AMMONIUM, NITRITE AND NITRATE ACCUMULATION IN THREE MANITOBA SOILS AS INFLUENCED BY ADDED AMMONIUM SULFATE AND UREA

1970 ◽  
Vol 50 (3) ◽  
pp. 331-338 ◽  
Author(s):  
R. W. JONES ◽  
R. A. HEDLIN

Samples of the Ap horizons of three Chernozemic Black soils of acid, neutral and alkaline pH were incubated with the addition of ammonium sulfate and urea in order to trace the formation and/or disappearance of ammonium, nitrite and nitrate. A nitrogen concentration of 50 ppm N (air-dry basis) resulted in little difference of nitrification rate in 12 days between ammonium sulfate and urea, although considerable differences existed between soils. At high nitrogen concentrations (200, 400, and 800 ppm N), urea led to high nitrite concentrations in the neutral Wellwood soil, as well as showing a higher rate of ammonium oxidation in all soils, particularly the acid Holland soil. Expressed as the difference between initial total mineral N and total mineral N after incubation, nitrogen showed a loss at the higher fertilizer rates with the Wellwood and Holland soils. This was greatest in the ammonium sulfate treatment with the initially most acid soil.

1992 ◽  
Vol 40 (1) ◽  
pp. 51-72 ◽  
Author(s):  
M. van Noordwijk ◽  
W.P. Wadman

A model based on a form-quadrant representation of N fertilizer experiments is presented. Calculations showed that spatial variability of mineral N in soil led to higher 'economic optimum' fertilizer rates and rates of Environmentally Acceptable Production (EAP) decreased. Without spatial variability a positive difference of 13 kg/ha was found between the N fertilizer rates for EAP and Maximum Economic Yield (MEY) even when the strictest environmental standard was applied (soil mineral N content at harvest not exceeding 34 kg/ha). At standard levels of variability there was a negative difference of 16 kg/ha, and at doubled variability the difference was 156 kg/ha. An N residue rate of 45 kg/ha at harvest could be met at standard varibility but not at doubled variability. The model showed that higher degrees of 'luxury consumption' and improved synchronization of N mineralization and crop demand had a positive effect on the difference between EAP and MEY. It was concluded that the degree of spatial variability in N supply must be taken into account for environmental and production targets. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1994 ◽  
Vol 10 (3) ◽  
pp. 399-416 ◽  
Author(s):  
Barrios E. ◽  
Herrera R.

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.


2013 ◽  
Vol 80 (2) ◽  
pp. 704-713 ◽  
Author(s):  
Estéfani García-Ríos ◽  
Alicia Gutiérrez ◽  
Zoel Salvadó ◽  
Francisco Noé Arroyo-López ◽  
José Manuel Guillamon

ABSTRACTThe effect of the main environmental factors governing wine fermentation on the fitness of industrial yeast strains has barely received attention. In this study, we used the concept of fitness advantage to measure how increasing nitrogen concentrations (0 to 200 mg N/liter), ethanol (0 to 20%), and temperature (4 to 45°C) affects competition among four commercial wine yeast strains (PDM, ARM, RVA, and TTA). We used a mathematical approach to model the hypothetical time needed for the control strain (PDM) to out-compete the other three strains in a theoretical mixed population. The theoretical values obtained were subsequently verified by competitive mixed fermentations in both synthetic and natural musts, which showed a good fit between the theoretical and experimental data. Specifically, the data show that the increase in nitrogen concentration and temperature values improved the fitness advantage of the PDM strain, whereas the presence of ethanol significantly reduced its competitiveness. However, the RVA strain proved to be the most competitive yeast for the three enological parameters assayed. The study of the fitness of these industrial strains is of paramount interest for the wine industry, which uses them as starters of their fermentations. Here, we propose a very simple method to model the fitness advantage, which allows the prediction of the competitiveness of one strain with respect to different abiotic factors.


