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Effects of cadmium and sewage-sludge on soil microbial biomass and enzyme activities
1996
Dar, G.H. | Effects of cadmium and sewage-sludge on soil microbial biomass and enzyme activities.
The effects of Cd and sewage-sludge on microbial biomass and enzyme activities in three soils were studied during two months incubation at 30 +/- 1 degrees C. The sewage-sludge amendment enhanced soil microbial biomass by 8-28%, with the greatest affect in clay-loam and the least in sandy-loam soil. The soil dehydrogenase, alkaline phosphatase and arginine-ammonification activities were enhanced by 18-25, 9-23 and 8-12%, respectively, by sludge. Cadmium addition at 10 micrograms g-1 caused no significant changes in these parameters. However, 50 micrograms Cd g-1 soil detrimentally influenced the soil microbial biomass and enzyme activities; more in sandy-loam than in loam or clay-loam soil. Cadmium adsorption in soils was 31-56%, high in clay-loam and low in sandy-loam soils. A significant negative correlation (r = -0.58* to 0.80*, P less than or equal to 0.05) was observed between DTPA-extractable Cd and microbial biomass. The changes in soil microbial biomass were interpreted as cell death and correlated well with soil dehydrogenase and alkaline phosphatase activities. However, no correlation existed between microbial biomass and arginine-ammonification activity. Sewage-sludge amendment did not mitigate the inhibitory effects of Cd.
Show more [+] Less [-]Influence of soil temperature and precipitation depth on the biomass production of fruiting bodies of macromycetes in a submountain beech forest stand Full text
2007
R. Janík | I. Mihál
Influence of soil temperature and precipitation depth on the biomass production of fruiting bodies of macromycetes in a submountain beech forest stand Full text
2007
R. Janík | I. Mihál
The paper deals with research on the biomass production of fruiting bodies of macromycetes in a submountain beech stand in dependence on selected climatic variables. The study was carried out at the Ecological Experimental Site (EES) Kremnické vrchy (Central Slovakia) in 2003 and 2004. The biomass production of sporocarps on the EES plots in the two study years was different (5.81 kg/ha of fresh biomass of sporocarps in 2003 and 39.95 kg/ha in 2004) due to better ecological and climatic conditions and higher abundance of sporocarps in 2004. It is necessary to mention that these values reflect the overall status of mycocoenoses on the plot. Unfavourable microclimate conditions and poor species composition of beech monocultures can be considered to be the main factors adversely influencing mycocoenoses in forest stands of the kind.
Show more [+] Less [-]Influence of soil temperature and precipitation depth on the biomass production of fruiting bodies of macromycetes in a submountain beech forest stand Full text
2007
Janik, R.,Slovenska Akademia Vied, Zvolen (Slovak Republic). Ustav Ekologie Lesa | Mihal, I.,Slovenska Akademia Vied, Zvolen (Slovak Republic). Ustav Ekologie Lesa
The paper deals with research on the biomass production of fruiting bodies of macromycetes in a submountain beech stand in dependence on selected climatic variables. The study was carried out at the Ecological Experimental Site (EES) Kremnicke vrchy (Central Slovakia) in 2003 and 2004. The biomass production of sporocarps on the EES plots in the two study years was different (5.81 kg/ha of fresh biomass of sporocarps in 2003 and 39.95 kg/ha in 2004) due to better ecological and climatic conditions and higher abundance of sporocarps in 2004. It is necessary to mention that these values reflect the overall status of mycocoenoses on the plot. Unfavourable microclimate conditions and poor species composition of beech monocultures can be considered to be the main factors adversely influencing mycocoenoses in this type of forests.
