scholarly journals Nitrogen Immobilization in Plant Growth Substrates: Clean Chip Residual, Pine Bark, and Peatmoss

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Cheryl R. Boyer ◽  
H. Allen Torbert ◽  
Charles H. Gilliam ◽  
Glenn B. Fain ◽  
Thomas V. Gallagher ◽  
...  

Rising costs of potting substrates have caused horticultural growers to search for alternative, lower-cost materials. Objectives of this study were to determine the extent of nitrogen immobilization and microbial respiration in a high wood-fiber content substrate, clean chip residual. Microbial activity and nitrogen availability of two screen sizes (0.95 cm and 0.48 cm) of clean chip residual were compared to control treatments of pine bark and peatmoss in a 60-day incubation experiment. Four rates (0, 1, 2, or 3 mg) of supplemental nitrogen were assessed. Peatmoss displayed little microbial respiration over the course of the study, regardless of nitrogen rate; followed by pine bark, 0.95 cm clean chip residual, and 0.48 cm clean chip residual. Respiration increased with increasing nitrogen. Total inorganic nitrogen (plant available nitrogen) was greatest with peatmoss; inorganic nitrogen in other treatments were similar at the 0, 1, and 2 mg supplemental nitrogen rates, while an increase occurred with the highest rate (3 mg). Clean chip residual and pine bark were similar in available nitrogen compared to peatmoss. This study suggests that nitrogen immobilization in substrates composed of clean chip residual is similar to pine bark and can be treated with similar fertilizer amendments during nursery production.

1992 ◽  
Vol 70 (2) ◽  
pp. 384-391 ◽  
Author(s):  
T. R. Seastedt ◽  
W. J. Parton ◽  
D. S. Ojima

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.


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.


2005 ◽  
Vol 5 (6) ◽  
pp. 1437-1448 ◽  
Author(s):  
J.-U. Grooß ◽  
G. Günther ◽  
R. Müller ◽  
P. Konopka ◽  
S. Bausch ◽  
...  

Abstract. We present simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS) for the Arctic winter 2002/2003. We integrated a Lagrangian denitrification scheme into the three-dimensional version of CLaMS that calculates the growth and sedimentation of nitric acid trihydrate (NAT) particles along individual particle trajectories. From those, we derive the HNO3 downward flux resulting from different particle nucleation assumptions. The simulation results show a clear vertical redistribution of total inorganic nitrogen ( ), with a maximum vortex average permanent removal of over 5ppb in late December between 500 and 550K and a corresponding increase of of over 2ppb below about 450K. The simulated vertical redistribution of is compared with balloon observations by MkIV and in-situ observations from the high altitude aircraft Geophysica. Assuming a globally uniform NAT particle nucleation rate of 7.8x10-6cm-3h-1 in the model, the observed denitrification is well reproduced. In the investigated winter 2002/2003, the denitrification has only moderate impact (≤14%) on the simulated vortex average ozone loss of about 1.1ppm near the 460K level. At higher altitudes, above 600K potential temperature, the simulations show significant ozone depletion through -catalytic cycles due to the unusual early exposure of vortex air to sunlight.


2018 ◽  
Author(s):  
◽  
Siphesihle Mangena Khumalo

South Africa is not an exception when it comes to the issue of fresh water scarcity perpetuated by environmental pollution among many other factors. Industrial wastewater particularly emanating from the brewing industry, contains high-strength organic, inorganic, and biological compounds which are toxic to the environment. Due to stringent industrial effluent dewatering standards enforced by both local and international environmental protection entities, industrial wastewater cannot be discharged into receiving water bodies prior to treatment. The overall aim of this study was to evaluate the performance or treatment efficacy of a laboratory scale sequencing batch reactor on biological nutrient removal using industrial wastewater from brewery. In this study, two laboratory scale sequencing batch reactors (SBRs) operated in a cyclic aerobic-anaerobic configuration inoculated with activated sludge were investigated for their removal of orthophosphates and nitrogen compounds from brewery wastewater. SBR-1 was investigated for nitrogen group pollutant removal and SBR-2 was investigated for orthophosphate removal. The findings of the study are reported based on overall removal efficacies for the following process monitoring parameters: orthophosphates, ammoniacal nitrogen, total Kjeldahl nitrogen, total nitrogen, total organic nitrogen, total inorganic nitrogen and NO3-N+NO2-N. From the investigation, the following overall removal efficacies were obtained: 69% orthophosphates, 69% ammoniacal nitrogen, 59% total Kjeldahl nitrogen, 60% total nitrogen, 64% total organic nitrogen, 67% total inorganic nitrogen and 56% NO3-N+NO2-N at an organic loading rate of 3.17 kg Total Chemical Oxygen Demand (TCOD) /m3.day with a food to microorganism ratio of 2.86 g TCOD/g Volatile Suspended Solids (VSS).day. These removal efficacies were attained for a hydraulic retention time of 18 hours for both SBRs with a solids retention time of 5 days for SBR-1 and 7 days for SBR-2. Both reactors were operated at a mesophilic temperature range of 23 to 26˚C and a pH range of 5 to 8.5. The temperature was left unadjusted because it was observed that it did not hinder any microbial activities during the biodegradation process. The Michealis-Menten’s and Monod models were implemented to study the substrate utilisation rate kinetics and microbial growth rate kinetics recording 15 141 g COD/m3.day; 12 518 g VSS/g VSS.day; 20 343 g COD/m3.day and 16 860 g VSS/g VSS.day for SBR-1 and SBR-2, respectively. The Monod model demonstrated a strong correlation fit between the substrate utilisation rate and microbial growth rate recording a polynomial correlation constant of R2 = 0.947 and 0.9582 for SBR-1 and SBR-2, respectively. The findings of this study showed that the cyclic aerobic-anaerobic configuration on a laboratory scale SBR inoculated with activated sludge for treatment of brewery wastewater for biological nutrients was feasible.