Bragantia ◽  
2012 ◽  
Vol 71 (3) ◽  
pp. 394-399 ◽  
Author(s):  
Djeimi Isabel Janisch ◽  
Jerônimo Luiz Andriolo ◽  
Vinícius Toso ◽  
Kamila Gabriele Ferreira dos Santos ◽  
Jéssica Maronez de Souza

The objective of this research was to determine growth and dry matter partitioning among organs of strawberry stock plants under five Nitrogen concentrations in the nutrient solution and its effects on emission and growth of runner tips. The experiment was carried out under greenhouse conditions, from September 2010 to March 2011, in a soilless system with Oso Grande and Camino Real cultivars. Nitrogen concentrations of 5.12, 7.6, 10.12 (control), 12.62 and 15.12 mmol L-1 in the nutrient solution were studied in a 5x2 factorial randomised experimental design. All runner tips bearing at least one expanded leaf (patent requested) were collected weekly and counted during the growth period. The number of leaves, dry matter (DM) of leaves, crown and root, specific leaf area and leaf area index (LAI) was determined at the final harvest. Increasing N concentration in the nutrient solution from 5.12 to 15.12 mmol L-1 reduces growth of crown, roots and LAI of strawberry stock plants but did not affect emission and growth of runner tips. It was concluded that for the commercial production of plug plants the optimal nitrogen concentration in the nutrient solution should be 5.12 mmol L-1.


Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 519 ◽  
Author(s):  
J. Sierra ◽  
S. Fontaine ◽  
L. Desfontaines

Laboratory incubations and a field experiment were carried out to determine the factors controlling N mineralization and nitrification, and to estimate the N losses (leaching and volatilization) in a sewage-sludge-amended Oxisol. Aerobically digested sludge was applied at a rate equivalent to 625 kg N/ha. The incubations were conducted as a factorial experiment of temperature (20˚C, 30˚C, and 40˚C) soil water (–30 kPa and –1500 kPa) sludge type [fresh (FS) water content 6230 g/kg; dry (DS) water content 50 g/kg]. The amount of nitrifiers was determined at the beginning and at the end of the experiment. The incubation lasted 24 weeks. The field study was conducted using bare microplots (4 m) and consisted of a factorial experiment of sludge type (FS and DS) sludge placement (subsurface, I+; surface, I–). Ammonia volatilization and the profile (0–0.90 m) of mineral N concentration were measured during 6 and 29 weeks after sludge application, respectively. After 24 weeks of incubation at 40˚C and –30 kPa, net N mineralization represented 52% (FS) and 71% (DS) of the applied N. The difference between sludges was due to an initial period of N immobilization in FS. Nitrification was more sensitive than N mineralization to changes in water potential and it was fully inhibited at –1500 kPa. The introduction of a large amount of nitrifiers with FS did not modify the rate of nitrification, which was principally limited by soil acidity (pH 4.9). Although N mineralization was greatest at 30˚C, nitrification increased continuously with temperature. Nitrogen mineralization from DS was well described by the double-exponential equation. For FS, the equation was modified to take into account an immobilization-remineralization period. Sludge placement significantly affected the soil NO-3/NH+4 ratio in the field: 16 for I+ and 1.5 for I–, after 11 weeks. In the I– treatment, nitrification of the released NH+4 was limited by soil moisture because of the dry soil mulch formed a few hours after rain. At the end of the field experiment, the estimated losses of N by leaching were 432 kg N/ha for I+ and 356 kg N/ha for I–. Volatilization was not detectable in the I+ microplots and it represented only 0.5% of the applied N in the I– microplots. The results showed that placement of sludge may be a valuable tool to decrease NO-3 leaching by placing the sludge under unfavourable conditions for nitrification.


1982 ◽  
Vol 28 (8) ◽  
pp. 959-975 ◽  
Author(s):  
Colin R. Bell ◽  
Maxine A. Holder-Franklin ◽  
Mervyn Franklin

Forty-eight continuous culture enrichments were performed on summer and winter water samples from two contrasting rivers. The cell output from each chemostat was dependant on the temperature and nitrogen concentration of each enrichment. The diversity of the populations from the continuous cultures, as assessed by species diversity analysis, was always greater than populations obtained on agar plates. However, the species isolated exclusively by continuous culture in these experiments were not unique to the chemostat. All of these species had been isolated at some time on plates directly. High nitrogen concentrations were found to decrease diversity. Populations sampled during the winter were influenced primarily by the concentration of nitrogen. Summer isolates were affected mainly by the temperature of the culture medium. The nutritional versatility of the population was not affected by enrichment of the continuous culture.