Show more [+] Less [-]Effect of highly efficient nutrient solution of biogas slurry on yield and quality of vegetables | 板楂娌兼恫ュ绘恫ㄨ浜ч璐ㄤ
2011
Gao Tongguo, China Agricultural University, Beijing (China), College of Biomass Engineering | Chen Nan, China Agricultural University, Beijing (China), College of Biomass Engineering | Li Weiqun, Soil and Fertilizer and Environment and Resource Institute of Heilongjiang Academy of Agricultural Sciences锛Harbin (China)
[Objective] The paper was to study highly efficient utilization of biogas slurry and the effect of highly efficient biogas slurry on vegetables, so as to provide basis for wide and effective application of biogas slurry. [Method] Using secondary aerobic fermentation technology, a small amount of humic acid was added into biogas slurry to enhance the biological activity of biogas slurry. Through greenhouse experiment, the effect of highly efficient nutrient solution of biogas slurry on yield and quality of green pepper, tomato and cucumber was studied. [Result] Compared with control and traditional application of biogas slurry, application of highly efficient nutrient solution of biogas slurry increased the yield of green pepper, tomato and cucumber, and the increase extents were 12.4%, 47.4%, 19.9% and 2.7%, 15.9%, 9.1%, respectively. Compared with traditional application of biogas slurry, application of highly efficient nutrient solution of biogas slurry significantly increased Vc content of green pepper and cucumber with the increase extent of 16.8% and 43.8%, respectively. [Conclusion] Application of highly efficient nutrient solution of biogas slurry can effectively promote the yield of green pepper, tomato and cucumber and change the qualities of vegetables, and significantly enhance the biological activity of biogas slurry.
Show more [+] Less [-]Evaluation of effect of different sterilization methods on soil biomass phosphorus extracted with NaHCO3 Full text
2010
A.A.S. Sinegani | A. Hosseinpur
Evaluation of effect of different sterilization methods on soil biomass phosphorus extracted with NaHCO3 Full text
2010
A.A.S. Sinegani | A. Hosseinpur
Soil microbial biomass is a dynamic force driving soil phosphorus cycling in soils. The temperature, time and method for killing soil organisms in soil biomass P determination are so important factors that affect the results. The aim of this study was to compare some methods of soil sterilization and soil microbial P (Pm) release in extraction with NaHCO3. Five samples of calcareous soils in three replicates were incubated in field capacity and 28°C. The texture of soils differed from loamy sand to sandy loam. They had 10-15% equivalent calcium carbonate, 1-3% organic carbon and 40-90 mg/kg available P content. After 1, 10, 30, and 50 days of incubation a portion of each soil was sterilized by five methods (chloroform fumigation, autoclaving at 121°C for 0.5 h, oven drying at 70°C for 48 h, oven drying at 180°C for 2 h, and ultrasonification). Phosphorus of the sterilized and control soils were extracted with 0.5M NaHCO3 (pH 8.5) and determined spectrophotometrically as blue molybdate-phosphate complexes under partial reduction with ascorbic acid. Results showed that the method of soil sterilization and soil type had significant effects on biomass P estimated in soils (P < 0.01). There were no significant differences between extracted biomass P at chloroform fumigation, autoclaving at 121°C for 0.5 h, and oven drying at 70°C for 48 h. However biomass P was significantly more extracted from soil by oven drying at 180°C for 2 h and by ultrasonification. Fixation of Pm in soil during the extraction period can reduce the precision of biomass P estimates. This effect was more obvious in biomass P determination by fumigation and oven drying at 70°C for 48 h. Biomass P determined by these methods and autoclaving had positive and significant correlations with soil sand contents, respectively due to long sterilization period and temperature. Ultrasonification released more P from these calcareous soils especially at the start of soil incubation. It released higher microbial P and reduced P sorption in soils; biomass P determined by this method compared to other methods had relatively higher correlations with fungi, glumales spore and P solubilizing bacteria numbers in soil.
Show more [+] Less [-]Evaluation of effect of different sterilization methods on soil biomass phosphorus extracted with NaHCO3 Full text
2010
Sinegani, A.A.S. | Hosseinpur, A.
Soil microbial biomass is a dynamic force driving soil phosphorus cycling in soils. The temperature, time and method for killing soil organisms in soil biomass P determination are so important factors that affect the results. The aim of this study was to compare some methods of soil sterilization and soil microbial P (Pm) release in extraction with NaHCO<SUB>3</SUB>. Five samples of calcareous soils in three replicates were incubated in field capacity and 28°C. The texture of soils differed from loamy sand to sandy loam. They had 10–15% equivalent calcium carbonate, 1–3% organic carbon and 40–90 mg/kg available P content. After 1, 10, 30, and 50 days of incubation a portion of each soil was sterilized by five methods (chloroform fumigation, autoclaving at 121°C for 0.5 h, oven drying at 70°C for 48 h, oven drying at 180°C for 2 h, and ultrasonification). Phosphorus of the sterilized and control soils were extracted with 0.5M NaHCO<SUB>3</SUB> (pH 8.5) and determined spectrophotometrically as blue molybdate-phosphate complexes under partial reduction with ascorbic acid. Results showed that the method of soil sterilization and soil type had significant effects on biomass P estimated in soils (<I>P</I> < 0.01). There were no significant differences between extracted biomass P at chloroform fumigation, autoclaving at 121°C for 0.5 h, and oven drying at 70°C for 48 h. However biomass P was significantly more extracted from soil by oven drying at 180°C for 2 h and by ultrasonification. Fixation of Pm in soil during the extraction period can reduce the precision of biomass P estimates. This effect was more obvious in biomass P determination by fumigation and oven drying at 70°C for 48 h. Biomass P determined by these methods and autoclaving had positive and significant correlations with soil sand contents, respectively due to long sterilization period and temperature. Ultrasonification released more P from these calcareous soils especially at the start of soil incubation. It released higher microbial P and reduced P sorption in soils; biomass P determined by this method compared to other methods had relatively higher correlations with fungi, glumales spore and P solubilizing bacteria numbers in soil.
