Fate of Bacillus thuringiensis in soil: effect of soil pH and organic amendment

1970 ◽  
Vol 16 (8) ◽  
pp. 677-680 ◽  
Author(s):  
S. M. Saleh ◽  
R. F. Harris ◽  
O. N. Allen
Keyword(s):  
Bacillus Thuringiensis ◽  
Incubation Period ◽  
Soil Ph ◽  
Organic Amendment ◽  
Acid Soils ◽  
Microbial Populations ◽  
Vegetative Cells ◽  
Soil Microbial ◽  
Neutral Ph

Bacillus thuringiensis spores germinated, grew, and sporulated in soils of neutral pH amended with alfalfa or casein. Numbers of viable spores of B. thuringiensis increased 100-fold and more than one million spores/g soil were maintained throughout a 3-month incubation period. B. thuringiensis spores apparently germinated but the resulting vegetative cells did not survive in acid soils amended with alfalfa or casein. It appears that B. thuringiensis spores can remain viable for long periods of time in soil and that the organism can compete successfully under conditions favoring the bacillus component of soil microbial populations.

scholarly journals Organic and Symbiotic Fertilization of Tomato Plants Monitored by Litterbag-NIRS and Foliar-NIRS Rapid Spectroscopic Methods

2020 ◽  
Vol 3 (1) ◽  
pp. 9-26
Author(s):  
Elena Baldi ◽  
Moreno Toselli ◽  
Giorgio Masoero ◽  
Marco Nuti
Keyword(s):  
Support Vector Machine Classifier ◽  
Organic Amendment ◽  
Microbial Populations ◽  
Support Vector ◽  
Spectroscopic Methods ◽  
Chemical Analyses ◽  
Average Yield ◽  
Tomato Plants ◽  
Soil Microbiota ◽  
Soil Microbial

Rapid analyses methods for the assessment of soil microbiota are lacking. In a commercial farm tomato plants were subjected to different fertilization strategies: 1. mineral Control (C); 2. Organic amendment (O); 3. Organic amendment + Micosat F © biofertilizer (OM). A first rapid method (Litterbag-NIRS) concerned hay litterbags coupled with a smart SCiOTM device. A second method (Foliar-NIRS) used the same device on the leaves. The plants showed positive responses to the amendment and biofertilization in the yield: C 60.5.1 t ha-1vs. 70.8 in O (+17%) and 74.2 in OM (+23% from C and + 5% (P 0.08) from O). The use of Litterbag-NIRS fingerprinting, completed with litterbags phenotyping and elaborated with a multivariate support vector machine classifier provided a similar knowledge to that obtained from microbial and chemical analyses of the soil. The reason for this response is that the analyses were embedded in the Litterbag-NIRS at medium-high precision. A polydromic function was hypothesized in order to disentangle the activities of different soil microbial populations from each other. The organic amendment delayed the functionality of the rapid r-strategist microbial populations, but at the same time activated slow k-strategists to intake the walls of the hay inside the litterbags. In this sense, the Litterbag-NIRS test can provide an effective “swamp” of the microbial fertility of the soil. Briefly, the Litterbag-NIRS coupled with Foliar-NIRS accounted for 95% of the average yield results, and both are therefore recommended for a rational assessment of microbial soil fertility.

EFFECTS OF SOIL ACIDITY ON RHIZOBIA NUMBERS, NODULATION AND NITROGEN FIXATION BY ALFALFA AND RED CLOVER

1977 ◽  
Vol 57 (2) ◽  
pp. 197-203 ◽  
Author(s):  
W. A. RICE ◽  
D. C. PENNEY ◽  
M. NYBORG
Keyword(s):  
Nitrogen Fixation ◽  
Soil Ph ◽  
Soil Acidity ◽  
Field Experiments ◽  
Rhizobium Meliloti ◽  
Acid Soils ◽  
Red Clover ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Greenhouse Experiments

The effects of soil acidity on nitrogen fixation by alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) were investigated in field experiments at 28 locations, and in greenhouse experiments using soils from these locations. The pH of the soils (limed and unlimed) varied from 4.5 to 7.2. Rhizobia populations in the soil, nodulation, and relative forage yields (yield without N/yield with N) were measured in both the field and greenhouse experiments. Rhizobium meliloti numbers, nodulation scores, and relative yields of alfalfa decreased sharply as the pH of the soils decreased below 6.0. For soils with pH 6.0 or greater, there was very little effect of pH on any of the above factors for alfalfa. Soil pH in the range studied had no effect on nodulation scores and relative yields of red clover. However, R. trifolii numbers were reduced when the pH of the soil was less than 4.9. These results demonstrate that hydrogen ion concentration is an important factor limiting alfalfa growth on acid soils of Alberta and northeastern British Columbia, but it is less important for red clover. This supports the continued use of measurements of soil pH, as well as plant-available Al and Mn for predicting crop response to lime.

