CHANGES IN MINERAL N AND NUMBERS OF BACTERIA AND ACTINOMYCETES DURING TWO YEARS UNDER WHEAT-FALLOW IN SOUTHWESTERN SASKATCHEWAN

1982 ◽  
Vol 62 (1) ◽  
pp. 125-137 ◽  
Author(s):  
C. A. CAMPBELL ◽  
V. O. BIEDERBECK
Keyword(s):  
Environmental Conditions ◽  
Microbial Growth ◽  
Crop Residues ◽  
Soil Depth ◽  
Soil Layer ◽  
Soil Microbial Activity ◽  
Plate Count ◽  
Upward Movement ◽  
Mineral N ◽  
Soil Microbial

The aim of this study was to identify, in situ, some of the microbial responses to environmental conditions previously noted in experiments in the laboratory and field. Soil samples were taken from a Brown Chernozem under a wheat-fallow rotation at 2-wk intervals during spring and autumn and at 4-wk intervals in winter and summer for a 2-yr period. Nitrate-N and exchangeable NH4-N, and numbers of bacteria and actinomycetes by plate count, were measured in 0- to 2.5-cm, 2.5- to 15-cm and 15- to 30-cm soil layers. Changes in microbial numbers and mineral N were correlated with soil depth, available carbon and environmental conditions. Bacterial numbers ranged between 14 and 119 million per gram of soil in the 0- to 2.5-cm layer, between 9 and 47 million in the 2.5-to 15-cm layer and were 4 million in the 15- to 30-cm soil layer. Bacteria:actinomycetes ratios were 3:1 in the 0- to 2.5-cm layer, 2:1 in the 2.5- to 15-cm layer and 1:1 in the 15- to 30-cm layer. Exchangeable NH4- and NO3-N as high as 20 and 280 ppm, respectively, were found in the top 2.5 cm. Different processes with similar or opposing effects often occurred simultaneously, thus making interpretation difficult. However, we identified (i) the stepwise nature of the ammonification-nitrification process; (ii) the importance of crop residues in microbial growth, and denitrification; (iii) the flush in microbial growth when a dry soil is moistened; (iv) the importance of the tilled layer as the prime site of soil microbial activity; and (v) the rapid decrease in microbial population and activity below the tilled soil layer. There was also evidence of possible upward movement of NO3 due to temperature gradient (as soil froze), and due to evaporation.

SOIL MICROBIAL ACTIVITY AS INFLUENCED BY TEMPERATURE TRENDS AND FLUCTUATIONS

1973 ◽  
Vol 53 (4) ◽  
pp. 363-376 ◽  
Author(s):  
V. O. BIEDERBECK ◽  
C. A. CAMPBELL
Keyword(s):  
Growth Response ◽  
Microbial Growth ◽  
Microbial Population ◽  
Incubation Temperature ◽  
Soil Microbial Activity ◽  
Mineral N ◽  
N Transformations ◽  
Soil Microbial ◽  
Temperature Trends ◽  
Fluctuating Temperatures

Unamended and NH4-N-amended soils were incubated for 14 days at three different diurnally fluctuating temperatures (T13/2, T18/7, T27/16), and at combinations of these for a further 14 days. Replicate samples were incubated simultaneously at the corresponding constant mean temperatures. Microbial growth was considerably greater at constant mean than at the corresponding diurnally fluctuating temperatures. The pattern of population changes in response to the temperature treatments was similar for bacteria, actinomycetes, and fungi. However, the extent of the growth response by these three groups differed, being greatest for the bacterial and least for the actinomycetal population. An upward shift in temperature after 14 days or maintenance of temperature at the same level for the full 28 days caused an increase in microbial numbers and increased the rate of N transformations. But when the incubation temperature was shifted downward, microbial population levels decreased markedly whereas ammonification and nitrification rates increased significantly, resulting in a temporary flush of mineral-N. This "kill" of microbial cells was much more pronounced with fluctuating than with constant temperature conditions. The validity of this phenomenon was supported by 4 yr field data that showed that the onset of the first cold spell each fall and late frosts in spring resulted in sudden flushes in NO3-N production. Microbial population levels and N transformation rates were generally higher in NH4-N-amended than in unamended soil.

scholarly journals Effect of nitrogen fertilization on maize yield responses to soil microbial activity and root length density in the North China Plain