Show more [+] Less [-]Evaluation of effect of different sterilization methods on soil biomass phosphorus extracted with NaHCO3 Full text
2010
Sinegani, A.A.S.,Bu-Ali Sina Univ., Hamedan (Iran Islamic Republic) | Hosseinpur, A.,Shaher-e-Kord Univ. (Iran Islamic Republic)
Soil microbial biomass is a dynamic force driving soil phosphorus cycling in soils. The temperature, time and method for killing soil organisms in soil biomass P determination are so important factors that affect the results. The aim of this study was to compare some methods of soil sterilization and soil microbial P (Pm) release in extraction with NaHCO3. Five samples of calcareous soils in three replicates were incubated in field capacity and 28 deg C. The texture of soils differed from loamy sand to sandy loam. They had 10-15% equivalent calcium carbonate, 1-3% organic carbon and 40-90 mg/kg available P content. After 1, 10, 30, and 50 days of incubation a portion of each soil was sterilized by five methods (chloroform fumigation, autoclaving at 121 deg C for 0.5 h, oven drying at 70 deg C for 48 h, oven drying at 180 deg C for 2 h, and ultrasonification). Phosphorus of the sterilized and control soils were extracted with 0.5M NaHCO3 (pH 8.5) and determined spectrophotometrically as blue molybdate-phosphate complexes under partial reduction with ascorbic acid. The method of soil sterilization and soil type had significant effects on biomass P. There were no significant differences between extracted biomass P at chloroform fumigation, autoclaving at 121 deg C for 0.5 h, and oven drying at 70 deg C for 48 h. However biomass P was significantly more extracted from soil by oven drying at 180 deg C for 2 h and by ultrasonification. Fixation of Pm in soil during the extraction period can reduce the precision of biomass P estimates. This effect was more obvious in biomass P determination by fumigation and oven drying at 70 deg C for 48 h. Biomass P determined by these methods and autoclaving had positive and significant correlations with soil sand contents, respectively due to long sterilization period and temperature. Ultrasonification released more P from these calcareous soils especially at the start of soil incubation. It released higher microbial P and reduced P sorption in soils; biomass P determined by this method compared to other methods had relatively higher correlations with fungi, glumales spore and P solubilizing bacteria numbers in soil.
Show more [+] Less [-]Impact of forest biomass for energy harvesting on soil compaction - Irish case study Full text
2014
J. Pohořalý | R. Klvač | T. Kent | M. Kleibl | E. Coates | B. Horgan
An assessment of soil compaction caused by machinery used in stump and/or logging residue extraction for energy on soils typical of Ireland. We determined unaffected soil conditions and to find the compaction grade after timber harvesting and bundling activities, and to compare those results with stands where timber harvesting was followed by stump extraction for energy. The investigation was carried out in Ireland on three different locations which had a slightly different proportion of stones in their soils. Two of the soils were purely mineral soils, and the third was a mineral soil affected by anthropogenic activities. To ensure comparable results as much as possible, the moisture content of the soil on wet basis was investigated. Each location was purposely treated. Therefore, on each location plots were identified as follows: plots unaffected by operation (reference area), plots after timber harvesting, plots after timber harvesting and bundling operation, and plots after timber harvesting and stump extraction operation. According to the experimental design 40 repetitions on each of the three different treatments were set. The results showed that the compaction of soil occurred on plots after timber harvesting, but there was not a significant difference between compaction grades with and without logging residue bundling operation. However, once the site was extracted of stumps, the soil became too loose and no significant difference was found compared to unaffected soil.
