deep overburden. Mycorrhizal development, microbial respiration and biomass and the degree of decomposition of slender wheatgrass roots in litter bags were determined in each plant species-overburden combination. Both ecto- and vesicular-arbuscular (VA) mycorrhizal inoculum was present in all four overburdens. The symbionts of slender wheatgrass were the "fine endophyte" and Glomus aggregatum. VA development was very low in peat whereas plants in the shallow overburdens became heavily mycorrhizal. Infection did not spread from the overburden layer to roots in the tailing sand. Jack pine roots in the peat and two shallow overburdens were heavily infected after 4 months. The most common symbiont was an ascomycete known as the E-strain. Microbial respiration was highest in the peat and was not influenced by plant species. Microbial biomass was also highest in the peat and much lower in the mineral overburdens. Only in the peat was the amount of microbial biomass larger with slender wheatgrass than with jack pine. Slender wheatgrass roots decomposed most rapidly in the peat overburden and least rapidly in the deep overburden. Key words: Microbial activity, jack pine, slender wheatgrass, mycorrhizae, reclamation, oil sands

scholarly journals The Influence of Selected Meteorological Factors on Microbial Biomass and Mineralization of Two Organic Fertilizers

2011 ◽  
Vol 39 (1) ◽  
pp. 107
Author(s):  
Mignon S. SANDOR ◽  
Traian BRAD ◽  
Aurel MAXIM ◽  
Constantin TOADER
Keyword(s):  
Biological Activity ◽  
Microbial Biomass ◽  
Soil Ph ◽  
Soil Microbial Biomass ◽  
Organic Fertilizers ◽  
Barley Straw ◽  
Short Term ◽  
Soil Microbial ◽  
Fertilized Soil ◽  
Mineralization Processes

A mesocosm study was conducted in order to evaluate the effects of short-term rainfall and temperature variation on soil microbial biomass and bacteria to fungi ratio. In addition, the relation between the decomposition process of two organic fertilizers, cattle manure and barley straw, and the activity of soil microbial biomass was also studied. In order to assess the effect of biological activity on soil fertility the dynamics of soil pH, N-NO3-, N-NH4+, Corg and Nt during plant growing season was measured. The results suggest that short-term variation of climate had a significant effect on microbial biomass with dry periods distinguished by a reduced microbial biomass compared to wet periods. The ratio bacteria to fungi seems also to be sensitive to variations in rainfall and temperature regime, however further studies are required to draw a definitive conclusion. Regarding the type of fertilizer used, the straw treatments showed higher microbial biomass than the manure treatments, but higher decomposition rate was observed in manure fertilized soil. The effect of soil biological activity on soil pH was limited for both manure and straw treatments while the changes of the soil nitrate amounts are related to the microbial biomass. The study indicates that nitrate immobilization and mineralization processes are influenced by meteorological conditions and microbial biomass dynamics. In contrast, soil organic carbon and total nitrogen did not seem to be affected by variations in temperature, rainfall and microbial activity.

Long-term effects of fire on the composition and activity of the soil microflora of a subalpine, coniferous forest

1980 ◽  
Vol 58 (15) ◽  
pp. 1704-1721 ◽  
Author(s):  
J. Bissett ◽  
D. Parkinson
Keyword(s):  
Microbial Biomass ◽  
Bacterial Flora ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Soil Microflora ◽  
Subalpine Forest ◽  
Long Term Effects ◽  
Soil Horizons ◽  
Cellulose Decomposition ◽  
Soil Temperatures

The biomass, community composition, and metabolic activity of soil microorganisms were studied in adjacent burnt and unburnt areas of spruce–fir subalpine forest razed 6 years previously by a moderately severe natural fire. Similar levels of microbial biomass were observed at comparable burnt and unburnt sites, although the ratio of fungal to bacterial biomass was higher in the unburnt soils. The decreased acidity of the surface horizons in the burn probably tended to favor the development of a bacterial flora rather than a fungal flora. Microbial biomass in the burnt sites peaked earlier in the season than in the unburnt sites in response to the warmer soil temperatures and earlier thaw in the spring in the burn area.Significant differences in the species composition of the mycoflora in the organic soil horizons were observed between the burnt and unburnt sites. Apparently, these were related to qualitative differences in the recent litter. Phoma, Cladosporium, and Botrytis, which are usually associated with early stages of decomposition of herbaceous litter, were more common in the burnt soil. The mycoflora of the mineral soil horizons varied considerably from one burn site to another, possibly reflecting the geographical variation in the intensity of the burn. In overall composition, however, the mycoflora in the mineral soil horizons of the burn was not appreciably different from that of the unburnt sites.Higher laboratory rates of respiration and cellulose decomposition were observed for soil samples from the undisturbed forest. However, the rate of decomposition of cellulose in the field was much higher in the burnt sites, probably as a result of the higher soil temperatures in the burn area. Low soil temperature was concluded to be the main factor limiting microbial activities in the study area, and the removal of the insulating plant canopy and increased heat absorption by the ash in the burn area were found to increase decomposition rates, at least at this stage in the succession following the disturbance of fire.

