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.

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

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 Sulphur and nitrogen concentrations and fluxes in bulk precipitation and throughfall in the mountain and highland spruce stands in the Czech Republic

2010 ◽  
Vol 56 (No. 10) ◽  
pp. 429-441 ◽  
Author(s):  
I. Drápelová ◽  
L. Menšík ◽  
J. Kulhavý ◽  
I. Marková
Keyword(s):  
Czech Republic ◽  
Inorganic Nitrogen ◽  
Ammonium Nitrogen ◽  
Nitrogen Compounds ◽  
Bulk Precipitation ◽  
Sulphur Deposition ◽  
The Czech Republic ◽  
Spruce Stands ◽  
Nitrogen Concentrations ◽  
Total Inorganic Nitrogen

Concentrations and fluxes of sulphur and nitrogen compounds in bulk precipitation and in throughfall were evaluated and compared for two experimental sites in the Czech Republic: one situated at R&aacute;jec (Drahansk&aacute; upland, 610 m a.s.l.) and the second one at B&iacute;l&yacute; Kř&iacute;ž (Moravian-Silesian Beskids, 908 m a.s.l.) both with similar stands of young Norway spruce. The three-year study performed during 2006&ndash;2008, revealed statistically significant differences in nitrate nitrogen concentrations in bulk precipitations and in ammonium nitrogen concentrations both in bulk precipitation and in throughfall between the two sites. Higher nitrogen compounds concentrations in bulk precipitation were found at R&aacute;jec. Differences between the two sites in sulphur concentrations were not found out neither in bulk precipitation nor in throughfall waters. Total sulphur deposition amounted to 8.1, 8.3 and 6.7 kg S&middot;ha<sup>&ndash;1</sup> at R&aacute;jec and to 14.8, 16.9 and 15.4 kg S&middot;ha<sup>&ndash;1</sup> at Beskids for the three years studied, respectively. Total inorganic nitrogen throughfall flux amounted to 12.1, 11.6 and 11.6 at R&aacute;jec and 13.8, 18.9 and 15.0 kg&middot;ha<sup>&ndash;1</sup> at B&iacute;l&yacute; Kř&iacute;ž for the years 2006, 2007 and 2008, respectively. &nbsp;

scholarly journals Green manure effects on inorganic nitrogen dynamics in soil and its accumulation in grape must

2019 ◽  
Vol 13 ◽  
pp. 04010
Author(s):  
Roberto Zanzotti ◽  
Enzo Mescalchin
Keyword(s):  
Soil Nitrogen ◽  
Green Manure ◽  
Nitrogen Availability ◽  
Fruit Set ◽  
Inorganic Nitrogen ◽  
Mineral Fertilizer ◽  
Climatic Trend ◽  
Yeast Assimilable Nitrogen ◽  
Assimilable Nitrogen ◽  
Phenological Phases

The adoption of green manure practices in organic agriculture is increasingly spreading. This work aims to prove whether winter green manure—when compared to a traditional mineral fertilizer— alters the dynamics of inorganic nitrogen (NO3− and NH4+) availability in soil and the yeast assimilable nitrogen (YAN) in grape musts. During a two-year period, the soil nitrogen content was influenced by climatic trend and, especially, by rainfall. In fact, rainy periods reduced inorganic nitrogen availability in the soil. In both years, the green manure plot presented higher soil content of inorganic nitrogen at fruit-set, while different dynamics were shown over the following phenological phases. The must YAN concentration did not differ among treatments over the two-year experiment.

scholarly journals Potential of Ulva sp. in biofiltration and bioenergy production

2012 ◽  
Vol 3 (1) ◽  
pp. 55-59
Author(s):  
Thom Thi Dang ◽  
Mishima Yasufumi ◽  
Dinh Kim Dang
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Nitrogen Concentration ◽  
Ammonium Nitrogen ◽  
Ammonium Concentration ◽  
Marine Aquaculture ◽  
Bioenergy Production ◽  
Carbohydrate Concentration ◽  
Nitrogen Concentrations ◽  
Very High

