Variabilité des sols et stratégie d'échantillonnage dans les études pédologiques détaillées de la plaine de Montréal

1991 ◽  
Vol 71 (4) ◽  
pp. 439-451 ◽  
Author(s):  
M. C. Nolin ◽  
M. J. Caillier ◽  
C. Wang
Keyword(s):  
Relative Error ◽  
Confidence Level ◽  
Clay Content ◽  
Soil Characteristics ◽  
Mean Value ◽  
Soil Survey ◽  
Mapping Unit ◽  
Population Mean ◽  
Soil Information ◽  
Soil Surveys

In order to estimate variability of soil information presented in detailed soil surveys of the Montreal lowlands area, more than 2000 samples were collected along stratified random transects in 133 mapping units. The coefficient of variation (CV) was used as variability criteria. Variability of selected soil characteristics of the plow layer was studied according to phases of surface texture. The CV of clay, silt, pH, CEC and exchangeable cations decrease with an increase in clay content. The CV of sand content follows the opposite direction. Four modes of deposition (marine, fluvial, till and estuarine) were compared according to the variability within taxon (soil series or variant) of soil characteristics of the A, B and C horizons. More samples are needed to estimate the population mean value with the same relative error and the same confidence level for soils developed in fluvial deposits than in those formed in marine sediments. At the 90% confidence level, the allocation of 15 samples per map unit allows one to estimate the population mean with a relative error ranging from 5 to 30% for most soils and variables studied. Quality standards are proposed for soil sampling in future soil survey projects. Key words: Soil variability, accuracy, sampling, taxon, mapping unit

scholarly journals Characterization and Evaluation of Land Resources of Valia Block, Bharuch District, Gujarat

Agropedology ◽  
2019 ◽  
Vol 28 (2) ◽  
Author(s):  
G. Tiwari ◽  
◽  
A. Jangir ◽  
R. P. Sharma ◽  
B. Dash ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Organic Carbon ◽  
Clay Content ◽  
Ground Truth ◽  
Alluvial Plain ◽  
Soil Survey ◽  
Alkaline Ph ◽  
Soil Series ◽  
Mapping Unit ◽  
High Calcium

Detailed soil survey (1:10000 scale) was carried out using base map prepared from satellite data (IRS-P6 LISS IV and Cartosat-1) and Digital Elevation Models (DEM) in conjunction with Survey of India (SOI) Toposheets of 1:50000 scale in Valia block, Bharuch district of Gujarat. On the basis of landform, slope, land use/land cover and ground truth, six landscape ecological Units (LEUs) were delineated and six soil series were identified in the block. Five soil series occur on alluvial plain (cover 66.16 %) and one soil series occupies pediplain 27.61 %. These series were mapped into ten soil mapping units as phases of soil series. The representative pedons of alluvial plain were moderately deep to very deep and their sand, silt and clay content ranged from 8.2 to 44.4, 9.8 to 40.2 and 43.8 to 55.6 per cent, respectively. These pedons were neutral to strongly alkaline (pH 6.8 - 9.7), non-saline with low to high organic carbon (0.18 – 1.2 %) content, low to high calcium carbonate (5.9 - 26.6 %) and high CEC [>35 cmol (p+) kg-1]. Exchangeable complex of these pedons were dominated by Ca2+ followed by Mg2+, Na+ and K+ cations with high base saturation (72.0 to 99. 4 %). Soils were classified as Vertic Haplustepts, Typic Haplusterts, Typic Calciustepts, Typic Haplustepts and Sodic Haplusterts. The representative pedon of pediplains was shallow, dark brown (7.5YR3/2), clayey, strongly alkaline (pH>8.5), non-saline (<2 dSm-1) and had moderate organic carbon (0.50-0.75 %) and calcium carbonate (5-15 %) with high CEC [>35 cmol (p+) kg-1] and classified as Lithic Haplustepts. The soils were evaluated for their suitability for commonly grown crops (cotton, pigeon pea, wheat and chick pea) and mapping unit 2 and 4 were highly suitable for cotton cultivation and other were moderately to marginal suitable for other crops.

