Turkey’s inland water ecosystem consists of 33 rivers (177.714 miles), 200 natural lakes (906.118 ha), 159 reservoirs (342.377 ha) and 750 ponds (15.500 ha). Sedimentological studies conducted on inland water ecosyst...Turkey’s inland water ecosystem consists of 33 rivers (177.714 miles), 200 natural lakes (906.118 ha), 159 reservoirs (342.377 ha) and 750 ponds (15.500 ha). Sedimentological studies conducted on inland water ecosystems during the last 15 years in Turkey can be categorized into two main topics. The first group of studies is concerned with heavy metal levels in sediment, with especial reference to the interaction between water, sediment and aquatic organisms. Additionally, the studies in question deal with the potential impacts of heavy metal concentrations on the ecosystem. The second group of studies is concerned with the role of eutrophication in the sediment as a result of serious contamination of inland water ecosystems. It is known that the sediment can directly influence the nutrient level in standing inland waters such as lakes and ponds by way of internal nutrient loading. In this context, studies regarding sediment, overlying water, sediment pore water and nutrient release from the sediment should be emphasized as these are important steps with respect to the eutrophication process. By keeping these studies in mind, the researcher in this study compiled and analyzed studies dealing with inland water ecosystems with differing nutrient levels and uses, including for drinking water, in Turkey’s drainage basins. In addition, field and laboratory studies regarding nutrient release from sediment into Turkey’s inland water ecosystems were evaluated in light of lake management practices.展开更多
Microbes are decomposers of crop residues,and climatic factors and residue composition are known to influence microbial growth and community composition,which in turn regulate residue decomposition.However,the success...Microbes are decomposers of crop residues,and climatic factors and residue composition are known to influence microbial growth and community composition,which in turn regulate residue decomposition.However,the succession of the bacterial community during residue decomposition in Northeast China is not well understood.To clarify the property of bacterial community succession and the corresponding factors regulating this succession,bags containing maize residue were buried in soil in Northeast China in October,and then at different intervals over the next 2 years,samples were analyzed for residue mass and bacterial community composition.After residue burial in the soil,the cumulative residue mass loss rates were 18,69,and 77%after 5,12,and 24 months,respectively.The release of residue nitrogen,phosphorus,and carbon followed a similar pattern as mass loss,but 79%of residue potassium was released after only 1 month.The abundance,richness,and community diversity of bacteria in the residue increased rapidly and peaked after 9 or 20 months.Residue decomposition was mainly influenced by temperature and chemical composition in the early stage,and was influenced by chemical composition in the later stage.Phyla Actinobacteria,Bacteroidetes,and Firmicutes dominated the bacterial community composition in residue in the early stage,and the abundances of phyla Chloroflexi,Acidobacteria,and Saccharibacteria gradually increased in the later stage of decomposition.In conclusion,maize residue decomposition in soil was greatly influenced by temperature and residue composition in Northeast China,and the bacterial community shifted from dominance of copiotrophic populations in the early stage to an increase in oligotrophic populations in the later stage.展开更多
Crop residues have the potential to enhance soil fertility, but this is dependent on their biochemical properties. This study aimed to evaluate the chemical composition, and nutrients release patterns of selected crop...Crop residues have the potential to enhance soil fertility, but this is dependent on their biochemical properties. This study aimed to evaluate the chemical composition, and nutrients release patterns of selected crop residues (corn stalk, rice straw, millet straw and sorghum stalk). Thus, 20 g of each crop residue were put in litter bags and placed in a plastic pot containing 10 kg of soil with a moisture content of 40% - 60%. Five replications were considered per type of residue and some samples were taken every 4 weeks. Results showed that crop residues got a pH varying between 5.09 and 6.5. The lowest C content (33.11%) and nitrogen (0.27%) were measured in sorghum stalk when the highest C content (47.6%) and nitrogen content (0.55%) were registered in corn stalk. The highest phosphorus content (0.58%) was got in corn stalk. Potassium content was higher in millet straw than in others. The highest calcium content (0.37%) and magnesium (0.29%) were found in rice straw. There was an increase of soil chemical composition after crop residues burial. Significant increase in carbon, nitrogen, and phosphorus content was noted in soil at week 4 with the highest at week 16. At the end of the experiment, the highest C content (53.1%) and the highest nitrogen content (0.88%) in the soil were observed after burial of rice straw. The highest phosphorus content (0.82%) registered in the soil was got with millet straw. Nutrient release efficiency of crop residues occurred in the following order: rice straw > millet straw > sorghum stalk > corn stalk. This study has demonstrated that rice straw and millet straw released nutrients faster and this is beneficial for early planted crops, while sorghum stalk and corn stalk released nutrients slowly which is appropriate for long-term availability of plant nutrients.展开更多
