scholarly journals Organic and inorganic nitrogen leaching from incubated soils subjected to freeze-thaw and flooding conditions

1994 ◽  
Vol 74 (2) ◽  
pp. 201-206 ◽  
Author(s):  
F. L. Wang ◽  
J. R. Bettany

Freeze-thaw and flooding of usually well-drained soils occur in the spring in the prairie and boreal regions of Canada. We studied the impact of these conditions on nitrogen leaching in a Black Chernozemic soil (Udic Boroll). Soil samples, subjected to different treatments, were incubated for 12 wk in the laboratory and leached every 2 wk with 0.001 M CaCl2 solution. The cumulative leaching loss of total N (mg kg−1 soil) was reduced by freeze-thaw (76.0), flooding (41.4) and a superimposition of the two treatments (28.8) compared to the control (109). All treatments affected the distribution of the forms of N leached. The total loss of water soluble organic N (SON) and ammonium-N was in the order of flooded > flooded-freeze-thaw > freeze-thaw = control. In the leachates from the flooded treatments, SON accounted for 71.5–77.4% of the total N leached. Nitrate- and nitrite-N dominated the total leachable N in the unflooded treatments following an order of control > freeze-thaw > flooded = flooded-freeze-thaw. During the incubation, the Eh of the flooded soils decreased from 344 to −46 mV, compared to a variation in Eh from 355 to 301 mV for the unflooded soils. The maximum rate of leaching of organic nitrogen from the flooded treatment (0.53 mg N kg−1 d−1) coincided with a sharp decrease in Eh, from 131 to 42 mV. It is concluded that climatic events will have a significant impact on the dynamics of soil nitrogen. Flooding, in particular, may promote the loss of N in water soluble organic matter. Key words: Flooding, freeze-thaw, organic and inorganic nitrogen leaching, redox potential

HortScience ◽  
1993 ◽  
Vol 28 (3) ◽  
pp. 189-191 ◽  
Author(s):  
Charles F. Mancino ◽  
Mohammad Barakat ◽  
Alison Maricic

This study examined the numbers of specific soil and thatch microbial populations in a U.S. Golf Association (USGA) specification sand-peat putting green of creeping bentgrass (Agrostis palustris Huds.) over 17 months. Changes caused by adding a water-soluble or bio-organic (water-insoluble, contains microbial inoculum) N source were examined. Thatch was found to contain 40 to 1600 times as many bacteria as the soil, 500 to 600 times as many fungi, and up to 100 times as many actinomycetes. Soil populations of nitrate- and nitrite-reducing anaerobes were similar and ranged from 103 to 105 per gram of dry soil. Adding the bio-organic N source increased soil fungal counts and thatch thickness when compared with the control (no N applied), but not as much as the water-soluble N source. The amendments had no effect on soil respiration, total organic carbon. or total N content.


2011 ◽  
Vol 347-353 ◽  
pp. 2302-2307 ◽  
Author(s):  
Hong Xiang Wang ◽  
Yi Shi ◽  
Jian Ma ◽  
Cai Yan Lu ◽  
Xin Chen

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.


2019 ◽  
Vol 99 (4) ◽  
pp. 579-583
Author(s):  
X.M. Yang ◽  
C.F. Drury ◽  
W. Xu ◽  
M. Reeb ◽  
T. Oloya

Mid-infrared spectroscopy in the transmission mode was used to predict inorganic nitrogen (N), organic N, and total N in soil leachate. The developed predictions were accurate and robust for total N, NH4+, NO3−, inorganic N (NH4+ + NO3−), and organic N (total N − inorganic N) with high determination coefficients (R2 = 96.7 − 99.0) and residual prediction deviation (RPD = 5.47 − 9.96). The proposed method simultaneously estimates the concentrations of dissolved nitrogen species in soil leachates accurately and with significant savings in time, cost, and chemicals relevant to conventional methods.


1980 ◽  
Vol 60 (2) ◽  
pp. 365-372 ◽  
Author(s):  
R. E. KARAMANOS ◽  
D. A. RENNIE

Rather marked variations in δa15N values were obtained in a study carried out on samples taken from four soils belonging to the Weyburn soil association. The δa15N of the total N of well-drained depressional profiles dropped sharply with depth and, in contrast, for upper slope positions was relatively constant to a depth of approximately 5 m. This characteristic enrichment in the heavier isotope of total nitrogen of surface horizons may represent long-term immobilization of partially oxidized ammonium N into the organic N fraction; δa15N of the total N more closely represents past soil-forming processes while that of the nitrate N appears to reflect, in addition, recent N cycle stresses.