A history of soil classification and soil survey in Canada: Personal perspectives

2011 ◽  
Vol 91 (5) ◽  
pp. 675-694 ◽  
Author(s):  
Darwin W. Anderson ◽  
C. A. Scott Smith
Keyword(s):  
Current System ◽  
Soil Classification ◽  
Soil Survey ◽  
Personal Experiences ◽  
History Of ◽  
Soil Information ◽  
Personal Perspectives ◽  
Land Inventory ◽  
Soil Surveys ◽  
Hard Cover

Anderson, D. W. and Smith, C. A. S. 2011. A history of soil classification and soil survey in Canada: Personal perspectives. Can. J. Soil Sci. 91: 675–694. This paper presents an overview of soil classification and soil survey in Canada based on both historical documentation and the personal experiences and perspectives of the two authors. The first soil surveys in Canada beginning in Ontario in 1914 are described along with the earliest systems of soil classification. The roots of the current system of soil classification in Canada can be traced back to the establishment of the first meeting of the National Soil Survey Committee (later the Canada Soil Survey Committee) held in Ottawa in 1945. The Committee met every 2 to 3 years and a hard-cover “first” edition, “The Canadian System of Soil Classification” was published in 1978 and a slightly revised second edition in 1987. The third edition (1998) includes a more complete key and a tenth order, the Vertisolic Order. The four to five decades starting in the late 1940s were the glory years for soil survey in Canada, with well-funded and productive programs in all provinces and territories, with major outputs like the Canada Land Inventory. The period between mid 1990s and 2010 saw declining activity in new field survey and reductions in staff levels by government agencies, but a rise in private sector soil survey, largely for environmental assessment purposes. There is a renewed and on-going interest in and need for soil information. The challenge for pedologists is to provide reliable information in innovative and proactive ways.

Naturally occurring gamma-emitting isotopes, radon release and properties of parent materials of Saskatchewan soils

1994 ◽  
Vol 74 (1) ◽  
pp. 47-53 ◽  
Author(s):  
E. de Jong ◽  
D. F. Acton ◽  
L. M. Kozak
Keyword(s):  
Natural Radioactivity ◽  
Gamma Spectroscopy ◽  
Clay Content ◽  
Decay Chain ◽  
Parent Material ◽  
Soil Survey ◽  
Parent Materials ◽  
Independent Variable ◽  
Soil Surveys ◽  
The Relationship

Mineral composition of the parent material is a major factor controlling natural radioactivity of soils. The objective of this study was to investigate the relationship between the natural radioactivity of 18 till and six lacustrine parent materials and their properties measured during soil surveys. Gamma spectroscopy was used to estimate 40K and daughters of 238U and 232Th; neutron activation analysis was used to determine total U; and alpha counting was used to measure 222Rn release from the soil. The amounts of the various radioisotopes were positively correlated with each other and with clay content; the correlation with sand content was negative; and the correlations with silt and inorganic C content were generally not significant. Adding the fine/total clay ratio as a further independent variable considerably improved the correlation between 40K and clay content. The data suggested considerable disequilibrium in the 238U decay chain, which appeared to be in part related to the mode of deposition of the parent materials. Soil survey information — in particular, texture — thus appears a readily available tool for preliminary screening of terrestrial radiation in Saskatchewan. Key words: Radioactivity, 40K, uranium, thorium, radon, texture

scholarly journals CONTROL OF GRAPEVINE DECLINE WITH THE USE OF DRAINS AND RIDGES

2016 ◽  
Vol 38 (2) ◽  
Author(s):  
REMI NATALIN DAMBROS ◽  
MARCO ANTONIO DALBÓ ◽  
CRISTIANO JOÃO ARIOLI ◽  
MILTON DA VEIGA
Keyword(s):  
Soil Fungi ◽  
Clay Content ◽  
Field Studies ◽  
Soil Characteristics ◽  
Southern Brazil ◽  
Plant Mortality ◽  
Drastic Reduction ◽  
Santa Catarina ◽  
Grapevine Decline ◽  
Santa Catarina State

ABSTRACT The incidence of grapevine decline and dye back is quite severe in grapevine-growing regions of southern Brazil, especially in the Midwest of Santa Catarina State. Field studies on problematic areas identified the presence of the Brazilian ground pearl or margarodes (Eurhizococcus brasiliensis Hempel) and soil fungi (Cylindrocarpon, Fusarium and others) associated with the disease. Soil characteristics such as high clay content and poor aeration were associated with the problem. To evaluate the effect of pre-planting tillage in reducing the incidence of grapevine decline, an experiment was carried out with two rootstocks and three pre-planting tillage (regular plowing, drains, and ridges) in an area where high plant mortality had been previously observed. Pre-planting tillage with the use of ridges along the rows gave the best results with a drastic reduction in the decline incidence. The number of ground pearl cysts was unaffected by pre-planting tillage and did not relate with the incidence of decline and death of plants.

scholarly journals P-sorption and desorption in Savanna Brazilian soils as a support for phosphorus fertilizer management

2013 ◽  
Vol 37 (6) ◽  
pp. 521-530 ◽  
Author(s):  
Flávio Araújo Pinto ◽  
Edicarlos Damacena de Souza ◽  
Helder Barbosa Paulino ◽  
Nilton Curi ◽  
Marco Aurélio Carbone Carneiro
Keyword(s):  
Clay Content ◽  
Soil Characteristics ◽  
Fertilizer Management ◽  
Phosphorus Fertilizer ◽  
Phosphorus Adsorption ◽  
P Sorption ◽  
Brazilian Soils ◽  
Soil Clay ◽  
Sand Base ◽  
Soil Clay Content