2021 ◽  
Vol 237 ◽  
pp. 01042
Author(s):  
Qiuhua Li ◽  
Jingjing Sun ◽  
Jun Yao ◽  
Qunhui Wang
Keyword(s):  
Microbial Activity ◽  
Root Length ◽  
Root Length Density ◽  
Soil Layer ◽  
Maize Yield ◽  
Soil Microbial Activity ◽  
N Fertilizer ◽  
Soil Microbial ◽  
The North ◽  
N Fertilizer Rate

A maize field experiment in the North China Plain was conducted to understand the effect of different N fertilizer rate on the yield of maize, using soil microbial activity and root length density (RLD) as performance parameters, due to their possibility to enhance productivity. The four N fertilizer rates were 0 (N0), 120 (N120), 210 (N210) and 300 (N300) kg N hm-2. The results indicated that nitrogen (N) fertilizer had a significant influence not only on yield (p<0.05), but also on root length density (p<0.05) and soil microbial activity (p<0.05). In addition, the soil microbial activity and RLD were significantly related with maize yield. RLD differences were generally evident within the 100 cm soil layer, whereas there was no difference in the deeper soil under different N treatments. The most RLD concentrated in 0-60cm soil layer under N0, N120 and in 0-90cm soil layer under N210, N300. The microbial growth rate constant (k) was greater in N210 than other treatments. Generally, N fertilizer application can stimulate root growth and microbial activity, meanwhile, they can interact with each other, heighten the availability of N fertilizer in soil, thus enhanced yield of maize. According to our study, 210 kg N hm-2 was the optimum N fertilizer rate to achieve maximum yield and sustain the soil productivity.

scholarly journals Potassium chloride: impacts on soil microbial activity and nitrogen mineralization

2019 ◽  
Vol 49 (5) ◽  
Author(s):  
David Gabriel Campos Pereira ◽  
Isadora Alves Santana ◽  
Marcio Mahmoud Megda ◽  
Michele Xavier Vieira Megda
Keyword(s):  
Potassium Chloride ◽  
Microbial Activity ◽  
Crop Residues ◽  
Initial Period ◽  
Chloride Content ◽  
Soil Microbial Activity ◽  
Soil Microbial ◽  
Continuous Use ◽  
Banana Crop ◽  
Soil Chloride

ABSTRACT: Potassium chloride is the most widely used potassium source worldwide, and due to its continuous use, the accumulation of its salts in the soil and in plants is becoming more common. Excess available ions can cause a series of physiological disturbances in organisms and can become a biocide in the soil. The objective of this study was to evaluate the effects of the application of KCl and banana crop residues on soil chloride content, microbial activity, and soil ammonification. The experiment utilized a completely randomized 2 × 4 factorial design with four replicates. Treatments were as follows: two doses of vegetal residue (200 and 400 mg dm-3) × four doses of KCl (0, 167, 334, and 668 mg dm-3 of KCl) and a control (untreated soil). The CO2 emission, ammonium (N-NH4 +) and soil chloride (Cl-) content, and mineralization/immobilization rates of the soils in each treatment were measured 4, 45, and 130 days after incubation (dai). Higher KCl dosages reduced soil microbial activity at 4 dai, regardless of the residue dosage. Microbial activity was reduced at 130 dai in all treatments when compared to the initial period. Higher dosages of banana crop residues increased the Cl- content of the soil and promoted the immobilization of N-NH4 +. We concluded that dosages of KCl (above 400 mg dm-3), when applied to soils that already contain crop residues, reduce microbial activity and mineralization of N in the soil.

scholarly journals Impact of transgenic cottons expressing cry1Ac on soil biological attributes

2013 ◽  
Vol 59 (No. 3) ◽  
pp. 108-114 ◽  
Author(s):  
K. Velmourougane ◽  
A. Sahu
Keyword(s):  
Soil Microbial Biomass ◽  
Microbial Biomass Carbon ◽  
Soil Depth ◽  
Diversity Indices ◽  
Soil Microbial Activity ◽  
Bt Cotton ◽  
Available N ◽  
Cry1ac Gene ◽  
Soil Microbial ◽  
Biological Attributes

Three transgenic Bt cotton hybrids (RCH-2 Bt, Bunny Bt and NHH 44 Bt) expressing cry1Ac gene were evaluated for their effects on soil biological, microbiological and diversity attributes at 0&ndash;15 cm and 15&ndash;30 cm soil depth under field conditions. At both soil depths, soil respiration rate and fluorescein diacetate hydrolysis were the highest in the soil under Bt cotton grown followed by non-Bt soil, and by the control bulk soil, indicating no adverse effects of Bt cotton on soil microbial activity. Urease and dehydrogenase activities, reflecting potentially available N and the oxidative metabolism in soil, respectively, also increased in the sequence no-crop variant &lt; non-Bt soil &lt; soil under Bt cotton at both soil depths. A similar trend was found with the soil microbial biomass carbon, microbial population and microbial diversity indices. These results suggest that cultivation of Bt cotton expressing cry1Ac gene may not pose ecological or environmental risk.

