Atrazine mineralisation in New Zealand topsoils and subsoils: influence of edaphic factors and numbers of atrazine-degrading microbes

Soil Research ◽  
1998 ◽  
Vol 36 (4) ◽  
pp. 557 ◽  
Author(s):  
Graham Sparling ◽  
Robert Dragten ◽  
Jackie Aislabie ◽  
Rhonda Fraser
Keyword(s):  
New Zealand ◽  
Moisture Content ◽  
Cation Exchange Capacity ◽  
Surface Soil ◽  
Exchange Capacity ◽  
Most Probable Number ◽  
Edaphic Factors ◽  
Decomposition Rates ◽  
Decomposition Products ◽  
Probable Number

The mineralisation of 14C-ring-labelled atrazine to 14CO2 was measured in 3 contrasting New Zealand soils under controlled conditions of temperature and moisture. The numbers of atrazine-degrading organisms were measured by a most probable number technique. Decomposition rates were slow, with a maximum of 41% of atrazine being mineralised over 263 days. Mineralisation was generally very low in subsoils and was much reduced by low moisture content. However, one subsoil from 60–90 cm depth had unusually high numbers of atrazine-degrading microbes and showed mineralisation greater than or equivalent to the surface soil. Mineralisation was approximately doubled by a 10°C rise in temperature over the range 16–28°C. In general, the rate of atrazine mineralisation over 7–96 days could be predicted from the number of atrazine-degrading microbes and the cation exchange capacity of the soil (R2 = 0·86). A large amount (54–77%) of 14C remained in the soil as non-extractable residues after 263 days, but only trace amounts of the added atrazine or the decomposition products de-ethyl atrazine and de-isopropyl atrazine were detected by extraction in organic solvent.

scholarly journals Long-Term Study of Vibrio parahaemolyticus Prevalence and Distribution in New Zealand Shellfish

2015 ◽  
Vol 81 (7) ◽  
pp. 2320-2327 ◽  
Author(s):  
C. D. Cruz ◽  
D. Hedderley ◽  
G. C. Fletcher
Keyword(s):  
New Zealand ◽  
Vibrio Parahaemolyticus ◽  
Most Probable Number ◽  
Pcr Analysis ◽  
Potential Hazard ◽  
Probable Number ◽  
Content Type ◽  
The North ◽  
Long Term Study ◽  
Food Borne

ABSTRACTThe food-borne pathogenVibrio parahaemolyticushas been reported as being present in New Zealand (NZ) seawaters, but there have been no reported outbreaks of food-borne infection from commercially grown NZ seafood. Our study determined the current incidence ofV. parahaemolyticusin NZ oysters and Greenshell mussels and the prevalence ofV. parahaemolyticustdhandtrhstrains. Pacific (235) and dredge (21) oyster samples and mussel samples (55) were obtained from commercial shellfish-growing areas between December 2009 and June 2012. TotalV. parahaemolyticusnumbers and the presence of pathogenic genestdhandtrhwere determined using the FDA most-probable-number (MPN) method and confirmed using PCR analysis. In samples from the North Island of NZ,V. parahaemolyticuswas detected in 81% of Pacific oysters and 34% of mussel samples, while the numbers ofV. parahaemolyticustdhandtrhstrains were low, with just 3/215 Pacific oyster samples carrying thetdhgene.V. parahaemolyticusorganisms carryingtdhandtrhwere not detected in South Island samples, andV. parahaemolyticuswas detected in just 1/21 dredge oyster and 2/16 mussel samples. Numbers ofV. parahaemolyticusorganisms increased when seawater temperatures were high, the season when most commercial shellfish-growing areas are not harvested. The numbers ofV. parahaemolyticusorganisms in samples exceeded 1,000 MPN/g only when the seawater temperatures exceeded 19°C, so this environmental parameter could be used as a trigger warning of potential hazard. There is some evidence that the totalV. parahaemolyticusnumbers increased compared with those reported from a previous 1981 to 1984 study, but the analytical methods differed significantly.

scholarly journals THE EVALUATION OF THE RESIDUAL EFFECT OF FERTILIZER IN LONG-TERM FERTILITY PLOTS: I. POTASSIUM

1963 ◽  
Vol 43 (2) ◽  
pp. 229-234 ◽  
Author(s):  
A. A. MacLean ◽  
J. J. Doyle
Keyword(s):  
Nitric Acid ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Surface Soil ◽  
Sandy Loam ◽  
Residual Effect ◽  
Exchange Capacity ◽  
Residual Effects ◽  
Intensive Cropping