The aim of this study was to evaluate the performance, nutrient utilisation and energy metabolism of broiler chicks fed 8 different wheat samples, supplemented or not with xylanase. Seven-hundred sixty eight male broi...The aim of this study was to evaluate the performance, nutrient utilisation and energy metabolism of broiler chicks fed 8 different wheat samples, supplemented or not with xylanase. Seven-hundred sixty eight male broilers(1-day-old) were distributed to 16 experimental treatments(6 replicates per treatment). The treatments were in a factorial arrangement with 8 different wheats and 2 levels of xylanase(0 or 16,000 BXU/kg). The predicted apparent metabolisable energy(AME) of the wheat samples ranged from 13.0 to 13.9 MJ/kg and all diets were formulated to contain the same amount of wheat. Body weight gain(BWG) and feed intake(FI) were measured at 21 d, as was jejunal digesta viscosity, and feed conversion ratio(FCR) calculated. On day 24, one representative bird per pen was selected to calculate whole body energetics. At 21 d, 3 chicks per replicate were randomly allocated to metabolism cages for energy and nutrient utilisation determinations, and were continued on the experimental diets until 24-d-old. No interactions were observed for any performance response variables, ileal nutrient utilisation or digesta viscosity. Xylanase improved BWG and reduced FCR and digesta viscosity(P < 0.05). Wheat influenced dry matter(DM) utilisation and xylanase increased ileal digestible energy(P = 0.04). Xylanase also improved(P < 0.05) DM and nitrogen retention. Apparent metabolisable energy and AME corrected for nitrogen(AMEn) were subject to an interaction whereby wheats 2 and 6, which returned the lowest AME and AMEn values, responded to xylanase supplementation and the remainder did not. Net energy for production and the efficiency of energy use for production were not influenced by xylanase, but were affected by wheat(P < 0.05). Despite the significant differences between wheats with regards to their nutrient utilisation and energy metabolism in birds, xylanase removed this variance and resulted in more homogeneous performance.展开更多
Plant litter decomposition has been studied extensively in the context of both warming and increased atmospheric nitrogen deposition. However, the temporal patterns of mass loss and nutrient release in response to war...Plant litter decomposition has been studied extensively in the context of both warming and increased atmospheric nitrogen deposition. However, the temporal patterns of mass loss and nutrient release in response to warming and nitrogen addition remain unclear. A 2-year decomposition experiment aimed to examine the effects of warming and nitrogen addition on decomposition rate, and nitrogen and phosphorus dynamics. The effects of warming and nitrogen addition on decomposition of litter of Stipa breviflora, a dominant species in a desert steppe of northern China, were studied. Warming and nitrogen addition significantly enhanced litter mass loss by 10% and 16%, respectively, and moreover promoted nitrogen and phosphorus release from the litter in the first year of decomposition, followed by an immobilization period. The interactive effects of warming and nitrogen addition on mass loss, nitrogen and phosphorus concentrations of litter were also found during the decomposition. This study indicates that warming and nitrogen addition increased litter mass loss through altering litter quality. These findings highlight that interactions between climate change and other global change factors could be highly important in driving decomposition responses.展开更多
The effects of two solid-based hydrogen peroxides sodium percarbonate(SPC) and calcium peroxide(CP)on waste activated sludge(WAS) disintegration were investigated. Both oxidants achieved efficient WAS disintegration f...The effects of two solid-based hydrogen peroxides sodium percarbonate(SPC) and calcium peroxide(CP)on waste activated sludge(WAS) disintegration were investigated. Both oxidants achieved efficient WAS disintegration for the synergistic effect of alkaline and oxidation. The strong alkaline condition led to the leakage of ammonia and the existence of abundant calcium ions accelerated the fixation of phosphorus via precipitation in CP WAS disintegration process. However, the spongy-like layer and low p H condition retarded the release of gaseous ammonia in SPC group. Hydroxyl radical was the main oxygen reactive species in SPC approaches which were more intense than CP by electron spin resonance(ESR) analysis.CP treated WAS contented more small particle size matter and total suspended solids(TSS) increased dramatically. In conclusion, CP pretreated sludge was more suitable for fertilization, while SPC was in favor of anaerobic digestion. This study clarified the differences between these two oxidants and their intermediates on nutrients release in sludge disintegration.展开更多
