Influence of soil texture on protozoa-induced mineralization of bacterial carbon and nitrogen

1992 ◽  
Vol 72 (3) ◽  
pp. 183-200 ◽  
Author(s):  
P. M. Rutherford ◽  
N. G. Juma
Keyword(s):  
N Mineralization ◽  
Pore Space ◽  
Mineralization Rate ◽  
Microcosm Experiment ◽  
Carbon And Nitrogen ◽  
Protozoan Grazing ◽  
C And N ◽  
Typic Cryoboroll ◽  
Bacterial C

Texture affects pore space, bacterial and protozoan populations and their activity in soil. The objective of this study was to test the hypothesis that protozoa grazing on bacteria increase the mineralization of bacterial C and N more in coarse-textured soils than in fine-textured soils. The microcosm experiment consisted of samples from three sterilized Orthic Black Chernozemic soils (SiC, CL and SL) inoculated with Pseudomonos bacteria, two treatments (with and without protozoa), and five sampling dates. The Pseudomonas population was labelled in situ by adding glucose- 14C and KNO3-15N (day 0). A species of Acanthamoeba was added to the microcosms on Day 2. On Day 4 bacterial numbers in all three soils were approximately 3 × 109 g−1 soil. The greatest reduction of bacteria due to protozoan grazing occurred between day 4 and day 7. All soils showed increased CO2-14C evolution and NH4-15N mineralization due to protozoan grazing but the mineralization rate of labelled N in the SL soil was much greater than in the fine-textured soils. The effect of texture on protozoan grazing was not as marked between day 12 and day 37 as earlier in the incubation. Protozoan-induced effects were transient in the soils studied and were most apparent in the coarse-textured soil. Key words: 14C, 15N, N mineralization-immobilization, bacteria, organic matter, Typic Cryoboroll, porosity, protozoa

Simulation of protozoa-induced mineralization of bacterial carbon and nitrogen

1992 ◽  
Vol 72 (3) ◽  
pp. 201-216 ◽  
Author(s):  
P. M. Rutherford ◽  
N. G. Juma
Keyword(s):  
N Mineralization ◽  
Ecological Research ◽  
Clay Loam ◽  
Glucose Addition ◽  
Soil C ◽  
Carbon And Nitrogen ◽  
Soil C And N ◽  
C And N ◽  
Typic Cryoboroll ◽  
Bacterial C

Modelling in soil ecological research is a means of linking the dynamics of microbial and faunal populations to soil processes. The objectives of this study were (i) to simulate bacterial-protozoan interactions and flows of C and N in clay loam Orthic Black Chernozemic soil under laboratory condtions; and (ii) to quantify the flux of C and N (inputs and outputs) through various pools using the simulation model. The unique features of this model are: (i) it combines the food chain with specific soil C and N pools, and (ii) it simultaneously traces the flows of C, 14C, N and 15N. It was possible to produce a model that fitted the data observed for the soil. The simulated CO2-C evolved during the first 12 d was due mainly to glucose addition (171 μg C g−1 soil) and cycling of C in the soil (160 μg C g−1 soil). During this interval, bacterial C uptake was 5.5-fold greater than the initial bacterial C pool size. In the first 12 d protozoa directly increased total CO2-C evolution by 11% and increased NH4-N mineralization 3-fold, compared to soil containing only bacteria. Mineralization of C and N was rapid when bacterial numbers were increased as a result of glucose addition. Key words: Acanthamoeba sp., modelling, N mineralization-immobilization, organic matter, Pseudomonas sp., Typic Cryoboroll

scholarly journals Relationship between Water Content and Mineralization of Carbon and Nitrogen in Soils Varying in Physical and Chemical Characteristics

2013 ◽  
Vol 18 (1) ◽  
pp. 45 ◽  
Author(s):  
Akhmad Rizalli Saidy
Keyword(s):  
Water Content ◽  
N Mineralization ◽  
Pore Space ◽  
Carbon And Nitrogen ◽  
Physical And Chemical Characteristics ◽  
Physico Chemical ◽  
C And N Mineralization ◽  
Water Filled Pore Space ◽  
C And N ◽  
Physical And Chemical