In order to evaluate the effect of seaweeds in bio-filtration for removing nitrogen from marine aquaculture and in bioenergy production, Ulva sp. was used in this study. Experiments were triplicated and run in 3-day incubation at salinities with 30 psu, 10 psu and 5 psu in different initial ammonium nitrogen concentrations from 100 µM to 10,000 µM, equivalently to marine aquaculture conditions. The highest concentrations of ammonium removed were about 690 µmol (12.42 mg) NH4+ at 30 psu, 410 µmol (7.38 mg) NH4+ at 10 psu and 350 µmol NH4+(6.3 mg NH4+) at 5 psu in three days of incubation, while highest growth rates of Ulva sp. were 49% and 150% per day at 500 µM of initial ammonium concentration, similarly to the growth rate reported in microalgae. Moreover, after  these experiments, biomass of Ulva sp. has been tested for bioenergy producing goals, because the carbohydrate concentration of this alga was very high, reaching 60-70% of DW. Thus, Ulva sp. can be cultured to remove nitrogen concentration in eutrophication conditions at aquaculture systems in combination with the purpose of bioenergy production after harvesting. Để đánh giá hiệu quả của tảo biển trong việc lọc sinh học loại bỏ hợp chất ni tơ từ việc nuôi trồng thủy sản và trong việc sản xuất năng lượng sinh học, Ulva sp. đã được sử dụng trong nghiên cứu này. Các thí nghiệm được lặp lại 3 lần và chạy trong 3 ngày trong tủ ổn nhiệt tại các điều kiện độ mặn 30psu, 10psu, 5psuở các nồng độ NH4+-N từ 100μM đến 10.000μM, tương đương với điều kiện nuôi trồng thủy sản nước mặn. Nồng độ cao nhất của NH4+-N được loại bỏ khoảng 690 μmol NH4+ (12,42mg NH4+) tại 30psu, 410μmol NH4+ (7,38mg NH4+) tại 10psu và 350 μmol NH4+ (6.3mg NH4+) tại 5psu, trong đó tỉ lệ sinh trưởng của Ulva sp. là rất cao, sinh trưởng từ 49 đến 150% mỗi ngày tại nồng độ ammonium ban đầu 500 μM tương đương với sinh trưởng của vi tảo. Hơn nữa, sau các thí nghiệm trên, sinh khối của Ulva sp. được thử nghiệm sản xuất năng lượng sinh học vì hàm lượng carbohydrate trong tảo rất cao, chiếm khoảng 60-70% trọng lượng khô của tảo. Như vậy, Ulva sp. có thể đượcnuôi trồng để loại bỏ hợp chất ni tơ trong điều kiện phú dưỡng của các hệ thống nuôi trồng thủy sản, kết hợp với mục tiêusản xuất năng lượng sinh học sau thu hoạch.

Nitrogen fixation makes biomass allocation to roots independent of soil nitrogen supply

2007 ◽  
Vol 85 (9) ◽  
pp. 787-793 ◽  
Author(s):  
John H. Markham ◽  
Corinthe Zekveld
Keyword(s):  
Nitrogen Fixation ◽  
Plant Growth ◽  
Biomass Allocation ◽  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
Nitrogen Concentration ◽  
Nitrogen Fixing ◽  
Soil Nitrogen Availability ◽  
Least Squares Fit ◽  
Allocation Patterns

Biomass allocation patterns in plants are known to be affected by soil nitrogen availability. Since nitrogen availability can depress symbiotic nitrogen fixation, and nitrogen fixation can make plant growth independent of soil nitrogen availability but is energetically costly, it is unclear how allocation patterns in nitrogen-fixing species should respond to variation in soil nitrogen availability. We examined the effect of nitrogen source and concentration on the growth and allocation patterns in the nitrogen-fixing shrub Alnus viridis subsp. crispa (Aiton) Turrill. Plants were grown with either NH4+-N or NO3–-N at a range of low N concentrations, from 0 to 2 mmol·L–1, and either inoculated with Frankia or not. Plants without nodules had 25.l% lower biomass and had double the allocation to roots at all but the 2 mmol·L–1 nitrogen concentration. Even though nodulated plants increased growth with nitrogen concentration, allocation to roots as a fraction of total biomass did not vary in these plants, suggesting increased growth resulted from more efficient nitrogen acquisition. Allocation to roots was a significant predictor of plant growth in non-nodulated plants (r2 = 0.318, for linear least squares fit with log mass) but not for nodulated plants (r2 = 0.108). As nitrogen concentrations increased, allocation to nodules, specific nodule numbers, and the proportion of nitrogen fixed by the plants decreased, demonstrating a shift to soil nitrogen use.

scholarly journals A Spatiotemporal Analysis of Nitrogen Pollution in a Coastal Region with Mangroves of the Southern Gulf of Mexico

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2143 ◽  
Author(s):  
Regina Temino-Boes ◽  
Rabindranarth Romero-López ◽  
Inmaculada Romero
Keyword(s):  
Gulf Of Mexico ◽  
Organic Nitrogen ◽  
Nitrogen Concentration ◽  
Nitrogen Pollution ◽  
Economic Damage ◽  
Environmental Damage ◽  
Wet Season ◽  
Southern Gulf Of Mexico ◽  
Nitrogen Concentrations ◽  
Water Hyacinths

