Short-term effects of nitrogen and phosphorus fertilizers on nitrogen mineralization and trophic structure of the soil ecosystem in forest clearcuts in the southern interior of British Columbia

2001 ◽  
Vol 81 (1) ◽  
pp. 11-20 ◽  
Author(s):  
T A Forge ◽  
S W Simard
Keyword(s):  
British Columbia ◽  
Ammonium Sulphate ◽  
N Mineralization ◽  
Trophic Structure ◽  
Ammonium Phosphate ◽  
Bacterial Biomass ◽  
Nitrogen And Phosphorus ◽  
Carbon And Nitrogen ◽  
Bacterial Decomposition ◽  
Aerobic And Anaerobic

Ammonium sulphate and an ammonium sulphate-ammonium phosphate mixture were applied at 200 kg N ha-1 and 200 kg P ha-1 at three clearcut sites within the Interior Cedar-Hemlock biogeoclimatic zone in southern British Columbia. N mineralised under aerobic and anaerobic conditions, nitrification, biomasses of fungi and bacteria,the abundance of protozoa, and the trophic structure of nematode communities were studied at 4, 12, 16, and 28 mo after fertilisation. Nitrogen mineralised under aerobic conditions was greater in fertilised soil than in non-fertilised soil at 4 and 16 mo after fertiliser applications. Nitrification also increased after fertilisation. Fertilisation did not affect bacterial or fungal biomasses, but did increase the ratio of bacterial biomass/fungal biomass, the abundance of bacterivorous nematodes, and the ratio of bacterivorous nematodes/fungivorous nematodes. Thus, the fertiliser-induced increase in N mineralization appears to have been the result of increased bacterial decomposition and flow of carbon and nitrogen through bacteria-bacterivore channels of the soil food web. Key words: N mineralization, fertilisation, microbial biomass, microfauna, nematode ecology

Trophic structure of nematode communities, microbial biomass, and nitrogen mineralization in soils of forests and clearcuts in the southern interior of British Columbia

2000 ◽  
Vol 80 (3) ◽  
pp. 401-410 ◽  
Author(s):  
T. A. Forge ◽  
S. W. Simard
Keyword(s):  
British Columbia ◽  
Microbial Biomass ◽  
Forest Soil ◽  
Nitrogen Mineralization ◽  
N Mineralization ◽  
Trophic Structure ◽  
Mineral Soil ◽  
Bacterial Biomass ◽  
Net N Mineralization ◽  
Nematode Communities

The trophic structure of nematode communities, lengths of fungal hyphae, and gross populations of protozoa and bacteria were compared between clearcuts and adjacent forests at three sites in the southern interior of British Columbia in 1996, 1997, and 1998. Total C and N, mineralizable N (anaerobic incubation), and N mineralised during aerobic incubations, were determined from the same soil samples used for biological assays. Net N mineralization did not differ between clearcuts and forests in 1997; in 1998 net N mineralization in the organic horizon was four times greater for forests than for clearcuts. Hyphal lengths and total microbial biomass were greater in forest soil than in clearcut soil. Bacterial abundance was greater in forest soil than in clearcut soil in 1996 only. The abundance of protozoa did not differ between clearcuts and forests. Fungivorous, omnivorous, and predacious nematodes were less abundant in clearcut soil than in forest soil. Bacterivorous nematodes were more abundant in the mineral soil of clearcuts than in forests in 1996, but did not differ between clearcuts and forests in any other combination of year and horizon. Net N mineralization was correlated with the ratio of bacterial biomass/fungal biomass (r = 0.72, 12 degrees of freedom), as well as the abundance of amoebae (r = 0.83), total nematodes (r = 0.80), bacterivorous nematodes (r = 0.74), and fungivorous nematodes (r = 0.83). Key words: Microfauna, nematode ecology, microbial biomass, clearcut harvesting, nitrogen mineralization

Simulation of protozoa-induced mineralization of bacterial carbon and nitrogen

1992 ◽  
Vol 72 (3) ◽  
pp. 201-216 ◽  
Author(s):  
P. M. Rutherford ◽  
N. G. Juma
Keyword(s):  
N Mineralization ◽  
Ecological Research ◽  
Clay Loam ◽  
Glucose Addition ◽  
Soil C ◽  
Carbon And Nitrogen ◽  
Soil C And N ◽  
C And N ◽  
Typic Cryoboroll ◽  
Bacterial C