1989 ◽  
Vol 37 (2) ◽  
pp. 143-155 ◽  
Author(s):  
J.J. Neeteson

The performances of 3 different N fertilizer recommendation methods were retrospectively tested with data obtained from 150 trials with sugarbeet and 98 trials with potatoes in the Netherlands in 1973-82. The recommendations consisted of applying a fixed N rate in all situations (126 kg N/ha for sugarbeet and 286 kg N/ha for potatoes), the current Dutch method, which takes only the amount of mineral N present in the soil in early spring into account, and a refinement of the current method, which also takes soil type and recent applications of organic manures into account. On av., significantly lower amounts of fertilizer N were recommended with the current method. The difference from the other methods was on av. 25 kg N/ha for sugarbeet and 30 kg N/ha for potatoes. With the refined current method the highest crop yields were obtained but the difference from the other methods was not significant and averaged only 0.3-0.4 t/ha for sugarbeet and 0.1-0.2 t/ha for potatoes. The recovery of fertilizer N by the potato tubers was 2% higher with the current method than with the other methods. Based on these findings it is concluded that the current recommendation method is preferable to the other methods. (Abstract retrieved from CAB Abstracts by CABI’s permission)


2012 ◽  
Vol 64 (3) ◽  
pp. 1079-1084 ◽  
Author(s):  
Nil Bagriaçik

The aim of this study was to determine and compare the nest materials and some physical features and elemental composition of the nests of Polistes gallicus (L.), Polistes dominulus (Christ) and Polistes nimpha (Christ) collected in similar ecological conditions. The nest architectures of the three species were similar. In the P. gallicus nest, the average thickness of the fibers was 5.73 ?m, the nitrogen concentration was 26.14%, and percentages of the fibers and saliva were 77% and 23%, respectively. In the P. dominulus nest, the average thickness of the fibers was 8.7 ?m, and the nitrogen concentration was 27.42%; the percentages of fiber and saliva were 78% and 22%, respectively. In the P. nimpha nest, the average thickness of the fibers was 9.04 ?m, the nitrogen concentration was 25.82%, and the percentages of the fiber and saliva were 42% and 58%, respectively. There were differences in the amount of saliva and nitrogen concentrations.


2020 ◽  
Vol 36 (6) ◽  
Author(s):  
Itaruã Machri Colla ◽  
Olavo Bilac Quaresma de Oliveira Filho ◽  
Janyeli Dorini Silva de Freitas ◽  
Míria Benetati Delgado Bertéli ◽  
Giani Andrea Linde ◽  
...  

Lentinus crinitus is a medicinal basidiomycete, little studied regarding the basic cultivation conditions, which is used in bioremediation and consumed by native Indians from the Brazilian Amazon. Also, it produces a fungal secondary metabolite panepoxydone that has been described as an essential regulator of the inflammatory and immune response. This study aimed to evaluate basic conditions of temperature, pH, and nitrogen concentration and source in the cultivation of L. crinitus mycelial biomass. In order to evaluate fungal growth temperature, 2% malt extract agar (MEA) medium, pH 5.5, was utilized from 19 to 40 °C. For pH, MEA had pH adjusted from 2 to 11 and cultivated at 28 °C. Urea or soybean meal was added to MEA to obtain final concentration from 0.5 and 16 g/L of nitrogen, pH of 5.5, cultivated at 28 °C. The best temperature growth varies from 31 to 34 ºC and the optimal one is 32.7º C, and the best pH ranges from 4.5 to 6.5 and the optimal one is 6.1. Protein or non-protein nitrogen concentration is inversely proportional to the mycelial biomass growth. Nitrogen concentrations of 2.0 g/L soybean meal and urea inhibit mycelial biomass growth in 11% and 12%, respectively, but high concentrations of 16.0 g/L nitrogen inhibit the growth in 46% and 95%, respectively. The fungus is robust and grows under extreme conditions of temperature and pH, but smaller adaptation with increasing nitrogen concentrations in the cultivation medium, mainly non-protein nitrogen.


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