scholarly journals Soil Nitrogen Dynamics in a Managed Temperate Grassland Under Changed Climatic Conditions

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 931
Author(s):  
Mona Giraud ◽  
Jannis Groh ◽  
Horst H. Gerke ◽  
Nicolas Brüggemann ◽  
Harry Vereecken ◽  
...  
Keyword(s):  
Nitrogen Uptake ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Nitrogen Dynamics ◽  
Climatic Conditions ◽  
Undisturbed Soil ◽  
Nitrogen Emissions ◽  
Growing Period ◽  
Grassland Type ◽  
Wide Range

Grasslands are one of the most common biomes in the world with a wide range of ecosystem services. Nevertheless, quantitative data on the change in nitrogen dynamics in extensively managed temperate grasslands caused by a shift from energy- to water-limited climatic conditions have not yet been reported. In this study, we experimentally studied this shift by translocating undisturbed soil monoliths from an energy-limited site (Rollesbroich) to a water-limited site (Selhausen). The soil monoliths were contained in weighable lysimeters and monitored for their water and nitrogen balance in the period between 2012 and 2018. At the water-limited site (Selhausen), annual plant nitrogen uptake decreased due to water stress compared to the energy-limited site (Rollesbroich), while nitrogen uptake was higher at the beginning of the growing period. Possibly because of this lower plant uptake, the lysimeters at the water-limited site showed an increased inorganic nitrogen concentration in the soil solution, indicating a higher net mineralization rate. The N2O gas emissions and nitrogen leaching remained low at both sites. Our findings suggest that in the short term, fertilizer should consequently be applied early in the growing period to increase nitrogen uptake and decrease nitrogen losses. Moreover, a shift from energy-limited to water-limited conditions will have a limited effect on gaseous nitrogen emissions and nitrate concentrations in the groundwater in the grassland type of this study because higher nitrogen concentrations are (over-) compensated by lower leaching rates.

Mass loss and nitrogen dynamics of decaying litter of grasslands: the apparent low nitrogen immobilization potential of root detritus

1992 ◽  
Vol 70 (2) ◽  
pp. 384-391 ◽  
Author(s):  
T. R. Seastedt ◽  
W. J. Parton ◽  
D. S. Ojima
Keyword(s):  
Mass Loss ◽  
Nitrogen Availability ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
C:N Ratio ◽  
Nitrogen Dynamics ◽  
Nitrogen Immobilization ◽  
Litter Bag ◽  
Root Litter ◽  
Low Nitrogen

Litter-bag studies and simulation modeling were used to examine the relationship between mass loss and nitrogen content of decaying prairie foliage and root litter. In contrast with forest studies, grassland roots were low in lignin and nitrogen, decayed more rapidly than foliage, and demonstrated very low nitrogen immobilization potentials. Our findings agree with reports indicating that buried substrates with high C:N ratios do not immobilize substantial amounts of nitrogen and that nitrogen-limited environments induce steeper slopes in the mass loss – nitrogen concentration relationship. However, results suggesting rapid nitrogen mineralization contradict our own studies demonstrating reduced inorganic nitrogen availability in soils of frequently burned prairie. Simulation of observed patterns using the CENTURY grassland model indicated that these results could not occur without creating soil organic matter with unrealistically high C:N ratios. Litter-bag studies of buried substrates therefore may provide an incomplete perspective on the mass loss and nitrogen dynamics of buried litter in grassland and agroecosystem soils. Key words: Andropogon gerardii, C:N ratio, decomposition, immobilization, mineralization, nitrogen.

scholarly journals Growth, Nitrogen Uptake of Maize (Zea mays L.) and Soil Chemical Properties, and Responses to Compost and Nitrogen Rates and Their Mixture on Different Textured Soils: Pot Experiment

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Ashenafi Nigussie ◽  
Wassie Haile ◽  
Getachew Agegnehu ◽  
Alemayehu Kiflu
Keyword(s):  
Nitrogen Uptake ◽  
Nitrogen Fertilizer ◽  
Agricultural Research ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Chemical Properties ◽  
Crop Productivity ◽  
Soil Chemical Properties ◽  
Pot Experiment ◽  
Mineral N

