A modified hydropneumo‐elutriation apparatus for quantitative root separation from large soil core samples

Unsaturated soil hydraulic conductivity K is a fundamental transfer property of soil but its measurement is costly, difficult, and time-consuming due to its large variations with water content (θ) or matric potential (h). Recently, C. Doussan and S. Ruy proposed a method/model using measurements of the electrical conductivity of soil core samples to predict K(h). This method requires the measurement or the setting of a range of matric potentials h in the core samples—a possible lengthy process requiring specialised devices. To avoid h estimation, we propose to simplify that method by introducing the particle-size distribution (PSD) of the soil as a proxy for soil pore diameters and matric potentials, with the Arya and Paris (AP) model. Tests of this simplified model (SM) with laboratory data on a broad range of soils and using the AP model with available, previously defined parameters showed that the accuracy was lower for the SM than for the original model (DR) in predicting K (RMSE of logK = 1.10 for SM v. 0.30 for DR; K in m s–1). However, accuracy was increased for SM when considering coarse- and medium-textured soils only (RMSE of logK = 0.61 for SM v. 0.26 for DR). Further tests with 51 soils from the UNSODA database and our own measurements, with estimated electrical properties, confirmed good agreement of the SM for coarse–medium-textured soils (<35–40% clay). For these textures, the SM also performed well compared with the van Genuchten–Mualem model. Error analysis of SM results and fitting of the AP parameter showed that most of the error for fine-textured soils came from poorer adequacy of the AP model’s previously defined parameters for defining the water retention curve, whereas this was much less so for coarse-textured soils. The SM, using readily accessible soil data, could be a relatively straightforward way to estimate, in situ or in the laboratory, K(h) for coarse–medium-textured soils. This requires, however, a prior check of the predictive efficacy of the AP model for the specific soil investigated, in particular for fine-textured/structured soils and when using previously defined AP parameters.

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Alternative method for volumetric core removal in hardsetting soils

Scientia Agricola ◽

10.1590/s0103-90162005000500015 ◽

2005 ◽

Vol 62 (5) ◽

pp. 493-497 ◽

Cited By ~ 2

Author(s):

Herdjania Veras de Lima ◽

Álvaro Pires da Silva ◽

Sílvia Imhoff ◽

Afrânio Ferreira Neves Junior

Keyword(s):

Soil Bulk Density ◽

Field Method ◽

Laboratory Method ◽

Soil Samples ◽

Soil Core ◽

Hydraulic Pump ◽

Undisturbed Soil ◽

Alternative Method ◽

Moisture Conditions ◽

Large Soil

Due to the narrow window of ideal moisture conditions required for collecting undisturbed soil samples from hardsetting horizons in the field, this study compared the efficiency of an alternative method of soil core removal in the laboratory with that of the traditional field method by using measurements of soil bulk density data (Db). In a first sampling, cylinders were removed with a soil sampler in the field. In a second sampling, large soil blocks were removed with Kubiena-type zinc (brass) boxes in the field. Volumetric core cylinder samples were removed from these blocks in the laboratory with a manual hydraulic pump. There were no differences between the Db values determined from the laboratory and the field coring method. The laboratory method was considered more efficient than the field method because it allowed reductions in the errors made by operators in the field, and those caused by differences in soil water content. The laboratory method allows sampling in hardsetting horizons throughout the year, and collecting soil core samples under conditions of controlled moisture and applied force.

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Assessing Uncertainty in Coastal Marsh Core Sampling for Waterfowl Foods

Journal of Fish and Wildlife Management ◽

10.3996/072014-jfwm-051 ◽

2015 ◽

Vol 6 (1) ◽

pp. 238-246 ◽

Cited By ~ 12

Author(s):

Kevin M. Ringelman ◽

Christopher K. Williams ◽

John M. Coluccy

Keyword(s):

Energy Density ◽

Habitat Type ◽

Coastal Marsh ◽

Energy Estimates ◽

Large Animal ◽

Soil Core ◽

Habitat Types ◽

Food Items ◽

Core Samples ◽

Landscape Scales

Abstract Quantifying foraging resources available to waterfowl in different habitat types is important for estimating energetic carrying capacity. To accomplish this, most studies collect soil-core samples from the marsh substrate, sieve and sort food items, and extrapolate energy values to wetland or landscape scales. This is a costly and time-intensive process; furthermore, extrapolation methods yield energy estimates with large variances relative to the mean. From both research and management perspectives, it is important to understand sources of this variation and estimate the number of soil cores needed to reduce the variance to desired levels. Using 2,341 cores collected from freshwater and salt marsh habitats at four sites along the Atlantic Coast, we examined sampling variation and biological variation among sites and habitats. When we removed extreme outliers in the data caused by large animal food items found in a small core sample, estimates of energy density decreased by an order of magnitude for most habitats. After removing outliers, we found inconsistent geographical variation among habitat types that was especially pronounced in freshwater and no evidence for within-season temporal depletion of food resources for any site or habitat. We used a Monte Carlo simulation approach to estimate the optimal number of cores (minimizing both cost and estimated variance) sampled in each habitat type. Across most contexts, a reduction in the coefficient of variation reached diminishing returns near 40 core samples. We recommend that researchers explicitly address outliers in the data and managers acknowledge the imprecision that can arise from including or excluding outliers when estimating energy density at landscape scales. Our results suggest that collecting 40–50 cores per habitat type was sufficient to reduce the variance to acceptable levels while minimizing overall sampling costs.