Nitrogen pollution is a growing problem in many rivers and estuaries of the Southern Gulf of Mexico. In Costa Esmeralda, a tourist destination in Veracruz, the increasing nitrogen pollution is causing severe environmental damage. However, very few studies addressed nitrogen pollution and its consequences for beaches and mangroves. In this study, a spatiotemporal evaluation of nitrogen concentrations was performed along two rivers discharging into Costa Esmeralda and the associated mangrove and coastal areas. The data used was obtained from the local government, which measured ammonium, nitrate and organic nitrogen concentrations between 2013 and 2016 with four annual measurements. Clustering analysis was used to detect the nitrogen concentration differences between riverine and coastal sites. Additionally, Mann-Kendall test was used to detect the trends throughout the study period. The Mann-Whitney W-test determined the difference in the median concentrations between the dry and the wet season. The results indicate that organic nitrogen concentrations are increasing in river mouths and coastal waters. Nitrogen pollution caused an intrusion of water hyacinths in touristic beaches and completely covered mangroves. The decomposition of these plants in saline waters was identified as the main potential source of increasing organic concentrations, driven by nitrogen pollution from wastewater, deforestation and fertilizers, and causing many environmental and socio-economic damage to the area. The results shed light on the prevailing water pollution problems in the Southern Gulf of Mexico.

scholarly journals Nitrous oxide and methane in two tropical estuaries in a peat-dominated region of northwestern Borneo

2016 ◽  
Vol 13 (8) ◽  
pp. 2415-2428 ◽  
Author(s):  
Denise Müller ◽  
Hermann W. Bange ◽  
Thorsten Warneke ◽  
Tim Rixen ◽  
Moritz Müller ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Inorganic Nitrogen ◽  
Monsoon Season ◽  
Peat Soil ◽  
Dry Season ◽  
N2o Emissions ◽  
Wet Season ◽  
Tropical Estuaries ◽  
Ch4 Emissions ◽  
Nitrogen Concentrations

Abstract. Estuaries are sources of nitrous oxide (N2O) and methane (CH4) to the atmosphere. However, our present knowledge of N2O and CH4 emissions from estuaries in the tropics is very limited because data are scarce. In this study, we present first measurements of dissolved N2O and CH4 from two estuaries in a peat-dominated region of northwestern Borneo. Two campaigns (during the dry season in June 2013 and during the wet season in March 2014) were conducted in the estuaries of the Lupar and Saribas rivers. Median N2O concentrations ranged between 7.2 and 12.3 nmol L−1 and were higher in the marine end-member (13.0 ± 7.0 nmol L−1). CH4 concentrations were low in the coastal ocean (3.6 ± 0.2 nmol L−1) and higher in the estuaries (medians between 10.6 and 64.0 nmol L−1). The respiration of abundant organic matter and presumably anthropogenic input caused slight eutrophication, which did not lead to hypoxia or enhanced N2O concentrations, however. Generally, N2O concentrations were not related to dissolved inorganic nitrogen concentrations. Thus, the use of an emission factor for the calculation of N2O emissions from the inorganic nitrogen load leads to an overestimation of the flux from the Lupar and Saribas estuaries. N2O was negatively correlated with salinity during the dry season, which suggests a riverine source. In contrast, N2O concentrations during the wet season were not correlated with salinity but locally enhanced within the estuaries, implying that there were additional estuarine sources during the wet (i.e., monsoon) season. Estuarine CH4 distributions were not driven by freshwater input but rather by tidal variations. Both N2O and CH4 concentrations were more variable during the wet season. We infer that the wet season dominates the variability of the N2O and CH4 concentrations and subsequent emissions from tropical estuaries. Thus, we speculate that any changes in the Southeast Asian monsoon system will lead to changes in the N2O and CH4 emissions from these systems. We also suggest that the ongoing cultivation of peat soil in Borneo is likely to increase N2O emissions from these estuaries, while the effect on CH4 remains uncertain.

scholarly journals Spatial and temporal assessment of soil nitrogen availability and relationships to biophysical variables in a high Arctic wetland

2021 ◽  
Author(s):  
Jacqueline K.Y. Hung
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
Inorganic Nitrogen ◽  
High Arctic ◽  
Ion Exchange Resin ◽  
Future Climate Change ◽  
Arctic Ecosystems ◽  
Soil Nitrogen Availability ◽  
Environmental Controls ◽  
Environmental Measures

Increased soil nutrient availability, and associated increase in ecosystem productivity, could create a negative feedback between Arctic ecosystem and the climate system, reducing the contribution of Arctic ecosystems to future climate change. This study explores the environmental controls over spatial patterns of soil nitrogen availability in a High Arctic wet sedge meadow and how they influence carbon exchange processes to predict whether this feedback will develop. Ion exchange resin membranes measured available inorganic nitrogen throughout the growing season at a high spatial resolution, while environmental variables and carbon flux measurements were taken at frequent intervals during the 2016 field season. Environmental measures correlated highly with total and late season nitrate with soil temperatures having the greatest effect. The results suggest that finer scale processes altering nitrogen availability may influence the C balance of wet sedge meadows in the High Arctic and how these ecosystems may respond to changes in climate.

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