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William H Schlesinger - One of the best experts on this subject based on the ideXlab platform.
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nutrient limitations to soil Microbial Biomass and activity in loblolly pine forests
Soil Biology & Biochemistry, 2004Co-Authors: A S Allen, William H SchlesingerAbstract:We performed an assay of nutrient limitations to soil Microbial Biomass in forest floor material and intact cores of mineral soil collected from three North Carolina loblolly pine (Pinus taeda) forests. We added solutions containing C, N or P alone and in all possible combinations, and we measured the effects of these treatments on Microbial Biomass and on Microbial respiration, which served as a proxy for Microbial activity, during a 7-day laboratory incubation at 22 °C. The C solution used was intended to simulate the initial products of fine root decay. Additions of C dramatically increased respiration in both mineral soil and forest floor material, and C addition increased Microbial Biomass C in the mineral soil. Additions of N increased respiration in forest floor material and increased Microbial Biomass N in the mineral soil. Addition of P caused a small increase in forest floor respiration, but had no effect on Microbial Biomass.
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factors determining soil Microbial Biomass and nutrient immobilization in desert soils
Biogeochemistry, 1995Co-Authors: Antonio Gallardo, William H SchlesingerAbstract:We examined the 10-day response of soil Microbial Biomass-N to additions of carbon (dextrose) and nitrogen (NH4NO3) to water-amended soils in a factorial experiment in four plant communities of the Chihuahuan desert of New Mexico (U.S.A.). In each site, Microbial Biomass-N and soil carbohydrates increased and extractable soil N decreased in response to watering alone. Fertilization with N increased Microbial Biomass-N in grassland soils; whereas, fertilization with C increased Microbial Biomass-N and decreased extractable N and P in all communities dominated by shrubs, which have invaded large areas of grassland in the Chihuahuan desert during the last 100 years. Our results support the hypothesis that the control of soil Microbial Biomass shifts from N to C when the ratio of C to N decreases during desertification.
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Carbon and nitrogen limitations of soil Microbial Biomass in desert ecosystems
Biogeochemistry, 1992Co-Authors: Antonio Gallardo, William H SchlesingerAbstract:Microbial Biomass nitrogen was measured in unamended (dry) and wetted soils in ten shrubland and grassland communities of the Chihuahuan desert, southern New Mexico, by the fumigation-extraction method. Microbial Biomass-N in dry soils was undetectable. Average Microbial Biomass-N in wetted soils among all plant communities was 15.3 μg g^-1 soil. Highest values were found in the communities with the lowest topographic positions, and the minimum values were detected in the spaces between shrubs. Microbial Biomass was positively and significantly correlated to soil organic carbon and extractable nitrogen (NH_4 ^+ + NO_3 ^-). In a stepwise multiple regression, organic carbon and extractable nitrogen accounted for 40.9 and 5.6%, respectively, of the variance in Microbial Biomass-N among all the samples. Among communities, the soil Microbial Biomass was affected by the ratio of carbon to extractable nitrogen. Our results suggest a succession in the control of Microbial Biomass from nitrogen to carbon when the ratio of carbon to nitrogen decreases during desertification.
Tadao Ando - One of the best experts on this subject based on the ideXlab platform.
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Minimum available N requirement for Microbial Biomass P formation in a regosol
Soil Biology and Biochemistry, 1999Co-Authors: Kenji Kouno, Hasta Pratopo Lukito, Tadao AndoAbstract:A soil incubation experiment was conducted to determine the effects of N application on Microbial Biomass C and P and to estimate the minimum requirement of available N for Microbial Biomass P formation. A granitic regosol soil was amended with N (as (NH4)2SO4) at rates of 0, 200, 400 or 800 mg N kg−1, C (as rice straw) at 2100 mg C kg−1 and P (as KH2PO4) at 500 mg P kg−1 soil. With increasing N application up to 200 mg N kg−1 soil, Microbial Biomass C significantly increased and remained constant or slightly decreased at higher N rates, while Microbial Biomass P increased up to 400 mg N kg−1 soil and remained constant or slightly increased at the highest N contents. The concentration of P in Microbial Biomass (assuming that dry Biomass contained 50% C) increased with increasing N rate and ranged from 32 to 76 mg g−1. Among the P fractions in soil, Microbial Biomass P and inorganic P (available P) fractions increased with increasing N rates, whilst the Ca–P fraction decreased. The critical P concentration in Microbial Biomass (defined as that required to achieve 80% of the maximum synthesis of Microbial Biomass C) was estimated to be 60±4.1 mg P g−1 Biomass. The corresponding minimum amount of available N in the soil required to increase the Biomass was estimated as 425±12 mg N kg−1 soil. The specific respiration of the Microbial Biomass was little affected by the N concentration and was very high even above an N concentration considered to be the optimum for Microbial Biomass C and P but also Microbial activity.
