Nitrogen Mineralization and Microbial Biomass Nitrogen Dynamics in Three Alpine Tundra Communities

1995 ◽  
Vol 59 (4) ◽  
pp. 1036-1043 ◽  
Author(s):  
Melany C. Fisk ◽  
Steven K. Schmidt
Keyword(s):  
Microbial Biomass ◽  
Nitrogen Mineralization ◽  
Nitrogen Dynamics ◽  
Alpine Tundra ◽  
Microbial Biomass Nitrogen

scholarly journals Dynamics of Microbial Biomass, Nitrogen Mineralization and Crop Uptake in Response to Placement of Maize Residue Returned to Chinese Mollisols over the Maize Growing Season

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1166
Author(s):  
Yan Gao ◽  
Aizhen Liang ◽  
Yan Zhang ◽  
Neil McLaughlin ◽  
Shixiu Zhang ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Nitrogen Mineralization ◽  
Inorganic Nitrogen ◽  
Nitrogen Loss ◽  
N Uptake ◽  
Soil Layer ◽  
Microbial Biomass N ◽  
Growth Stages ◽  
Microbial Biomass Nitrogen ◽  
Maize Growth

Returning residue to soils is not only an effective nutrient management method, but also can reduce the air pollution caused by residue burning, which has become an important factor in global warming. However, it is not clear whether returning residue to the soil can affect the nitrogen mineralization and the nitrogen cycle process, and the environmental impact caused by the nitrogen loss in gaseous forms. Therefore, a pot experiment was conducted to study the effects of residue placement on the nitrogen turnover process, including microbial biomass N (MBN) and C (MBC), inorganic N, crop N uptake, and the contribution of residue-derived N to maize at different maize growth stages. Three treatments were assessed: no residue addition (T0), residue addition to the soil surface (T1), and residue incorporation into the 0–10 cm soil layer (T2). Soil samples were taken at the 0–5 and 5–10 cm layers for all residue treatments. Residue retention (T1 and T2) significantly affected the MBC and MBN contents and decreased MBC/MBN ratio at different maize growth stages. MBC/MBN markedly increased at the R1 stage compared to other growth stages. The differences in total inorganic nitrogen (TIN) were attributed to the balance in net N immobilization and net mineralization in the different maize growth stages. In addition, T2 significantly increased the residue-derived N source for maize by 11.3% compared to T0 in the R3 growth stage. Overall, relative to T1, T2 is a better agriculture management measure to promote N transformation and supply, and enhance residue-derived N release and uptake in maize.

Influence of long-term fertilization on soil microbial biomass and dehydrogenase activity in relation to crop productivity in an acid Inceptisols

2019 ◽  
Vol 56 (3) ◽  
pp. 305-311
Author(s):  
Debasis Purohit ◽  
Mitali Mandal ◽  
Avisek Dash ◽  
Kumbha Karna Rout ◽  
Narayan Panda ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Dehydrogenase Activity ◽  
Nutrient Content ◽  
Crop Productivity ◽  
Maturity Stage ◽  
Microbial Biomass Nitrogen ◽  
Biological Potential ◽  
Initiation Stage ◽  
The Impact

An effective approach for improving nutrient use efficiency and crop productivity simultaneously through exploitation of biological potential for efficient acquisition and utilization of nutrients by crops is very much needed in this current era. Thus, an attempt is made here to investigate the impact of long term fertilization in the soil ecology in rice-rice cropping system in post kharif - 2015 in flooded tropical rice (Oryza sativa L.) in an acidic sandy soil. The experiment was laid out in a randomized block design with quadruplicated treatments. Soil samples at different growth stages of rice were collected from long term fertilizer experiment.The studied long-term manured treatments included 100 % N, 100% NP, 100 % NPK, 150 % NPK and 100 % NPK+FYM (5 t ha-1) and an unmanured control. Soil fertility status like SOC content and other available nutrient content has decreased continuously towards the crop growth period. Comparing the results of different treatments, it was found that the application of 100% NPK + FYM exhibited highest nutrient content in soils. With regards to microbial properties it was also observed that the amount of microbial biomass carbon (MBC) and microbial biomass nitrogen ( MBN) showed highest accumulation in 100 % NPK + FYM at maximum tillering stage of the rice. The results further reveal that dehydrogenase activity was maximum at panicle initiation stage and thereafter it decreases. Soil organic carbon content, MBC, MBN and dehydrogenase activity were significantly correlated with each other. Significant correlations were observed between rice yield and MBC at maturity stage( R2 = 0.94**) and panicle initiation stage( R2 = 0.92**) and available nitrogen content at maturity stage( R2 = 0.91**).

