Soil nitrogen transformations on a subantarctic island

1992 ◽  
Vol 4 (1) ◽  
pp. 41-50 ◽  
Author(s):  
V. R. Smith ◽  
Marianna Steenkamp
Keyword(s):  
Growth Period ◽  
Organic N ◽  
Nitrogen Transformations ◽  
Inorganic N ◽  
Biological Fixation ◽  
Available N ◽  
Grassland Community ◽  
Soil Macroinvertebrates ◽  
Soil Nitrogen Transformations

The vascular vegetation of a mire-grassland community on Marion Island (47°S, 38°E) takes up c. 158 mg N m−2 d−1 in summer. Bryophytes take up c. 36 mg N m−2 d−1 during their peak growth period. Since inputs of N through precipitation and biological fixation are negligible, mineralization of organic N must have supplied the bulk of this N. From changes in peat inorganic N levels and rates of uptake by the vegetation we estimate mean mineralization rates of 178 mg N m−2 d−1 in summer and 55 mg N m−2d−1 in winter. In situ incubation of peat give a maximum mineralization rate of 48 mg N m−2 d−1. At this rate the small (700 mg m−2) pool of available N in the upper 25 cm of peat would be depleted by the vascular vegetation in about seven days and bryophytes would deplete the available N pool in the top 25 mm in two days. Hence the rate of N mineralization measured by incubation is much too low to account for the fluctuations in concentrations of inorganic N in the peat and the amounts taken up by the vegetation. This may be due to losses through denitrification or to the fact that soil macroinvertebrates were excluded from the incubation.

CORN RESPONSE AND SOIL NITROGEN TRANSFORMATIONS FOLLOWING VARIED APPLICATION OF POULTRY MANURE TREATED TO MINIMIZE ODOR

1975 ◽  
Vol 55 (1) ◽  
pp. 29-34 ◽  
Author(s):  
K. A. MACMILLAN ◽  
T. W. SCOTT ◽  
T. W. BATEMAN
Keyword(s):  
Soil Ph ◽  
Dry Matter ◽  
Poultry Manure ◽  
Organic N ◽  
Nitrogen Transformations ◽  
Inorganic N ◽  
N Source ◽  
Soil Inorganic N ◽  
Ph Conditions ◽  
Soil Nitrogen Transformations

The response of corn (Zea mays L.) to manure that had been treated to minimize odor was investigated in a greenhouse trial with two silt loam soils of pH 4.2 and 7.1. Pretreatment of manure resulted in sources initially high in organic N and NH4+, but low in NO3−. One pretreatment gave high initial NO2− concentrations. In soil at pH 4.2, NH4+ was the major N source utilized by corn grown to 36 days, and dry matter yields were superior to those from soil at pH 7.1 where soluble NO3− was the major source of N. At pH 7.1, NO2− remained in significant quantities and decreased dry matter yields at 6 wk. Soil inorganic N concentrations varied between soils and was attributed to soil pH differences. Rate of NO2− disappearance decreased with increase in soil pH, and NH4+ accumulation increased with decrease in soil pH, whereas NO3+ production was favored by neutral pH conditions. Some NO3− production was observed in pH 4.2 soil after 36 days' incubation

Benthic metabolism and nitrogen transformations affected by fish cage farming in the tropical Nha Phu estuary (Vietnam)

2012 ◽  
Vol 63 (10) ◽  
pp. 887 ◽  
Author(s):  
Hanh Kim Nguyen ◽  
Erik Kristensen ◽  
Lars Chresten Lund-Hansen
Keyword(s):  
Fish Farming ◽  
Total Carbon ◽  
Reference Station ◽  
Organic N ◽  
Nitrogen Transformations ◽  
Inorganic N ◽  
Available N ◽  
Benthic Metabolism ◽  
Water Currents ◽  
Fish Cages

Effects of organic-waste loading from fish farming on benthic metabolism and nitrogen (N) cycling were studied in the tropical Nha Phu Estuary, Vietnam. The loading of fish excreta and feed waste enhanced benthic oxygen (O2) uptake two times and total carbon dioxide (TCO2) release three times, compared with the reference station. NH4+ was the major form of released N, comprising 94–100% of dissolved inorganic N (DIN) flux below and near fish cages. Only 3% and 1% of organic carbon (OC) and organic N (ON) deposited from the fish farm was degraded in the sediment, whereas the rest was dispersed to adjacent areas via tidal currents or buried into the sediment. Coupled nitrification–denitrification were almost 0 under fish cages but increased at distances greater than 10 m from fish cages. Consequently, biologically available N was not removed permanently near fish cages as the excess N deposited under cages were mineralised and released as DIN. The nutrient efflux could therefore potentially be a source for pelagic primary production in the vicinity of cages. However, the water currents and low water residence time may have distributed and diluted the nutrient effect of cages to the entire estuary and the adjacent ocean.