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Phosphorus requirements of Microbial Biomass in a regosol and an andosol
Soil Biology and Biochemistry, 1998Co-Authors: Hasta Pratopo Lukito, Kenji Kouno, Tadao AndoAbstract:Abstract The critical P concentration in Microbial Biomass (defined as that required to achieve 80% of the maximum synthesis of Microbial Biomass C) and minimum amount of available P to obtain the critical P concentration in the Microbial Biomass of a granitic regosol and an andosol of Japan were examined. Phosphorus was applied as KH2PO4 at rates of 0, 25, 50, 200 and 400 mg P kg−1 soil to a regosol and 0, 25, 100, 400 and 800 mg P kg−1 to an andosol together with 2000 mg C (rice straw) and 200 mg N (ammonium sulphate) kg−1. With increasing P application, the available P in soil markedly increased in the regosol and gradually increased in the andosol. The amount of Microbial Biomass C and P increased with available P up to 76 and 29 mg P kg−1 in the regosol and andosol, respectively, and either remained constant or was slightly decreased at a higher available P value. The concentration of P in the Microbial Biomass was higher in the regosol (29 to 89 mg P g−1) than in the andosol (13 to 32 mg P g−1), assuming that 1 g of dry Biomass contained 0.5 g C. The Microbial Biomass C to P ratio was higher in the andosol (16 to 38) than in the regosol (6 to 17). The critical P concentration in Microbial Biomass was estimated to be 62 mg P g−1 Biomass in the regosol and 19 mg P g−1 in the andosol. The corresponding minimum value of available P in soil to increase Microbial Biomass was estimated as 38 and 6 mg P kg−1 soil in the regosol and andosol, respectively. The specific respiration of Microbial Biomass was also very high at those P concentrations which were considered optimum in both soils to increase not only the amount of Microbial Biomass C and P but also Microbial activity. These were 38 mg P kg−1 soil in the regosol and 6 mg P kg−1 soil in the andosol.
Fusuo Zhang - One of the best experts on this subject based on the ideXlab platform.
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Soil Microbial Biomass as affected by non-flooded plastic mulching cultivation in rice
Biology and Fertility of Soils, 2006Co-Authors: Limei Zhao, Qiao-lan Fan, Fusuo ZhangAbstract:The long-term field experiments were initiated in 2001 on five sites in Zhejiang province of China to monitor the impacts of non-flooded plastic mulching management on rice soil Microbial Biomass for sustainable agro-ecosystem. The three treatments were plastic film mulching with no flooding (PM), no plastic film mulching and no flooding (UM), and the traditional flooding management (TF). Microbial Biomass C accounted for 0.3–2.4% of the soil total organic C, Microbial Biomass N for 0.79–4.3% of the soil total N, and Microbial Biomass P for 0.1–1.6% of the soil total P. Three years of non-flooded plastic film mulching reduced Microbial Biomass C and N and increased Microbial Biomass P in rice soil.
Markus Raubuch - One of the best experts on this subject based on the ideXlab platform.