Author(s):  
O. V. Kravtsova ◽  
V. I. Scherbak ◽  
M. I. Linchuk

The seasonal dynamics of the concentration of nutrients in the form of inorganic nitrogen (NH4+, NO2, NO3-, ΣN), dissolved phosphorus, organic matter and the connection with the development of phytoplankton in waters with high content of total inorganic nitrogen (from 23.31 to 102.65 mg N/dm3) and its compounds (ammonia - from 8.42 to 76.60, nitrate - from 4.94 to 15.93, nitrite - from 0.077 to 4.35 mg N/dm3) and organic matter (from 8.00 to 21.92 mg O/dm3 by permanganate oxidation values and from 58.46 to 265.2 mg O/dm3 by dichromate oxidation values) were analyzed in paper. The peculiarity of the hydrochemical regime of the reservoirs was phenomenally high relations ΣN:P (133,54-12152,86) during the growing seasons. Found that response algal plankton communities such features hydrochemical regime is a simplification of the structure due to the predominance of representatives of departments Euglenophyta, Chlorophyta and Bacillariophyta, while Chrysophyta, Dinophyta, Charophyta and presented Cryptophyta 1-3 species. The response of phytoplankton to the high content of compounds of inorganic nitrogen is the increase in the number and biomass of green algae, and organic matter - eugenic algae.THE REGULARITIES OF PHYTOPLANKTON FORMATION AT VARIOS BIOGENIC ELEMENTS AND ORGANIC MATTER CONCENTRATIONS 


2017 ◽  
Vol 35 (3) ◽  
pp. 99-102
Author(s):  
Lori Robertson ◽  
Jeffrey F. Derr

Abstract Dimethenamid and the granular combination product pendimethalin plus dimethenamid are herbicides registered for use in nursery production and landscape maintenance. The objectives of this study were: (1) to compare the effectiveness of sprayed dimethenamid and the granular combination of pendimethalin plus dimethenamid in container nursery production, (2) to determine the impact of formulation on leaching of dimethenamid in soilless media versus field soil and (3) to determine the influence of irrigation volume on herbicide leaching. Dimethenamid is less mobile in pine bark than field soil, while pendimethalin is more mobile in pine bark. The leaching profile for the granular pendimethalin plus dimethenamid combination product was similar to dimethenamid in field soil and similar to pendimethalin in pine bark. There was no significant difference in herbicide movement in pine bark or field soil after doubling the irrigation volume from 17.8 cm (7 in) to 35.6 cm (14 in). Compared to pendimethalin, dimethenamid leaches less in pine bark, explaining its greater effectiveness for weed control in container production. Index words: Herbicide leaching, soilless mix, pine bark, ornamentals, adsorption. Species used in this study: southern crabgrass [Digitaria ciliaris (Retz.) Koel.]; spotted spurge [Chamaesyce maculata (L.) Small]. Chemicals used in this study: dimethenamid (Tower); dimethenamid plus pendimethalin (FreeHand); pendimethalin (Pendulum 2G).


Author(s):  
Nils Henriksson ◽  
Oskar Franklin ◽  
Lasse Tarvainen ◽  
John Marshall ◽  
Judith Lundberg-Felten ◽  
...  

The mycorrhizal symbiosis is ubiquitous in boreal forests. Trees and plants provide their fungal partners with photosynthetic carbon in exchange for soil nutrients like nitrogen, which is critical to the growth and survival of the plants. But plant carbon allocation to mycorrhizal symbionts can also fuel nitrogen immobilization, hampering tree growth. Here we present results from field and greenhouse experiments combined with mathematical modelling, showing that mycorrhizal fungi can be simultaneously mutualistic to an individual tree and parasitic to the networked community of trees. Mycorrhizal networks connect multiple plants and fungi, and we show that each tree gains additional nitrogen at the expense of its neighbors by supplying more carbon to the fungi. But this additional carbon supply eventually aggravates nitrogen immobilization in the shared fungal biomass. Individual trees may thus independently benefit from increasing their carbon investment to mycorrhiza, while causing a decline in nitrogen availability for the whole plant community. We illustrate the evolutionary underpinnings of this situation by drawing on the analogous the tragedy of the commons, and explain how rising atmospheric CO2 may lead to greater nitrogen immobilization in the future.


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