Detection and Degradation of Linuron in Organic Soils

Weed Science ◽  
1983 ◽  
Vol 31 (1) ◽  
pp. 8-13 ◽  
Author(s):  
L. Mapplebeck ◽  
C. Waywell
Keyword(s):  
Organic Soil ◽  
Solvent System ◽  
Soil Samples ◽  
Organic Soils ◽  
Growth Reduction ◽  
Biological Assays ◽  
Chromatographic Techniques ◽  
Phytotoxic Metabolite ◽  
Florisil Column Chromatography ◽  
Field Plots

Detection and degradation of linuron [3-(3,4-dichlorophenyl) -1 - methoxy -1 - methylurea] in organic soils were studied using biological assays and chromatographic techniques. The level of linuron that caused 50% growth reduction of onion (Allium cepa L.) varied among three soils of greatly differing organic matter contents. Linuron and its metabolites were successfully separated with florisil column chromatography using a five-fraction solvent system; however, only linuron and 3 - (3,4 - dichlorophenyl) -1 -methylurea could be extracted from organic soil samples at satisfactory recovery rates. Soil samples from eight grower fields and from field plots were analyzed to determine the residue level of these two compounds. Quantitative assessment of the compounds was made with high pressure liquid chromatography. Results of the biological assay and chromatographic analysis showed that linuron and its phytotoxic metabolite, 3 - (3,4 - dichlorophenyl) -1 - methylurea, were not accumulating in the organic soils of Ontario and that the levels detected were not phytotoxic to onions when grown in pot bioassays.

RELEASE OF P IN ORGANIC SOILS UNDER AEROBIC AND ANAEROBIC CONDITIONS

1979 ◽  
Vol 59 (3) ◽  
pp. 337-339 ◽  
Author(s):  
G. J. RACZ
Keyword(s):  
Organic Soil ◽  
Soil Samples ◽  
Organic Soils ◽  
Anaerobic Conditions ◽  
Inorganic P ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Two organic soil samples were incubated at 10 °C aerobically and anaerobically for varying durations up to 24 mo. After incubation, the inorganic P concentrations were determined by successively extracting the soils with 1 N NH4Cl, 0.5 N neutral NH4, 0.1 N NaOH and 0.5 N H2SO4. All extractable forms of inorganic P increased upon incubation in both samples and for both methods of incubation. Total and all extractable forms of inorganic P for samples incubated anaerobically were usually greater than or about equal to P concentrations in samples incubated aerobically.

CARBOXYL AND PHENOLIC HYDROXYL GROUPS IN SOME ORGANIC SOILS AND THEIR RELATION TO THE DEGREE OF HUMIFICATION

1965 ◽  
Vol 45 (3) ◽  
pp. 257-264 ◽  
Author(s):  
M. Schnitzer ◽  
J. G. Desjardins
Keyword(s):  
Carboxylic Acid ◽  
Infrared Spectra ◽  
Colorimetric Method ◽  
Organic Soil ◽  
Soil Samples ◽  
Phenolic Hydroxyl ◽  
Total Carbon ◽  
Organic Soils ◽  
Hydroxyl Groups ◽  
Phenolic Hydroxyl Groups

The degree of humification of 17 organic soil samples was determined by the pyrophosphate test of Dawson as described by MacLean et al. (5) and the colorimetric method of Kaila (4). The latter procedure, although more laborious, was preferred because of good replication and exclusion of the personal judgment of an observer.Treatment with HCl–HF solution resulted in a significant reduction in the ash content of most samples; concomitant losses of organic matter were less than 5%. The main effect of the HCl–HF treatment was to free carboxyl groups. By contrast, phenolic hydroxyl groups remained apparently unaffected. Carboxyls appeared to be the most reactive groups in these organic soil samples. Infrared spectra of untreated peats and of mucky peats exhibited bands at 1720 cm−1, indicative of the presence of free carboxylic acid groups. These bands were absent in the spectra of mucks. After the acid treatment, however, infrared spectra of mucks showed new strong bands at 1720 cm−1 and decreased absorption at 1625 cm−1, apparently due to the conversion of carboxylate to carboxylic acid groups.The total carbon, hydrogen, sulphur, and oxygen contents were similar for all samples, but peats and mucky peats tended to contain less total nitrogen than mucks.

