Changes in microbial metabolic C- and N- limitations in the rhizosphere and bulk soils along afforestation chronosequence in desertified ecosystems

The performance of a bench scale upflow sludge bed (USB) denitrifying reactor was evaluated in order to integrate it into a C and N removal system for Sanitary Landfill Leachate. The raw leachate used presented COD and NH4-N average values of 30000 mg/l and 1000 mg/l, respectively. The complete system comprises in addition an UASB reactor and a nitrifying RBC. A portion of the aerobic reactor effluent was recycled into the denitrification stage and some raw leachate was also added as an additional C source. In order to obtain operating parameters the denitrifying reactor was operated alone. Sludge from an aerobic reactor (RBC) treating raw leachate was used as inoculum. Shortly after the start up, good granulation of the sludge bed was observed. Using raw leachate and UASB outlet as carbon sources with COD/NO3-N ratios of 4 and 12, respectively, denitrification efficiencies of about 90% were reached. A sludge yield of 0.16 gVSS/gCODremoved was obtained operating with raw leachate. For the anoxic reactor operating in the complete system, denitrification efficiencies of 90% were also achieved. A nitrogen gas recycle was a successful way to avoid frequently observed sludge bed rising problems.

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SOIL C AND N AS INDICATORS OF VINEYARD SOIL QUALITY IN THE RAVNI KOTARI REGION OF CROATIA

10.1130/abs/2020se-345231 ◽

2020 ◽

Author(s):

Sonia C. Clemens ◽

◽

Mia Brkljaca ◽

Delaina Pearson ◽

C. Brannon Andersen

Keyword(s):

Soil Quality ◽

Soil C ◽

Vineyard Soil ◽

Soil C And N ◽

C And N

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Forest defoliator pests alter carbon and nitrogen cycles

Royal Society Open Science ◽

10.1098/rsos.160361 ◽

2016 ◽

Vol 3 (10) ◽

pp. 160361 ◽

Cited By ~ 12

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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Spatially Related Sampling Uncertainty in the Assessment of Labile Soil Carbon and Nitrogen in an Irish Forest Plantation

Applied Sciences ◽

10.3390/app11052139 ◽

2021 ◽

Vol 11 (5) ◽

pp. 2139

Author(s):

Junliang Zou ◽

Bruce Osborne

Keyword(s):

Spatial Variability ◽

Soil Carbon ◽

Sampling Effort ◽

Limited Information ◽

Sampling Area ◽

Soil C ◽

Distribution Maps ◽

Soil C And N ◽

C And N ◽

Highly Correlated

The importance of labile soil carbon (C) and nitrogen (N) in soil biogeochemical processes is now well recognized. However, the quantification of labile soil C and N in soils and the assessment of their contribution to ecosystem C and N budgets is often constrained by limited information on spatial variability. To address this, we examined spatial variability in dissolved organic carbon (DOC) and dissolved total nitrogen (DTN) in a Sitka spruce forest in central Ireland. The results showed moderate variations in the concentrations of DOC and DTN based on the mean, minimum, and maximum, as well as the coefficients of variation. Residual values of DOC and DTN were shown to have moderate spatial autocorrelations, and the nugget sill ratios were 0.09% and 0.10%, respectively. Distribution maps revealed that both DOC and DTN concentrations in the study area decreased from the southeast. The variability of both DOC and DTN increased as the sampling area expanded and could be well parameterized as a power function of the sampling area. The cokriging technique performed better than the ordinary kriging for predictions of DOC and DTN, which are highly correlated. This study provides a statistically based assessment of spatial variations in DOC and DTN and identifies the sampling effort required for their accurate quantification, leading to improved assessments of forest ecosystem C and N budgets.

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An Integrated Approach to Convert Lignocellulosic and Wool Residues into Balanced Fertilisers

Energies ◽

10.3390/en14020497 ◽

2021 ◽

Vol 14 (2) ◽

pp. 497

Author(s):

Filippo Marchelli ◽

Giorgio Rovero ◽

Massimo Curti ◽

Elisabetta Arato ◽

Barbara Bosio ◽

...

Keyword(s):

Mechanical Properties ◽

Renewable Energy ◽

Circular Economy ◽

Integrated Approach ◽

Lignocellulosic Residues ◽

Biomass Waste ◽

Slow Pyrolysis ◽

C And N ◽

Water Hydrolysis ◽

Conversion Technologies

Valorising biomass waste and producing renewable energy or materials is the aim of several conversion technologies. In this work, we consider two residues from different production chains: lignocellulosic residues from agriculture and wool residues from sheep husbandry. These materials are produced in large quantities, and their disposal is often costly and challenging for farmers. For their valorisation, we focus on slow pyrolysis for the former and water hydrolysis for the latter, concisely presenting the main literature related to these two processes. Pyrolysis produces the C-rich biochar, suitable for soil amending. Hydrolysis produces a N-rich fertiliser. We demonstrate how these two processes could be fruitfully integrated, as their products can be flexibly mixed to produce fertilisers. This solution would allow the achievement of balanced and tuneable ratios between C and N and the enhancement of the mechanical properties. We propose scenarios for this combined valorisation and for its coupling with other industries. As a result, biomass waste would be returned to the field, following the principles of circular economy.