Modelling in soil ecological research is a means of linking the dynamics of microbial and faunal populations to soil processes. The objectives of this study were (i) to simulate bacterial-protozoan interactions and flows of C and N in clay loam Orthic Black Chernozemic soil under laboratory condtions; and (ii) to quantify the flux of C and N (inputs and outputs) through various pools using the simulation model. The unique features of this model are: (i) it combines the food chain with specific soil C and N pools, and (ii) it simultaneously traces the flows of C, 14C, N and 15N. It was possible to produce a model that fitted the data observed for the soil. The simulated CO2-C evolved during the first 12 d was due mainly to glucose addition (171 μg C g−1 soil) and cycling of C in the soil (160 μg C g−1 soil). During this interval, bacterial C uptake was 5.5-fold greater than the initial bacterial C pool size. In the first 12 d protozoa directly increased total CO2-C evolution by 11% and increased NH4-N mineralization 3-fold, compared to soil containing only bacteria. Mineralization of C and N was rapid when bacterial numbers were increased as a result of glucose addition. Key words: Acanthamoeba sp., modelling, N mineralization-immobilization, organic matter, Pseudomonas sp., Typic Cryoboroll

Bacterioplankton, Phytoplankton, and Zooplankton Communities in a British Columbia Coastal Lake Before and After Nutrient Reduction

1986 ◽  
Vol 43 (8) ◽  
pp. 1504-1514 ◽  
Author(s):  
F. Joan Hardy ◽  
Ken S. Shortreed ◽  
John G. Stockner
Keyword(s):  
British Columbia ◽  
Sockeye Salmon ◽  
Inorganic Nitrogen ◽  
Size Fraction ◽  
Growing Season ◽  
Nutrient Reduction ◽  
Nitrogen And Phosphorus ◽  
Coastal Lake ◽  
Before And After ◽  
High Concentrations

Inorganic nitrogen and phosphorus were applied weekly during the growing season from 1980 to 1982 and twice weekly in 1983 to Hobiton Lake, a warm monomictic coastal lake in British Columbia. The lake was not fertilized in 1984. Average numbers of bacteria during the growing season decreased from a high of 1.53 × 106∙mL−1 in the fertilized condition to 0.84 × 106∙mL−1 in the unfertilized condition. Chlorophyll a concentrations decreased from a maximum seasonal average of 2.69 μg∙L−1 (1981) to 1.30 μg∙L−1 (1984), and algal numbers decreased from 5.83 × 104∙mL−1 (1983) to 2.29 × 104∙mL−1 (1984). Although the numbers of phytoplankton in each size fraction (picoplankton, nanoplankton, or microplankton) decreased in the unfertilized condition, the greatest change was an almost fourfold decrease in picoplankton, which consisted of 90% cyanobacteria (primarily Synechococcus spp.). Abundance of the large diatoms Rhizosolenia spp. and Melosira spp. increased in 1984, resulting in an increase in average seasonal algal volume. Average densities of medium (0.15–0.84 mm) and large (0.85–1.5 mm) zooplankton were greatest in 1982, while rotifers and small zooplankton (0.10–0.14 mm) were most dense in 1984 following nutrient reduction. The lake had relatively high concentrations of planktivorous juvenile sockeye salmon (Oncorhynchus nerka) that appeared to minimize any direct effect of nutrient additions on zooplankton densities.

scholarly journals Subsurface-Applied Coated Nitrogen Fertilizer Enhanced Wheat Production by Improving Nutrient-Use Efficiency with Less Ammonia Volatilization

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2396
Author(s):  
Muhammad Yaseen ◽  
Adeel Ahmad ◽  
Muhammad Naveed ◽  
Muhammad Asif Ali ◽  
Syed Shahid Hussain Shah ◽  
...  
Keyword(s):  
Ammonia Volatilization ◽  
Nutrient Use Efficiency ◽  
Ammonium Phosphate ◽  
Crop Productivity ◽  
N Fertilization ◽  
N Fertilizer ◽  
Ammonia Emissions ◽  
Nitrogen And Phosphorus ◽  
Nutrient Use ◽  
Use Efficiency

Nitrogen (N) is an essential plant nutrient, therefore, N-deficient soils affect plant growth and development. The excessive and unwise application of N fertilizers result in nutrient losses and lower nutrient use efficiency that leads to the low crop productivity. Ammonia volatilization causes a major loss after N fertilization that causes environmental pollution. This experiment was conducted to evaluate the effectiveness of coating and uncoating N fertilizer in enhancing yield and nutrient-use efficiency with reduced ammonia emissions. The recommended rate of nitrogen and phosphorus, urea and di-ammonium phosphate (DAP) fertilizers were coated manually with 1% polymer solution. DAP (coated/uncoated) and potassium were applied at the time of sowing as subsurface application. While urea (coated/uncoated) was applied as surface and subsurface application. Results showed that nutrient use efficiencies of wheat were found to be maximum with the subsurface application of coated N fertilizer which increased nutrient-use efficiency by 44.57 (N), 44.56 (P) and 44.53% (K) higher than the surface application of uncoated N fertilizer. Ammonia emissions were found the lowest with subsurface-applied coated N fertilizer. Thus, coated fertilizer applied via subsurface was found the best technique to overcome the ammonia volatilization with an improvement in the yield and nutrient-use efficiency of wheat.