Show more [+] Less [-]BIOMASS-BASED SOIL IN ECOLOGICAL AGRICULTURE: CHARACTERISTICS AND WHEAT GRAINS DEVELOPMENT TRENDS Full text
2022
Ramona Elena TĂTARU-FARMUȘ | Carmen ZAHARIA | Daniela ȘUTEU | Alexandra Cristina BLAGA
BIOMASS-BASED SOIL IN ECOLOGICAL AGRICULTURE: CHARACTERISTICS AND WHEAT GRAINS DEVELOPMENT TRENDS Full text
2022
Ramona Elena TĂTARU-FARMUȘ | Carmen ZAHARIA | Daniela ȘUTEU | Alexandra Cristina BLAGA
The biomass-based soils are used in the ecological agriculture, being already proposed in sustainable organic production systems with reduced costs for assuring the good cropping productivity, and also high quality of the crops. For the elimination of the synthetic inorganic fertilizers’ utilization on soil, the use of certain types of residual biomass in mixture with the reference soil was proposed as they have a positive impact on the adsorption and absorption of nutrients and water for the nutrition of plants. The aim of this paper is to present four mixtures of reference soil and residual biomass, considered as biosoil used as support for development of wheat seeds. These biosoils were characterized in terms of real density, actual and potential pH, content of total organic carbon, humus, exchangeable calcium, total and available nitrogen and phosphorus, and the trends of grain seeds germination and plants growth were registered in association with the evolution of soil pH for a period greater than a month. The results encourage the use of these biosoils (mixtures of soil with residual biomass) as support for plants cropping.
Show more [+] Less [-]Using the sensitivity of biomass production to soil water for physiological drought evaluation Full text
2008
Viliam Novák
Using the sensitivity of biomass production to soil water for physiological drought evaluation Full text
2008
Viliam Novák
The analysis of drought as a phenomenon and the proposal of how to define and quantify the deficiency of water in soil for plants, so called physiological drought, are described. The presented approach is based on the theoretical considerations supported by empirically estimated relationships between the biomass production of a particular plant and the transpiration total of this plant during its vegetation period. This relationship is linear and is valid for particular plant and environmental conditions (nutrition, agrotechnics). Optimal plant production can be reached for maximum seasonal transpiration total, therefore the potential transpiration total corresponds to the maximum possible yield. The transpiration rate lower than the potential one leads to a biomass production decrease. This phenomenon can be used to define the physiological drought, under which the soil water content in the root zone decreases below the so called critical soil water content of limited availability for plants, under which the transpiration rate drops below its potential transpiration rate. Methodology is illustrated on the basis of the results of mathematical modelling of soil water movement in Soil - Plant - Atmosphere system, with loamy soil and maize canopy.
Show more [+] Less [-]Using the sensitivity of biomass production to soil water for physiological drought evaluation Full text
2008
Novák, V.
The analysis of drought as a phenomenon and the proposal of how to define and quantify the deficiency of water in soil for plants, so called physiological drought, are described. The presented approach is based on the theoretical considerations supported by empirically estimated relationships between the biomass production of a particular plant and the transpiration total of this plant during its vegetation period. This relationship is linear and is valid for particular plant and environmental conditions (nutrition, agrotechnics). Optimal plant production can be reached for maximum seasonal transpiration total, therefore the potential transpiration total corresponds to the maximum possible yield. The transpiration rate lower than the potential one leads to a biomass production decrease. This phenomenon can be used to define the physiological drought, under which the soil water content in the root zone decreases below the so called critical soil water content of limited availability for plants, under which the transpiration rate drops below its potential transpiration rate. Methodology is illustrated on the basis of the results of mathematical modelling of soil water movement in Soil – Plant – Atmosphere system, with loamy soil and maize canopy.