scholarly journals Determination of critical pH and Al concentration of acidic Ultisols for wheat and canola crops

2016 ◽  
Author(s):  
Abdulaha-Al Baquy ◽  
Jiu-Yu Li ◽  
Chen-Yang Xu ◽  
Khalid Mehmood ◽  
Ren-Kou Xu
Keyword(s):  
Soil Ph ◽  
Crop Production ◽  
Soil Acidity ◽  
Production Systems ◽  
Southern China ◽  
Chemical Properties ◽  
Dry Weight ◽  
Hydrated Lime ◽  
Dry Land

Abstract. Soil acidity has become a serious constraint in dry land crop production systems of acidic Ultisols in tropical and subtropical regions of southern China, where winter wheat and canola are cultivated as important rotational crops. Regardless of other common existing concerns in acidic Ultisols of southern China, it needs to be investigated whether soil acidity has any effect on wheat and canola growth. There is little information on the determination of critical soil pH as well as aluminium (Al) concentration for wheat and canola crops. The objective of this study was to determine the critical soil pH and exchangeable aluminium concentration (AlKCl) for wheat and canola production. Two pot cultures with two Ultisols from Hunan and Anhui were conducted for wheat and canola crops in a controlled growth chamber, with a completely randomized design. A soil pH gradient ranging from 3.7 (Hunan) and 3.97 (Anhui) to 6.5, with three replications, was used as a treatment. Aluminium sulfate (Al2(SO4)3) and hydrated lime (Ca(OH)2) were used to obtain the target soil pH levels. Plant height, shoot dry weight, root dry weight, and chlorophyll content (SPAD value) of wheat and canola were adversely affected by soil acidity in both locations. The critical soil pH and AlKCl of the Ultisol from Hunan for wheat were 5.29 and 0.56 cmol kg−1, respectively. At Anhui, the threshold soil pH and AlKCl for wheat were 4.66 and 2.36 cmol kg−1, respectively. On the other hand, the critical soil pH for canola was 5.65 and 4.87 for the Ultisols from Hunan and Anhui, respectively. The critical soil exchangeable Al for canola cannot be determined from the experiment of this study. The results suggested that the critical soil pH and AlKCl varied between different locations for the same variety of crop, due to the different soil types and their other soil chemical properties. The critical soil pH for canola was higher than that for wheat for both Ultisols, thus canola was more sensitive to soil acidity. Therefore, we recommend that liming should be undertaken to increase soil pH if it falls below these critical soil pH levels for wheat and canola production.

Growth, Fruit Yield, Photosynthetic Characteristics, and Leaf Microelement Concentration of Two Blueberry Cultivars under Different Long-Term Soil pH Treatments

Agronomy ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 357 ◽  
Author(s):  
Yanqin Jiang ◽  
Qilong Zeng ◽  
Jiguang Wei ◽  
Jiafeng Jiang ◽  
Yajing Li ◽  
...  
Keyword(s):  
Soil Ph ◽  
Photochemical Efficiency ◽  
Dry Weight ◽  
Photosynthetic Characteristics ◽  
Fruit Yield ◽  
Downward Trend ◽  
Branch Number ◽  
Plant Weight ◽  
High Ph ◽  
Flowering Date

Soil pH is a key factor affecting the growth of blueberries. Understanding the response mechanism of blueberries to different pH values and selecting suitable evaluation indexes are the basis of breeding new blueberry cultivars with high pH tolerances. The effects of different soil pH treatments for 17 months on the plant growth, fruit yield, photosynthetic characteristics, and leaf microelement concentration of Vaccinium ashei Reade ‘Climax’ and V. corymbosum hybrid ‘Chaoyue No. 1′ were studied. Plant height, main stem diameter, branch number per plant, leaf dry weight, stem dry weight, root dry weight, and total dry weight decreased with increasing soil pH. With an increase in soil pH, the first flowering date, 50% flowering date, first ripening date, and 50% ripening date of the two cultivars were postponed, and the flower bud numbers per plant, the floret numbers per bud, and yield per plant showed a downward trend. Moreover, the fruit quality decreased, which was reflected in the increase in the titratable acid content (TA) and the decrease in the total soluble solids content (TSS) and the TSS:TA ratio in the high pH treatment. With increasing soil pH, the chlorophyll content index (CCI), maximal photochemical efficiency of the PSII (Fv/Fm), quantum photosynthetic yield of the PSII (Y(II)) and net photosynthetic rate (Pn) of the two cultivars showed a downward trend, and some microelement concentrations in the leaves were imbalanced. Under high pH treatment, ‘Chaoyue No. 1′ had a relatively higher plant biomass and fruit yield, so it had a stronger tolerance to high pH than ‘Climax’ did. More strongly acidified rhizosphere soil capacity, as well as higher CCI, Fv/Fm, Y(II), and Pn values were the main reasons for the high pH tolerance of ‘Chaoyue No. 1′. Compared with destructive biomass indicators such as plant weight, nondestructive indicators such as CCI, Fv/Fm, and Y(II) can be more valuable indicators for fast and accurate evaluation of blueberry tolerance to high pH at early stages of treatment.