A Rapid Method of taking Soil Samples from Field Plots 1

1924 ◽  
Vol 16 (8) ◽  
pp. 486-488
Author(s):  
E. P. Deatrick ◽  
O. C. Bryan
Keyword(s):  
Rapid Method ◽  
Soil Samples ◽  
Field Plots

RELATIONSHIPS BETWEEN SOME PROPERTIES OF ORGANIC SOILS FROM THE SOUTHERN CANADIAN SHIELD

1990 ◽  
Vol 70 (3) ◽  
pp. 363-377 ◽  
Author(s):  
D. ANN BROWN ◽  
S. P. MATHUR ◽  
ANTON BROWN ◽  
D. J. KUSHNER
Keyword(s):  
Principal Component Analysis ◽  
Acid Leaching ◽  
Principal Component ◽  
Organic Soil ◽  
Component Analysis ◽  
Soil Types ◽  
Organic Soils ◽  
Mining Districts ◽  
Two Populations ◽  
Inorganic Components

Different numerical methods used to distinguish between organic soil types are evaluated. The research was initiated by the suggestion that acid leaching from mining wastes could be prevented by capping the tailings with a self-renewing methane-producing muskeg bog, in order to prevent the penetration of oxygen to the wastes. Thirty organic soils from bogs in the mining districts of Elliot Lake, Sudbury, and Timmins, Ontario, and Noranda, Quebec, were sampled and 28 soil characteristics were measured. These characteristics, whose values are normally or lognormally distributed, were analyzed by several different statistical methods. Some characteristics indicate the existence of two populations, and others are bivariantly correlated. Canonical discriminant analysis was more successful than cluster analysis in separating the bogs into well-defined geographical groups. However, principal component analysis proved best at grouping the organic soils according to their organic and inorganic components, and we suggest that this is a suitable method for the general discrimination of organic soil types. Methane was present in all the 17 bogs tested for it, and in two very wet bogs more than 2 mmol of methane per liter were extracted. Key words: Muskeg bog, organic soils, soil characterization, principal component analysis

scholarly journals A Novel Approach to the Analysis of the Soil Consolidation Problem by Using Non-Classical Rheological Schemes

2021 ◽  
Vol 11 (5) ◽  
pp. 1980
Author(s):  
Kazimierz Józefiak ◽  
Artur Zbiciak ◽  
Karol Brzeziński ◽  
Maciej Maślakowski
Keyword(s):  
Constitutive Models ◽  
Organic Soil ◽  
Organic Soils ◽  
Soil Consolidation ◽  
Flexible Tool ◽  
One Dimensional ◽  
Novel Approach ◽  
Soil Skeleton ◽  
The One ◽  
The Relationship

The paper presents classical and non-classical rheological schemes used to formulate constitutive models of the one-dimensional consolidation problem. The authors paid special attention to the secondary consolidation effects in organic soils as well as the soil over-consolidation phenomenon. The systems of partial differential equations were formulated for every model and solved numerically to obtain settlement curves. Selected numerical results were compared with standard oedometer laboratory test data carried out by the authors on organic soil samples. Additionally, plasticity phenomenon and non-classical rheological elements were included in order to take into account soil over-consolidation behaviour in the one-dimensional settlement model. A new way of formulating constitutive equations for the soil skeleton and predicting the relationship between the effective stress and strain or void ratio was presented. Rheological structures provide a flexible tool for creating complex constitutive relationships of soil.

scholarly journals A fertile peatland forest does not constitute a major greenhouse gas sink

2013 ◽  
Vol 10 (11) ◽  
pp. 7739-7758 ◽  
Author(s):  
A. Meyer ◽  
L. Tarvainen ◽  
A. Nousratpour ◽  
R. G. Björk ◽  
M. Ernfors ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Eddy Covariance ◽  
Organic Matter Content ◽  
C Sequestration ◽  
Organic Soil ◽  
Organic Soils ◽  
Indirect Approach ◽  
Short Period ◽  
N2o Fluxes ◽  
C Assimilation