An understanding on relationship between water content and mineralization of carbon (C) and nitrogen (N) across soils varying in physical and chemical characteristics is required to assess the influence of soil physico-chemical properties on soil organic matter decomposition. However, such information is rarely available. Relationship between C and N mineralization of three soils varying in physico-chemical properties with different measurements of water content (water-filled pore space, gravimetric water content, volumetric water content, and water holding capacity) was studied through an incubation experiment for 8 weeks. Results of the experiment showed that C and N mineralization increased with increasing water content, reached a maximum, and then decreased with subsequent increasing water content levels. Maximum C and N mineralizations were observed at 70-80% and 50% water-filled pore space (WFPS),  respectively. The ranges of WFPS for C and N mineralization were the narrowest among other measurements of water content. Therefore, it was likely that a single WFPS could be used in subsequent incubations to examine either C or N  mineralization of soils with different characteristics. Result of this study suggests that the preliminary experiment on the   relationship between mineralization of C and N and water content is necessary to do where mineralization is needed to be assessed in soils that have different physico-chemical  characteristics.Keywords: Carbon and nitrogen mineralization, percent of water-filled pore space, water content[How to Cite : Saidy AR. 2013. Relationship between Water Content and Mineralization of Carbon and Nitrogen in Soils Varying in Physical and Chemical Characteristics. J Trop Soils, 18 (1) : 45-52. doi: 10.5400/jts.2013.18.1.45][Permalink/DOI: www.dx.doi.org/10.5400/jts.2013.18.1.45]

scholarly journals Relationship between mineral N content and N mineralization rate in disturbed and undisturbed soil samples incubated under field and laboratory conditions

Soil Research ◽  
1992 ◽  
Vol 30 (4) ◽  
pp. 477 ◽  
Author(s):  
J Sierra
Keyword(s):  
N Mineralization ◽  
Negative Relationship ◽  
Feedback Mechanism ◽  
Soil Samples ◽  
Mineralization Rate ◽  
Mineral N ◽  
Undisturbed Soil ◽  
N Content ◽  
Undisturbed Samples

An investigation of in situ N mineralization, using undisturbed soil samples, indicated a negative relationship between the mineral N content [(NO3+NH4)-N] at the beginning of the experiment and the mineral N produced during it. This suggests that a maximum value of mineral N accumulation in intact soil cores could be calculated from the relationship between mineral N content and N mineralization rate. This value would be related to the size of the mineralizable N pool. If this hypothesis is true, the amount of mineralizable N could be estimated from in situ incubations and utilized in the modelling of N mineralization in the field. The aim of this work was to verify this hypothesis. The relationship between the mineral N content and the N mineralization rate was analysed for in situ and laboratory incubations of disturbed and undisturbed soil samples. A negative relationship between the two variables was only obtained for the experiments carried out with undisturbed samples (in the field and laboratory incubations) when the soil moisture content was not limiting for N mineralization. Futhermore, in undisturbed samples, a negative relationship between mineralization rates of consecutive incubation periods was observed, i.e. the soil sample producing relatively more, during a given period, produced relatively less in the following period. This relationship suggests a feedback mechanism operating in N mineralization which would be related to a mineralization-immobilization process in soil microsites. Thus, the N mineralization pattern was more complex than that described by initial hypothesis. The possible consequence of this feedback mechanism on in situ N dynamics is discussed.

scholarly journals First in situ estimations of small phytoplankton carbon and nitrogen uptake rates in the Kara, Laptev, and East Siberian seas

2018 ◽  
Vol 15 (18) ◽  
pp. 5503-5517 ◽  
Author(s):  
P. Sadanandan Bhavya ◽  
Jang Han Lee ◽  
Ho Won Lee ◽  
Jae Joong Kang ◽  
Jae Hyung Lee ◽  
...  
Keyword(s):  
Sea Ice ◽  
Nitrogen Uptake ◽  
Isotope Labeling ◽  
N Uptake ◽  
The Arctic ◽  
Carbon And Nitrogen ◽  
Uptake Rates ◽  
Small Phytoplankton ◽  
C And N

