scholarly journals Ammonia Oxidizing Prokaryotes Respond Differently to Fertilization and Termination Methods in Common Oat’s Rhizosphere

2021 ◽  
Vol 12 ◽  
Author(s):  
Marco Allegrini ◽  
Marianela E. Morales ◽  
Maria B. Villamil ◽  
María Celina Zabaloy
Keyword(s):  
Community Structure ◽  
Cover Crops ◽  
Untreated Control ◽  
Soil Microbial Communities ◽  
Amplicon Sequencing ◽  
N Fertilization ◽  
Ammonia Oxidizing Bacteria ◽  
Beneficial Effects ◽  
Potential Nitrification ◽  
Gene Copies

Cover crops (CC) have demonstrated beneficial effects on several soil properties yet questions remain regarding their effects on soil microbial communities. Among them, ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) have a key role for N cycling in soil and their responses in the rhizosphere of terminated CC deserve further investigation. A greenhouse experiment was established to assess N fertilization (with or without N) and termination methods (glyphosate, mowing, and untreated control) of common oat (Avena sativa L.) as potential drivers of AOA and AOB responses in the rhizosphere. The abundance of amoA genes was determined by quantitative real-time PCR (qPCR), the community structure was assessed with Illumina amplicon sequencing of these genes, while the function was assessed from potential nitrification activity (PNA). While N fertilization had no influence on AOA, the termination method significantly increased amoA gene copies of AOA in mowed plants relative to glyphosate termination or the untreated control (1.76 and 1.49-fold change, respectively), and shifted AOA community structure (PERMANOVA, p<0.05). Ordination methods indicated a separation between AOA communities from control and glyphosate-terminated plants relative to mowed plants for both UniFrac and Aitchison distance. Converserly, N fertilization significantly increased AOB abundance in the rhizosphere of mowed and control plants, yet not in glyphosate-treated plants. Analyses of community structure showed that AOB changed only in response to N fertilization and not to the termination method. In line with these results, significantly higher PNA values were measured in all fertilized samples, regardless of the termination methods. Overall, the results of this study indicated that bacterial and archaeal nitrifiers have contrasting responses to fertlization and plant termination methods. While AOA were responsive to the termination method, AOB were more sensitive to N additions, although, the stimulative effect of N fertilization on amoAAOB abundance was dependent on the termination method.

scholarly journals Abundance and diversity of ammonia-oxidizing archaea and bacteria in the rhizosphere soil of three plants in the Ebinur Lake wetland

2017 ◽  
Vol 63 (7) ◽  
pp. 573-582 ◽  
Author(s):  
Yuan He ◽  
Wenge Hu ◽  
Decao Ma ◽  
Hongzhu Lan ◽  
Yang Yang ◽  
...  
Keyword(s):  
Community Structure ◽  
Rhizosphere Soil ◽  
Ammonia Oxidation ◽  
Arid Zone ◽  
Quantitative Polymerase Chain Reaction ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonia Oxidizing Archaea ◽  
Ebinur Lake ◽  
Gene Copies ◽  
Abundance And Diversity

Ammonia oxidation is carried out by ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA). The Ebinur Lake wetland is the best example of a temperate arid zone wetland ecosystem in China. Soil samples were collected from rhizosphere and non-rhizosphere soil containing Halocnemum strobilaceum (samples H and H′), Phragmites australis (samples R and R′), and Karelinia caspia (samples K and K′) to study the relationship between environmental factors and the community structure of AOB and AOA. Phylogenetic analysis showed that the AOA sequences belonged to the Nitrosopumilus and Nitrososphaera clusters. AOB were grouped into Nitrosospira sp. and Nitrosomonas sp. Quantitative polymerase chain reaction results showed that the AOA abundance ranged from 2.09 × 104 to 2.94 × 105 gene copies/g soil. The highest number of AOA was detected in sample K, followed by samples R and H. AOB abundance varied between 2.91 × 105 and 1.05 × 106 gene copies/g soil, which was higher than that of AOA. Redundancy analysis indicated that electrical conductivity, pH, and NH4+-N might influence the community structure of AOA and AOB. AOB might play a more crucial role than AOA in ammonia oxidation based on AOB’s higher diversity and abundance in the Ebinur Lake wetland in Xinjiang.