Alkaline soil pH affects bulk soil, rhizosphere and root endosphere microbiomes of plants growing in a Sandhills ecosystem

2021 ◽  
Vol 97 (4) ◽  
Author(s):  
Lucas Dantas Lopes ◽  
Jingjie Hao ◽  
Daniel P Schachtman
Keyword(s):  
Microbial Communities ◽  
Plant Species ◽  
Soil Ph ◽  
Soil Microbial Communities ◽  
Bulk Soil ◽  
Strong Impact ◽  
Alkaline Soil ◽  
Alkaline Soils ◽  
Soil Microbial ◽  
Soil Rhizosphere

ABSTRACT Soil pH is a major factor shaping bulk soil microbial communities. However, it is unclear whether the belowground microbial habitats shaped by plants (e.g. rhizosphere and root endosphere) are also affected by soil pH. We investigated this question by comparing the microbial communities associated with plants growing in neutral and strongly alkaline soils in the Sandhills, which is the largest sand dune complex in the northern hemisphere. Bulk soil, rhizosphere and root endosphere DNA were extracted from multiple plant species and analyzed using 16S rRNA amplicon sequencing. Results showed that rhizosphere, root endosphere and bulk soil microbiomes were different in the contrasting soil pH ranges. The strongest impact of plant species on the belowground microbiomes was in alkaline soils, suggesting a greater selective effect under alkali stress. Evaluation of soil chemical components showed that in addition to soil pH, cation exchange capacity also had a strong impact on shaping bulk soil microbial communities. This study extends our knowledge regarding the importance of pH to microbial ecology showing that root endosphere and rhizosphere microbial communities were also influenced by this soil component, and highlights the important role that plants play particularly in shaping the belowground microbiomes in alkaline soils.

AN ASSESSMENT OF THE SOIL ACIDITY PROBLEM IN ALBERTA AND NORTHEASTERN BRITISH COLUMBIA

1977 ◽  
Vol 57 (2) ◽  
pp. 157-164 ◽  
Author(s):  
D. C. PENNEY ◽  
M. NYBORG ◽  
P. B. HOYT ◽  
W. A. RICE ◽  
B. SIEMENS ◽  
...  
Keyword(s):  
British Columbia ◽  
Soil Ph ◽  
Soil Acidity ◽  
Field Experiments ◽  
Trifolium Pratense ◽  
Acid Soil ◽  
Acid Soils ◽  
Red Clover ◽  
Hordeum Vulgare L ◽  
Crop Species

The amount of cultivated acid soil in Alberta and northeastern British Columbia was estimated from pH values of farm samples analyzed by the Alberta Soil Testing Laboratory, and the effect of soil acidity on crops was assessed from field experiments on 28 typical acid soils. The field experiments consisted of two cultivars of barley (Hordeum vulgare L.) and one cultivar each of rapeseed (Brassica campestris L.), red clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.) grown with and without lime for 2 yr. There are about 30,000 ha of soils with a pH of 5.0 or less where soil acidity seriously restricts yields of all four crop species. There are approximately 300,000 ha with a soil pH of 5.1–5.5 where liming will on the average increase yields of alfalfa by 100%, yields of barley by 10–15%, and yields of rapeseed and red clover by 5–10%. There are a further 1,600,000 ha where soil pH ranges from 5.6 to 6.0 and liming will increase yields of alfalfa by approximately 50% and yields of barley, rapeseed and red clover by at least 4–5%.

scholarly journals The Influence of Selected Meteorological Factors on Microbial Biomass and Mineralization of Two Organic Fertilizers

2011 ◽  
Vol 39 (1) ◽  
pp. 107
Author(s):  
Mignon S. SANDOR ◽  
Traian BRAD ◽  
Aurel MAXIM ◽  
Constantin TOADER
Keyword(s):  
Biological Activity ◽  
Microbial Biomass ◽  
Soil Ph ◽  
Soil Microbial Biomass ◽  
Organic Fertilizers ◽  
Barley Straw ◽  
Short Term ◽  
Soil Microbial ◽  
Fertilized Soil ◽  
Mineralization Processes

A mesocosm study was conducted in order to evaluate the effects of short-term rainfall and temperature variation on soil microbial biomass and bacteria to fungi ratio. In addition, the relation between the decomposition process of two organic fertilizers, cattle manure and barley straw, and the activity of soil microbial biomass was also studied. In order to assess the effect of biological activity on soil fertility the dynamics of soil pH, N-NO3-, N-NH4+, Corg and Nt during plant growing season was measured. The results suggest that short-term variation of climate had a significant effect on microbial biomass with dry periods distinguished by a reduced microbial biomass compared to wet periods. The ratio bacteria to fungi seems also to be sensitive to variations in rainfall and temperature regime, however further studies are required to draw a definitive conclusion. Regarding the type of fertilizer used, the straw treatments showed higher microbial biomass than the manure treatments, but higher decomposition rate was observed in manure fertilized soil. The effect of soil biological activity on soil pH was limited for both manure and straw treatments while the changes of the soil nitrate amounts are related to the microbial biomass. The study indicates that nitrate immobilization and mineralization processes are influenced by meteorological conditions and microbial biomass dynamics. In contrast, soil organic carbon and total nitrogen did not seem to be affected by variations in temperature, rainfall and microbial activity.