scholarly journals Response of soil microbiota to nine-year application of swine manure and urea

2015 ◽  
Vol 46 (2) ◽  
pp. 260-266 ◽  
Author(s):  
Diana Morales ◽  
Mónica Machado Vargas ◽  
Michele Pottes de Oliveira ◽  
Bruna Lunarde Taffe ◽  
Jucinei Comin ◽  
...  
Keyword(s):  
Organic Matter ◽  
Microbial Activity ◽  
Microbial Biomass Carbon ◽  
Soil Layer ◽  
Swine Manure ◽  
Soil Microbial Activity ◽  
Basal Respiration ◽  
Pig Slurry ◽  
Soil Microbial ◽  
Tillage System

ABSTRACT: Manure fertilization is a common practice, but little is known about its impacts on soil microbial activity and organic matter. Aiming to evaluate soil microbial response to nine years of successive applications of swine manure, organic carbon (TOC), total nitrogen (TN), pH, microbial biomass carbon (MBC), basal respiration (BR), metabolic quotient (qCO2), and enzyme (ß-glucosidase, phosphatase, arylsulphatase, and FDA) activities were measured in the 0-10cm soil layer, in a no-tillage system. Treatments were: control soil without fertilization (C), and application of two doses (104 and 209kg of N ha-1year-1) of urea (U1 and U2), pig slurry (PS1 and PS2) and deep litter (DL1 and DL2). TOC, TN, soil pH, MBC, and BR increased in soil fertilized with DL, and were lower in U treatments. Soils with U and DL application had higher qCO2, related to different sources of stressors like nutrient imbalance. Phosphatase and ß-glucosidase activities were not affected by treatments, increased with time, and had a strong correlation with MBC. We conclude that long-term swine manure applications increase microbial activity and soil organic matter, mainly in DL form; while urea applications have negative impacts on these indicators.

Impact of rhizobial inoculum and inorganic fertilizers on nutrients (NPK) availability and uptake in wheat crop

2016 ◽  
Vol 96 (2) ◽  
pp. 169-176 ◽  
Author(s):  
Muhammad Adnan ◽  
Zahir Shah ◽  
Muhammad Arif ◽  
Muhammad Jamal Khan ◽  
Ishaq Ahmad Mian ◽  
...  
Keyword(s):  
Interactive Effect ◽  
Plant Growth Promoting Rhizobacteria ◽  
Soil Microbial Activity ◽  
Wheat Crop ◽  
Mineral N ◽  
Inorganic Fertilizers ◽  
Soil Microbial ◽  
Two Factors ◽  
Plant Growth Promoting ◽  
Growth Promoting

Experiments were conducted to evaluate the effect of rhizobial inoculums and inorganic fertilizers on NP availability, soil microbial activity, wheat NPK concentration and uptake. These experiments were consisted of two factors, four inoculums (no, lentil, peas, and chickpeas) and two NPK doses (120:90:60 and 96:72:48 kg ha−1). Inoculums significantly increased plant total NPK concentration by 39, 57, and 37%, and their uptake by 66, 86, and 56%, respectively. Peas inoculum was most efficient in wheat NPK concentration and uptake. The interactive effect of inoculums and NPK demonstrated that peas and lentil inoculums with 20% less NPK had statistically better role than full NPK without inoculation. AB-DTPA extractible P and mineral N were progressively increased with incubation periods and exhibited significant differences between inoculated and uninoculated treatments during all incubation intervals for NP except at day 7 for N. Peas inoculum showed maximum mean net NP availability of 131.5 and 3.48 mg kg−1over 56 d of incubation, respectively. Significantly higher cumulative CO2of 1429 mg kg−1with a net increase of 866 mg kg−1was recorded for pea’s inoculums during 12 d of incubation interval. It is concluded that peas rhizobium could be used as a plant-growth-promoting rhizobacteria for wheat and other cereal crops.