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Subsampling Reduces Sorting Effort for Waterfowl Foods in Salt-Marsh Core Samples

Journal of Fish and Wildlife Management ◽

10.3996/012014-jfwm-002 ◽

2014 ◽

Vol 5 (2) ◽

pp. 380-386 ◽

Cited By ~ 7

Author(s):

Mark C. Livolsi ◽

Kevin M. Ringelman ◽

Christopher K. Williams

Keyword(s):

Salt Marsh ◽

Food Availability ◽

Carrying Capacity ◽

Processing Time ◽

Soil Core ◽

Habitat Types ◽

Core Samples ◽

Large Numbers ◽

Significant Difference ◽

Time Savings

Abstract Waterfowl researchers often use soil core samples to estimate food availability in foraging habitats, and these estimates are needed for bioenergetic models of carrying capacity. However, core sampling is frequently a time- and resource-intensive process, and some researchers have suggested that subsampling may be a valuable way to reduce processing time. We evaluated whether 10% and 25% by mass subsampling are appropriate techniques for reducing core-sorting effort while maintaining precision for samples taken in six separate habitat types along the Delaware bayshore. We found no significant difference between biomass found in 100% sorted cores and estimated biomass obtained by 10% and 25% subsampling. We found that 10% subsampling offered the greatest time savings, reducing mean sorting times by 77% (from 13.7 hours to 3.3 hours) from 100% sorted cores. We recommend that researchers consider subsampling to reduce core-sorting effort and cost, particularly when processing large numbers of cores.

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Field evaluation of plaster-based temephos pellets for residual control of midge larvae (Diptera: Chironomidae) in establishing rice crops

Australian Journal of Experimental Agriculture ◽

10.1071/ea9940659 ◽

1994 ◽

Vol 34 (5) ◽

pp. 659 ◽

Cited By ~ 1

Author(s):

MM Stevens ◽

GN Warren

Keyword(s):

Water Column ◽

Water Samples ◽

Field Evaluation ◽

Application Rate ◽

Control Agent ◽

Fourth Instar ◽

Soil Core ◽

Potential Control ◽

Core Samples ◽

Application Rates

A pelletised formulation of temephos (5% a.i.) was evaluated as a potential control agent for chironomid midge larvae in establishing rice crops. Four application rates between 0.03 and 0.53 mg a.i./L (42-732 g a.i./ha) were applied to 80 m2 experimental rice bays immediately after flooding. Water samples and soil core samples were taken at regular intervals until 29 days post-treatment. Larvae were extracted from core samples using magnesium sulfate (MgSO4) flotation, whilst laboratory-reared fourth instar Chironomus tepperi Skuse larvae were used in bioassays with field-collected water samples to determine pesticide activity in the water column. All treatments significantly suppressed C. tepperi-type larvae in the field for at least 13 days. Some suppression of non-C. tepperi-type larvae was obtained at 0.27 mg a.i./L, whilst at 0.53 mg a.i./L all chironomids were reduced to negligible levels for the full period of the trial. In bioassays, significant levels of water column toxicity to fourth instar C. tepperi larvae were only recorded for 2 days after treatment at the highest application rate. Our results indicate that plaster-based temephos pellets have the potential to provide effective, single application control of chironomid larvae in establishing rice crops without the risk of spray drift inherent in the aerial application of liquid insecticides.

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A method of processing soil core samples for root studies by subsampling

Biology and Fertility of Soils ◽

10.1007/bf00336446 ◽

1994 ◽

Vol 18 (1) ◽

pp. 60-62 ◽

Cited By ~ 27

Author(s):

G�tz Schroth ◽

Dorothee Kolbe

Keyword(s):

Soil Core ◽

Core Samples

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Quantitative and qualitative evaluation of the impact of the G2 enhancer, bead sizes and lysing tubes on the bacterial community composition during DNA extraction from recalcitrant soil core samples based on community sequencing and qPCR

PLoS ONE ◽

10.1371/journal.pone.0200979 ◽

2019 ◽

Vol 14 (4) ◽

pp. e0200979 ◽

Cited By ~ 8

Author(s):

Alex Gobbi ◽

Rui G. Santini ◽

Elisa Filippi ◽

Lea Ellegaard-Jensen ◽

Carsten S. Jacobsen ◽

...

Keyword(s):

Bacterial Community ◽

Dna Extraction ◽

Community Composition ◽

Bacterial Community Composition ◽

Qualitative Evaluation ◽

Soil Core ◽

Core Samples ◽

The Impact

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Field Extraction of Large Intact Soil Cores for Leaching Studies in the Laboratory

Weed Technology ◽

10.1017/s0890037x00045930 ◽

1996 ◽

Vol 10 (1) ◽

pp. 210-216 ◽

Cited By ~ 1

Author(s):

She-Kong Chong ◽

Suling Zhao ◽

Brian P. Klubek

Keyword(s):

Hydraulic Conductivity ◽

Low Cost ◽

Sampling Procedure ◽

Soil Horizon ◽

Soil Core ◽

Soil Cores ◽

Intact Soil Cores ◽

Large Soil ◽

Intact Soil

Various samplers have been developed for taking intact soil cores. Very often, the sampler was used once or twice to take only a few soil cores then it became either obsolete or a burden for maintenance and storage. An economic portable hand-operated soil core sampler was developed to obtain large soil cores with a diameter of 19 cm and a length of 120 cm. The quality of large soil cores was evaluated and compared with that obtained from short cores from each soil horizon. In addition, the large intact column was used to evaluate atrazine transport under the saturated condition. Results showed that the hydraulic conductivity of the large cores were of the same magnitude as that of short cores, except for the A horizon; the hydraulic conductivity of the large cores was about 10 times greater than the short cores. Even though the sampling procedure is labor intensive, the soil sampler has the flexibility to collect different size soil cores and can be constructed at a very low cost (less than $200 including labor). Lastly, the sampler is maintenance free and can be stored easily in a limited space.

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