Abstract. Carbon and nitrogen uptake rates by small phytoplankton (0.7–5 µm) in the Kara, Laptev, and East Siberian seas in the Arctic Ocean were quantified using in situ isotope labeling experiments; this research, which was novel and part of the NABOS (Nansen and Amundsen Basins Observational System) program, took place from 21 August to 22 September 2013. The depth-integrated carbon (C), nitrate (NO3-), and ammonium (NH4+) uptake rates by small phytoplankton ranged from 0.54 to 15.96 mg C m−2 h−1, 0.05 to 1.02 mg C m−2 h−1, and 0.11 to 3.73 mg N m−2 h−1, respectively. The contributions of small phytoplankton towards the total C, NO3-, and NH4+ varied from 25 % to 89 %, 31 % to 89 %, and 28 % to 91 %, respectively. The turnover times for NO3- and NH4+ by small phytoplankton found in the present study indicate the longer residence times (years) of the nutrients in the deeper waters, particularly for NO3-. Additionally, the relatively higher C and N uptake rates by small phytoplankton obtained in the present study from locations with less sea ice concentration indicate the possibility that small phytoplankton thrive under the retreat of sea ice as a result of warming conditions. The high contributions of small phytoplankton to the total C and N uptake rates suggest the capability of small autotrophs to withstand the adverse hydrographic conditions introduced by climate change.

scholarly journals Litter Controls Earthworm-Mediated Carbon and Nitrogen Transformations in Soil from Temperate Riparian Buffers

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Maria Kernecker ◽  
Joann K. Whalen ◽  
Robert L. Bradley
Keyword(s):  
Vegetation Management ◽  
Riparian Buffers ◽  
Litter Type ◽  
Nitrogen Transformations ◽  
Microcosm Experiment ◽  
Reed Canarygrass ◽  
N Losses ◽  
Carbon And Nitrogen ◽  
C And N ◽  
Native Tree Species

Nutrient cycling in riparian buffers is partly influenced by decomposition of crop, grass, and native tree species litter. Nonnative earthworms in riparian soils in southern Quebec are expected to speed the processes of litter decomposition and nitrogen (N) mineralization, increasing carbon (C) and N losses in gaseous forms or via leachate. A 5-month microcosm experiment evaluated the effect ofAporrectodea turgidaon the decomposition of 3 litter types (deciduous leaves, reed canarygrass, and soybean stem residue). Earthworms increased CO2and N2O losses from microcosms with soybean residue, by 112% and 670%, respectively, but reduced CO2and N2O fluxes from microcosms with reed canarygrass by 120% and 220%, respectively. Litter type controlled the CO2flux (soybean ≥ deciduous-mix litter = reed canarygrass > no litter) and the N2O flux (soybean ≥ no litter ≥ reed canarygrass > deciduous-mix litter). However, in the presence of earthworms, there was a slight increase in C and N gaseous losses of C and N relative to their losses via leachate, across litter treatments. We conclude that litter type determines the earthworm-mediated decomposition effect, highlighting the importance of vegetation management in controlling C and N losses from riparian buffers to the environment.

Performance of a simulation model describing protozoa-induced mineralization of bacterial C and N in a sandy loam

1992 ◽  
Vol 72 (3) ◽  
pp. 217-228 ◽  
Author(s):  
P. M. Rutherford ◽  
N. G. Juma
Keyword(s):  
N Mineralization ◽  
Sandy Loam ◽  
Simulated Data ◽  
State Variables ◽  
Clay Loam ◽  
Data Set ◽  
Half Saturation Constant ◽  
Loam Soil ◽  
C And N ◽  
Bacterial C

Mathematical modelling of a microcosm experiment provided a rigorous link between soil organism populations and the processes in the C and N cycles for a clay loam soil. In order to check the internal consistency of the model, we tested its performance with the data set obtained for a sandy loam. We empirically lowered the value of the half saturation constant for the protozoan consumption of bacteria from 175 to 50 (μg C g−1 soil) and initialized the state variables with the appropriate values. The model was also used to quantify the effect of texture on bacterial-protozoan interactions and flows of C and N using the simulated data for a clay loam and a sandy loam. The CO2-C evolved during the first 12 d was mainly due to glucose addition (180 μg C g−1 soil) and cycling of C in the soil (130 μg C g−1 soil). During this interval, C inputs into bacteria were 14-fold greater than the initial pool size. Protozoa increased total CO2-C evolution by 16% and increased net NH4-N mineralization 3.5-fold compared with the protozoa-minus treatment. Mineralization of bacterial C and N was more rapid in the sandy loam than in the clay loam. Key words: N mineralization-immobilization, bacteria, model, protozoa, Typic Cryoboroll, sandy loam

