scholarly journals TERRESTRIAL C SEQUESTRATION AT ELEVATED CO2AND TEMPERATURE: THE ROLE OF DISSOLVED ORGANIC N LOSS

2005 ◽  
Vol 15 (1) ◽  
pp. 71-86 ◽  
Author(s):  
Edward B. Rastetter ◽  
Steven S. Perakis ◽  
Gaius R. Shaver ◽  
Göran I. Ågren
Keyword(s):  
C Sequestration ◽  
Organic N ◽  
N Loss ◽  
Dissolved Organic N

Characteristics of Non-Point Source N Export via Surface Runoff from Sloping Croplands in Northeast China

2011 ◽  
Vol 347-353 ◽  
pp. 2302-2307 ◽  
Author(s):  
Hong Xiang Wang ◽  
Yi Shi ◽  
Jian Ma ◽  
Cai Yan Lu ◽  
Xin Chen
Keyword(s):  
Point Source ◽  
Surface Runoff ◽  
Rainfall Intensity ◽  
Inorganic Nitrogen ◽  
Rainfall Amount ◽  
Organic N ◽  
Dissolved Inorganic Nitrogen ◽  
Slope Gradient ◽  
N Loss ◽  
Total N

A field experiment was conducted to study the characteristics of non-point source nitrogen (N) in the surface runoff from sloping croplands and the influences of rainfall and cropland slope gradient. The results showed that dissolved total N (DTN) was the major form of N in the runoff, and the proportion occupied by dissolved inorganic nitrogen (DIN) ranged from 45% to 85%. The level of NH4+-N was generally higher than the level of NO3--N, and averaged at 2.50 mg·L-1and 1.07 mg·L-1respectively. DIN was positively correlated with DTN (R2=0.962). Dissolved organic N (DON) presented a moderate seasonal change and averaged at 1.40 mg·L-1. Rainfall amount and rainfall intensity significantly affected the components of DTN in the runoff. With the increase of rainfall amount and rainfall intensity, the concentrations of DTN, NH4+-N and NO3--N presented a decreased trend, while the concentration of DON showed an increased trend. N loss went up with an increase in the gradient of sloping cropland, and was less when the duration was longer from the time of N fertilization.fertilization.

scholarly journals Integrated Transcriptional and Proteomic Profiling Reveals Potential Amino Acid Transporters Targeted by Nitrogen Limitation Adaptation

2020 ◽  
Vol 21 (6) ◽  
pp. 2171
Author(s):  
Qiong Liao ◽  
Tian-jiao Tang ◽  
Ting Zhou ◽  
Hai-xing Song ◽  
Ying-peng Hua ◽  
...  
Keyword(s):  
Amino Acid ◽  
Crop Productivity ◽  
Regulatory Role ◽  
Organic N ◽  
Amino Acid Transporters ◽  
Proteomic Profiling ◽  
N Limitation ◽  
N Remobilization ◽  
Proteomic Analyses

Nitrogen (N) is essential for plant growth and crop productivity. Organic N is a major form of remobilized N in plants’ response to N limitation. It is necessary to understand the regulatory role of N limitation adaption (NLA) in organic N remobilization for this adaptive response. Transcriptional and proteomic analyses were integrated to investigate differential responses of wild-type (WT) and nla mutant plants to N limitation and to identify the core organic N transporters targeted by NLA. Under N limitation, the nla mutant presented an early senescence with faster chlorophyll loss and less anthocyanin accumulation than the WT, and more N was transported out of the aging leaves in the form of amino acids. High-throughput transcriptomic and proteomic analyses revealed that N limitation repressed genes involved in photosynthesis and protein synthesis, and promoted proteolysis; these changes were higher in the nla mutant than in the WT. Both transcriptional and proteomic profiling demonstrated that LHT1, responsible for amino acid remobilization, were only significantly upregulated in the nla mutant under N limitation. These findings indicate that NLA might target LHT1 and regulate organic N remobilization, thereby improving our understanding of the regulatory role of NLA on N remobilization under N limitation.