Residual effects of long-term annual applications of fertilizer potassium on the potassium status of an acid sandy loam Podzol were investigated, in a greenhouse experiment. Potassium accumulated in the surface soil in a form readily available to plants.On plots with higher cation exchange capacities, resulting from manurial treatments, there was no evidence to indicate leaching below 15 inches. On plots where cation exchange capacity was not increased by treatment, a higher percentage potassium saturation at greater depths indicates that leaching of potassium had occurred to a depth of 21 inches. An increased concentration of nitric acid-soluble potassium at greater depths suggests that some of the leached potassium has been converted to the non-exchangeable form.Accumulation in the surface soil was sufficient to supply most of the potassium requirement of ladino clover under conditions of intensive cropping. The results suggest that exchangeable and nitric acid-soluble potassium are reliable criteria of available potassium.

scholarly journals Impacts of Stone Bund on Soil Quality in Masha-Deniba Micro-water Shed Loma woreda Dawuro Zone of Southern Ethiopia

2020 ◽  
Author(s):  
Kero Alemu Danano ◽  
Fanuel Laikemariam Laikemariam
Keyword(s):  
Water Conservation ◽  
Agricultural Production ◽  
Cation Exchange Capacity ◽  
Surface Soil ◽  
Chemical Properties ◽  
Soil Nutrient ◽  
Soil Bulk Density ◽  
Exchange Capacity ◽  
Southern Ethiopia ◽  
Topographic Position

Abstract Background: - Land degradation is one of the major challenges in agricultural production Ethiopia. To combat the problem different Soil and Water Conservation (SWC) measures were introduced. Methods: - This research was conducted in the Masha Deniba micro-watershed, Dawuro Zone, Southern Ethiopia aimed to assess impact of stone bund conservation on soil properties. This study compared the effects of stone bund age along landscape positions. Surface soil sample from 17 farms were collected and analyzed for soil bulk density (BD), organic matter (OM), total nitrogen (TN), pH and cation exchange capacity (CEC) of soil. Result:- Results showed that farms treated with stone bunds showed improvement in soil chemical properties. For most parameters, the peak was obtained from stone bunds having 10 years age. The non- conserved plots had the lowest soil nutrients contents. Lower topographic position had shown higher nutrients contents than farms in upper topographic position. Overall, OC, TN, S and B contents were low in the watershed. Conclusion: - From the finding we can conclude that stone bunds improved soil nutrient when compared to non-treated farm with the respect of age and landscape position. But constructing physical structures alone does not restore the soil fertility to the level that the crop is demanding. Thus, integration of physical conservation with agronomic and biological measures is highly recommended.

scholarly journals Morphogenesis Of Three Surface-Water Gley Soils From The Meghna Floodplain Of Bangladesh

1970 ◽  
Vol 21 (1) ◽  
pp. 17-28
Author(s):  
ZH Khan ◽  
MS Hussain ◽  
F Ottner
Keyword(s):  
Surface Water ◽  
Cation Exchange Capacity ◽  
Surface Soil ◽  
Organic Matter Content ◽  
Exchange Capacity ◽  
Matter Content ◽  
Morphological Properties ◽  
Soil Profiles ◽  
Silty Clay ◽  
Silt Loam

Surface-water gley soils comprise extensive area on the seasonally wet landscape of Meghna floodplain in Bangladesh. Three typical surface-water gley soils from the above floodplain were studied in the field and laboratory for their pedogenesis. Morphological properties indicate that there is formation of gleyed/ pseudogleyed horizons in the soil profiles. Extensive development of mottles, ploughpans and flood coatings or gleyans is the most notable morphogenetic features in these soils. Physically, these soils are medium to fine textured where textural class ranged between silt loam and silty clay. Chemically, the soils are moderately acidic to neutral in reaction with seasonally fluctuating pH in the surface horizon. The ΔpH values are all negative and range from – 0.90 to – 2.01. The organic matter content in the surface soil is relatively low that decreases steadily with depth. The cation exchange capacity (CEC) of the soils ranged from 3.53 to 14.08 cmol p+/kg with an average of 10.10 cmol p+/kg and base saturation per cent (BSP) varied from 59 to 86. The Ca++/Mg++ ratio is less than unity indicating loss of Ca++ due to gleization in these soils.  

