Diurnal dynamics can modify plant–microbial competition for N uptake via C allocation

2021 ◽  
Author(s):  
Min Liu ◽  
Xingliang Xu ◽  
Paolo Nannipieri ◽  
Yakov Kuzyakov ◽  
Anna Gunina
Keyword(s):  
N Uptake ◽  
Microbial Competition ◽  
Diurnal Dynamics

scholarly journals Upland streamwater nitrate dynamics across decadal to sub-daily timescales: a case study of Plynlimon, Wales

2013 ◽  
Vol 10 (12) ◽  
pp. 8013-8038 ◽  
Author(s):  
S. J. Halliday ◽  
R. A. Skeffington ◽  
A. J. Wade ◽  
C. Neal ◽  
B. Reynolds ◽  
...  
Keyword(s):  
High Frequency ◽  
N Uptake ◽  
Low Flow ◽  
Downstream Site ◽  
Drought Period ◽  
Diurnal Dynamics ◽  
Early Afternoon ◽  
Wide Range ◽  
Nitrate Concentrations

Abstract. Streamwater nitrate dynamics in the River Hafren, Plynlimon, mid-Wales were investigated over decadal to sub-daily timescales using a range of statistical techniques. Long-term data were derived from weekly grab samples (1984–2010) and high-frequency data from 7-hourly samples (2007–2009) both measured at two sites: a headwater stream draining moorland and a downstream site below plantation forest. This study is one of the first to analyse upland streamwater nitrate dynamics across such a wide range of timescales and report on the principal mechanisms identified. The data analysis provided no clear evidence that the long-term decline in streamwater nitrate concentrations was related to a decline in atmospheric deposition alone, because nitrogen deposition first increased and then decreased during the study period. Increased streamwater temperature and denitrification may also have contributed to the decline in stream nitrate concentrations, the former through increased N uptake rates and the latter resultant from increased dissolved organic carbon concentrations. Strong seasonal cycles, with concentration minimums in the summer, were driven by seasonal flow minimums and seasonal biological activity enhancing nitrate uptake. Complex diurnal dynamics were observed, with seasonal changes in phase and amplitude of the cycling, and the diurnal dynamics were variable along the river. At the moorland site, a regular daily cycle, with minimum concentrations in the early afternoon, corresponding with peak air temperatures, indicated the importance of instream biological processing. At the downstream site, the diurnal dynamics were a composite signal, resultant from advection, dispersion and nitrate processing in the soils of the lower catchment. The diurnal streamwater nitrate dynamics were also affected by drought conditions. Enhanced diurnal cycling in Spring 2007 was attributed to increased nitrate availability in the post-drought period as well as low flow rates and high temperatures over this period. The combination of high-frequency short-term measurements and long-term monitoring provides a powerful tool for increasing understanding of the controls of element fluxes and concentrations in surface waters.

scholarly journals Upland streamwater nitrate dynamics across decadal to sub-daily timescales: a case study of Plynlimon, Wales

2013 ◽  
Vol 10 (8) ◽  
pp. 13129-13189 ◽  
Author(s):  
S. J. Halliday ◽  
R. A. Skeffington ◽  
A. J. Wade ◽  
C. Neal ◽  
B. Reynolds ◽  
...  
Keyword(s):  
High Frequency ◽  
N Uptake ◽  
Low Flow ◽  
Downstream Site ◽  
Drought Period ◽  
Diurnal Dynamics ◽  
Early Afternoon ◽  
Wide Range ◽  
Nitrate Concentrations