The relationship between inorganic and organic nutrients in sea water

1979 ◽  
Vol 59 (1) ◽  
pp. 239-250 ◽  
Author(s):  
E. I. Butler ◽  
Susan Knox ◽  
M. I. Liddicoat
Keyword(s):  
Seasonal Variations ◽  
Sea Water ◽  
Organic N ◽  
English Channel ◽  
Organic Nutrients ◽  
Dissolved Organic N ◽  
The Relationship ◽  
Inorganic And Organic

The seasonal variations of dissolved inorganic and organic N and P in the waters of the English Channel during an 11-year study are discussed. The N results show that as NO3 is utilized by phytoplankton there is an increase in the concentration of the dissolved organic N fraction and there are always significant amounts of dissolved N in some form in the water.

scholarly journals Spatial and Temporal Hydrochemical Variation of a Third Order River Network in a Quasi Pristine Coastal Watershed, at Southern Bahia, Brazil

2013 ◽  
Vol 85 (4) ◽  
pp. 1357-1370 ◽  
Author(s):  
ELLY R.S. DE SOUZA ◽  
FRANCISCO C.F. DE PAULA
Keyword(s):  
Dissolved Oxygen ◽  
Electric Conductivity ◽  
Fecal Coliforms ◽  
Organic N ◽  
Third Order ◽  
Total N ◽  
Coastal Watershed ◽  
Southern Bahia ◽  
Hydrochemical Variation ◽  
Dissolved Organic N

ABSTRACT Rio da Serra watershed presents well preserved fragments of rain forest at the headwaters and small farms at middle and final stretches. These features allowed the study of fluvial hydrochemistry, under quasi pristine conditions. Sampling stations were established in order to represent the basin, and visited during dry, intermediate and wet periods. Obtained results are: temperature (22.1 – 28.6 °C); electric conductivity (34 – 52 µS/cm); dissolved oxygen (35 – 110%); pH (3.8 – 7.7); total suspended solids (1.1 – 20 mg/L); chlorophyll (1.0 – 9.2 µg/L); total N (74 – 580 µmol/L); particulate N (60 – 550 µmol/L); N-NO3 (0.1 – 9.3 µmol/L); dissolved organic N (4 -70 µmol/L); total phosphorous (5.3 – 47 µmol/L); particulate P (4.4 – 59 µmol/L); P-PO4 (0.1 – 0.7 µmol/L); dissolved organic P (0.01 – 2.0 µmol/L); silicate (30 -90 µmol/L); fecal coliforms (80 – 700 CFU/100mL). In seasonal terms dissolved oxygen, electric conductivity, nitrate and silicate concentrations were higher during the dry, whereas TSS was higher during the wet period. Seasonal differences of dissolved oxygen, temperature, pH and nitrate were also detected near wetlands areas. Along the basin results showed a distinction between headwaters and other sections, revealing a control of fluvial hydrochemistry by the preserved area, mostly for the dissolved organic N and P species and phosphate.

scholarly journals How do terrestrial plants access high molecular mass organic nitrogen, and why does it matter for soil organic matter stabilization?

2021 ◽  
Author(s):  
Bartosz Adamczyk
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Root Growth ◽  
Molecular Mass ◽  
High Molecular Mass ◽  
Organic N ◽  
Terrestrial Plants ◽  
Plant Use ◽  
Organic Matter Stabilization

AbstractAlthough there is increasing awareness of the potential role of organic N compounds (ON) in plant nutrition, its implications for soil organic matter (SOM) stabilization have hardly been discussed yet. The aim of this paper is therefore to gather the newest insights into plant use of high molecular mass organic N, its effect on root growth and anatomy, and finally, to discuss the implications of plant use of organic N for SOM stabilization. I propose that modified root growth due to the uptake of ON provides greater root and root-associated microbe input, leading to enhanced SOM stabilization. Finally, I discuss the role of the proposed framework in different ecosystems, and I encourage future studies combining plant N nutrition and SOM stabilization.