VARIABILITY OF SOIL PROPERTIES IN RELATION TO SIZE OF MAP UNIT DELINEATION

1982 ◽  
Vol 62 (4) ◽  
pp. 657-662 ◽  
Author(s):  
C. WANG
Keyword(s):  
Organic Carbon ◽  
Soil Properties ◽  
Cation Exchange Capacity ◽  
Surface Soil ◽  
Boundary Effect ◽  
Clay Content ◽  
Soil Characteristics ◽  
Exchange Capacity ◽  
Coefficient Of Variability ◽  
Range Of Variation

The results of a study which compared some selected soil characteristics of small and large map unit delineations are presented. Color, organic carbon, pH, cation exchange capacity and clay content were measured. Properties, such as pH and CEC of surface soil and pH of subsoil, were found to be significantly different between large and small delineations. Although Brandon is selected to be a simple and relatively uniform map unit, the range of variation was wide for all of the selected soil properties. For each property measured the coefficient of variability was always larger in surface soils than in subsoils. However, variance of measured soil properties did not differ between the two groups of delineations. Consequently, the soil boundary effect is considered to be insignificant for the Brandon unit of the Dalhousie association studied.

scholarly journals Phytoremediation of Copper and Nickel Contaminated Soil Using Eleusine indica on Soil Properties

2020 ◽  
pp. 1-8
Author(s):  
G. I. Ameh ◽  
E. J. Onuh
Keyword(s):  
Organic Carbon ◽  
Moisture Content ◽  
Soil Properties ◽  
Total Organic Carbon ◽  
Cation Exchange ◽  
Contaminated Soil ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Soil Samples ◽  
Eleusine Indica

The effects of Eleusine indica phytoremediation on the soil properties of Copper and Nickel contaminated soil samples were investigated using standard techniques. Soil sample and seeds of E. inidca were collected from a farmland in Obe, Nkanu West L.G.A of Enugu State. 0%, 1%, 2% and 3% potted treatments of Copper and Nickel contaminated soil were made for three samples (initial sample, sample without plant and sample with plant). The plant showed BAF and TF greater than 1. The Soil samples after the plant was harvested were subjected to soil analysis tests (Metal determination, pH, Soil moisture content, total organic carbon, and cation exchange capacity). The results from the study revealed that soil samples with plant showed a lower pH level within the range of 6.50 to 7.80 and higher percentage moisture content for both Cu and Ni contaminated soil samples, of which 1% treatment showed the highest percentage moisture of 0.679% for Cu contamination and 3.16% for Ni contamination. Heavy metal contamination of soil reduces its total organic carbon and increases its cation exchange capacity. Eleusine indica is a hyperaccumulator, its root stores more heavy metals and thus suitable for phytoremediation.

scholarly journals Genetic Markers for Rapid PCR-Based Identification of Gull, Canada Goose, Duck, and Chicken Fecal Contamination in Water

2011 ◽  
Vol 78 (2) ◽  
pp. 503-510 ◽  
Author(s):  
Hyatt C. Green ◽  
Linda K. Dick ◽  
Brent Gilpin ◽  
Mansour Samadpour ◽  
Katharine G. Field
Keyword(s):  
New Zealand ◽  
Fecal Contamination ◽  
The United States ◽  
Rrna Genes ◽  
Most Probable Number ◽  
Rrna Gene ◽  
Probable Number ◽  
Content Type ◽  
16S Rna ◽  
Pcr Assays

ABSTRACTAvian feces contaminate waterways but contribute fewer human pathogens than human sources. Rapid identification and quantification of avian contamination would therefore be useful to prevent overestimation of human health risk. We used subtractive hybridization of PCR-amplified gull fecal 16S RNA genes to identify avian-specific fecal rRNA gene sequences. The subtracters were rRNA genes amplified from human, dog, cat, cow, and pig feces. Recovered sequences were related toEnterobacteriaceae(47%),Helicobacter(26%),Catellicoccus(11%),Fusobacterium(11%), andCampylobacter(5%). Three PCR assays, designated GFB, GFC, and GFD, were based on recovered sequence fragments. Quantitative PCR assays for GFC and GFD were developed using SYBR green. GFC detected down to 0.1 mg gull feces/100 ml (corresponding to 2 gull enterococci most probable number [MPN]/100 ml). GFD detected down to 0.1 mg chicken feces/100 ml (corresponding to 13Escherichia coliMPN/100 ml). GFB and GFC were 97% and 94% specific to gulls, respectively. GFC cross-reacted with 35% of sheep samples but occurred at about 100,000 times lower concentrations in sheep. GFD was 100% avian specific and occurred in gulls, geese, chickens, and ducks. In the United States, Canada, and New Zealand, the three markers differed in their geographic distributions but were found across the range tested. These assays detected four important bird groups contributing to fecal contamination of waterways: gulls, geese, ducks, and chickens. Marker distributions across North America and in New Zealand suggest that they will have broad applicability in other parts of the world as well.