Phytoplankton Productivity Changes in a Small, Double-Basin Lake in Response to Termination of Experimental Fertilization

1987 ◽  
Vol 44 (S1) ◽  
pp. s47-s54 ◽  
Author(s):  
J. A. Shearer ◽  
E. J. Fee ◽  
E. R. DeBruyn ◽  
D. R. DeClercq
Keyword(s):  
Numerical Model ◽  
Primary Production ◽  
The Other ◽  
Production Rates ◽  
Nitrogen And Phosphorus ◽  
Phytoplankton Productivity ◽  
Phytoplankton Primary Production ◽  
Carbon And Nitrogen ◽  
Model Technique ◽  
Reference Lakes

One basin of a small, double-basin lake was fertilized with carbon, nitrogen, and phosphorus for eight years, and then fertilization was stopped. The other basin was fertilized simultaneously with equivalent amounts of carbon and nitrogen only. Phytoplankton primary production was monitored using an incubator–numerical model technique. Production increased dramatically in the basin receiving artificial additions of C, N, and P. The increase was particularly large in the epilimnion where Cyanophyte blooms occurred during each year of fertilization and production rates averaged 2 to 10 times higher than in nearby, unfertilized reference lakes. Phosphorus, not nitrogen or carbon, was the critical nutrient. The productivity of the other basin also increased, but to a lesser degree and no Cyanophyte blooms were observed in this basin. When all fertilization was terminated, production in both basins immediately decreased. No more surface blooms were observed in either basin. Within 3 yr, the production had dropped to levels typical of reference lakes.

Use of image analysis to determine algal and bacterial biomass in a high rate algal pond following Percoll® fractionation

2003 ◽  
Vol 48 (2) ◽  
pp. 53-60 ◽  
Author(s):  
N.J. Cromar ◽  
H.J. Fallowfield
Keyword(s):  
Image Analysis ◽  
Gradient Centrifugation ◽  
Bacterial Biomass ◽  
Nutrient Status ◽  
High Rate ◽  
Carbon And Nitrogen ◽  
Chemical Treatments ◽  
Gravimetric Determination ◽  
Physical And Chemical

This paper reports the results of work to allow a more accurate enumeration, and gravimetric determination, of the relative proportions of algae and bacteria within the floccular matrix present in a High Rate Algal Pond (HRAP). Methodology involving a combination of physical and chemical treatments was used and the resulting material was separated using density gradient centrifugation. The “fractions” were analysed using microscopical image analysis. Each “fraction” was categorised as containing bacteria only, algae only or an association of bacteria and algae, the relative proportions of which were then determined by image analysis to enable a “true” gravimetric determination of the algal and bacterial components of HRAP biomass for the first time. The biomass from HRAPs operated both outdoors and in a glasshouse was examined over complete operational seasons to investigate environmental effects as well as possible effects of variation in COD loading rate and retention time on cell biovolumes and cell quotients. In this study, the accurate assessment of both algal and bacterial biomass, determined as cell volume or dry matter, in addition to measurement of carbon and nitrogen has enabled the calculation of cell quotients. This allows a direct comparison between these values obtained from a nutrient-rich system and those published values obtained from systems with various nutrient status. Conversion factors obtained may also be of value for deriving inputs for computer models for the design and operation of high rate algal ponds.

Simultaneous Organic Matter Removal in a Cyclic Activated Sludge Reactor from Municipal Waste Water

2010 ◽  
Vol 113-116 ◽  
pp. 952-955
Author(s):  
Hong Wei Wang ◽  
Jian Huang ◽  
Xin Yu Wang ◽  
Xiao Hong Wu ◽  
Tie Dong Liu ◽  
...  
Keyword(s):  
Waste Water ◽  
Organic Matter ◽  
Activated Sludge ◽  
Municipal Waste ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Organic Matter Removal ◽  
Activated Sludge Reactor ◽  
Aerobic And Anaerobic ◽  
Degradation Ability

The aerobic and anaerobic cyclic activated sludge reactor of A/O process was separated into an A/O domestication segments and organic matter removal ability strengthen segments. In the A/O disposal system, organic carbon degradation, nitrogen and phosphorus removal from municipal waste water in reactor were investigated. Results showed that good performance of the A/O disposal system was achieved and the highest removal efficiencies of COD, TN and TP were 96%, 50% and 75%, respectively. When organic loadings varied from low to high, the removal ability increased and then the hybrid microbe in activated sludge degradation ability became strong. So the cyclic activated sludge was a useful method for eliminate organic matter removal from municipal waste water.

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