Integrated nutrient management, which primarily involves the combined application of organic and inorganic nutrient sources, is one of the simplest approaches to handle declining soil fertility challenges and increase crop productivity and production. Keeping in view this fact, a pot experiment was conducted to evaluate the effects of compost and inorganic nitrogen fertilizer and their mixture on soil properties, growth, and nitrogen uptake of maize on loam and clay textured soils at the Awada Agricultural Research Subcenter. Treatments comprised factorial combinations of five compost rates (0, 5, 10, 15, and 20 t·ha−1) and four rates of inorganic nitrogen fertilizer (0, 46, 92, and 138 kg·N·ha−1) laid out as a completely randomized design with three replications. Results showed that both the main and interaction effects of compost and mineral N fertilizer rates significantly affected the selected soil chemical properties and yield, and nitrogen concentration of maize. There were significant associations between plant parameters and soil nitrogen contents. The addition of 92 kg·ha−1·N + 10 t·ha−1 compost and 46 kg·ha−1·N + 10 t·ha−1 compost was the best treatments for loam and clay textured soils of the study areas, which improved shoot dry matter by 179.5 and 284.5%, compared to the unfertilized pot, respectively. From the results of this experiment, we concluded that the integrated application of compost and mineral nitrogen fertilizer enhanced soil chemical properties and thus improved nitrogen uptake and sustainable production of maize in the study areas.

Effects of subterranean, rose and cupped clovers on soil nitrogen and on a subsequent cereal crop

1980 ◽  
Vol 20 (104) ◽  
pp. 354 ◽  
Author(s):  
ER Watson ◽  
P Lapins ◽  
RJW Barron
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Uptake ◽  
Dry Matter ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Wheat Crop ◽  
Cereal Crop ◽  
Nitrogen Concentrations

Three annual clover species : subterranean clover, Trifolium subterraneum (cv. Geraldton), rose clover, T. hirtum (cv. Kondinin), and cupped clover, T. cherleri (cv. Yamina) were compared for yield of dry matter, for their effects on soil nitrogen, dry matter yield, and nitrogen uptake by a subsequent cereal crop. In one experiment, the three clover species and annual ryegrass (Lolium rigidum), were grown in lysimeters to provide measurements of dry matter and nitrogen yields of plant tops and roots. Half of the lysimeters, from which the plant roots had not been removed, were later sown with wheat. Rose clover produced the highest yield of root nitrogen, and this was reflected in higher nitrogen uptake in the succeeding wheat crop. Nitrogen yield of wheat after ryegrass was 60% of the average yield after clovers. The three clover species were also included in a pasture experiment, which was grazed by sheep for five years. Samples were taken from the field plots to provide soil for a glasshouse pot experiment, and for chemical analysis. In the pasture experiment, build up of soil nitrogen over six years did not differ significantly between the subterranean and rose clover treatments, although there were large differences in clover plant numbers and herbage production, and botanical composition of the pastures. However, inorganic nitrogen concentrations were much higher in soil from the subterranean clover plots than in soil from the rose or cupped clover plots, particularly in the later stages of the field experiment. Total nitrogen increase and mineral nitrogen concentration were lowest in soil from the cupped clover plots, although herbage yield was comparable with that of rose clover

scholarly journals Implications of mycorrhiza for biogeochemical cycling and coexistance of soil microbiota- a modelling study

2020 ◽  
Author(s):  
Frank Berninger
Keyword(s):  
Nitrogen Uptake ◽  
Mycorrhizal Fungi ◽  
Higher Plants ◽  
Inorganic Nitrogen ◽  
Environmental Parameters ◽  
Plant Productivity ◽  
Nitrogen Transfer ◽  
Wide Range ◽  
Fixed Proportion ◽  
Mycorrhizal Plants