scholarly journals Community Structure of Ammonia-Oxidizing Bacteria under Long-Term Application of Mineral Fertilizer and Organic Manure in a Sandy Loam Soil

2006 ◽  
Vol 73 (2) ◽  
pp. 485-491 ◽  
Author(s):  
Haiyan Chu ◽  
Takeshi Fujii ◽  
Sho Morimoto ◽  
Xiangui Lin ◽  
Kazuyuki Yagi ◽  
...  
Keyword(s):  
Community Structure ◽  
Mineral Fertilizer ◽  
N Fertilization ◽  
Organic Manure ◽  
N Fertilizer ◽  
Ammonia Oxidizing Bacteria ◽  
Fertilizer N ◽  
Soil Nitrification ◽  
Nitrification Potential

ABSTRACT The effects of mineral fertilizer (NPK) and organic manure on the community structure of soil ammonia-oxidizing bacteria (AOB) was investigated in a long-term (16-year) fertilizer experiment. The experiment included seven treatments: organic manure, half organic manure N plus half fertilizer N, fertilizer NPK, fertilizer NP, fertilizer NK, fertilizer PK, and the control (without fertilization). N fertilization greatly increased soil nitrification potential, and mineral N fertilizer had a greater impact than organic manure, while N deficiency treatment (PK) had no significant effect. AOB community structure was analyzed by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) of the amoA gene, which encodes the α subunit of ammonia monooxygenase. DGGE profiles showed that the AOB community was more diverse in N-fertilized treatments than in the PK-fertilized treatment or the control, while one dominant band observed in the control could not be detected in any of the fertilized treatments. Phylogenetic analysis showed that the DGGE bands derived from N-fertilized treatments belonged to Nitrosospira cluster 3, indicating that N fertilization resulted in the dominance of Nitrosospira cluster 3 in soil. These results demonstrate that long-term application of N fertilizers could result in increased soil nitrification potential and the AOB community shifts in soil. Our results also showed the different effects of mineral fertilizer N versus organic manure N; the effects of P and K on the soil AOB community; and the importance of balanced fertilization with N, P, and K in promoting nitrification functions in arable soils.

scholarly journals Competition between Ammonia-Oxidizing Bacteria and Benthic Microalgae

2004 ◽  
Vol 70 (9) ◽  
pp. 5528-5537 ◽  
Author(s):  
Nils Risgaard-Petersen ◽  
Mette H. Nicolaisen ◽  
Niels Peter Revsbech ◽  
Bente Aa Lomstein
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
N Uptake ◽  
Benthic Algae ◽  
Rrna Gene ◽  
Ammonia Oxidizing Bacteria ◽  
Growth And Survival ◽  
Nitrification Potential ◽  
Potential Nitrification ◽  
Gene Copies ◽  
Oxic Zone

ABSTRACT The abundance, activity, and diversity of ammonia-oxidizing bacteria (AOB) were studied in prepared microcosms with and without microphytobenthic activity. In the microcosm without alga activity, both AOB abundance, estimated by real-time PCR, and potential nitrification increased during the course of the experiment. AOB present in the oxic zone of these sediments were able to fully exploit their nitrification potential because NH4 + did not limit growth. In contrast, AOB in the alga-colonized sediments reached less than 20% of their potential activity, suggesting starvation of cells. Starvation resulted in a decrease with time in the abundance of AOB as well as in nitrification potential. This decrease was correlated with an increase in alga biomass, suggesting competitive exclusion of AOB by microalgae. Induction of N limitation in the oxic zone of the alga-colonized sediments and O2 limitation of the majority of AOB in darkness were major mechanisms by which microalgae suppressed the growth and survival of AOB. The competition pressure from the algae seemed to act on the entire population of AOB, as no differences were observed by denaturing gradient gel electrophoresis of amoA fragments during the course of the experiment. Enumeration of bacteria based on 16S rRNA gene copies and d-amino acids suggested that the algae also affected other bacterial groups negatively. Our data indicate that direct competitive interaction takes place between algae and AOB and that benthic algae are superior competitors because they have higher N uptake rates and grow faster than AOB.