Show more [+] Less [-]BIOMASS-BASED SOIL IN ECOLOGICAL AGRICULTURE: CHARACTERISTICS AND WHEAT GRAINS DEVELOPMENT TRENDS Full text
2022
Tătaru-Farmuș, Ramona Elena | Zaharia, Carmen | Șuteu, Daniela | Blaga, Alexandra Cristina
The biomass-based soils are used in the ecological agriculture, being already proposed in sustainable organic production systems with reduced costs for assuring the good cropping productivity, and also high quality of the crops. For the elimination of the synthetic inorganic fertilizers’ utilization on soil, the use of certain types of residual biomass in mixture with the reference soil was proposed as they have a positive impact on the adsorption and absorption of nutrients and water for the nutrition of plants. The aim of this paper is to present four mixtures of reference soil and residual biomass, considered as biosoil used as support for development of wheat seeds. These biosoils were characterized in terms of real density, actual and potential pH, content of total organic carbon, humus, exchangeable calcium, total and available nitrogen and phosphorus, and the trends of grain seeds germination and plants growth were registered in association with the evolution of soil pH for a period greater than a month. The results encourage the use of these biosoils (mixtures of soil with residual biomass) as support for plants cropping.
Show more [+] Less [-]Dominant Plant Functional Group Determine the Response of the Temporal Stability of Plant Community Biomass to 9-Year Warming on the Qinghai–Tibetan Plateau Full text
2021
Chengyang Li | Chengyang Li | Chimin Lai | Chimin Lai | Fei Peng | Fei Peng | Fei Peng | Fei Peng | Xian Xue | Xian Xue | Quangang You | Quangang You | Feiyao Liu | Feiyao Liu | Feiyao Liu | Pinglin Guo | Pinglin Guo | Pinglin Guo | Jie Liao | Tao Wang
Ecosystem stability characterizes ecosystem responses to natural and anthropogenic disturbance and affects the feedback between ecosystem and climate. A 9-year warming experiment (2010–2018) was conducted to examine how climatic warming and its interaction with the soil moisture condition impact the temporal stability of plant community aboveground biomass (AGB) of an alpine meadow in the central Qinghai-Tibetan Plateau (QTP). Under a warming environment, the AGB percentage of grasses and forbs significantly increased but that of sedges decreased regardless of the soil water availability in the experimental plots. The warming effects on plant AGB varied with annual precipitation. In the dry condition, the AGB showed no significant change under warming in the normal and relatively wet years, but it significantly decreased in relatively drought years (16% in 2013 and 12% in 2015). In the wet condition, the AGB showed no significant change under warming in the normal and relatively drought years, while it significantly increased in relatively wet years (12% in 2018). Warming significantly decreased the temporal stability of AGB of plant community and sedges. Species richness remained stable even under the warming treatment in both the dry and wet conditions. The temporal stability of AGB of sedges (dominant plant functional group) explained 66.69% variance of the temporal stability of plant community AGB. Our findings highlight that the temporal stability of plant community AGB is largely regulated by the dominant plant functional group of alpine meadow that has a relatively low species diversity.
Show more [+] Less [-]Plant Communities, Soil Carbon, and Soil Nitrogen Properties in a Successional Gradient of Sub-Alpine Meadows on the Eastern Tibetan Plateau of China Full text
2009
Li, Wen-Jin | Li, Jin-Hua | Knops, Johannes M. H. | Wang, Gang | Jia, Ju-Jie | Qin, Yan-Yan
To assess the recovery trajectory and self-maintenance of restored ecosystems, a successional gradient (1, 3, 5, 15, and 30 years after abandonment) was established in a sub-alpine meadow of the eastern Tibetan Plateau in China. Plant communities and soil carbon and nitrogen properties were investigated and analyzed. Regression analyses were used to assess the models (linear or quadratic) relating measures of species richness, soil carbon and nitrogen properties to fallow time. We found that species richness (S) increased over the first 20 years but decreased thereafter, and aboveground biomass showed a linear increase along the fallow time gradient. The richness of different functional groups (forb, grass and legume) changed little along the fallow time gradient, but their corresponding above ground biomass showed the U-shaped, humped or linear pattern. Soil microbial carbon (MBC) and nitrogen (MBN) in the upper 20 cm showed a U-shaped pattern along the fallow time gradient. However, soil organic carbon (Corg) and total nitrogen (TN) in the soil at depth greater than 20 cm showed significant patterns of linear decline along the fallow time gradient. The threshold models of species richness reflected best the recovery over the 15 year fallow period. These results indicated that fallow time had a greater influence on development of the plant community than soil processes in abandoned fields in sub-alpine meadow ecosystem. These results also suggested that although the succession process did not significantly increase soil C, an increase in microbial biomass at the latter stage of succession could promote the decomposability of plant litter. Therefore, abandoned fields in sub-alpine meadow ecosystem may have a high resilience and strong rehabilitating capability under natural recovery condition.
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