scholarly journals The Influence of Mineral Fertilizer Combined With a Nitrification Inhibitor on Microbial Populations and Activities in Calcareous Uzbekistanian Soil Under Cotton Cultivation

2001 ◽  
Vol 1 ◽  
pp. 108-113 ◽  
Author(s):  
Dilfuza Egamberdiyeva ◽  
Muhiddin Mamiev ◽  
Svetlana K. Poberejskaya

Application of fertilizers combined with nitrification inhibitors affects soil microbial biomass and activity. The objective of this research was to determine the effects of fertilizer application combined with the nitrification inhibitor potassium oxalate (PO) on soil microbial population and activities in nitrogen-poor soil under cotton cultivation in Uzbekistan. Fertilizer treatments were N as urea, P as ammophos, and K as potassium chloride. The nitrification inhibitor PO was added to urea and ammophos at the rate of 2%. Three treatments—N200P140K60(T1), N200P140 POK60(T2), and N200P140 POK60(T3) mg kg-1soil—were applied for this study. The control (C) was without fertilizer and PO. The populations of oligotrophic bacteria, ammonifying bacteria, nitrifying bacteria, denitrifying bacteria, mineral assimilating bacteria, oligonitrophilic bacteria, and bacteria group Azotobacter were determined by the most probable number method. The treatments T2 and T3 increased the number of oligonitrophilic bacteria and utilization mineral forms of nitrogen on the background of reducing number of ammonifying bacteria. T2 and T3 also decreased the number of nitrifying bacteria, denitrifying bacteria, and net nitrification. In conclusion, our experiments showed that PO combined with mineral fertilizer is one of the most promising compounds for inhibiting nitrification rate, which was reflected in the increased availability and efficiency of fertilizer nitrogen to the cotton plants. PO combined with mineral fertilizer has no negative effects on nitrogen-fixing bacteria Azotobacter and oligo-nitrophilic bacteria.

2009 ◽  
Vol 60 (6) ◽  
pp. 1597-1605 ◽  
Author(s):  
Y. Jiao ◽  
W. B. Jin ◽  
Q. L. Zhao ◽  
G. D. Zhang ◽  
Y. Yan ◽  
...  

Most researchers focused on either nitrogen species or microbial community for polluted urban stream while ignoring the interaction between them and its effect on nitrogen transformation, which restricted the rational selection of an effective and feasible remediation technology. Taking Buji stream in Shenzhen (China) as target stream, the distribution of nitrogen-related bacteria was investigated by most probable number (MPN) besides analysis of nitrogen species etc. The nitrogen-related bacteria in sediment were 102 times richer than those in water. Owing to their faster growth, the MPN of ammonifying bacteria and denitrifying bacteria were 105 and 102 times higher than those of nitrifying bacteria, respectively. The ammonifying bacteria numbers were significantly related to BOD5 in water, while nitrifying bacteria in sediment correlated well with nitrate in water. Thus, nitrification occurred mainly in sediment surface and was limited by low proportion of nitrifying bacteria. The denitrifying bacteria in sediment had good relationship with BOD5 and nitrite and nitrate in water. Low DO and rich organic compounds were beneficial to denitrification but unfavourable to nitrification. Denitrification was restricted by low nitrite and nitrate concentration. These results could be served as a reference for implementing the remediation scheme of nitrogen polluted urban stream.


2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
A. Marais ◽  
M. Hardy ◽  
M. Booyse ◽  
A. Botha

Different plants are known to have different soil microbial communities associated with them. Agricultural management practices such as fertiliser and pesticide addition, crop rotation, and grazing animals can lead to different microbial communities in the associated agricultural soils. Soil dilution plates, most-probable-number (MPN), community level physiological profiling (CLPP), and buried slide technique as well as some measured soil physicochemical parameters were used to determine changes during the growing season in the ecosystem profile in wheat fields subjected to wheat monoculture or wheat in annual rotation with medic/clover pasture. Statistical analyses showed that soil moisture had an over-riding effect on seasonal fluctuations in soil physicochemical and microbial populations. While within season soil microbial activity could be differentiated between wheat fields under rotational and monoculture management, these differences were not significant.


2021 ◽  
Vol 26 (1) ◽  
pp. 1-16
Author(s):  
Julian Esteban Másmela-Mendoza ◽  
Luz Marina Lizarazo Forero

The objective of study was to isolate and determine the identity of denitrifying bacteria from limnetic areas of Lake Tota (Colombian Andes) with and without rainbow trout production activities. We examined the relationships between the lake’s physicochemical factors (oxygen, nitrogen, and phosphorus content) and two bacterial communities (denitrifying bacteria and coliforms). Water samples were taken 20m below the surface from July to September at five limnetic zones; two of which were close to rainbow trout farming areas. In each zone, the concentrations of oxygen, nitrogen, and phosphorus were measured. To identify and quantify the abundance of bacteria, the most probable number (MPN) technique was used, employing minimal medium for denitrifying bacteria and medium for nitrate reducing bacteria (NRB). A greater number of denitrifying bacteria were found in the fish farming zones, identifying bacteria of the genera Bacillus, Pseudomonas, Nocardia, and Streptomyces. The number of nitrate-reducing bacteria revealed statistically significant differences throughout the sampling period, increasing from July to September and was related to a decrease in precipitation. The density of NRB and total phosphorus were directly correlated. High bacterial densities of denitrifyingbacteria and coliforms are indicative of changes from oligotrophic to eutrophic states in the studied limnetic areas.