scholarly journals Cover Crop Species Composition Alters the Soil Bacterial Community in a Continuous Pepper Cropping System

2022 ◽  
Vol 12 ◽  
Author(s):  
Huan Gao ◽  
Gangming Tian ◽  
Muhammad Khashi u Rahman ◽  
Fengzhi Wu
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Faba Bean ◽  
Cover Crops ◽  
Cover Crop ◽  
Soil Microbial Communities ◽  
Cropping System ◽  
Soil Physicochemical Properties ◽  
Soil Microbial ◽  
Wild Rocket

Cover crops can improve soil biological health and alter the composition of soil microbial communities in agricultural systems. However, the effects of diversified cover crops on soil microbial communities in continuous cropping systems are unclear. Here, using different soil biochemical analysis, quantitative PCR and 16S rRNA amplicon sequencing, we investigated the effects of cover crops, alone or in mixture, on soil physicochemical properties in 2019 and 2020, and soil bacterial communities in 2020 in a continuous pepper cropping system. A field trial was established before pepper planting and eight treatments were included: fallow (no cover crop; CK); three sole cover crop treatments: wheat (Triticum aestivum L.; W), faba bean (Vicia faba L.; B), and wild rocket (Diplotaxis tenuifolia; R); and four mixed treatments: wheat + wild rocket (WR), wheat + faba bean (WB), wild rocket + faba bean (RB), and wheat + wild rocket + faba bean (WRB). The pepper yield was increased in the WR and WB in 2019 and 2020, and in the WRB in 2020. Cover crops increased the soil pH, but decreased the concentrations of NH4+ and available phosphorus. Bacterial abundance was increased by cover crop treatments, and community structure was altered in the W, WB, and WRB treatments. Moreover, we found that pH was the key factor associated with the changes in the abundance and structure of the bacterial community. Cover crop treatments altered the bacterial community structure with shifts in the dominant genera, which have plant-growth-promoting and/or pathogen-antagonistic potentials, e.g., increased the abundances of Streptomyces, Arthrobacter, and Bacillus spp. in the W and WRB, and Gaiella spp. in the WB. Overall, we found that cover crops altered the soil physicochemical properties and bacterial community, and these changes varied with species composition of the cover crops, with wheat and its combination with legumes as most effective treatments. These results suggest that the diversification within cover crops could provide better crop yield stimulatory affects by altering soil biochemical environment.

Effects of Cover Crops and Tillage on Sweet Corn Production

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 476d-476
Author(s):  
Gary R. Cline ◽  
Anthony F. Silvernail
Keyword(s):  
Cover Crops ◽  
Sweet Corn ◽  
N Fertilization ◽  
Winter Rye ◽  
No Tillage ◽  
Corn Production ◽  
Total N ◽  
No Till ◽  
Winter Cover ◽  
Winter Cover Crops

A split-plot factorial experiment examined effects of tillage and winter cover crops on sweet corn in 1997. Main plots received tillage or no tillage. Cover crops consisted of hairy vetch, winter rye, or a mix, and N treatments consisted of plus or minus N fertilization. Following watermelon not receiving inorganic N, vetch, and mix cover cropsproduced total N yields of ≈90 kg/ha that were more than four times greater than those obtained with rye. However, vetch dry weight yields (2.7 mg/ha) were only about 60% of those obtained in previous years due to winter kill. Following rye winter cover crops, addition of ammonium nitrate to corn greatly increased (P < 0.05) corn yields and foliar N concentrations compared to treatments not receiving N. Following vetch, corn yields obtained in tilled treatments without N fertilization equaled those obtained with N fertilization. However, yields obtained from unfertilized no-till treatments were significantly (P < 0.05) lower than yields of N-fertilized treatments. Available soil N was significantly (P < 0.05) greater following vetch compared to rye after corn planting. No significant effects of tillage on sweet corn plant densities or yields were detected. It was concluded that no-tillage sweet corn was successful, and N fixed by vetch was able to sustain sweet corn production in tilled treatments but not in no-till treatments.In previous years normal, higher-yielding vetch cover crops were able to sustain sweet corn in both tilled and no-till treatments.