Abstract. Streamwater nitrate dynamics in the River Hafren, Plynlimon, mid-Wales were investigated over decadal to sub-daily timescales using a range of statistical techniques. Long-term data were derived from weekly grab samples (1984–2010) and high-frequency data from 7 hourly samples (2007–2009) both measured at two sites: a headwater stream draining moorland and a downstream site below plantation forest. This study is one of the first to analyse upland streamwater nitrate dynamics across such a wide range of timescales and report on the principal mechanisms identified. The data analysis provided no clear evidence that the long term decline in streamwater nitrate concentrations was related to a decline in atmospheric deposition only; nitrogen deposition first increased and then decreased during the study period. Increased streamwater temperature and denitrification may also have contributed to the decline in stream nitrate concentrations, the former through increased N uptake rates and the latter resultant from increased dissolved organic carbon concentrations. Strong seasonal cycles, with concentration minimums in the summer, were driven by seasonal flow minimums and seasonal biological activity enhancing nitrate uptake. Complex diurnal dynamics were observed, with seasonal changes in phase and amplitude of the cycling, and the diurnal dynamics were variable along the river. At the moorland site, a regular daily cycle, with minimum concentrations in the early afternoon, corresponding with peak air temperatures, indicated the importance of instream biological processing. At the downstream site, the diurnal dynamics were a composite signal, resultant from advection and nitrate processing in the soils of the lower catchment. The diurnal streamwater nitrate dynamics were also affected by drought conditions. Enhanced diurnal cycling in spring 2007 was attributed to increased nitrate availability in the post-drought period as well as low flow rates and high temperatures over this period. The combination of high-frequency short-term measurements and long-term monitoring provides a powerful tool for increasing understanding of the controls of element fluxes and concentrations in surface waters.

scholarly journals Inter-microbial competition for N and plant NO3− uptake rather than BNI determines soil net nitrification under intensively managed Brachiaria humidicola

2021 ◽  
Author(s):  
Konrad Egenolf ◽  
Philipp Schad ◽  
Ashly Arevalo ◽  
Daniel Villegas ◽  
Jacobo Arango ◽  
...  
Keyword(s):  
Soil Ph ◽  
N Uptake ◽  
N Immobilization ◽  
Ammonia Oxidizing Bacteria ◽  
Gross Nitrification ◽  
Plant N Uptake ◽  
Microbial Competition ◽  
Brachiaria Humidicola ◽  
Net Nitrification ◽  
Intensively Managed

AbstractBrachiaria humidicola (syn. Urochloa humidicola) has been acknowledged to control soil nitrification through release of nitrification inhibitors (NI), a phenomenon conceptualized as biological nitrification inhibition (BNI). Liming and N fertilization as features of agricultural intensification may suppress BNI performance, due to a decrease in NI exudation, increased NH3 availability and promotion of ammonia oxidizing bacteria (AOB) over archaea (AOA). A 2-year three-factorial pot trial was conducted to investigate the influence of soil pH and soil microbial background (ratio of archaea to bacteria) on BNI performance of B. humidicola. The study verified the capacity of B. humidicola to reduce net nitrification rates by 50 to 85% compared to the non-planted control, irrespective of soil pH and microbial background. The reduction of net nitrification, however, was largely dependent on microbial N immobilization and efficient plant N uptake. A reduction of gross nitrification could not be confirmed for the AOA dominated soil, but possibly contributed to reduced net nitrification rates in the AOB-dominated soil. However, this putative reduction of gross nitrification was attributed to plant-facilitated inter-microbial competition between bacterial heterotrophs and nitrifiers rather than BNI. It was concluded that BNI may play a dominant role in extensive B. humidicola pasture systems, while N immobilization and efficient plant N uptake may display the dominant factors controlling net nitrification rates under intensively managed B. humidicola.

Relating particulate organic matter-nitrogen (POM-N) and non-POM-N with pulse crop residues, residue management and cereal N uptake

Agronomie ◽  
2002 ◽  
Vol 22 (7-8) ◽  
pp. 777-787 ◽  
Author(s):  
Graeme D. Schwenke ◽  
Warwick L. Felton ◽  
David F. Herridge ◽  
Dil F. Khan ◽  
Mark B. Peoples
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Crop Residues ◽  
N Uptake ◽  
Residue Management ◽  
Pulse Crop

Desynchronosis markers in risk assessment of metabolic syndrome development

2019 ◽  
Vol 1 (4) ◽  
pp. 21-26 ◽  
Author(s):  
O. V. Bobko ◽  
O. V. Tikhomirova ◽  
N. N. Zybina ◽  
O. A. Klitsenko
Keyword(s):  
Risk Assessment ◽  
Metabolic Syndrome ◽  
Threshold Values ◽  
Fat Tissue ◽  
Diurnal Dynamics ◽  
Laboratory Markers ◽  
Dyscirculatory Encephalopathy ◽  
Melatonin Production ◽  
Pai 1 ◽  
Logistic Regression Equation