2011 ◽  
Vol 8 (6) ◽  
pp. 11311-11335 ◽  
Author(s):  
E. Gioseffi ◽  
A. de Neergaard ◽  
J. K. Schjoerring

Abstract. Soil-borne amino acids may constitute a nitrogen (N) source for plants in various terrestrial ecosystems but their importance for total N nutrition is unclear, particularly in nutrient-rich arable soils. One reason for this uncertainty is lack of information on how the absorption of amino acids by plant roots is affected by the simultaneous presence of inorganic N forms. The objective of the present study was to study absorption of glycine (Gly) and glutamine (Gln) by wheat roots and their interactions with nitrate (NO3–) and (NH4+) during uptake. The underlying hypothesis was that amino acids, when present in nutrient solution together with inorganic N, may lead to down-regulation of the inorganic N uptake. Amino acids were enriched with double-labelled 15N and 13C, while NO3– and NH4+ acquisition was determined by their rate of removal from the nutrient solution surrounding the roots. The uptake rates of NO3– and NH4+ did not differ from each other and were about twice as high as the uptake rate of organic N when the different N forms were supplied separately in concentrations of 2 mM. Nevertheless, replacement of 50 % of the inorganic N with organic N was able to restore the N uptake to the same level as that in the presence of only inorganic N. Co-provision of NO3– did not affect glycine uptake, while the presence of glycine down-regulated NO3– uptake. The ratio between 13C and 15N were lower in shoots than in roots and also lower than the theoretical values, reflecting higher C losses via respiratory processes compared to N losses. It is concluded that organic N can constitute a significant N-source for wheat plants and that there is an interaction between the uptake of inorganic and organic nitrogen.


2010 ◽  
pp. 134-140
Author(s):  
Andrea Balla Kovács ◽  
Anita Szabó ◽  
Emese Bartáné Szabó

A field experiment was conducted to examine the effects of different nitrogen fertilizers in combination with bacterial fertilizer onnutrient uptake of horseradish and plant available nutrients of the soil. Three different N fertilizers, ammonium-nitrate, urea and calciumnitrate(116 kg ha-1 N) in combination with Microbion UNC bacterial fertilizer (2 kg ha-1) were applied as treatments in a randomizedcomplete block design in three replications. In this paper we presented the results of soil measurements. The soil of the experimental areawas chernozem with medium sufficiency level of N and P and poor level of K.Our main results:The amount of 0.01M CaCl2 soluble inorganic nitrogen fractions, NO3--N and NH4+-N and also the quantity of soluble organic-N werealmost the same in the soil. N fertilizers significantly increased all the soluble N fractions. The amount of NO3--N increased to the greatestextent and the increase of organic N was the slightest. We measured the largest CaCl2 soluble NO3- -N and total-N contents in the plotstreated with ammonium-nitrate, the largest NH4+-N in the plots treated with calcium-nitrate and the largest organic-N fraction in plotstreated with urea.Bacterial inoculation also increased both soluble inorganic nitrogen forms and also total-N content of soil compared to the control. Inthe case of combined (artificial and bacterial fertilizer) treatments we measured lower NO3--N, organic-N and total-N compared to thevalues of plots having only nitrogen fertilizer treatments. On the contrary in the plots with combined treatments the CaCl2 soluble NH4+-Ncontent of soil in more cases were higher than that of values with artificial fertilizer treatment.As a function of calcium-nitrate application increased AL-P2O5 and AL-K2O values were measured compared to control. MicrobionUNC supplement of calcium nitrate yielded also increase in AL-P2O5 and AL-K2O values, till then supplement of ammonium-nitrate fertilizeryielded a decrease in these values compared to the control.All nitrogen fertilizers resulted in a significant decrease in AL-Mg content of soil compared to the control. Nevertheless bacterialfertilizer increased AL-Mg values in any cases.


Author(s):  
Moh Sholichin ◽  
Tri Budi Prayogo

Lake Tondano is the largest natural lake in North Sulawesi, Indonesia, which functions as a provider of clean water, hydroelectric power, rice field irrigation, inland fisheries, and tourism. This research aims to determine the effect of land cover types from the Tondano watershed on the lake water quality. The Soil and Water Assessment Tool (SWAT) model was used to evaluate the rate of soil erosion and the pollutant load of various land types in the watershed during the last ten years. Rainfall data is obtained from two rainfall stations, namely Paleloan Station and Noonan Station. The model is calibrated and validated before being used for analysis. We use climatological data from 2014 to 2019. The process of the SWAT model calibration and validation was carried out with the statistical formulas of the coefficient of determination (R2) and Nash-Sutcliffe efficiency (NSE). The results show that the potential for pollution load from the Tondao watershed is organic N of 0.039 kg/ha and organic P of 0.006 kg/ha coming from the agricultural land. The results of this study conclude that the fertility conditions of Lake Tondano are at the eutrophic level, where the pollutant inflow is collected in the lake waters, especially for the parameters of total N (1503697.44kg/year) and total P (144831.36kg/year). The SWAT simulation results show deviation between the modeling and field data collected with the value of R2 = 0.9303, and the significant level ≤ 10.