Effect of Storage Temperature on the Survival of New Zealand Egg-Associated Salmonella Isolates in and on Eggs

2019 ◽  
Vol 82 (12) ◽  
pp. 2161-2168 ◽  
Author(s):  
JOANNE M. KINGSBURY ◽  
KIRSTIN THOM ◽  
TANYA SOBOLEVA
Keyword(s):  
New Zealand ◽  
Incubation Temperature ◽  
Storage Temperature ◽  
Limit Of Detection ◽  
Most Probable Number ◽  
Probable Number ◽  
Egg Storage ◽  
Chicken Feces ◽  
Storage Times ◽  
Storage Temperatures

ABSTRACT The influence of egg storage temperature on Salmonella contamination of eggs is a key consideration in determining storage and shelf life recommendations for eggs. In this study, experiments assessed the survival of Salmonella isolates on and in eggs at storage temperatures (15 and 22°C) currently used in New Zealand. Eggshell surfaces were inoculated with a cocktail of 10 Salmonella isolates comprising five serotypes, at a concentration of ∼106 CFU per egg (for determining shell surface survival) or ∼103 CFU per egg (for determining internalization). Additionally, a subset of eggs was artificially contaminated with sterile chicken feces prior to Salmonella inoculation. Inoculated eggs were incubated at 15 and 22°C. At 0, 21, and 35 days of incubation, eggshells were enumerated for Salmonella, and egg contents were tested for Salmonella presence or absence (yolk) or most probable number (albumen). Higher levels of Salmonella were recovered from eggshells following incubation at 15°C (31% relative humidity [RH]) compared with 22°C (45% RH) after both 21 and 35 days of incubation. Recoverable numbers of Salmonella from visibly clean eggshell surfaces declined over time at both storage temperatures and were at, or below, the limit of detection from eggs stored at 22°C and 45% RH for 35 days. A substantially higher concentration of viable Salmonella was recovered from eggshells that were experimentally contaminated with chicken feces compared with those without, particularly from eggs stored at 15°C and 31% RH for 35 days (2.38 log higher CFU from eggs containing feces). No Salmonella was detected in egg contents (albumen or yolk) at any incubation temperature or time point, regardless of the presence of feces. Findings emphasize the importance of current regulations that require eggs sold at retail to be visibly clean and will inform risk management decisions regarding egg storage times and temperatures with respect to Salmonella control in and on New Zealand eggs at retail. HIGHLIGHTS

Relationship of mycorrhizal activity to time following reclamation of surface mine land in western Kentucky. I. Propagule and spore population densities

1996 ◽  
Vol 74 (2) ◽  
pp. 247-261 ◽  
Author(s):  
Ann B. Gould ◽  
James W. Hendrix ◽  
Richard S. Ferriss
Keyword(s):  
Mycorrhizal Fungi ◽  
Most Probable Number ◽  
Edaphic Factors ◽  
Population Densities ◽  
Surface Mine ◽  
Probable Number ◽  
Spore Population ◽  
Mine Sites ◽  
Highly Correlated ◽  
Western Kentucky

The relationships between estimates of mycorrhizal activity, time following reclamation, and soil edaphic factors were investigated over a period of 2.5 years during reclamation of five abandoned surface mine sites in western Kentucky. These sites were reclaimed at different times and were in varying stages of revegetation. At the seeding stage of reclamation and soon thereafter, propagule and spore population densities were low but invariably present. Roots recovered from minespoil during this period were not colonized, and colonization was not observed until a full year following reclamation. During the first 2 years following reclamation, colonization of roots, population densities of propagules and spores, and total spore volume increased rapidly. Thereafter, vegetative and mycorrhizal parameters appeared to stabilize. Each estimate of mycorrhizal activity in minespoil was highly correlated with time following reclamation and all other mycorrhizal parameters. Edaphic factors with positive relationships to mycorrhizal propagule and spore population densities included soil organic matter and calcium. Keywords: Glomales mycorrhizal fungi, reclamation, abandoned minespoil, most probable number, propagule population density.

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