Abstract. Afforestation has been proposed as a strategy to mitigate the often high greenhouse gas (GHG) emissions from agricultural soils with high organic matter content. However, the carbon dioxide (CO2) and nitrous oxide (N2O) fluxes after afforestation can be considerable, depending predominantly on site drainage and nutrient availability. Studies on the full GHG budget of afforested organic soils are scarce and hampered by the uncertainties associated with methodology. In this study we determined the GHG budget of a spruce-dominated forest on a drained organic soil with an agricultural history. Two different approaches for determining the net ecosystem CO2 exchange (NEE) were applied, for the year 2008, one direct (eddy covariance) and the other indirect (analyzing the different components of the GHG budget), so that uncertainties in each method could be evaluated. The annual tree production in 2008 was 8.3 ± 3.9 t C ha−1 yr−1 due to the high levels of soil nutrients, the favorable climatic conditions and the fact that the forest was probably in its phase of maximum C assimilation or shortly past it. The N2O fluxes were determined by the closed-chamber technique and amounted to 0.9 ± 0.8 t Ceq ha−1 yr−1. According to the direct measurements from the eddy covariance technique, the site acts as a minor GHG sink of −1.2 ± 0.8 t Ceq ha−1 yr−1. This contrasts with the NEE estimate derived from the indirect approach which suggests that the site is a net GHG emitter of 0.6 ± 4.5 t Ceq ha−1 yr−1. Irrespective of the approach applied, the soil CO2 effluxes counter large amounts of the C sequestration by trees. Due to accumulated uncertainties involved in the indirect approach, the direct approach is considered the more reliable tool. As the rate of C sequestration will likely decrease with forest age, the site will probably become a GHG source once again as the trees do not compensate for the soil C and N losses. Also forests in younger age stages have been shown to have lower C assimilation rates; thus, the overall GHG sink potential of this afforested nutrient-rich organic soil is probably limited to the short period of maximum C assimilation.

scholarly journals A fertile peatland forest does not constitute a major greenhouse gas sink

2013 ◽  
Vol 10 (3) ◽  
pp. 5107-5148 ◽  
Author(s):  
A. Meyer ◽  
L. Tarvainen ◽  
A. Nousratpour ◽  
R. G. Björk ◽  
M. Ernfors ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Eddy Covariance ◽  
Organic Matter Content ◽  
C Sequestration ◽  
Organic Soil ◽  
Organic Soils ◽  
Optimum Growth ◽  
Indirect Approach ◽  
Short Period ◽  
N2o Fluxes

Abstract. Afforestation has been proposed as a strategy to mitigate the often high greenhouse gas (GHG) emissions from agricultural soils with a high organic matter content. However, the carbon dioxide (CO2) and nitrous oxide (N2O) fluxes after afforestation can be considerable, depending predominantly on site drainage and nutrient availability. Studies on the full GHG budget of afforested organic soils are scarce and hampered by the uncertainties associated with methodology. In this study we determined the GHG budget of a spruce-dominated forest on a drained organic soil with an agricultural history. Two different approaches for determining the net ecosystem CO2 exchange (NEE) were applied: for the year 2008, direct (eddy covariance) and an indirect (analyzing the different components of the GHG budget), so that uncertainties in each method could be evaluated. The annual tree production in 2008 was 8.2 (± 1.7)t C ha–1yr–1 due to the high levels of soil nutrients, the favorable climatic conditions and the fact that the forest was in its optimum growth phase. N2O fluxes were determined by the closed chamber technique and amounted to 3.3 (± 2.4) t CO2eq ha–1 yr–1. According to the direct measurements from the eddy covariance technique, the site acts as a minor GHG sink of −4.1 (± 2.6) t CO2eq ha–1 yr–1. This contrasts with the NEE estimate derived from the indirect approach which suggests that the site is a net GHG emitter of 3.3 (± 10.1)t CO2eq ha–1 yr–1. Irrespective of the approach applied, the soil CO2 effluxes counter large amounts of the C sequestration by trees. Due to major uncertainties involved in the indirect approach, the direct approach is considered the more reliable tool. As the site was in its optimum growth stage, i.e. the rate of C sequestration was at its maximum and will decrease with forest age, it will probably become a GHG source once again as the trees mature. Since forests in their younger stages are usually GHG sources or have no effect on GHGs, the overall sink potential of this afforested nutrient-rich organic soil is probably limited to only a short period.

scholarly journals Water repellency of clay, sand and organic soils in Finland

2008 ◽  
Vol 16 (3) ◽  
pp. 267 ◽  
Author(s):  
K. RASA ◽  
R. HORN ◽  
M. RÄTY
Keyword(s):  
Preferential Flow ◽  
Management Practice ◽  
Soil Surface ◽  
Water Repellency ◽  
Organic Soil ◽  
Water Infiltration ◽  
Organic Soils ◽  
Water Repellent ◽  
Moisture Regime ◽  
Wetting Process