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Adenylates in the soil Microbial Biomass at different temperatures
Soil Biology and Biochemistry, 2003Co-Authors: Rainer Georg Joergensen, Markus RaubuchAbstract:Abstract Five soils from temperate sites (Germany; 2 arable and 3 grassland) were incubated aerobically at 5, 10, 15, 20, 25, 35, and 40 °C for 8 days. Soils were analysed for soil Microbial Biomass C, Biomass N, AMP, ADP, and ATP to determine whether the increase in the ATP-to-Microbial Biomass C ratio with increasing temperature was either due to an increase in the adenylate energy charge (AEC) or de novo synthesis of ATP, or both. Around 80% of the variance in Microbial Biomass C and Biomass N was explained by differences in soil properties, only 7% by the temperature treatments. Averaging the data of all 5 soils for each incubation temperature, the Microbial Biomass C content decreased with increasing temperature from 15 to 40 °C continuously by 2.5 μg g −1 soil °C −1 after 8-days' incubation. However, this decrease was not accompanied by a similar decrease in Microbial Biomass N. The average Microbial Biomass C/N ratio was 6.8. Between 54 and 76% of the variance in AMP, ADP, ATP and the sum of adenylates was explained by differences in soil properties and between 14 (ADP) and 27% (ATP) by the temperature treatments. However, temperature effects on AMP and ADP were variable and inconsistent. In contrast, ATP and consequently also the sum of adenylates increased continuously from 5 to 30 °C followed by a decline to 40 °C. The AEC showed similarly a small, but significant increase with increasing temperature from 0.73 to 0.85 at 30 °C. Consequently, the majority of the variance, i.e. roughly 60% in AEC values, but also in ATP-to-Microbial Biomass C ratios was explained by the incubation temperature. The mean ATP-to-Microbial Biomass C ratio increased from 4.7 μmol g −1 at 5 °C to a 2.5 fold maximum of 12.0 μmol g −1 at 35 °C. This increase was linear with a rate of 0.26 μmol ATP g −1 Microbial Biomass C °C −1 . The energy for the extra ATP produced during temperature increase is probably derived from an accelerated turnover of endocellular C reserves in the Microbial Biomass.
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Adenylates as an estimate of Microbial Biomass C in different soil groups
Soil Biology and Biochemistry, 2003Co-Authors: Jens Dyckmans, Rainer Georg Joergensen, Markus Raubuch, Krishan Chander, Jörg Priess, Ulrike SehyAbstract:Abstract Adenylate (i.e. adenosine tri- (ATP), di- (ADP) and monophosphates (AMP)) and Microbial Biomass C data were collected over a wide range of sites including forest floor layers and forest, grassland and arable soils. Microbial Biomass C was measured by fumigation extraction and adenylates after alkaline Na 3 PO 4 /DMSO/EDTA extraction and HPLC detection. Our aims were (1) to test whether the sum of adenylates is a better estimate for Microbial Biomass than the determination of ATP, (2) to compare our conversion values with those proposed by others, and (3) to analyse whether soil properties or land use form affect the relationships between ATP, adenylates and Microbial Biomass C. A close relationship was found between Microbial Biomass C and ATP ( r =0.96), but also with the sum of adenylates ( r =0.96) within all appropriately conditioned soil samples ( n =112). In the mineral soil ( n =98), the geometric means of the ATP-to-Microbial Biomass C ratio and the adenylates-to-Microbial Biomass C ratio were 7.4 and 11.4 μmol g −1 , respectively. The mean ratios did not differ significantly between the different texture classes and land use forms. In the forest floor, the ATP-to-Microbial Biomass C ratio and the adenylates-to-Microbial Biomass C ratio were both roughly two-thirds of those of the mineral soil. The average adenylate energy charge (AEC) of all soil samples was 0.79 and showed a strong negative relationship with the soil pH ( r =−0.69). However, the AEC is presumably only indirectly affected by the soil pH.
Rainer Georg Joergensen - One of the best experts on this subject based on the ideXlab platform.
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Determination of Microbial Biomass and fungal and bacterial distribution in cattle faeces
Soil Biology and Biochemistry, 2011Co-Authors: Daphne Isabel Jost, Rainer Georg Joergensen, Caroline Indorf, Albert SundrumAbstract:Abstract As an important component of organic fertilizers, animal faeces require methods for determining diet effects on their Microbial quality to improve nutrient use efficiency in soil and to decrease gaseous greenhouse emissions to the environment. The objectives of the present study were (i) to apply the chloroform fumigation extraction (CFE) method for determining Microbial Biomass in cattle faeces, (ii) to determine the fungal cell-membrane component ergosterol, and (iii) to measure the cell-wall components fungal glucosamine and bacterial muramic acid as indices for the Microbial community structure. Additionally, ergosterol and amino sugar data provide independent control values for the reliability of the Microbial Biomass range obtained by the CFE method. A variety of extractant solutions were tested for the CFE method to obtain stable extracts and reproducible Microbial Biomass C and N values, leading to the replacement of the original 0.5 M K2SO4 extractant for 0.05 M CuSO4. The plausibility of the data was assessed in a 28-day incubation study at 25 °C with cattle faeces of one heifer, where Microbial Biomass C and N were repeatedly measured together with ergosterol. Here, the Microbial Biomass indices showed dynamic characteristics and possible shifts in the Microbial community. In faeces of five different heifers, the mean Microbial Biomass C/N ratio was 5.6, the mean Microbial Biomass to organic C ratio was 2.2%, and the mean ergosterol to Microbial Biomass C ratio was 1.1‰. Ergosterol and amino sugar analysis revealed a significant contribution of fungi, with a percentage of more than 40% to the Microbial community. All three methods are expected to be suitable tools for analysing the quality of cattle faeces.