The objective of the study is to show significance of desynchronosis laboratory markers in risk assessment of metabolic syndrome (MS) development. Materials and Methods. There were examined 98 men, aged 43-88, diagnosed with dyscirculatory encephalopathy showing one and more risk factors for development of cardiovascular diseases. They were divided into 2 groups according to the international guidelines of 2009: with MS (n = 61) and without MS (n = 37). Parameters of fats, glucose metabolism, inflammatory mediators, fat tissue metabolism markers, melatonin metabolite excretion (6-sulfatoxymelatonin) were defined in blood serum and urine. Results. The article presents data on changes in leptin, adiponectin, PAI-1, testosterone production and 6-sulfatoxymela-tonin excretion in patients with MS. There are calculated threshold values of these markers definitely increasing MS risk and logistic regression equation which allows assessing MS risk for an individual patient. Conclusion. Detected disorders of melatonin synthesis diurnal dynamics in patients with MS and interconnection between melatonin production and adiponectin, leptin, PAI-1, testosterone synthesis allow considering these parameters as desynchronosis markers significant for MS development.

Effect of N management approaches and planting densities on nitrogen accumulation by transplanted rice

2005 ◽  
Vol 53 (4) ◽  
pp. 405-415 ◽  
Author(s):  
P. Janaki ◽  
T. M. Thiyagarajan
Keyword(s):  
Grain Yield ◽  
Uptake Rate ◽  
Aboveground Biomass ◽  
N Uptake ◽  
Planting Density ◽  
Transplanted Rice ◽  
The Mean ◽  
N Uptake Rate ◽  
Management Approaches ◽  
N Management

Field experiments were conducted during 1998 and 1999 in June-September with rice variety ASD18 at the wetland farm, Tamil Nadu Agricultural University, Coimbatore, India to find out theeffect of N management approaches and planting densities on N accumulation by transplanted rice in a split plot design.The main plot consisted of three plant populations (33, 66 and 100 hills m-2) and the sub-plot treatments of five N management approaches. The results revealed thatthe average N uptake in roots and aboveground biomass progressively increased with growth stages. The mean root and aboveground biomass Nuptake were 26.1 to 130.6 and 6.4 to 17.8 kg ha-1, respectively. The N uptake of grain and straw was higher in theSesbania rostratagreen manuring + 150 kg N treatment, but it was not effective in increasing the grain yield. The mean total N uptake was found to be significantly lower at 33 hills m-2(76.9 kg ha-1) and increased with an increase in planting density (100.9 and 117.2 kg ha-1at 66 and 100 hills m-2density). N application had a significant influence on N uptake and the time course of N uptake in all the SPAD-guided N approaches. A significant regression coefficient was observed between the crop N uptake and grain yield. The relationship between cumulative N uptake at the flowering stage and the grain yield was quadratic at all three densities. The N uptake rate (µN) was maximum during the active tillering to panicle initiation period and declined sharply after that. In general, µNincreased with an increase in planting density and the increase was significant up to the panicle initiation to flowering period.thereafter, the N uptake rate was similar at densities of 66 and 100 hills m-2.

Nitrogen Demand of Cut Chrysanthemums in Relation to Shoot Height and Planting Date

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 523c-523
Author(s):  
Siegfried Zerche
Keyword(s):  
Dry Matter ◽  
Plant Density ◽  
Plant Biomass ◽  
N Uptake ◽  
Planting Date ◽  
Dry Matter Accumulation ◽  
Planting Dates ◽  
Shoot Height ◽  
Climate Conditions ◽  
Growing Period