Nitrogen mineralization in beef- and pig-manure-amended soils measured using anion resin method

2015 ◽  
Vol 95 (4) ◽  
pp. 305-319 ◽  
Author(s):  
D. V. Ige ◽  
S. M. Sayem ◽  
O. O. Akinremi
Keyword(s):  
Nitrogen Mineralization ◽  
Growing Season ◽  
Organic N ◽  
Pig Manure ◽  
Inorganic N ◽  
Available N ◽  
Amended Soils ◽  
Anion Resin ◽  
Resin Method ◽  
Fertilizer Equivalence

Ige, D. V., Sayem, S. M. and Akinremi, O. O. 2015. Nitrogen mineralization in beef- and pig-manure-amended soils measured using anion resin method. Can. J. Soil Sci. 95: 305–319. A major challenge facing the widespread use of manure is the uncertainty about its fertilizer equivalence. This study was carried out to determine the fertilizer equivalence of locally available manures in two soils in Manitoba. A randomized complete block design was adopted with six treatments [nitrogen fertilizer, a liquid swine manure (LSM), three solid beef manures (SBM) and a control] and four replicates. Each treatment was applied to a cylindrical soil column installed at the site at the rate of 100 kg ha−1of “available N”, and leached NO3-N was captured by resin bags at the bottom of the cylinder. The soils and resin bags removed from the cylinders were sampled at 0, 1, 2, 4, 6, 8, 10, 14, and 18 wk following treatment application. Ammonium nitrogen in the amendments was nitrified within the first 2 to 3 wk with significant build-up of NO3-N in the soil above the control (P<0.05). The greatest available N was in the fertilizer treatment, followed by the LSM and the smallest was in the SBM. The available N in the three SBM was statistically similar (P>0.05). Approximately 50% of the inorganic N in LSM was available during the growing season, while 68 to 100% of SBM inorganic N was available. Between 4 and 25% of the organic N in the three SBM was mineralized during the growing season. High soil moisture hindered N mineralization and enhanced N loss in the clay soil. LSM has the greatest fertilizer equivalence, with a mean of 65 to 68%, of the four manure types used. The fertilizer equivalence of the three SBM ranged between 42 and 59% and was influenced by the manure C:N ratio and the soil environmental conditions. Our study suggests the need to revise the assumptions regarding manure N availability by considering soil environmental factors in the estimation of available N.

scholarly journals Nitrogen Dynamics Associated with Organic and Inorganic Inputs to Substrate Commonly Used on Rooftop Farms

HortScience ◽  
2015 ◽  
Vol 50 (6) ◽  
pp. 806-813 ◽  
Author(s):  
Angela Y.Y. Kong ◽  
Cynthia Rosenzweig ◽  
Joshua Arky
Keyword(s):  
The United States ◽  
Organic N ◽  
N Availability ◽  
Inorganic N ◽  
Available N ◽  
Nutrient Runoff ◽  
Swiss Chard ◽  
Rooftop Farming ◽  
N Input ◽  
Synthetic Fertilizer