Water repellency (WR) delays soil wetting process, increases preferential flow and may give rise to surface runoff and consequent erosion. WR is commonly recognized in the soils of warm and temperate climates. To explore the occurrence of WR in soils in Finland, soil R index was studied on 12 sites of different soil types. The effects of soil management practice, vegetation age, soil moisture and drying temperature on WR were studied by a mini-infiltrometer with samples from depths of 0-5 and 5-10 cm. All studied sites exhibited WR (R index >1.95) at the time of sampling. WR increased as follows: sand (R = 1.8-5.0) < clay (R = 2.4-10.3) < organic (R = 7.9-undefined). At clay and sand, WR was generally higher at the soil surface and at the older sites (14 yr.), where organic matter is accumulated. Below 41 vol. % water content these mineral soils were water repellent whereas organic soil exhibited WR even at saturation. These results show that soil WR also reduces water infiltration at the prevalent field moisture regime in the soils of boreal climate. The ageing of vegetation increases WR and on the other hand, cultivation reduces or hinders the development of WR.;

TITRATIONS OF ORGANIC SOILS WITH STANDARD BASE: SOLUBILITY OF IONIZABLE FUNCTIONAL GROUPS AT 25 °C

1989 ◽  
Vol 69 (2) ◽  
pp. 313-325 ◽  
Author(s):  
DONALD S. GAMBLE
Keyword(s):  
Functional Groups ◽  
External Solution ◽  
Organic Soil ◽  
Organic Soils ◽  
Total Acid ◽  
Dissociation Equilibrium ◽  
Carboxylate Anions ◽  
Data Production ◽  
Standard Base ◽  
Automatic Titrator

The conversion of undissolved acidic functional groups into dissolved carboxylate anions has been monitored during potentiometric titration of a Typic Mesisol Peat at 25 °C. The analytical chemical calculations of total acid functional groups and of H+ dissociation equilibrium functions take the dissolution process into account. With 0.05 g of sample suspended in 20 mL of 0.1 N NaCl, the molarity of carboxylate anions in the external solution ranged from 4.3 × 10−4 M at 1 mL g−1 0.1 N NaOH, to 1.5 × 10−3 M at 6 mL g−1 0.1 N NaOH. The corresponding amounts of undissolved carboxyl groups were 5.2 × 10−4 and 1.0 × 10−4 mol g−1. Differential acid constants (KGA) for the undissolved carboxyls were 7.6 × 10−4 (σ 1.4 × 10−4) for αG < 0.02 (0.016 – 0.02) and 1.4 × 10−5 (σ 0.04 × 10−5) for αG > 0.026 (0.026 – 0.60). A substantial increase in productivity was achieved by means of an automatic titrator and a microcomputer with spreadsheet software. Types of data production and processing that were previously labor intensive have now become much more practical. Key words: Organic soils, organic matter solubility, organic soil carboxyls, organic soil ion exchange, organic soil titration, pH dependent solubility

scholarly journals A new method for performing smouldering combustion field experiments in peatlands and rich-organic soils

2017 ◽  
Vol 26 (12) ◽  
pp. 1040 ◽  
Author(s):  
E. Pastor ◽  
I. Oliveras ◽  
E. Urquiaga-Flores ◽  
J. A. Quintano-Loayza ◽  
M. I. Manta ◽  
...  
Keyword(s):  
Field Experiments ◽  
Organic Soil ◽  
Ecological Effects ◽  
Organic Soils ◽  
Rating Systems ◽  
Environmental Implications ◽  
Combustion Dynamics ◽  
Peruvian Andes ◽  
Undisturbed Soils ◽  
Smouldering Combustion

Smouldering ground fires have severe environmental implications. Their main effects are the release of large amounts of carbon to the atmosphere with loses of organic soil and its biota. Quantitative data on the behaviour of smouldering wildfires are very scarce and are needed to understand its ecological effects, to validate fuel consumption and smouldering propagation models and to develop danger-rating systems. We present, for the first time, a methodology for conducting smouldering experiments in field conditions. This method provides key data to investigate smouldering combustion dynamics, acquire fire behaviour metrics and obtain indicators for ecological effects of smouldering fires. It is to be applied in all types of undisturbed soils. The experimental protocol is based on a non-electric ignition source and the monitoring system relies on combining both point and surface specific temperature measurements. The methodology has been developed and applied by means of large series of replicate experiments in highly organic soils at the forest–grassland treeline of the Peruvian Andes. The soil tested exhibited weak ignition conditions. However, transition to oxidation phase was observed, with smouldering combustion during 9 h at 15-cm depth and residence times at temperatures above dehydration of ~22 h.

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