Refined nutrient delivery systems are important for environmentally friendly production of cut flowers in both soil and hydroponic culture. They have to be closely orientated at the actual nutrient demand. To solve current problems, express analysis and nutrient uptake models have been developed in horticulture. However, the necessity of relatively laborious analysis or estimation of model input parameters have prevented their commercial use up to now. For this reason, we studied relationships between easily determinable parameters of plant biomass structure as shoot height, plant density and dry matter production as well as amount of nitrogen removal of hydroponically grown year-round cut chrysanthemums. In four experiments (planting dates 5.11.91; 25.3.92; 4.1.93; 1.7.93) with cultivar `Puma white' and a fixed plant density of 64 m2, shoots were harvested every 14 days from planting until flowering, with dry matter, internal N concentration and shoot height being measured. For each planting date, N uptake (y) was closely (r2 = 0.94; 0.93; 0.84; 0.93, respectively) related to shoot height (x) at the time of cutting and could be characterized by the equation y = a * × b. In the soilless cultivation system, dry matter concentrations of N remained constant over the whole growing period, indicating non-limiting nitrogen supply. In agreement with constant internal N concentrations, N uptake was linearly related (r2 = 0.94 to 0.99) to dry matter accumulation. It is concluded that shoot height is a useful parameter to include in a simple model of N uptake. However, in consideration of fluctuating greenhouse climate conditions needs more sophisticated approaches including processes such as water uptake and photosynthetically active radiation.

NLEAP Computer Model and Multiple Linear Regression Prediction of Nitrate Leaching in Vegetable Systems

2002 ◽  
Vol 12 (2) ◽  
pp. 250-256 ◽  
Author(s):  
Hudson Minshew ◽  
John Selker ◽  
Delbert Hemphill ◽  
Richard P. Dick
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Nitrate Leaching ◽  
Cover Crops ◽  
N Uptake ◽  
N Leaching ◽  
Residual Soil ◽  
Vegetable Crops ◽  
Crop N Uptake ◽  
Mlr Model

Predicting leaching of residual soil nitrate-nitrogen (NO3-N) in wet climates is important for reducing risks of groundwater contamination and conserving soil N. The goal of this research was to determine the potential to use easily measurable or readily available soilclimatic-plant data that could be put into simple computer models and used to predict NO3 leaching under various management systems. Two computer programs were compared for their potential to predict monthly NO3-N leaching losses in western Oregon vegetable systems with or without cover crops. The models were a statistical multiple linear regression (MLR) model and the commercially available Nitrate Leaching and Economical Analysis Package model (NLEAP 1.13). The best MLR model found using stepwise regression to predict annual leachate NO3-N had four independent variables (log transformed fall soil NO3-N, leachate volume, summer crop N uptake, and N fertilizer rate) (P < 0.001, R2 = 0.57). Comparisons were made between NLEAP and field data for mass of NO3-N leached between the months of September and May from 1992 to 1997. Predictions with NLEAP showed greater correlation to observed data during high-rainfall years compared to dry or averagerainfall years. The model was found to be sensitive to yield estimates, but vegetation management choices were limiting for vegetable crops and for systems that included a cover crop.

scholarly journals Biochar and urease inhibitor mitigate NH3 and N2O emissions and improve wheat yield in a urea fertilized alkaline soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Khadim Dawar ◽  
Shah Fahad ◽  
M. M. R. Jahangir ◽  
Iqbal Munir ◽  
Syed Sartaj Alam ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Grain Yield ◽  
Block Design ◽  
N Uptake ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Urease Inhibitor ◽  
Alkaline Soil ◽  
Total N ◽  
N Assimilation

AbstractIn this study, we explored the role of biochar (BC) and/or urease inhibitor (UI) in mitigating ammonia (NH3) and nitrous oxide (N2O) discharge from urea fertilized wheat cultivated fields in Pakistan (34.01°N, 71.71°E). The experiment included five treatments [control, urea (150 kg N ha−1), BC (10 Mg ha−1), urea + BC and urea + BC + UI (1 L ton−1)], which were all repeated four times and were carried out in a randomized complete block design. Urea supplementation along with BC and BC + UI reduced soil NH3 emissions by 27% and 69%, respectively, compared to sole urea application. Nitrous oxide emissions from urea fertilized plots were also reduced by 24% and 53% applying BC and BC + UI, respectively, compared to urea alone. Application of BC with urea improved the grain yield, shoot biomass, and total N uptake of wheat by 13%, 24%, and 12%, respectively, compared to urea alone. Moreover, UI further promoted biomass and grain yield, and N assimilation in wheat by 38%, 22% and 27%, respectively, over sole urea application. In conclusion, application of BC and/or UI can mitigate NH3 and N2O emissions from urea fertilized soil, improve N use efficiency (NUE) and overall crop productivity.

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