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Adenylates in the soil Microbial Biomass at different temperatures
Soil Biology and Biochemistry, 2003Co-Authors: Rainer Georg Joergensen, Markus RaubuchAbstract:Abstract Five soils from temperate sites (Germany; 2 arable and 3 grassland) were incubated aerobically at 5, 10, 15, 20, 25, 35, and 40 °C for 8 days. Soils were analysed for soil Microbial Biomass C, Biomass N, AMP, ADP, and ATP to determine whether the increase in the ATP-to-Microbial Biomass C ratio with increasing temperature was either due to an increase in the adenylate energy charge (AEC) or de novo synthesis of ATP, or both. Around 80% of the variance in Microbial Biomass C and Biomass N was explained by differences in soil properties, only 7% by the temperature treatments. Averaging the data of all 5 soils for each incubation temperature, the Microbial Biomass C content decreased with increasing temperature from 15 to 40 °C continuously by 2.5 μg g −1 soil °C −1 after 8-days' incubation. However, this decrease was not accompanied by a similar decrease in Microbial Biomass N. The average Microbial Biomass C/N ratio was 6.8. Between 54 and 76% of the variance in AMP, ADP, ATP and the sum of adenylates was explained by differences in soil properties and between 14 (ADP) and 27% (ATP) by the temperature treatments. However, temperature effects on AMP and ADP were variable and inconsistent. In contrast, ATP and consequently also the sum of adenylates increased continuously from 5 to 30 °C followed by a decline to 40 °C. The AEC showed similarly a small, but significant increase with increasing temperature from 0.73 to 0.85 at 30 °C. Consequently, the majority of the variance, i.e. roughly 60% in AEC values, but also in ATP-to-Microbial Biomass C ratios was explained by the incubation temperature. The mean ATP-to-Microbial Biomass C ratio increased from 4.7 μmol g −1 at 5 °C to a 2.5 fold maximum of 12.0 μmol g −1 at 35 °C. This increase was linear with a rate of 0.26 μmol ATP g −1 Microbial Biomass C °C −1 . The energy for the extra ATP produced during temperature increase is probably derived from an accelerated turnover of endocellular C reserves in the Microbial Biomass.
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Adenylates as an estimate of Microbial Biomass C in different soil groups
Soil Biology and Biochemistry, 2003Co-Authors: Jens Dyckmans, Rainer Georg Joergensen, Markus Raubuch, Krishan Chander, Jörg Priess, Ulrike SehyAbstract:Abstract Adenylate (i.e. adenosine tri- (ATP), di- (ADP) and monophosphates (AMP)) and Microbial Biomass C data were collected over a wide range of sites including forest floor layers and forest, grassland and arable soils. Microbial Biomass C was measured by fumigation extraction and adenylates after alkaline Na 3 PO 4 /DMSO/EDTA extraction and HPLC detection. Our aims were (1) to test whether the sum of adenylates is a better estimate for Microbial Biomass than the determination of ATP, (2) to compare our conversion values with those proposed by others, and (3) to analyse whether soil properties or land use form affect the relationships between ATP, adenylates and Microbial Biomass C. A close relationship was found between Microbial Biomass C and ATP ( r =0.96), but also with the sum of adenylates ( r =0.96) within all appropriately conditioned soil samples ( n =112). In the mineral soil ( n =98), the geometric means of the ATP-to-Microbial Biomass C ratio and the adenylates-to-Microbial Biomass C ratio were 7.4 and 11.4 μmol g −1 , respectively. The mean ratios did not differ significantly between the different texture classes and land use forms. In the forest floor, the ATP-to-Microbial Biomass C ratio and the adenylates-to-Microbial Biomass C ratio were both roughly two-thirds of those of the mineral soil. The average adenylate energy charge (AEC) of all soil samples was 0.79 and showed a strong negative relationship with the soil pH ( r =−0.69). However, the AEC is presumably only indirectly affected by the soil pH.