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Ammonium application mitigates the effects of elevated carbon dioxide on the carbon/nitrogen balance of Phoebe bournei seedlings

Tree Physiology ◽

10.1093/treephys/tpab026 ◽

2021 ◽

Author(s):

Xiao Wang ◽

Xiaoli Wei ◽

Gaoyin Wu ◽

Shengqun Chen

Keyword(s):

Carbon Dioxide ◽

Enzyme Activities ◽

Atmospheric Carbon Dioxide ◽

Global Climate ◽

Co2 Concentration ◽

Rubisco Activase ◽

Plant Responses ◽

N Metabolism ◽

C And N ◽

Phoebe Bournei

Abstract The study of plant responses to increases in atmospheric carbon dioxide (CO2) concentration is crucial to understand and to predict the effect of future global climate change on plant adaptation and evolution. Increasing amount of nitrogen (N) can promote the positive effect of CO2, while how N forms would modify the degree of CO2 effect is rarely studied. The aim of this study was to determine whether the amount and form of nitrogen (N) could mitigate the effects of elevated CO2 (eCO2) on enzyme activities related to carbon (C) and N metabolism, the C/N ratio, and growth of Phoebe bournei (Hemsl.) Y.C. Yang. One-year-old P. bournei seedlings were grown in an open-top air chamber under either an ambient CO2 (aCO2) (350 ± 70 μmol•mol−1) or an eCO2 (700 ± 10 μmol•mol−1) concentration and cultivated in soil treated with either moderate (0.8 g per seedling) or high applications (1.2 g per seedling) of nitrate or ammonium. In seedlings treated with a moderate level of nitrate, the activities of key enzymes involved in C and N metabolism (i.e., Rubisco, Rubisco activase and glutamine synthetase) were lower under eCO2 than under aCO2. By contrast, key enzyme activities (except GS) in seedlings treated with high nitrate or ammonium were not significantly different between aCO2 and eCO2 or higher under eCO2 than under aCO2. The C/N ratio of seedlings treated with moderate or high nitrate under eCO2was significantly changed compared with the seedlings grown under aCO2, whereas the C/N ratio of seedlings treated with ammonium was not significantly different between aCO2 and eCO2. Therefore, under eCO2, application of ammonium can be beneficial C and N metabolism and mitigate effects on the C/N ratio.

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Long‐term Tillage Induced Differential C and N Responses

CSA News ◽

10.1002/csan.20556 ◽

2021 ◽

Keyword(s):

C And N

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Distribution and altitudinal patterns of carbon and nitrogen storage in various forest ecosystems in the central Yunnan Plateau, China

Scientific Reports ◽

10.1038/s41598-021-85710-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jianqiang Li ◽

Qibo Chen ◽

Zhuang Li ◽

Bangxiao Peng ◽

Jianlong Zhang ◽

...

Keyword(s):

Forest Ecosystems ◽

Sustainable Forest Management ◽

Carbon And Nitrogen ◽

Pinus Yunnanensis ◽

Yunnan Plateau ◽

Baseline Information ◽

C And N ◽

Quercus Semecarpifolia ◽

Management Policies

AbstractThe carbon (C) pool in forest ecosystems plays a long-term and sustained role in mitigating the impacts of global warming, and the sequestration of C is closely linked to the nitrogen (N) cycle. Accurate estimates C and N storage (SC, SN) of forest can improve our understanding of C and N cycles and help develop sustainable forest management policies in the content of climate change. In this study, the SC and SN of various forest ecosystems dominated respectively by Castanopsis carlesii and Lithocarpus mairei (EB), Pinus yunnanensis (PY), Pinus armandii (PA), Keteleeria evelyniana (KE), and Quercus semecarpifolia (QS) in the central Yunnan Plateau of China, were estimated on the basis of a field inventory to determine the distribution and altitudinal patterns of SC and SN among various forest ecosystems. The results showed that (1) the forest SC ranged from 179.58 ± 20.57 t hm−1 in QS to 365.89 ± 35.03 t hm−1 in EB. Soil, living biomass and litter contributed an average of 64.73%, 31.72% and 2.86% to forest SC, respectively; (2) the forest SN ranged from 4.47 ± 0.94 t ha−1 in PY to 8.91 ± 1.83 t ha−1 in PA. Soil, plants and litter contributed an average of 86.88%, 10.27% and 2.85% to forest SN, respectively; (3) the forest SC and SN decreased apparently with increasing altitude. The result demonstrates that changes in forest types can strongly affect the forest SC and SN. This study provides baseline information for forestland managers regarding forest resource utilization and C management.

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