Employing rooftops for the cultivation of crops in limited urban space has garnered interest in densely populated cities in the United States, where there is a growing demand for locally sourced vegetable products. Fertility management recommendations for rooftop farming, however, are scant. With insufficient research on nutrient cycling within rooftop farming systems, which tend to use soilless substrates with low organic matter content, the potential tradeoffs between the negative impacts (e.g., nutrient runoff) and the benefits (e.g., increased locally produced vegetables, stormwater retention, etc.) associated with rooftop farms are unclear. The objective of this study was to evaluate the effects of organic and inorganic nitrogen (N) inputs on the N dynamics within substrate typically used on rooftop farms. Substrate without added N inputs (control) was compared with substrates receiving N sources that are both realistic for and/or reflective of amendments currently applied on urban rooftop farms: a synthetic fertilizer (Osmocote® 14N–4.2P–11.6K), and three organic N inputs—composted poultry manure, municipal green waste (MGW) compost, and vermicompost. Aboveground crop biomass and yields of Beta vulgaris (swiss chard), along with inorganic N availability (ammonium: and nitrate: ), potentially mineralizable nitrogen (PMN), leachate-inorganic N concentrations, and pH and electrical conductivity (EC) levels were measured during an 8-week greenhouse experiment. Despite differences in carbon-to-nitrogen ratios (C:N), few differences in N cycling and yields were found among the treatments receiving organic N inputs. Crop yields from the synthetic fertilizer and MGW compost treatments were higher than the other organic N input treatments. Inorganic N levels in the synthetic fertilizer treatment decreased from 129 mg N/L at the start of the season to 113 mg N/L at the end of the season, while nearly 10-fold decreases of inorganic N concentrations in the substrate of the control and organic N input treatments from week 0 (79.5–117.8 mg N/L) to week 8 (12.8–16.6 mg N/L) were observed. Greater N availability at critical periods during the season may have promoted greater crop N uptake efficiency and, therefore, higher yields in the system receiving synthetic fertilizer. However, the greatest losses of and via leachate were also measured from this treatment. Our results show that the type of N input influenced plant-available N and yields and that the MGW compost treatment best achieved the balance between higher yields and reduced N losses to potential roof runoff. Furthermore, additional N inputs to these systems, particularly to the treatments receiving organic composts, will likely be necessary if a high N-demanding crop (such as swiss chard) is to be grown in the same substrates for more than 8 weeks. Rooftop farming is an emergent component of urban agriculture; regulations and guidelines for nutrient management of rooftop farms are necessary to optimize productivity and long-term benefits and to minimize negative environmental impacts.

Effects of long-term soil warming on nitrogen fluxes in forest soils

2020 ◽  
Author(s):  
Erich Inselsbacher ◽  
Jakob Heinzle ◽  
Andreas Schindlbacher
Keyword(s):  
Amino Acids ◽  
Global Warming ◽  
Soil Temperature ◽  
Organic N ◽  
Soil N ◽  
Inorganic N ◽  
Soil Warming ◽  
N Fluxes

&lt;p&gt;Forests are the main contributors to the global terrestrial carbon (C) sink but several studies suggest that global warming could significantly reduce their CO&lt;sub&gt;2&lt;/sub&gt; mitigation potential. The capacity of forest plants to sequester C is closely linked to soil nitrogen (N) availability, a major control of plant growth and ecosystem functioning. An increase of soil temperature caused by global change is critically affecting soil N supply rates, both directly by increasing diffusive N fluxes in the soil solution and indirectly by accelerating soil N turn-over rates. In recent short-term laboratory incubation studies, an increase in soil temperature has not only led to a significant increase in diffusive N fluxes but also to a concomitant shift in N quality available for plant uptake towards a higher portion of inorganic N forms compared to small organic N forms such as amino acids. However, until now long-term effects of soil warming on soil N fluxes have not been studied. Here, we present first results from a study on soil N availabilities at the long-term soil warming experimental site Achenkirch (Austria) in the Limestone Alps. This site is one of the few&lt;em&gt; in situ&lt;/em&gt; climate manipulation experiments operational for more than 10 years and has already provided a wealth of novel insights into the potential effects of global warming on forest ecosystem responses. Applying &lt;em&gt;in situ&lt;/em&gt; microdialysis, we estimated diffusive fluxes of inorganic N and amino acids along the growing season in soils warmed by resistance heating cables since 2005 (+4 &amp;#176;C compared to control plots) and control soils. Fluxes of all N forms were highly variable within each subplot (2 x 2 m) and reflected the high heterogeneity of soils at this forest site. Interestingly, fluxes of amino acids were less variable than of nitrate or ammonium throughout the year, indicating comparably stable protein depolymerization rates. In summary, long-term soil warming affected diffusive N fluxes but less than other factors operating on smaller (&lt; 1 cm) scales.&lt;/p&gt;

C and N mineralization of composted and anaerobically stored ruminant manure in differently textured soils

2000 ◽  
Vol 135 (2) ◽  
pp. 151-159 ◽  
Author(s):  
INGRID K. THOMSEN ◽  
JØRGEN E. OLESEN
Keyword(s):  
N Mineralization ◽  
Storage Period ◽  
Clay Content ◽  
Organic N ◽  
Net N Mineralization ◽  
Turnover Rates ◽  
Inorganic N ◽  
Available N ◽  
C Pools ◽  
Anaerobic Storage