Soil carbon and nitrogen pools and processes in an old-growth conifer forest 13 years after trenching

1998 ◽  
Vol 28 (8) ◽  
pp. 1261-1265 ◽  
Author(s):  
Stephen C Hart ◽  
Phil Sollins
Keyword(s):  
Water Content ◽  
N Mineralization ◽  
Microbial Biomass C ◽  
Net N Mineralization ◽  
Conifer Forest ◽  
Old Growth ◽  
Soil C ◽  
Carbon And Nitrogen ◽  
Soil C And N ◽  
C And N

We measured surface soil (0-15cm) C and N pools and processes inside and outside an area that had been trenched 13 years earlier in an old-growth conifer forest (>450 years) to assess the long-term impacts of reduced root inputs on C and N turnover. Trenching, combined with frequent clipping of understory plants, was originally conducted to prevent nutrient uptake by plants, as part of a study of the role of vegetation in ecosystem retention of N. Thirteen years following trenching, the median values of bulk density, pH, total C and N concentrations, annual rates of in situ net N mineralization and nitrification, microbial biomass C and N, microbial respiration, and anaerobically mineralizable N in the trenched plot were all within the 25-75% interquartile range of values found in the replicated, untrenched plots. The trenched plot had higher rates of net N mineralization (41% higher in October, 484% higher in June) and net nitrification (25% higher in October, and lower net NO3- immobilization in June) during laboratory incubation and a 22% higher water content in October. In June, soil water content in the trenched plot was about 8% lower than in the untrenched plots. Our results suggest that soil C and N dynamics in these old-growth forests are relatively resistant to perturbations resulting from major reductions in root input to the soil.

scholarly journals Interactive effects of belowground organic matter input, increased precipitation and clipping on soil carbon and nitrogen mineralization in a temperate steppe

2013 ◽  
Vol 10 (6) ◽  
pp. 9493-9521
Author(s):  
L. N. Ma ◽  
C. Y. Guo ◽  
X. P. Xin ◽  
S. Yuan ◽  
R. Z. Wang
Keyword(s):  
Organic Matter ◽  
N Mineralization ◽  
Interactive Effects ◽  
Mineralization Rate ◽  
Temperate Steppe ◽  
Soil Microbial Community Structure ◽  
Soil C ◽  
C And N Mineralization ◽  
Soil C And N ◽  
C And N

Abstract. Soil organic matter (SOM) inputs, increased precipitation and clipping (reducing belowground photosynthates allocation) are predicted to affect soil C and N cycling in temperate grassland ecosystems. However, the interactive effects between SOM inputs (or increased precipitation) and clipping on soil C and N mineralization in temperate steppes are still poorly understood. A field manipulation experiment was conducted to quantify the effects of SOM inputs, increased precipitation, clipping and their interactions on soil C and N mineralization in a temperate steppe of northeastern China from 2010 to 2011. The results showed that SOM inputs significantly increased soil C mineralization rate (CMR) and net N mineralization rate (NMR). Increased precipitation-induced enhancement of soil CMR essentially ceased after the first year, stimulation of soil NMR and NNR continued into the second year. However, clipping only marginally decreased soil CMR and NMR during the two years. There were significant synergistic interactions between SOM inputs (or increased precipitation) and clipping on soil CMR and NMR, as SOM inputs (or increased precipitation) showed greater effects on soil CMR and NMR under clipped plots than under unclipped plots, which could be explained by the relative shifts in soil microbial community structure because of bacterial biomass increases, and by the relative decreases in arbuscular mycorrhizal fungi biomass due to the reduction of belowground photosynthates allocation. These results highlight the importance of plants in mediating the responses of soil C and N mineralization to potentially increased SOM and precipitation by controlling belowground photosynthates allocation in the temperate steppe. Thus, the findings have important implications for improving prediction of C and N sequestration potential and its feedbacks to climate change in temperate steppe ecosystems.