Ectomycorrhizae are widespread symbionts of higher plants. However, their benefits for plant productivity and growth have not been well demonstrated since many studies do not suggest any improvement of plant growth or of plant nutrition for mycorrhizal plants. We use mechanistic modelling based on the population dynamics of decomposers to simulate the coexistence of mycorrhizal and non-mycorrhizal plants as well as the development of the soil decomposer community. The model assumed a fixed stoichiometry of each decomposer functional type. Decomposer growth depended on its carbon and nitrogen uptake. For mycorrhiza a part of the carbon is modelled to be supplied from the plant while a fixed proportion of the mycorrhizal nitrogen uptake is translocated to the plant. Carbon nitrogen ratios of decomposers were adjusted mineralization of nitrogen or overflow respiration of carbon. The results suggest that mycorrhizal plants do often outcompete non-mycorrhizal plants at no or little improvement of plant productivity. The main mechanism of mycorrhizal dominance is a reduction of the soil inorganic nitrogen pool and a rerouting of the nitrogen uptake of plants to the transfer nitrogen transfer from mycorrhizae to plants. On the other hand carbon subsidies from the trees allow to expand the niche of mycorrhizal fungi and to outcompete saprohytic fungi under a wide range of physiological and environmental parameters. This leads to dominance of mycorrhizal plants under a broad range of conditions and parameters including low transfer rates of nitrogen from the mycorrhiza to the plant, and low allocation of the plants to mycorrhiza.

Soil Temperature, Nitrogen Concentration, and Residence Time Affect Nitrogen Uptake Efficiency in Citrus

2002 ◽  
Vol 31 (3) ◽  
pp. 759 ◽  
Author(s):  
J. M. S. Scholberg ◽  
L. R. Parsons ◽  
T. A. Wheaton ◽  
B. L. McNeal ◽  
K. T. Morgan
Keyword(s):  
Soil Temperature ◽  
Residence Time ◽  
Nitrogen Uptake ◽  
Nitrogen Concentration ◽  
Nitrogen Uptake Efficiency ◽  
Uptake Efficiency

scholarly journals Environmental Drivers and Age Trends in Site Productivity for Oak in Southern Poland

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 209
Author(s):  
Luiza Tymińska-Czabańska ◽  
Jarosław Socha ◽  
Marek Maj ◽  
Dominika Cywicka ◽  
Xo Viet Hoang Duong
Keyword(s):  
Nitrogen Deposition ◽  
Management Practices ◽  
Additive Model ◽  
Climatic Conditions ◽  
Environmental Indicators ◽  
Environmental Drivers ◽  
Site Productivity ◽  
Site Factors ◽  
Wide Range ◽  
Si Model

Site productivity provides critical information for forest management practices and is a fundamental measure in forestry. It is determined using site index (SI) models, which are developed using two primary groups of methods, namely, phytocentric (plant-based) or geocentric (earth-based). Geocentric methods allow for direct site growth modelling, in which the SI is predicted using multiple environmental indicators. However, changes in non-static site factors—particularly nitrogen deposition and rising CO2 concentration—lead to an increase in site productivity, which may be visible as an age trend in the SI. In this study, we developed a geocentric SI model for oak. For the development of the SI model, we used data from 150 sample plots, representing a wide range of local topographic and site conditions. A generalized additive model was used to model site productivity. We found that the oak SI depended predominantly on physicochemical soil properties—mainly nitrogen, carbon, sand, and clay content. Additionally, the oak SI value was found to be slightly shaped by the topography, especially by altitude above sea level, and topographic position. We also detected a significant relationship between the SI and the age of oak stands, indicating the long-term increasing site productivity for oak, most likely caused by nitrogen deposition and changes in climatic conditions. The developed geocentric site productivity model for oak explained 77.2% of the SI variation.

Fire regime shift linked to increased forest density in a piñon–juniper savanna landscape

2014 ◽  
Vol 23 (2) ◽  
pp. 234 ◽  
Author(s):  
Ellis Q. Margolis
Keyword(s):  
Regime Shift ◽  
Fire History ◽  
Fire Regime ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Climatic Conditions ◽  
Tree Density ◽  
High Severity ◽  
Wide Range ◽  
In Fire