Three animal manures cross-labelled with 15N in either the urine, faeces or straw fractions were prepared. After a storage period of 86 days when the manures were exposed to either composting or to anaerobic storage, portions of the manures were incubated in six differently textured soils with clay contents ranging from 11 to 45%. Evolved CO2-C was determined during a 266 day incubation and inorganic N and 15N in soil were measured at the termination of the incubation. The mineralization of C was analysed using first-order kinetics, and two C pools with fast (P1) and slow (P2) turnover rates were estimated. The total conversion of added C (Ps) was estimated as Ps=P1+P2.The cumulated CO2 production was considerably higher from soils incubated with anaerobically stored manure compared with soils amended with composted manure. CO2 production levelled off after c. 60 days in the three sandier soils whereas CO2 continued to be produced throughout the incubation from the three soils with the highest clay content. More C was assigned to the easily decomposable P1 pool in the sandiest soils whereas the more recalcitrant P2 pool was larger in the soils with higher clay content. Because of the different relationships between soil texture and C pools, Ps ended up being similar for five of the six soils. When taking C losses during the preceding storage into account, the accumulated C losses during storage and after incubation in soil accounted for 60 and 54% of C initially present in the composted and anaerobically stored manure, respectively.Net N mineralization which averaged 16% of applied organic N took place in all soils amended with composted manure. Soils with anaerobically stored manure showed net immobilization after the 266 days of incubation. The amount of N immobilized accounted for up to 30% of the inorganic N applied with the manure. As anaerobically stored manure generally loses less inorganic N during storage, it may contain more inorganic N than composted manure at the time of field application. Because of the immobilization that takes place after application of anaerobically stored manure to soil, the immediate levels of plant available N in soil may not be as different from soil supplied with composted manure as could be expected from the inorganic N content in the two types of manure. However, when considering the manure as a N resource, anaerobic storage is superior to composting.

Different characteristics of nitrogen utilization between lupin and soybean: can lupin utilize organic nitrogen in soils?

2006 ◽  
Vol 84 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Toshihiro Watanabe ◽  
Miwa Okamoto ◽  
Seiji Misawa ◽  
Masaru Urayama ◽  
Mitsuru Osaki
Keyword(s):  
Amino Acids ◽  
Ammonium Sulphate ◽  
Farmyard Manure ◽  
White Lupin ◽  
Organic N ◽  
Cluster Roots ◽  
Inorganic N ◽  
Available N ◽  
Microbial Decomposition ◽  
Glycine Uptake

It is well known that lupin forms cluster roots, which help in dissolving insoluble P in soils. In nonleguminous species, cluster roots also appear to contribute to the utilization of organic N in soils. In white lupin ( Lupinus albus L.), however, the characteristics of its organic N utilization have not been studied. Therefore, we examined whether white lupin can utilize organic N in soils. Soybean ( Glycine max (L.) Merr.), which does not form cluster roots, was used as a control plant. Seedlings of lupin and soybean were cultivated in soils with different N sources (non-N, ammonium sulphate, ammonium sulphate plus cattle farmyard manure, or cattle farmyard manure). The rate of glycine uptake by excised roots was determined in a hydroponic experiment to investigate the ability of lupin and soybean to directly utilize amino acids. Nitrogen accumulation in soybean corresponded to the decrease in inorganic N in the soils. In contrast, N accumulation in lupin was higher than the decrease in inorganic N in the soil, especially with the cattle farmyard manure treatment, indicating that lupin derived more N from an organic N source. Wheat ( Triticum aestivum L.) cultivated with lupin in a pot accessed more available N than wheat with soybean or wheat in monoculture, suggesting that lupin roots themselves or the lupin rhizosphere microorganisms were able to decompose organic N in soils. Excised roots of lupin, especially cluster roots, exhibited higher rates of glycine uptake than roots of soybean. In conclusion, lupin decomposed organic N in the rhizosphere and was able to absorb amino acids from decomposition in addition to any inorganic N produced by further microbial decomposition.