Effects of Soil pH on Competitive Ability and Leaf Nutrient Content of Corn (Zea maysL.) and Three Weed Species

Weed Science ◽  
1985 ◽  
Vol 33 (4) ◽  
pp. 447-451 ◽  
Author(s):  
Susan E. Weaver ◽  
Allan S. Hamill
Keyword(s):  
Soil Ph ◽  
Competitive Ability ◽  
Leaf Tissue ◽  
Dry Weight ◽  
Nutrient Content ◽  
Setaria Viridis ◽  
Weed Species ◽  
Field Corn ◽  
Green Foxtail ◽  
Companion Plant

Effects of soil pH on growth, competitive ability, and leaf nutrient content of corn (Zea maysL.), Powell amaranth (Amaranthus powelliiS. Wats. ♯ AMAPO), velvetleaf (Abutilon theophrastiMedic. ♯ ABUTH), and green foxtail [Setaria viridis(L.) Beauv. ♯ SETVI] were measured in the field. Corn yields were significantly reduced by weed competition at all pH levels, but leaf nutrient content, as a percentage of dry weight, was not affected. Aboveground dry weights of Powell amaranth and velvetleaf were significantly lower at pH 4.8 than at pH 6.0 or 7.3, whereas growth of green foxtail was greater at pH 4.8 than at pH 7.3. Weed competitive ability, as evidenced by reductions in dry weight, varied with soil pH and companion plant. Powell amaranth and velvetleaf had higher levels of S, Zn, and especially Mn, at pH 4.8 than at pH 7.3. N and K in the leaf tissue were greater in the weed species than in corn at all soil pH levels. The dicot species had higher percentages of Ca and Mg in leaf tissue at all soil pH levels and accumulated higher percentages of Mn at low pH than the monocot species.

scholarly journals Accumulation of Norfloxacin byBacteroides fragilis

2000 ◽  
Vol 44 (9) ◽  
pp. 2361-2366 ◽  
Author(s):  
Vito Ricci ◽  
Laura J. V. Piddock
Keyword(s):  
Dry Weight ◽  
Aerobic Bacteria ◽  
External Concentration ◽  
Low Concentrations ◽  
Carbonyl Cyanide ◽  
The Mean ◽  
Time Required ◽  
State Concentration ◽  
Anaerobic Environment ◽  
Burk Plot

ABSTRACT The accumulation of norfloxacin by Bacteroides fragilisNCTC 9343 was determined by the modified fluorescence method. The time required to achieve a steady-state concentration (SSC) after allowingB. fragilis to accumulate norfloxacin in an aerobic or an anaerobic environment was ∼2 min; the SSC achieved in air was 90.28 ± 9.32 ng of norfloxacin/mg (dry weight) of cells, and that achieved anaerobically was 98.45 ± 3.7 ng of norfloxacin/mg (dry weight) of cells. Initial rates of accumulation were determined with a range of external concentrations, as up to 8 μg/ml the concentration of norfloxacin accumulated increased proportionally to the external concentration, 12.13 ng/mg (dry weight) of cells per μg of exogenous norfloxacin per ml. At concentrations above 10 μg/ml no increase in the rate of norfloxacin accumulation was observed. From the kinetic data, a Lineweaver-Burk plot calculated a Km of 5.03 μg/ml and a V max of 25.1 ng of norfloxacin/s. With an increase in temperature of between 0 and 30°C, the concentration of norfloxacin accumulated also increased proportionally at 4.722 ng of norfloxacin/mg (dry weight) of cells/°C. At low concentrations of glucose (<0.2%; 11 mM), the concentration of norfloxacin accumulated was decreased. With the addition of 100 μM carbonyl cyanidem-chlorophenylhydrazone (CCCP) the mean SSC of norfloxacin was increased to 116 ± 7.01 ng of norfloxacin/mg (dry weight) of cells; glucose had no significant effect in the presence of CCCP. Magnesium chloride (20 mM) decreased the SSC of norfloxacin to 40.5 ± 3.76 ng of norfloxacin per mg (dry weight) of cells. These data suggest that the mechanism of accumulation of norfloxacin byB. fragilis is similar to that of aerobic bacteria and that the fluoresence procedure is suitable for use with an anaerobic bacterium.

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