文摘Turkey’s inland water ecosystem consists of 33 rivers (177.714 miles), 200 natural lakes (906.118 ha), 159 reservoirs (342.377 ha) and 750 ponds (15.500 ha). Sedimentological studies conducted on inland water ecosystems during the last 15 years in Turkey can be categorized into two main topics. The first group of studies is concerned with heavy metal levels in sediment, with especial reference to the interaction between water, sediment and aquatic organisms. Additionally, the studies in question deal with the potential impacts of heavy metal concentrations on the ecosystem. The second group of studies is concerned with the role of eutrophication in the sediment as a result of serious contamination of inland water ecosystems. It is known that the sediment can directly influence the nutrient level in standing inland waters such as lakes and ponds by way of internal nutrient loading. In this context, studies regarding sediment, overlying water, sediment pore water and nutrient release from the sediment should be emphasized as these are important steps with respect to the eutrophication process. By keeping these studies in mind, the researcher in this study compiled and analyzed studies dealing with inland water ecosystems with differing nutrient levels and uses, including for drinking water, in Turkey’s drainage basins. In addition, field and laboratory studies regarding nutrient release from sediment into Turkey’s inland water ecosystems were evaluated in light of lake management practices.
基金the National Key Research&Development Program of China(2016YFD0200102 and 2018YFD0201001).
文摘Microbes are decomposers of crop residues,and climatic factors and residue composition are known to influence microbial growth and community composition,which in turn regulate residue decomposition.However,the succession of the bacterial community during residue decomposition in Northeast China is not well understood.To clarify the property of bacterial community succession and the corresponding factors regulating this succession,bags containing maize residue were buried in soil in Northeast China in October,and then at different intervals over the next 2 years,samples were analyzed for residue mass and bacterial community composition.After residue burial in the soil,the cumulative residue mass loss rates were 18,69,and 77%after 5,12,and 24 months,respectively.The release of residue nitrogen,phosphorus,and carbon followed a similar pattern as mass loss,but 79%of residue potassium was released after only 1 month.The abundance,richness,and community diversity of bacteria in the residue increased rapidly and peaked after 9 or 20 months.Residue decomposition was mainly influenced by temperature and chemical composition in the early stage,and was influenced by chemical composition in the later stage.Phyla Actinobacteria,Bacteroidetes,and Firmicutes dominated the bacterial community composition in residue in the early stage,and the abundances of phyla Chloroflexi,Acidobacteria,and Saccharibacteria gradually increased in the later stage of decomposition.In conclusion,maize residue decomposition in soil was greatly influenced by temperature and residue composition in Northeast China,and the bacterial community shifted from dominance of copiotrophic populations in the early stage to an increase in oligotrophic populations in the later stage.
文摘Crop residues have the potential to enhance soil fertility, but this is dependent on their biochemical properties. This study aimed to evaluate the chemical composition, and nutrients release patterns of selected crop residues (corn stalk, rice straw, millet straw and sorghum stalk). Thus, 20 g of each crop residue were put in litter bags and placed in a plastic pot containing 10 kg of soil with a moisture content of 40% - 60%. Five replications were considered per type of residue and some samples were taken every 4 weeks. Results showed that crop residues got a pH varying between 5.09 and 6.5. The lowest C content (33.11%) and nitrogen (0.27%) were measured in sorghum stalk when the highest C content (47.6%) and nitrogen content (0.55%) were registered in corn stalk. The highest phosphorus content (0.58%) was got in corn stalk. Potassium content was higher in millet straw than in others. The highest calcium content (0.37%) and magnesium (0.29%) were found in rice straw. There was an increase of soil chemical composition after crop residues burial. Significant increase in carbon, nitrogen, and phosphorus content was noted in soil at week 4 with the highest at week 16. At the end of the experiment, the highest C content (53.1%) and the highest nitrogen content (0.88%) in the soil were observed after burial of rice straw. The highest phosphorus content (0.82%) registered in the soil was got with millet straw. Nutrient release efficiency of crop residues occurred in the following order: rice straw > millet straw > sorghum stalk > corn stalk. This study has demonstrated that rice straw and millet straw released nutrients faster and this is beneficial for early planted crops, while sorghum stalk and corn stalk released nutrients slowly which is appropriate for long-term availability of plant nutrients.