Soil Research ◽  
2004 ◽  
Vol 42 (8) ◽  
pp. 927 ◽  
Author(s):  
H. J. Di ◽  
K. C. Cameron

Abstract. The nitrification inhibitor dicyandiamide (DCD) has recently been shown to be effective in reducing nitrate leaching from grazed pasture soils. The objective of this study was to determine the influence of temperature and application rate on the effectiveness of DCD in nitrification inhibition. Possible effects on soil microbial biomass were also determined. The soil, Lismore silt loam (Pallic orthic brown soil; Udic Haplustept loamy skeletal), was incubated at a moisture content near field capacity under 2 temperatures (8 or 20°C). Urea was applied at 25 kg N/ha and dairy cow urine at 1000 kg N/ha. DCD was applied at 2 rates equivalent to 7.5 or 15 kg/ha. The results show that at a soil temperature of 8°C, the half-life of DCD was 111–116 days. The half-life of NH4+ changed from 44 days without DCD to 243–491 days when DCD was applied. In contrast, at a soil temperature of 20°C the half-life of DCD was 18–25 days. The half-life of NH4+ changed from 22 days without DCD to 64–55 days with DCD. The 2 different rates of DCD had a small effect on the NH4+ concentration in the soil. The application of DCD did not have a significant effect on soil microbial biomass. DCD would therefore be most effective in inhibiting nitrification and thus reducing nitrate leaching in late autumn–winter–early spring in most parts of New Zealand when daily average soil temperatures are generally below 10°C and when drainage is high.


2013 ◽  
Vol 807-809 ◽  
pp. 676-679
Author(s):  
Hui Xing Liang ◽  
Ai Hui Chen ◽  
Cheng Ding ◽  
Zhao Xia Li

The potential effect of 1,2-dichlorobenzene (1,2-DCB) on anaerobic microbial populations was investigated in a flooded wetland soil. Numbers of anaerobic fermentative bacteria (AFB), denitrifying bacteria (DNB) and hydrogen-producing acetogenic bacteria (HPAB) were numerated by three-tube anaerobic most-probable-number (MPN) methods with anaerobic liquid enrichment media. In anaerobic microbe groups, the changes of bacterium group were not the same. 1,2-Dichlorobenzene had the maximum influence on microbial groups of wetland soil at the initial pollution. In dealing with 14-35 days, bacterium groups in each processing soil have different amplitude bouncing back. In the experimental process, bacteria which produces hydrogen and acetic acid is most sensitive to 1,2-Dichlorobenzene. Hydrolysis fermentation bacteria second, and denitrifying bacteria was the smallest.


2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Lea Deinert ◽  
Israel Ikoyi ◽  
Achim Schmalenberger

Phosphorus (P) is an essential macronutrient for all living organisms and is applied as fertilizer in agroecosystems to improve crop growth. Recycling-derived fertilizers (RDFs) have been developed for nutrient recovery from Europe’s largest waste streams as a sustainable alternative to this finite resource. The impact of four RDFs (two ashes, two struvites) on the soil microbiome in comparison with a P-free control and triple super phosphate (TSP) as mineral fertilizer was investigated in a pot trial and a subsequent microcosm trial (subset of samples). For both experiments perennial ryegrass was cultivated for 54 days. The pot trial was conducted at P fertilization rates of 20 and 60 kg P ha-1 in quadruplicates. After the pot harvest the bulk soil was stored until the microcosm trial was conducted, using the control, TSP and the two ashes at 60 kg P ha-1 in six replicates. Pot trial results showed highest P bioavailability from struvites at high P rates, also resulting in higher biomass yield on average. Furthermore, P solubilization capabilities from tri-calcium phosphate was enhanced in the RDFs treatments, while the TSP treatments were negatively affected. For the microcosm trial, most probable number (MPN) analysis showed that phytate-utilizing bacterial abundance was significantly increased in one of the ashes and had also remained higher in the RDF treatments after storage. Understanding the effects of recycling-derived fertilizer application on the soil P cycle is vital for developing a more sustainable agriculture.


1997 ◽  
Vol 122 (5) ◽  
pp. 709-714 ◽  
Author(s):  
Harvey J. Lang ◽  
George C. Elliott

Autotrophic nitrifying organisms were enumerated in soilless potting media using the most probable number (MPN) technique. Populations of NH4+ and NO2- oxidizing organisms varied widely between two soilless media—Metro-Mix 220 and 350. Estimates for NH4+ oxidizing organisms ranged from 0.7 to 7.8 × 105 organisms/cm3, while NO2- oxidizers ranged from 1.3 to 9.5 × 105 organisms/cm3. Population numbers were similar to those typically reported in soils. There was a significant effect of medium type, NH4+ N : NO3- N fertilizer ratio, and planting on MPN counts of both groups of organisms, with significant interaction between several of the factors. Estimates of NH4+ oxidizers were not linearly correlated with NH4+ oxidizing activity, implying low counting efficiency, heterotrophic nitrification, or rate-limiting substrate NH4+ level. In a separate study, a soilless potting medium was inoculated with pure cultures of either Nitrosomonas europaea or Nitrobacter agilis. Rates of NH4+ and NO2- oxidation increased, respectively, as inoculum volume increased. Inoculation with nitrifying bacteria may help in the overall management of N in the rhizosphere and be feasible alternatives for the prevention of either NH4+ or NO2- phytotoxicity with fertilizers containing urea or NH4+.


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