scholarly journals Effects of belowground litter addition, increased precipitation and clipping on soil carbon and nitrogen mineralization in a temperate steppe

2013 ◽  
Vol 10 (11) ◽  
pp. 7361-7372 ◽  
Author(s):  
L. Ma ◽  
C. Guo ◽  
X. Xin ◽  
S. Yuan ◽  
R. Wang
Keyword(s):  
Soil Carbon ◽  
N Mineralization ◽  
Mineralization Rate ◽  
Temperate Steppe ◽  
Soil Microbial Community Structure ◽  
Soil C ◽  
C And N Mineralization ◽  
Soil C And N ◽  
C And N ◽  
Photosynthate Allocation

Abstract. Soil carbon (C) and nitrogen (N) cycling are sensitive to changes in environmental factors and play critical roles in the responses of terrestrial ecosystems to natural and anthropogenic perturbations. This study was conducted to quantify the effects of belowground particulate litter (BPL) addition, increased precipitation and their interactions on soil C and N mineralization in two adjacent sites where belowground photosynthate allocation was manipulated through vegetation clipping in a temperate steppe of northeastern China from 2010 to 2011. The results show that BPL addition significantly increase soil C mineralization rate (CMR) and net N mineralization rate (NMR). Although increased precipitation-induced enhancement of soil CMR essentially ceased after the first year, stimulation of soil NMR and net nitrification rate continued into the second year. Clipping only marginally decreased soil CMR and NMR during the two years. There were significant synergistic interactions between BPL addition (and increased precipitation) and clipping on soil CMR and NMR, likely to reflect shifts in soil microbial community structure and a decrease in arbuscular mycorrhizal fungi biomass due to the reduction of belowground photosynthate allocation. These results highlight the importance of plants in mediating the responses of soil C and N mineralization to potentially increased BPL and precipitation by controlling belowground photosynthate allocation in the temperate steppe.

scholarly journals Forest defoliator pests alter carbon and nitrogen cycles

2016 ◽  
Vol 3 (10) ◽  
pp. 160361 ◽  
Author(s):  
Anne l-M-Arnold ◽  
Maren Grüning ◽  
Judy Simon ◽  
Annett-Barbara Reinhardt ◽  
Norbert Lamersdorf ◽  
...  
Keyword(s):  
Climate Change ◽  
Leaf Litter ◽  
Soil Microbial Activity ◽  
Quercus Petraea ◽  
Oak Forests ◽  
Operophtera Brumata ◽  
Winter Moth ◽  
Carbon And Nitrogen ◽  
Soil Microbial ◽  
C And N

Climate change may foster pest epidemics in forests, and thereby the fluxes of elements that are indicators of ecosystem functioning. We examined compounds of carbon (C) and nitrogen (N) in insect faeces, leaf litter, throughfall and analysed the soils of deciduous oak forests ( Quercus petraea  L.) that were heavily infested by the leaf herbivores winter moth ( Operophtera brumata  L.) and mottled umber ( Erannis defoliaria  L.). In infested forests, total net canopy-to-soil fluxes of C and N deriving from insect faeces, leaf litter and throughfall were 30- and 18-fold higher compared with uninfested oak forests, with 4333 kg C ha −1 and 319 kg N ha −1 , respectively, during a pest outbreak over 3 years. In infested forests, C and N levels in soil solutions were enhanced and C/N ratios in humus layers were reduced indicating an extended canopy-to-soil element pathway compared with the non-infested forests. In a microcosm incubation experiment, soil treatments with insect faeces showed 16-fold higher fluxes of carbon dioxide and 10-fold higher fluxes of dissolved organic carbon compared with soil treatments without added insect faeces (control). Thus, the deposition of high rates of nitrogen and rapidly decomposable carbon compounds in the course of forest pest epidemics appears to stimulate soil microbial activity (i.e. heterotrophic respiration), and therefore, may represent an important mechanism by which climate change can initiate a carbon cycle feedback.

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