Nitrogen transformations and ammonia loss following injection and surface application of pig slurry: a laboratory experiment using slurry labelled with 15N-ammonium

2001 ◽  
Vol 136 (2) ◽  
pp. 231-240 ◽  
Author(s):  
D. R. CHADWICK ◽  
J. MARTINEZ ◽  
C. MAROL ◽  
F. BÉLINE
Keyword(s):  
Laboratory Experiment ◽  
N Uptake ◽  
Organic N ◽  
Pig Slurry ◽  
Nitrogen Transformations ◽  
Inorganic N ◽  
Undisturbed Soil ◽  
Soil Inorganic N ◽  
Slurry Injection ◽  
Soil Inorganic

A laboratory experiment was designed to determine the fate of 15N-labelled slurry ammonium (15NH4-N) and compare soil inorganic-N distribution following surface applied or injected pig slurry. A system of cylindrical volatilization chambers equipped to allow continuous trapping of ammonia (NH3) was used. Undisturbed soil columns were placed in the chambers prior to the application of slurry. A nitrogen balance including soil, air and plant analysis was established for both treatments, 8 days after application. Average cumulative emissions of NH3 were 15% and 11% of the total ammoniacal-N added with the surface and injected treatments, respectively. After 8 days 55% of the 15NH4-N applied through slurry injection was recovered in the soil inorganic-N pool: 37% as 15NH4-N and 18% as 15NO3-N. These figures compare with only 25% 15NH4-N recovered with the surface applied slurry treatment: 7% as 15NH-N and 17% as 15NO3-N. Immobilization into soil organic-N accounted for 8% of the 15NH4-N applied for the injected treatment and 6% of the surface applied slurry-15N. 15N uptake by the grass was 2% and 7% for the injected and surface applied treatments, respectively. The percentage of added 15N accounted for was 76% for the injected treatment and 53% for the surface applied slurry treatment.

Nitrogen dynamics in soil amended with composted cattle manure

2007 ◽  
Vol 87 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Bobbi L Helgason ◽  
Francis J Larney ◽  
H. Henry Janzen ◽  
Barry M Olson
Keyword(s):  
N Uptake ◽  
Wood Chip ◽  
N Fertilizer ◽  
Organic N ◽  
Inorganic N ◽  
Available Nitrogen ◽  
N Content ◽  
Total N ◽  
Available N ◽  
Plant Available Nitrogen

The amount and pattern of plant-available nitrogen (N) release from composts are variable and not well-defined. We used a 425-d canola (Brassica napus L.) bioassay to follow the release of N from eight composted cattle manures applied to soil at 20 g kg-1. Two stockpiled manures, one inorganic fertilizer and an unamended control were also included for comparison. Eight consecutive 30-d growth cycles were conducted in a controlled environment chamber (20°C) and plant N uptake was measured. Total N uptake was greatest from the N fertilizer and least from the wood-chip bedded manure. Addition of compost increased N uptake by 27–99% compared with that in the control. Nitrogen uptake from compost was directly proportional to its inorganic N content (r2 = 0.98; P < 0.0001) showing that the initial inorganic N content of compost, analyzed prior to its application can be used to predict plant available N. In seven of the eight composts studied, less than 5% of organic N was mineralized over 425 d, suggesting that little of the organic N in compost becomes available in the year of application. Compost is a valuable organic amendment, but co-application of N fertilizer is recommended to supply adequate N and optimize the benefits of compost for crop growth. Key words: Plant-available nitrogen, compost, nitrogen mineralization, beef manure

scholarly journals Root-Derived Proteases as a Plant Tool to Access Soil Organic Nitrogen; Current Stage of Knowledge and Controversies

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 731
Author(s):  
Bartosz Adamczyk
Keyword(s):  
Cropping Systems ◽  
N Uptake ◽  
Organic N ◽  
Inorganic N ◽  
Available N ◽  
Plant Nitrogen ◽  
N Cycle ◽  
Soil Organic Nitrogen ◽  
Use Efficiency ◽  
N Pool

Anthropogenic deterioration of the global nitrogen (N) cycle emerges mainly from overuse of inorganic N fertilizers in nutrient-limited cropping systems. To counteract a further dysregulation of the N cycle, we need to improve plant nitrogen use efficiency. This aim may be reached via unravelling all plant mechanisms to access soil N, with special attention to the dominating high-molecular-mass N pool. Traditionally, we believe that inorganic N is the only plant-available N pool, however, more recent studies point to acquisition of organic N compounds, i.e., amino acids, short peptides, and proteins. The least known mechanism of plants to increase the N uptake is a direct increase of soil proteolysis via root-derived proteases. This paper provides a review of the knowledge about root-derived proteases and also controversies behind this phenomenon.

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