文摘The aim of this study was to evaluate the performance, nutrient utilisation and energy metabolism of broiler chicks fed 8 different wheat samples, supplemented or not with xylanase. Seven-hundred sixty eight male broilers(1-day-old) were distributed to 16 experimental treatments(6 replicates per treatment). The treatments were in a factorial arrangement with 8 different wheats and 2 levels of xylanase(0 or 16,000 BXU/kg). The predicted apparent metabolisable energy(AME) of the wheat samples ranged from 13.0 to 13.9 MJ/kg and all diets were formulated to contain the same amount of wheat. Body weight gain(BWG) and feed intake(FI) were measured at 21 d, as was jejunal digesta viscosity, and feed conversion ratio(FCR) calculated. On day 24, one representative bird per pen was selected to calculate whole body energetics. At 21 d, 3 chicks per replicate were randomly allocated to metabolism cages for energy and nutrient utilisation determinations, and were continued on the experimental diets until 24-d-old. No interactions were observed for any performance response variables, ileal nutrient utilisation or digesta viscosity. Xylanase improved BWG and reduced FCR and digesta viscosity(P < 0.05). Wheat influenced dry matter(DM) utilisation and xylanase increased ileal digestible energy(P = 0.04). Xylanase also improved(P < 0.05) DM and nitrogen retention. Apparent metabolisable energy and AME corrected for nitrogen(AMEn) were subject to an interaction whereby wheats 2 and 6, which returned the lowest AME and AMEn values, responded to xylanase supplementation and the remainder did not. Net energy for production and the efficiency of energy use for production were not influenced by xylanase, but were affected by wheat(P < 0.05). Despite the significant differences between wheats with regards to their nutrient utilisation and energy metabolism in birds, xylanase removed this variance and resulted in more homogeneous performance.
基金supported by the Scientific Research Foundation for Advanced Talents by Inner Mongolia Agricultural University (NDGCC2016-19)the National Natural Science Foundation of China (31760146, 31770500)+2 种基金National Key Project (2016YFC0500504)the Innovative Team of Grassland Resources from the Ministry of Education of China (IRT_17R59)received long-term support from the Academy of Agriculture and Animal Husbandry Sciences
文摘Plant litter decomposition has been studied extensively in the context of both warming and increased atmospheric nitrogen deposition. However, the temporal patterns of mass loss and nutrient release in response to warming and nitrogen addition remain unclear. A 2-year decomposition experiment aimed to examine the effects of warming and nitrogen addition on decomposition rate, and nitrogen and phosphorus dynamics. The effects of warming and nitrogen addition on decomposition of litter of Stipa breviflora, a dominant species in a desert steppe of northern China, were studied. Warming and nitrogen addition significantly enhanced litter mass loss by 10% and 16%, respectively, and moreover promoted nitrogen and phosphorus release from the litter in the first year of decomposition, followed by an immobilization period. The interactive effects of warming and nitrogen addition on mass loss, nitrogen and phosphorus concentrations of litter were also found during the decomposition. This study indicates that warming and nitrogen addition increased litter mass loss through altering litter quality. These findings highlight that interactions between climate change and other global change factors could be highly important in driving decomposition responses.
基金financially supported by the National Natural Science Foundation of China (No. 51978201)the State Key Laboratory of Urban Water Resource and Environment (No.2020DX08)。
文摘The effects of two solid-based hydrogen peroxides sodium percarbonate(SPC) and calcium peroxide(CP)on waste activated sludge(WAS) disintegration were investigated. Both oxidants achieved efficient WAS disintegration for the synergistic effect of alkaline and oxidation. The strong alkaline condition led to the leakage of ammonia and the existence of abundant calcium ions accelerated the fixation of phosphorus via precipitation in CP WAS disintegration process. However, the spongy-like layer and low p H condition retarded the release of gaseous ammonia in SPC group. Hydroxyl radical was the main oxygen reactive species in SPC approaches which were more intense than CP by electron spin resonance(ESR) analysis.CP treated WAS contented more small particle size matter and total suspended solids(TSS) increased dramatically. In conclusion, CP pretreated sludge was more suitable for fertilization, while SPC was in favor of anaerobic digestion. This study clarified the differences between these two oxidants and their intermediates on nutrients release in sludge disintegration.