scholarly journals Higher Sensitivity of Soil Microbial Network Than Community Structure under Acid Rain

2021 ◽  
Vol 9 (1) ◽  
pp. 118
Author(s):  
Ziqiang Liu ◽  
Hui Wei ◽  
Jiaen Zhang ◽  
Muhammad Saleem ◽  
Yanan He ◽  
...  
Keyword(s):  
Community Structure ◽  
Acid Rain ◽  
Natural Soil ◽  
Available Phosphorus ◽  
Global Changes ◽  
N2o Emissions ◽  
Ammonia Oxidizing Bacteria ◽  
Soil Core ◽  
N Cycle ◽  
Microbial Network

Acid rain (AR), as a global environmental threat, has profoundly adverse effects on natural soil ecosystems. Microorganisms involved in the nitrogen (N) cycle regulate the global N balance and climate stabilization, but little is known whether and how AR influences the structure and complexity of these microbial communities. Herein, we conducted an intact soil core experiment by manipulating the acidity of simulated rain (pH 7.5 (control, CK) vs. pH 4.0 (AR)) in subtropical agricultural soil, to reveal the differences in the structure and complexity of soil nitrifying and denitrifying microbiota using Illumina amplicon sequencing of functional genes (amoA, nirS, and nosZ). Networks of ammonia-oxidizing archaea (AOA) and nirS-carrying denitrifiers in AR treatment were less complex with fewer nodes and lower connectivity, while network of nosZ-carrying denitrifiers in AR treatment had higher complexity and connectivity relative to CK. Supporting this, AR reduced the abundance of keystone taxa in networks of AOA and nirS-carrying denitrifiers, but increased the abundance of keystone taxa in nosZ-carrying denitrifiers network. However, AR did not alter the community structure of AOA, ammonia-oxidizing bacteria (AOB), nirS-, and nosZ-carrying denitrifiers. Moreover, AR did not change soil N2O emissions during the experimental period. AOB community structure significantly correlated with content of soil available phosphorus (P), while the community structures of nirS- and nosZ-carrying denitrifiers both correlated with soil pH and available P content. Soil N2O emission was mainly driven by the nirS-carrying denitrifiers. Our results present new perspective on the impacts of AR on soil N-cycle microbial network complexity and keystone taxa in the context of global changes.

scholarly journals The Growth of Leaf Lettuce and Bacterial Communities in a Closed Aquaponics System with Catfish

Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 222
Author(s):  
Kenji Yamane ◽  
Yuuki Kimura ◽  
Keita Takahashi ◽  
Isamu Maeda ◽  
Masayuki Iigo ◽  
...  
Keyword(s):  
Plant Growth ◽  
Early Stage ◽  
Amplicon Sequencing ◽  
Small Scale ◽  
Rrna Gene ◽  
Culture Solution ◽  
Beneficial Effects ◽  
Sustainable Cultivation ◽  
Microbial Groups ◽  
Production Period

Aquaponics is a circulating and sustainable system that combines aquaculture and hydroponics and forms a symbiotic relationship between fish, plants, and microorganisms. We hypothesized that feed alone could support plant growth, but the symbiosis with fish adds some beneficial effects on plant growth in aquaponics. In this study, we created three closed culture systems, namely, aquaponics, hydroponics without nitrogen (N) and phosphorus (P), and aquaculture, and added the same amount of feed containing N and P to all the treatments in order to test the hypothesis. Accumulation of NO3− and PO43− was alleviated in aquaponics and hydroponics as a result of plant uptake. Lettuce plants grown in aquaponics grew vigorously until 2 weeks and contained a constant level of N in plants throughout the production period, whereas those in hydroponics grew slowly in the early stage and then vigorously after 2 weeks with a late increment of N concentration. These results suggest that catfish help with the faster decomposition of the feed, but, in hydroponics, feed can be slowly dissolved and decomposed owing to the absence of the fish. The bacterial community structures of the culture solution were investigated using 16S rRNA gene amplicon sequencing. At the class level, Actinobacteria, Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria were the major microbial groups in the solutions. Aquaponics prevented the pollution of tank solution and maintained a higher water quality compared with hydroponics and aquaculture, suggesting that aquaponics is a more sustainable cultivation system even in a small-scale system.