2021 ◽  
Author(s):  
Yinliu Wang ◽  
Signe Lett ◽  
Kathrin Rousk

Abstract Moss-associated nitrogen (N2) fixation is one of the main inputs of new N in pristine ecosystems that receive low amounts of atmospheric N deposition. Previous studies have shown that N2 fixation is inhibited by inorganic N (IN) inputs, but if N2 fixation in mosses is similarly affected by organic N (ON) remains unknown. Here, we assessed N2 fixation in two dominant mosses in boreal forests (Pleurozium schreberi and Sphagnum capillifolium) in response to different levels of N, simulating realistic (up to 4 kg N ha−1 yr−1) and extreme N deposition rates in pristine ecosystems (up to 20 kg N ha−1 yr−1) of IN (NH4NO3) and ON (alanine and urea). We also assessed if N2 fixation can recover from the N additions. In the realistic scenario, N2 fixation was inhibited by increasing NH4NO3 additions in P. schreberi but not in S. capillifolium, and alanine and urea stimulated N2 fixation in both moss species. In contrast, in the extreme N additions, increasing N inputs inhibited N2 fixation in both moss species and all N forms. Nitrogen fixation was more sensitive to N inputs in P. schreberi than in S. capillifolium and was higher in the recovery phase after the realistic compared to the extreme N additions. These results demonstrate that N2 fixation in mosses is less sensitive to organic than inorganic N inputs and highlight the importance of considering different N forms and species-specific responses when estimating the impact of N inputs on ecosystem functions such as moss-associated N2 fixation.


2015 ◽  
Vol 39 (1) ◽  
pp. 127-139 ◽  
Author(s):  
Marco André Grohskopf ◽  
Paulo Cezar Cassol ◽  
Juliano Corulli Correa ◽  
Maria Sueli Heberle Mafra ◽  
Jonas Panisson

The application of pig slurry may have a different effect on nitrogen dynamics in soil compared to mineral fertilization. Thus, the aim of this study was to determine the different forms of organic N in a Latossolo Vermelho distroférrico (Typic Hapludox) and their relationship to N uptake by crops in response to 10 years of annual application of pig slurry and mineral fertilizer. The treatments were application rates of 0, 25, 50, 100, and 200 m3 ha-1 of pig slurry, in addition to mineral fertilizer, organized in a randomized block design with four replications. The N contents were determined in the plant tissue and in the forms of total N and acid hydrolyzed fractions: ammonium-N, hexosamine-N, α-amino-N, amide-N, and unidentified-N. Annual application of pig slurry or mineral fertilizer increased the total-N content in the 0-10 cm depth layer. The main fractions of organic N in the soil were α-amino-N when pig slurry was applied and unidentified-N in the case of mineral fertilizers. Pig slurry increased the N fractions considered as labile: α-amino-N, ammonium-N, and amide-N. The increase in these labile organic N fractions in the soil through pig slurry application allows greater N uptake by the maize and oat crops in a no-tillage system.


2011 ◽  
Vol 51 (5) ◽  
pp. 416 ◽  
Author(s):  
C. J. Hoogendoorn ◽  
K. Betteridge ◽  
S. F. Ledgard ◽  
D. A. Costall ◽  
Z. A. Park ◽  
...  

A replicated grazing study measuring nitrogen (N) leaching from cattle-, sheep- and deer-grazed pastures was conducted to investigate the impact of different animal species on N leaching in the Lake Taupo catchment in New Zealand. Leaching losses of nitrate N from intensively grazed pastures on a highly porous pumice soil in the catchment averaged 37, 26 and 25 kg N/ha.year for cattle-, sheep- and deer-grazed areas, respectively, over the 3-year study and were not significantly different (P > 0.05). Leaching losses of ammonium N were much lower (3 kg N/ha.year for all three species of grazer; P > 0.05). Amounts of dissolved organic N leached were significantly higher than that of mineral N (nitrate N + ammonium N), and over the 3-year study averaged 44, 43 and 39 kg N/ha.year for cattle-, sheep- and deer-grazed areas, respectively (P > 0.05). On a stock unit equivalence basis (1 stock unit is equivalent to 550 kg DM consumed/year), cattle-grazed areas leached significantly more mineral N than sheep- or deer-grazed areas (5.5, 2.9 and 3.4 g mineral N leached/24 h grazing by 1 stock unit, for cattle, sheep and deer, respectively) (P < 0.001). Likewise, based on the amount of N apparently consumed (estimated by difference in mass of herbage N pre- and post-grazing), cattle-grazed pastures leached more mineral N than sheep- or deer-grazed pastures (123, 75 and 75 g mineral N/kg N apparently consumed for cattle, sheep and deer, respectively) (P < 0.01). This study gives valuable information on mineral N leaching in a high-rainfall environment on this free-draining pumice soil, and provides new data to assist in developing strategies to mitigate mineral N leaching losses from grazed pastures using different animal species.


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