The interaction between soil pH and phosphorus for wheat yield and the impact of lime-induced changes to soil aluminium and potassium

Soil Research ◽  
2017 ◽  
Vol 55 (4) ◽  
pp. 341 ◽  
Author(s):  
Craig A. Scanlan ◽  
Ross F. Brennan ◽  
Mario F. D'Antuono ◽  
Gavin A. Sarre
Keyword(s):  
Grain Yield ◽  
Soil Ph ◽  
Field Experiments ◽  
Wheat Yield ◽  
Acid Soils ◽  
Combined Effect ◽  
Additive Effect ◽  
Yield Response ◽  
Response Curves ◽  
The Impact

Interactions between soil pH and phosphorus (P) for plant growth have been widely reported; however, most studies have been based on pasture species, and the agronomic importance of this interaction for acid-tolerant wheat in soils with near-sufficient levels of fertility is unclear. We conducted field experiments with wheat at two sites with acid soils where lime treatments that had been applied in the 6 years preceding the experiments caused significant changes to soil pH, extractable aluminium (Al), soil nutrients and exchangeable cations. Soil pH(CaCl2) at 0–10cm was 4.7 without lime and 6.2 with lime at Merredin, and 4.7 without lime and 6.5 with lime at Wongan Hills. A significant lime×P interaction (P<0.05) for grain yield was observed at both sites. At Merredin, this interaction was negative, i.e. the combined effect of soil pH and P was less than their additive effect; the difference between the dose–response curves without lime and with lime was greatest at 0kgPha–1 and the curves converged at 32kgPha–1. At Wongan Hills, the interaction was positive (combined effect greater than the additive effect), and lime application reduced grain yield. The lime×P interactions observed are agronomically important because different fertiliser P levels were required to maximise grain yield. A lime-induced reduction in Al phytotoxicity was the dominant mechanism for this interaction at Merredin. The negative grain yield response to lime at Wongan Hills was attributed to a combination of marginal soil potassium (K) supply and lime-induced reduction in soil K availability.

Effects of potassium azide on soil microbial populations and soil enzymatic activities

1975 ◽  
Vol 21 (4) ◽  
pp. 565-570 ◽  
Author(s):  
W. D. Kelley ◽  
R. Rodriguez-Kabana
Keyword(s):  
Soil Enzyme ◽  
Soil Microflora ◽  
Microbial Populations ◽  
Bacterial Populations ◽  
Soil Microbial ◽  
Fungal Populations ◽  
Potassium Azide ◽  
Time Changes ◽  
Bacteria And Fungi ◽  
Microbial Numbers

Preplant applications of potassium azide (KN3) to pine nursery beds were evaluated for effect on the soil microflora and on soil enzyme activity where either plastic-sealing or water-sealing techniques were used. Two weeks after incorporation of azide (0–224 kg/ha), soil samplings revealed reduced populations of bacteria and fungi and a corresponding decline in invertase and amylase activities. These effects were proportionate to the amount of azide used and were more pronounced in plastic-sealed plots. Phosphatase activity was little affected. Five weeks after azide application, bacterial populations were higher in treated plots than in controls. Greater numbers of bacteria were recorded from plastic-sealed plots and highest populations coincided with plots receiving the highest rates of azide, regardless of the sealing technique. Fungal populations at this sampling were generally less in treated plots than in the controls, but were higher under plastic seal. At this time, changes in invertase and amylase activities did not correspond to increased microbial numbers. Sixteen weeks after applications of KN3, bacterial populations in treated plots did not differ significantly from controls, but remained higher in plastic-sealed than water-sealed plots. Fungal populations under plastic seal had changed little and remained significantly lower in treated water-sealed plots than in controls. The earlier recorded reduction in invertase and amylase activities was still evident at the final sampling.

scholarly journals Linking Toluene Degradation with Specific Microbial Populations in Soil

1999 ◽  
Vol 65 (12) ◽  
pp. 5403-5408 ◽  
Author(s):  
Jessica R. Hanson ◽  
Jennifer L. Macalady ◽  
David Harris ◽  
Kate M. Scow
Keyword(s):  
Microbial Community ◽  
Microbial Population ◽  
Phospholipid Fatty Acid ◽  
Microbial Populations ◽  
Complex Environments ◽  
Toluene Degradation ◽  
Effective Technique ◽  
Soil Microbial ◽  
Isotope Tracer ◽  
Plfa Analysis

ABSTRACT Phospholipid fatty acid (PLFA) analysis of a soil microbial community was coupled with 13C isotope tracer analysis to measure the community’s response to addition of 35 μg of [13C]toluene ml of soil solution−1. After 119 h of incubation with toluene, 96% of the incorporated13C was detected in only 16 of the total 59 PLFAs (27%) extracted from the soil. Of the total 13C-enriched PLFAs, 85% were identical to the PLFAs contained in a toluene-metabolizing bacterium isolated from the same soil. In contrast, the majority of the soil PLFAs (91%) became labeled when the same soil was incubated with [13C]glucose. Our study showed that coupling13C tracer analysis with PLFA analysis is an effective technique for distinguishing a specific microbial population involved in metabolism of a labeled substrate in complex environments such as soil.

Sign in / Sign up

Export Citation Format

Share Document