scholarly journals USING THE RESPIRATORY QUOTIENT AS A MICROBIAL INDICATOR TO MONITOR SOIL BIODEGRADATION

2018 ◽  
Vol 55 (4C) ◽  
pp. 51 ◽  
Author(s):  
Tran Thanh Chi
Keyword(s):  
Respiratory Quotient ◽  
Microbial Growth ◽  
Physiological State ◽  
Soil Microbial Activity ◽  
Co2 Production ◽  
Soil Microbial ◽  
Chromatography Analysis ◽  
Gas Chromatography Analysis ◽  
Plate Counts ◽  
Degradation Activity

The effects of nutrient amendments on the variation in time of the respiratory quotient (RQ) were investigated in soil. Microbial activity measured by CO2 production, biomass growth determined by plate counts technique and residual contaminants quantified by gas chromatography analysis were monitored in order to check their relation to RQ fluctuations. RQ values in all treatments displayed significant fluctuations over time which were closely related to the phases of the respiratory response as well as to microbial growth. After pollutant addition, an increase of RQ occurred in all microcosms. RQ values decreased when high degradation activity and microbial growth took place. RQ values slightly increased in all microcosms at the end of the incubation. These results show that the respiratory quotient is closely related to the physiological state of microorganisms and may be a determinable indicator for the efficiency of bioremediation.

Fungi Associated with Caryopses ofSetariaSpecies from Field-Harvested Seeds and from Soil Under Two Tillage Systems

Weed Science ◽  
1987 ◽  
Vol 35 (3) ◽  
pp. 319-323 ◽  
Author(s):  
Abelino Pitty ◽  
David W. Staniforth ◽  
Lois H. Tiffany
Keyword(s):  
Detrimental Effect ◽  
Crop Residues ◽  
Soil Depth ◽  
Soil Layer ◽  
Fungal Colonization ◽  
Giant Foxtail ◽  
Green Foxtail ◽  
Top Soil ◽  
Lower Depth ◽  
Sterile Mycelium

Seeds of green foxtail [Setaria viridis(L.) P. Beauv. # SETVI] and giant foxtail (S. faberiHerrm. # SETFA) were collected from mature plants in the field and recovered from three soil depths under two types of tillage. Fungi colonizing the caryopses were isolated to determine the effect of tillage and soil depth on fungal colonization and the field flora.Alternaria alternata(Fr.) Keissler andEpicoccum purpurascensEhrenb. ex Schlecht. were the two fungi most frequently isolated from the hand-harvested seeds. Percentages of fungal colonization were directly related to size of the caryopses. The most frequently isolated fungus species recovered from seeds from soil wereA. alternata, Cladosporium cladosporioides(Fresen.) de Vries,E. purpurascens, and two unidentified fungi with sterile mycelium. One sterile fungus had white rough mycelium, and the other had dark mycelium. These two sterile fungi had a detrimental effect on foxtail seed germination in the laboratory. Caryopsis colonization seems to be related to the placement of the crop residues in the soil. In reduced-tillage plots, more caryopses were colonized in the top soil layer (0 to 7.5 cm) than in the 7.5- to 15-cm layer. In plowed soils, greater colonization occurred at the lower depth.

scholarly journals The Change of Catalase Enzyme Activity in Soils by The Land Use

2021 ◽  
Vol 9 (6) ◽  
pp. 1186-1192
Author(s):  
İnci Sevinç Kravkaz Kuşçu ◽  
Mustafa Ömer Karaöz
Keyword(s):  
Land Use ◽  
Enzyme Activity ◽  
Enzyme Activities ◽  
Soil Enzymes ◽  
Soil Depth ◽  
Soil Microbial Activity ◽  
Natural Ecosystems ◽  
Soil Microbial ◽  
Level Of Activity ◽  
Ecological Relationship

Analysing the factors driving the population size and activities of soil microorganisms is important for understanding the soil ecosystem’s structure and functioning. For this purpose, the soil enzymes are used as an indicator of soil microbial activity and soil fertility. Although there are many studies on the distribution and activities of various soil enzymes in soils under monoculture or crop alternation conditions, there are only few studies examining the ecological relationship in natural ecosystems, especially by using enzymes. In this study, it was aimed to determine the effect of different land uses on the catalase enzyme activity in soil. For this purpose, the catalase enzyme activities in soil samples taken from 0-5cm and 5-10cm depths in agricultural, forest, and pasture lands in north and south exposures were determined and the effects of different land use, exposure, and soil depth conditions on the enzyme activities were investigated. At the end of the study, it was determined that the catalase enzyme activity significantly differed by the land use and the highest level of catalase enzyme activity in both south and north exposures and at both depth levels was found in forest soils, whereas the lowest level of activity was found in agricultural lands in north exposure and pasture soils in south exposure.

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