Biochemical and histopathological effects of low dose vanadium in the healing of acetic acid-induced colitis in male wistar rats

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tosan Peter Omayone ◽  
Samuel Babafemi Olaleye
Keyword(s):  
Acetic Acid ◽  
Untreated Control ◽  
Wistar Rats ◽  
Low Dose ◽  
Healing Process ◽  
Beneficial Effects ◽  
Male Wistar Rats ◽  
Haematological Changes ◽  
Therapeutic Properties ◽  
Histopathological Effects

Abstract Objectives Vanadium has been reported to possess relevant therapeutic properties such as anti-diabetic and anti-tumoral. This study aimed at determining the effects of vanadium on experimentally induced colitis in rats. Methods Forty-five male Wistar rats (103 ± 3.90 g, n=15) were used for this study and were divided into three groups. Group 1 (Untreated control) had nothing added to their drinking, while groups 2 and 3 received sodium metavanadate at a dose of 50 and 200 mg/L respectively in their drinking water for 10 weeks. Colitis was thereafter induced by intra colonic administration of 1.50 mL of 6% acetic acid. Animals were sacrificed on day 0 (pre-induction), three- and seven-days post induction. Blood samples were collected for haematological variables and the distal 8 cm of the colon was collected for macroscopic, histological and biochemical (malondialdehyde-MDA, superoxide dismutase-SOD, catalase-CAT, glutathione peroxidase- GPx and nitrite concentration- NO) assessment. Results Low dose vanadium proved beneficial in ameliorating acetic acid-induced colitis by improving both histopathological and haematological changes. Gross observation showed a faster healing rate in vanadium treated groups (50 and 200 mg/L) compared with untreated control at day 3 (40 and 26.20 vs. 2.50%) and day 7 (80 and 66.70 vs. 42%) respectively. Vanadium also appears to exert its beneficial effects on acetic acid-induced colitis via up regulation of antioxidant enzymes (SOD, CAT, GPx) and NO while decreasing the over production of MDA. Conclusions Vanadium at small concentration functions as an essential trace element and may be able to promote healing process during ulcerative colitis.

scholarly journals Winter pasture and cover crops and their effects on soil and summer grain crops

2011 ◽  
Vol 46 (10) ◽  
pp. 1357-1363 ◽  
Author(s):  
Alvadi Antonio Balbinot Junior ◽  
Milton da Veiga ◽  
Anibal de Moraes ◽  
Adelino Pelissari ◽  
Álvaro Luiz Mafra ◽  
...  
Keyword(s):  
Land Use ◽  
Common Bean ◽  
Cover Crops ◽  
Nitrogen Fertilization ◽  
Soil Compaction ◽  
Surface Soil ◽  
Soil Layer ◽  
N Fertilization ◽  
The North ◽  
Oilseed Radish

The objective of this work was to evaluate the effect of winter land use on the amount of residual straw, the physical soil properties and grain yields of maize, common bean and soybean summer crops cultivated in succession. The experiment was carried out in the North Plateau of Santa Catarina state, Brazil, from May 2006 to April 2010. Five strategies of land use in winter were evaluated: intercropping with black oat + ryegrass + vetch, without grazing and nitrogen (N) fertilization (intercropping cover); the same intercropping, with grazing and 100 kg ha-1 of N per year topdressing (pasture with N); the same intercropping, with grazing and without nitrogen fertilization (pasture without N); oilseed radish, without grazing and nitrogen fertilization (oilseed radish); and natural vegetation, without grazing and nitrogen fertilization (fallow). Intercropping cover produces a greater amount of biomass in the system and, consequently, a greater accumulation of total and particulate organic carbon on the surface soil layer. However, land use in winter does not significantly affect soil physical properties related to soil compaction, nor the grain yield of maize, soybean and common bean cultivated in succession.

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