Piñon–juniper (PJ) fire regimes are generally characterised as infrequent high-severity. However, PJ ecosystems vary across a large geographic and bio-climatic range and little is known about one of the principal PJ functional types, PJ savannas. It is logical that (1) grass in PJ savannas could support frequent, low-severity fire and (2) exclusion of frequent fire could explain increased tree density in PJ savannas. To assess these hypotheses I used dendroecological methods to reconstruct fire history and forest structure in a PJ-dominated savanna. Evidence of high-severity fire was not observed. From 112 fire-scarred trees I reconstructed 87 fire years (1547–1899). Mean fire interval was 7.8 years for fires recorded at ≥2 sites. Tree establishment was negatively correlated with fire frequency (r=–0.74) and peak PJ establishment was synchronous with dry (unfavourable) conditions and a regime shift (decline) in fire frequency in the late 1800s. The collapse of the grass-fuelled, frequent, surface fire regime in this PJ savanna was likely the primary driver of current high tree density (mean=881treesha–1) that is >600% of the historical estimate. Variability in bio-climatic conditions likely drive variability in fire regimes across the wide range of PJ ecosystems.

Nitrogen cycling in a Venezuelan tropical seasonally flooded forest: soil nitrogen mineralization and nitrification

1994 ◽  
Vol 10 (3) ◽  
pp. 399-416 ◽  
Author(s):  
Barrios E. ◽  
Herrera R.
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Ammonium Nitrogen ◽  
Wet Season ◽  
Flooded Forest ◽  
Nitrogen Concentrations ◽  
Minimum Stress ◽  
Seasonally Flooded

ABSTRACTSeasonally flooded forests represent a transition between terrestrial and aquatic ecosystems. The Mapire river, a tributary of the Orinoco river, floods its surrounding forests during the wet season (May–December). The soils are very acid and the total nitrogen concentration (0.1%) is only half that found in nearby soils flooded by Orinoco waters. Ammonium-nitrogen predominates in the soil during the flooded period while nitrate-nitrogen concentrations are higher in the dry period. Wide fluctuations in the inorganic nitrogen fractions did not considerably affect the annual course of soil nitrogen.The predominance of mineralization versus nitrification (56 and 5 μgsoil month−1respectively) and possibly the synchronization of nitrogen availability with plant demand could be considered as nitrogen conserving mechanisms.In synchrony with the hydrologic cycle, the seasonally flooded forest studied shows a nitrogencycle where inputs and accumulation are maximized when the system is under minimum stress (dry season). During flooding, the system enters a period of dormancy making minimal use of nutrient and energy to avoid or tolerate anaerobiosis.

scholarly journals A reliable rainfall–runoff model for flood forecasting: review and application to a semi-urbanized watershed at high flood risk in Italy

2016 ◽  
Vol 48 (3) ◽  
pp. 726-740 ◽  
Author(s):  
Daniele Masseroni ◽  
Alessio Cislaghi ◽  
Stefania Camici ◽  
Christian Massari ◽  
Luca Brocca
Keyword(s):  
Flood Risk ◽  
Climatic Conditions ◽  
Rainfall Runoff ◽  
Number Of Factors ◽  
Wide Range ◽  
Median Volume ◽  
Flood Estimation ◽  
High Flood ◽  
Rainfall Runoff Model ◽  
Flooding Events

Many rainfall–runoff (RR) models are available in the scientific literature. Selecting the best structure and parameterization for a model is not straightforward and depends on a broad number of factors, including climatic conditions, catchment characteristics, temporal/spatial resolution and model objectives. In this study, the RR model ‘Modello Idrologico Semi-Distribuito in continuo’ (MISDc), mainly developed for flood simulation in Mediterranean basins, was tested on the Seveso basin, which is stressed several times a year by flooding events mainly caused by excessive urbanization. The work summarizes a compendium of the MISDc applications over a wide range of catchments in European countries and then it analyses the performances over the Seveso basin. The results show a good fit behaviour during both the calibration and the validation periods with a Nash–Sutcliffe coefficient index larger than 0.9. Moreover, the median volume and peak discharge errors calculated on several flood events were less than 25%. In conclusion, we can be assured that the reliability and computational speed could make the MISDc model suitable for flood estimation in many catchments of different geographical contexts and land use characteristics. Moreover, MISDc will also be useful for future support of real-time decision-making for flood risk management in the Seveso basin.

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