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.

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.

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.

scholarly journals Comparison of heat output and CO2 respiration to assess soil microbial activity: a case of ultisol soil

2018 ◽  
Vol 64 (No. 10) ◽  
pp. 470-478 ◽  
Author(s):  
Jia Xiuhong ◽  
Cao Haichuan ◽  
Jiang Lanlan ◽  
Yuan Jihong ◽  
Zheng Shixue
Keyword(s):  
Microbial Communities ◽  
Microbial Activity ◽  
Total Phospholipid ◽  
Chemical Properties ◽  
Soil Microbial Activity ◽  
Soil Samples ◽  
Heat Output ◽  
Mineral N ◽  
Soil Microbial ◽  
Comprehensive Indicator

Glucose-induced microcalorimetry and carbon dioxide (CO<sub>2</sub>) production are two widely applied methods to assess microbial activity in soil. However, the links among them, microbial communities and soil chemical properties based on large number of soil samples are still not fully understood. Seventy-two soil samples of different land uses were collected from an ultisol soil area in south China. The best correlation between the rate of heat output and the rate of CO<sub>2</sub> respiration occurred in 8–16 h reaction (R<sup>2</sup> = 0.64), followed by 0–8 h (R<sup>2</sup> = 0.50) (P &lt; 0.001). However, the correlations decreased sharply after 16 h. The heat output per biomass unit (Q<sub>T</sub>/MBC) was well correlated with the total phospholipid fatty acids (PLFAs) (R<sup>2</sup> = 0.56) and bacterial PLFAs (R<sup>2</sup> = 0.53) (P &lt; 0.001). In contrast, these links were not apparent between soil respiratory quotient (qCO<sub>2</sub>) and the total PLFAs and microbial communities. Redundancy analysis further confirmed that Q<sub>T</sub>/MBC was a more comprehensive indicator to assess soil microbial activity and soil quality than qCO<sub>2</sub>, showing a good negative correlation to soil organic carbon, total nitrogen (N) and mineral N, and pH. This work is very helpful to better guide the application of calorimetry and CO<sub>2</sub> respiration in assessing microbial activity in soils.

scholarly journals Powders of kudzu, velvetbean, and pine bark added to soil increase microbial population and reduce Southern blight of soybean

2006 ◽  
Vol 31 (6) ◽  
pp. 551-556 ◽  
Author(s):  
Luiz E. B. Blum ◽  
Rodrigo Rodríguez-Kábana
Keyword(s):  
Microbial Population ◽  
Disease Incidence ◽  
Soil Amendments ◽  
Sclerotium Rolfsii ◽  
Enterobacter Aerogenes ◽  
Soil Microbial Activity ◽  
Pine Bark ◽  
Southern Blight ◽  
Soil Microbial ◽  
Soil Microbial Population

Southern blight (Sclerotium rolfsii) of soybean (Glycine max) is an important disease throughout the world. Some soil amendments can reduce disease levels by improving soil microbial activity. The main goals of this study were to investigate the effects of soil amendments such as dried powders of kudzu (Pueraria lobata), velvetbean (Mucuna deeringiana), and pine bark (Pinus taeda), on soil microbial population and disease caused by S. rolfsii on soybean. Pine bark, velvetbean (mucuna) and kudzu (25 g kg-1) added to soil were effective in reducing disease incidence [non-amended (NA) ~ 39%; amended (A) ~ 2 to 11%)]. Bacillus megaterium was the bacteria most frequently isolated in soils with velvetbean or kudzu (NA ~ log 5.7 CFU g-1 of dried soil; A ~ log 6.2). Soils with velvetbean and kudzu stimulated increase in population of Enterobacter aerogenes (NA ~ log 3; A ~ log 5.1-5.8). Pseudomonas putida population was higher in A than in NA (NA ~ log 4; A ~ log 5.5), and was negatively correlated (r = -0.83, P = 1%) to disease incidence. Soil amended with kudzu and pine bark stimulated increases in populations of Trichoderma koningii (NA ~ log 1.6; A ~ log 2.9) and Penicillium citreonigrum (NA ~ log 1.3; A ~ log 2.6), respectively. Penicillium herquei soil population increased with addition of kudzu (NA ~ log 1.2; A, ~ log 2.5). These microorganisms are antagonists of soil-borne pathogens. Powders of velvetbean, kudzu, and pine bark can increase antagonistic population in soil and reduce disease.

scholarly journals Comparison of the Agricultural Use of Products from Organic Waste Processing with Conventional Mineral Fertilizer: Potential Effects on Mineral Nitrogen Leaching and Soil Quality

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 226
Author(s):  
Jakub Elbl ◽  
Jana Šimečková ◽  
Petr Škarpa ◽  
Antonín Kintl ◽  
Martin Brtnický ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Microbial Activity ◽  
Plant Biomass ◽  
Mineral Fertilizer ◽  
Soil Microbial Activity ◽  
Mineral N ◽  
Soil Microbial ◽  
Compost Application ◽  
Substrate Induced Respiration ◽  
Positive Effect

Currently, there is an increasing emphasis on the use of renewable sources. The Czech Republic is no exception. There has been an increase in the number of biogas plants and composting plants. The main purpose of these facilities is to process organic wastes of various origins in order to utilize the waste, both for energy production and as soil fertility enhancers. Last but not least, the biogas station produces digestate, which could be further utilized. The present work deals with the assessment of the effect of digestate (doses of 220; 150 and 80 kg N ha−1), mineral fertilizer (150 kg N ha−1), and compost application (150 kg N ha−1) on selected indicators of soil environment: (a) soil microbial activity (basal and substrate-induced respiration); (b) plant nutrient content (P, K, Ca, Mg); (c) leaching mineral N from the soil; and (d) production of plant biomass of model plant Lactuca sativa L. Furthermore, the work aims to assess the individual doses of digestate and to determine the optimal one. The above effects were studied within a pot experiment for 63 days in controlled conditions. There were significant differences in Nmin leaching, which was significantly the highest in the variant with the application of a mineral fertilizer and lowest in variants with the application of digestate (variant 150 and 80 kg N ha−1) and compost (150 kg N ha−1). In terms of soil microbial activity, a significant effect of digestate application (150 kg N ha−1) on basal respiration versus the mineral fertilizer application was found (difference > 20%). This dose of digestate also had the highest positive effect on substrate-induced respiration, proven against all other variants, except for the digestate application at 220 kg N ha−1. Particularly, as compared with the mere application of mineral fertilizer, the application of digestate dose at 150 kg N ha−1 had the best positive effect on plant biomass production (+20%). On the other hand, compost application most positively affected the increase in available contents of nutrients and thus long-term soil fertility. Therefore, the dose of 150 kg N ha−1 digestate may represent an interesting alternative to increase actual soil fertility and thus to partially replace conventional mineral nutrition.

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