Phosphorus (P) sorption by soils is a phenomenon that varies depending on soil characteristics, influencing its intensity and magnitude, which makes it a source or drain of P. The objective of this study was to determine the Maximum Phosphorus Adsorption Capacity (MPAC) and desorption of P from soils under native Savanna Brazilian and verify the correlation between MPAC and P Capacity Factor (PCF) with the chemical and physical properties of these soils. The study was conducted in seven soils under native Savannas. The Langmuir isotherms were adjusted from the values obtained in sorption assays, being evaluated the MPAC, the energy adsorption (EA) and PCF, which was calculated according to the levels of P-adsorbed and P-sorbed. Values of MPAC were classified as high in most soils, ranging from 283 up to 2635 mg kg-1 of P in the soil and were correlated with soil organic matter, clay, silt, sand, base saturation and pH. The PCF was higher in soils where the MPAC was also higher. The use of only one attribute of soil (clay content) as a criterion for the recommendation of phosphated fertilization, as routinely done, is susceptible to errors, needing the use of more attributes for a more accurate recommendation, as a function of the complexity of the interactions involved in the process.

scholarly journals Geostatistical prediction of clay percentage based on soil survey data

2002 ◽  
Vol 11 (4) ◽  
pp. 381-390
Author(s):  
A. TALKKARI ◽  
L. JAUHIAINEN ◽  
M. YLI-HALLA
Keyword(s):  
Soil Properties ◽  
Spatial Variation ◽  
Survey Data ◽  
Clay Content ◽  
Spherical Model ◽  
Simulation Method ◽  
Soil Survey ◽  
Management Zones ◽  
Additional Information ◽  
Clay Percentage

In precision farming fields may be divided into management zones according to the spatial variation in soil properties. Clay content is an important soil characteristic, because it is associated with other soil properties that are important in management. Soil survey data from 150 sampling sites taken from an area of 218 ha were used to predict the spatial variation of clay percentage geostatistically in an agricultural soil in Jokioinen, Finland. The exponential and spherical models with a nugget component were fitted to the experimental variogram. This indicated that the medium-range pattern could be modelled, but the short-range variation could not, due to sparsity of sample points at short distances. The effect of sampling density on the kriging error was evaluated using the random simulation method. Kriging with a spherical model produced a map with smooth variation in clay percentage. The standard error of kriging estimates decreased only slightly when the density of samples was increased. The predictions were divided into three classes based on the clay percentage. Areas with clay content below 30%, between 30% and 60% and over 60% belong to non-clay, clay and heavy clay zones, respectively. With additional information from the soil samples on the contents of nutrients and organic matter these areas can serve as agricultural management zones.;

RATE OF RELEASE OF NON-EXCHANGEABLE POTASSIUM BY ONTARIO SOILS IN RELATION TO NATURAL SOIL CHARACTERISTICS AND MANAGEMENT PRACTICES

1958 ◽  
Vol 38 (1) ◽  
pp. 36-43 ◽  
Author(s):  
H. B. McEwen ◽  
B. C. Matthews
Keyword(s):  
Management Practices ◽  
Clay Content ◽  
Soil Characteristics ◽  
Soil Testing ◽  
Natural Soil ◽  
Exchangeable Potassium ◽  
Fertilizer Requirement ◽  
Predominant Factor ◽  
Intensive Cropping ◽  
Power Measurements

The rate of release of non-exchangeable potassium, i.e. potassium-supplying power, of 41 Ontario soils was measured by a continuous percolation procedure. It was found that clay content of the soil was the predominant factor affecting potassium-supplying power (r = 0.978). Potassium fertilization or intensive cropping of the soil caused no change in the potassium-supplying power of the soil. As potassium-supplying power was found to be a constant characteristic of soil and not a function of previous management, potassium-supplying power measurements should not be necessary in routine soil testing. Knowledge of potassium-supplying power can be deduced from particle size distribution. Because soils of different texture have different potassium-supplying power, the interpretation of measured exchangeable potassium in terms of fertilizer requirement will be different for soils of different textural class.