Artificial Measures Are Not Necessarily Better Than Natural Recovery for the Extremely Degraded Alpine Meadow: The Results of Simulated Degradation Restoration After Three Years

2021 ◽  
Vol 15 (2) ◽  
pp. 224-230
Author(s):  
Liuyan Tang ◽  
Lin Chen ◽  
Zhen’an Yang
Keyword(s):  
Microbial Biomass ◽  
Alpine Meadow ◽  
Total Carbon ◽  
Tibet Plateau ◽  
Microbial Biomass Nitrogen ◽  
Natural Recovery ◽  
Advantages And Disadvantages ◽  
Natural Treatment ◽  
Artificial Restoration ◽  
Better Than

Natural and artificial restoration measures are widely used to restore degraded ecosystems, such as degraded alpine meadow. The objective of this research was to evaluate the advantages and disadvantages of natural and artificial measures for extremely degraded alpine meadows. We removed the surface soil (0–10 cm) of the alpine meadow to simulate the extremely degraded “black soil beach,” and set artificial measures (planting Festuca sinensis (E) and Elymus sibircus L. cv. chuan-cao No. 1 (F)) and natural recovery (N) (without any artificial auxiliary measures) in the northeastern part of the Qinghai-Tibet Plateau (QTP), China. After 3 years, we determined the characteristics of community and soil in the artificial and natural treatment. The results show that the species number, above-and below-ground biomass (AB, BB), root-shoot ratio (R/S) in N is significantly higher than that in artificial restoration (E and F); while the community coverage and concentration of soil total carbon, total nitrogen, microbial biomass carbon, microbial biomass nitrogen and microbial biomass phosphorus (TC, TN, MBC, MBN and MBP) in artificial restoration is significantly higher than that in N. In conclusion, compared with N, artificial measures (E and F) are not completely beneficial to the development of plant community diversity and the restoration of soil nutrients in the extremely degraded meadow. Thus, the establishment of artificial grassland is not necessarily better than natural recovery for the extremely degraded alpine meadow.

Effects of acetylene at low concentrations on nitrification, mineralization and microbial biomass nitrogen concentrations in forest soils

2008 ◽  
Vol 54 (2) ◽  
pp. 296-303 ◽  
Author(s):  
TengYu Zhang ◽  
XingKai Xu ◽  
XianBao Luo ◽  
Lin Han ◽  
YingHong Wang ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Forest Soils ◽  
Microbial Biomass Nitrogen ◽  
Low Concentrations ◽  
Nitrogen Concentrations

Modeling Biodegradation of Subsurface Oil in Sand Beaches Polluted with Oil

2014 ◽  
Vol 2014 (1) ◽  
pp. 1113-1125
Author(s):  
Xiaolong Geng ◽  
Michel C. Boufadel
Keyword(s):  
Microbial Biomass ◽  
Galvanized Steel ◽  
Sensitivity Analyses ◽  
Parameter Estimates ◽  
Model Parameters ◽  
Zone Model ◽  
Residual Oil ◽  
Monod Kinetics ◽  
Microbial Biomass Nitrogen ◽  
Total N

ABSTRACT In April 2010, the explosion of the Deepwater Horizon (DWH) drilling platform led to the release of nearly 4.9 million barrels of crude oil into the Gulf of Mexico. The oil was brought to the supratidal zone of beaches (landward of the high tide line) by waves during storms, and was buried during subsequent storms. The objective of this paper is to investigate the biodegradation of subsurface oil in a tidally influenced sand beach located at Bon Secour National Wildlife Refuge and polluted by the DWH oil spill. Two transects were installed perpendicular to the shoreline within the supratidal zone of the beach. One transect had four galvanized steel piezometer wells to measure the water level. The other transect had four stainless steel multiport sampling wells that were used to collect pore water samples below the beach surface. The samples were analyzed for dissolved oxygen (DO), nitrogen, and redox conditions. Sediment samples were also collected at different depths to measure residual oil concentrations and microbial biomass. As the biodegradation of hydrocarbons was of interest, a biological model based on Monod kinetics was developed and coupled to the transport model MARUN, which is a two dimensional (vertical slice) finite element model for water flow and solute transport in tidally influenced beaches. The resulting coupled model, BIOMARUN, was used to simulate the biodegradation of total n-alkanes and polycyclic aromatic hydrocarbons (PAHs) trapped as residual oil in the unsaturated zone. Model parameter estimates were constrained by published Monod kinetics parameters. The field measurements, such as the concentrations of the oil, microbial biomass, nitrogen, and DO, were used as inputs for the simulations. The biodegradation of alkanes and PAHs was predicted in the simulation, and sensitivity analyses were conducted to assess the effect of the model parameters on the modeling results. Simulation results indicated that n-alkanes and PAHs would be biodegraded by 80% after 2 ± 0.5 years and 3.5 ± 0.5 years, respectively.

Sign in / Sign up

Export Citation Format

Share Document