scholarly journals The role of temperate treed swamps as a carbon sink in southwestern Nova Scotia

2021 ◽  
Vol 51 (1) ◽  
pp. 78-88
Author(s):  
Rachel A. Kendall ◽  
Karen A. Harper ◽  
David Burton ◽  
Kevin Hamdan
Keyword(s):  
Climate Change ◽  
Nova Scotia ◽  
Carbon Sink ◽  
Ghg Emissions ◽  
Forested Wetlands ◽  
C Sequestration ◽  
Soil C ◽  
C Storage ◽  
C Cycle

Forested wetlands may represent important ecosystems for mitigating climate change effects through carbon (C) sequestration because of their slow decomposition and C storage by trees. Despite this potential importance, few studies have acknowledged the role of temperate treed swamps in the C cycle. In southwestern Nova Scotia, Canada, we examined the role of treed swamps in the soil C cycle by determining C inputs through litterfall, assessing decomposition rates and soil C pools, and quantifying C outputs through soil greenhouse gas (GHG) emissions. The treed swamps were found to represent large supplies of C inputs through litterfall to the forest floor. The swamp soils had substantially greater C stores than the swamp–upland edge or upland soils. We found growing season C inputs via litterfall to exceed C outputs via GHG emissions in the swamps by a factor of about 2.5. Our findings indicate that temperate treed swamps can remain a C sink even if soil GHG emissions were to double, supporting conservation efforts to preserve temperate treed swamps as a measure to mitigate climate change.

scholarly journals Effects of soil properties and organic residues management on C sequestration and N losses

2008 ◽  
Author(s):  
Asher Bar-Tal ◽  
Paul R. Bloom ◽  
Pinchas Fine ◽  
C. Edward Clapp ◽  
Aviva Hadas ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Management Practices ◽  
Root Exudation ◽  
C Sequestration ◽  
Organic N ◽  
Plant Residues ◽  
N Transformations ◽  
Microbial Decomposition ◽  
Gaseous Emission

Objectives - The overall objective of this proposal was to explore the effects of soil properties and management practices on C sequestration in soils and off-site losses of N.The specific objectives were: 1. to investigate and to quantify the effects of soil properties on C transformations that follow OW decomposition, C losses by gaseous emission, and its sequestration by organic and mineral components of the soil; 2. to investigate and to quantify the effects of soil properties on organic N mineralization and transformations in soil, its losses by leaching and gaseous emission; 3. to investigate and to quantify the effects of management practices and plants root activity and decomposition on C and N transformations; and 4. to upgrade the models NCSOIL and NCSWAP to include inorganic C and root exudation dynamics. The last objective has not been fulfilled due to difficulties in experimentally quantification of the effects of soil inorganic component on root exudation dynamics. Objective 4 was modified to explore the ability of NCSOIL to simulate organic matter decomposition and N transformations in non- and calcareous soils. Background - Rates of decomposition of organic plant residues or organic manures in soil determine the amount of carbon (C), which is mineralized and released as CO₂ versus the amount of C that is retained in soil organic matter (SOM). Decomposition rates also greatly influence the amount of nitrogen (N) which becomes available for plant uptake, is leached from the soil or lost as gaseous emission, versus that which is retained in SOM. Microbial decomposition of residues in soil is strongly influenced by soil management as well as soil chemical and physical properties and also by plant roots via the processes of mineral N uptake, respiration, exudation and decay.

The Role of Decomposition in C Sequestration in Ecosystems

1995 ◽  
pp. 85-112 ◽  
Author(s):  
P. S. J. Verburg ◽  
D. van Dam ◽  
J. C. Y. Marinissen ◽  
R. Westerhof ◽  
N. van Breemen
Keyword(s):  
C Sequestration
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