Topographic and edaphic effects on the distribution of terrestrially reproducing anurans in Central Amazonia: mesoscale spatial patterns

2007 ◽  
Vol 23 (5) ◽  
pp. 539-547 ◽  
Author(s):  
Marcelo Menin ◽  
Albertina P. Lima ◽  
William E. Magnusson ◽  
Fabiano Waldez
Keyword(s):  
Leaf Litter ◽  
Environmental Gradients ◽  
Free Water ◽  
Clay Content ◽  
Soil Characteristics ◽  
Environmental Predictors ◽  
Anuran Species ◽  
Habitat Variation ◽  
Central Amazonia ◽  
Edaphic Variables

Many studies suggest that edaphic variables are major determinants of frog distributions. However, leaf-litter depth and soil characteristics are influenced by distance from streams, so the apparent relationship between edaphic characteristics and species distributions could be an artefact of the dependence of species on free water for reproduction. Therefore, we investigated the effect of edaphic variables on the mesoscale distribution of frog species not dependent on free water for reproduction. We evaluated the effects of soil texture, pH, slope, number of trees and leaf-litter volume on the distribution of nine terrestrially reproducing anuran species in the Reserva Ducke, a 100-km2 terra firme forest preserve in central Amazonia. Diurnal and nocturnal assemblages of anuran species were sampled in 72 plots systematically distributed across the reserve. We sampled the diurnal anuran assemblage by visual encounter in 250 × 1-m plots and the nocturnal assemblage in 250 × 20-m plots using both auditory and visual surveys. The majority of terrestrially breeding anuran species were influenced by topographic and/or edaphic variables, such as slope, soil clay content and pH. However, responses to environmental predictors differed among species. Most species occurred throughout all environmental gradients and relationships with soil characteristics were subtle, indicating that these species occur in the majority of habitats in Reserva Ducke. The results of this study indicate that terrestrially breeding frogs are habitat generalists that show little mesoscale beta diversity associated with habitat variation.

Obtaining soil hydraulic properties for water balance and leaching models from survey data. 1. Water retention

1999 ◽  
Vol 50 (2) ◽  
pp. 283 ◽  
Author(s):  
K. R. J. Smettem ◽  
K. L. Bristow ◽  
L. K. Heng ◽  
Y. M. Oliver ◽  
E. J. Ford
Keyword(s):  
Water Retention ◽  
Clay Content ◽  
Water Retention Curve ◽  
Sampling Location ◽  
Soil Hydraulic Properties ◽  
Risk Models ◽  
Transport Modelling ◽  
Distribution Index ◽  
Soil Surveys ◽  
Leaching Models

A physico-empirical 2-parameter power law model of the draining water retention curve (WRC) based solely on clay content is described and further developed using 6 datasets obtained from Australian and New Zealand soils. The slope of the WRC, or pore-size distribution index, is well described by the model but the bubbling pressure, or inflection point is poorly described. Without a good estimation of the bubbling pressure it is not possible to scale the physico-empirical model to the WRC. To achieve the scaling, a single measured point on the WRC in the unsaturated range is required. The resulting estimated water contents may be satisfactory for application within broad-scale leaching risk models and for generalised extrapolation of results from detailed experimental sites but caution is still required for quantitative applications of nitrate leaching models at a particular site. It is concluded that soil surveys could usefully include a single WRC measurement in the field at each sampling location to improve their utility for water and chemical transport modelling.

Improving the field estimation of saturated hydraulic conductivity in soil survey

Soil Research ◽  
1997 ◽  
Vol 35 (4) ◽  
pp. 803 ◽  
Author(s):  
Neil McKenzie ◽  
David Jacquier
Keyword(s):  
Hydraulic Conductivity ◽  
Water Movement ◽  
Saturated Hydraulic Conductivity ◽  
Soil Survey ◽  
Land Evaluation ◽  
Levels Of Detail ◽  
Eastern Australia ◽  
Field Estimation ◽  
Morphological Variables ◽  
Soil Surveys

Prediction of the movement and storage of water in soil is central to quantitative land evaluation. However, spatial and temporal predictions have not been provided by most Australian soil surveys. The saturated hydraulic conductivity (Ks) is an essential parameter for description of water movement in soil and its estimation has been considered too difficult for logistic and technical reasons. The Ks cannot be measured everywhere and relationships with readily observed morphological variables have to be established. However, conventional morphology by itself is a poor predictor of Ks. We have developed a more functional set of morphological descriptors better suited to the prediction of Ks. The descriptors can be applied at several levels of detail. Measurements of functional morphology and Ks were made on 99 horizons from 36 sites across south-eastern Australia. Useful predictions of Ks were possible using field texture, grade of structure, areal porosity, bulk density, dispersion index, and horizon type. A simple visual estimate of areal porosity was satisfactory, although a more quantitative system of measurement provided only slightly better predictions. Regression trees gave more plausible predictive models than standard multiple regressions because they provided a realistic portrayal of the non-additive and conditional nature of the relationships between morphology and Ks. The results are encouraging and indicate that coarse-level prediction of Ks is possible in routine soil survey. Direct measurement of Ks does not appear to be generally feasible because of the high cost, dynamic nature of Ks, and substantial short-range variation in the field. Prediction is further constrained by the limited returns from more sophisticated morphological predictors. The degree to which this limits practical land evaluation is yet to be demonstrated.

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