The Soil Physics Laboratory

Last changed: 22 August 2018
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At the Soil Physics Laboratory we prepare soil samples and determine their soil physical properties. Many of these properties are fundamental to measure in order to understand how the soil interacts with water, nutrients and vegetation, both for research analyses and practical applications. Soil physical properties are for example important for modelling water balances or estimate nutrient or sediment losses in most types of land use.

We analyze soil physical properties for a range of soils and purposes on agriculture and forest land, meadows, as well as urban/peri-urban land. Please do contact for specific questions and needs.

Types of analyses

Soil samples can be brought or sent to us as loose soil or as undisturbed soil samples, depending on what analyses should be performed. Short descriptions of the methods we use are listed below.

Analysis

Soil samples can be brought or sent to us as loose soil or as undisturbed soil samples, depending on what analyses should be performed. Short descriptions of the methods we use are listed below.

Loose soil in bags, cups, boxes, containers etc

For many of the analyses the original soil sample is first air-dried, grinded and sieved at 2 mm mesh to get the “prepared fine soil sample”.

Soil particle size distribution

The particle size distribution in a soil sample is determined with different methods as related to fraction size. The content of particles larger than 2 mm are determined in the fine soil preparation by dry sieving of the air-dried, grinded sample. For determining the content of particles smaller than 2 mm, a combination of wet sieving (0.06-2 mm) and pipette method (<0.2 mm) is performed with the prepared fine soil. The fractions that can be obtained are: Coarse sand (0.6-2 mm), Medium sand (0.2-0.6 mm), Fine sand (0.06-0.2 mm), Coarse silt (0.02-0.06 mm), Medium silt (0.006-0.02 mm), Fine silt (0.002-0.006 mm) and Clay (< 0.002 mm).

Furthermore, particle sizes in the range from 2 mm to 0.000010 mm (10 nm) can be determined with laser scattering particle size distribution analyzer (partica LA-950 V2 from HORIBA). This analysis is carried out in solvent (water) that allows for measuring dry (soil) and wet (water) samples.

Gravimetric soil water content

Original soil sample is weighed, oven-dried overnight at 105° C and then weighed again. The water content is then calculated from weight before and after oven-drying (percentage by weight).

Loss in ignition and organic matter content

Prepared fine soil sample is oven-dried overnight at 105°C to get rid of water. The sample is subsequently oven-dried at 550°C for 4 hours to get the loss on ignition. The organic matter content is approximated from the loss on ignition with a reduction factor related to clay content.

Wilting point

Prepared fine soil sample is wetted and placed in a pressure plate extractor at 1500 kPa to get the water content remaining at -1500 kPa soil water pressure.

Particle density

Particle density is calculated from the volume displacement of prepared fine soil sample in a flask with ethanol.

Soil core samples in cylinders

At the Soil Physics Laboratory we use cylinders with 5 or 10 cm height, 7.5 cm outer diameter, and 7.2 cm inner diameter to analyze the soil core properties.

Water retention properties

Water retention properties are measured by placing soil cylinder samples in sandbox (-0.05 to -10 kPa), on suction plate (-10 to -60 kPa), and in pressure plate extractor (-60 kPa to -100 kPa).

The last step for the water retention curve is the wilting point in pressure plate extractor (-1500 kPa) using prepared fine soil sample.

Actual field soil water content and dry bulk density

Field water content (percentage by volume) and dry bulk density are obtained by oven-drying the soil cylinder samples at 105°C during 3 days, and base calculations on weight before and after drying and cylinder or soil core volume.

Porosity

Porosity is calculated from dry bulk density and particle density values.

Saturated hydraulic conductivity 

Saturated hydraulic conductivity is estimated by means of a constant head permeameter. Water passes through the water saturated soil cylinder sample at a constant water head, and it is collected in a graduated cylinder at the outlet of the sample. The saturated hydraulic conductivity is then calculated from water head, soil sample length, water temperature and outflow velocity.

Shrinkage

The actual volume of the core sample after drying in the oven at 105°C is measured, and compared with the original cylinder volume.

 

Price list (All prices excluding VAT)

Prices updated 2018-04-27

Loose soil (in bags, cups, boxes, containers, etc)

Soil that has been air dried (<5% water content, max. temp. 35°C) and sieved at 2 mm. Fresh soil requires preparation.

Test
PRICE (sek/sample)
Sample preparation (air dry, grind and sieve) 150
Soil Particle Distribution (0-20 mm)* 750
    Loss on ignition
    Pipette method and wet sieving (0-2 mm)
    Gravel content (2-20 mm)*
Gravimetric water content 100
Loss on ignition 120
Wilting point 345
Particle density 275
Soil particle distribution (0-2 mm). Laser analysis in soil samples 750
Soil particle distribution (0-2 mm). Laser analysis in water samples     300

*Bigger fractions can be considered

Soil cylinders 

Soil cylinders with exact volume. Otherwise preparation is required (trim and/or measuring actual volume).

Test
PRICE (sek/sample)
Sample preparation (trim and/or measure holes)      80
Water retention properties 180
    1 tension
   Dry bulk density
   + Porosity (Particle density)** + 275
   + Extra tension + 130
   + Actual field water content + 60
Actual field water content 200
  Dry bulk density
Saturated hydraulic conductivity 255
Dry bulk density 140
Shrinkage 80
Porosity** 420
   Dry bulk density
   Particle density
Rent cylinders 5/10 cm height, 7,2 cm diameter 30
Damaged or lost cylinder 500

 

** It is necessary to provide soil cylinders, but also loose soil for the particle density calculations.

Contact

Ana María Mingot Soriano

ana.mingot@slu.se, 070-3768443, 018-671170

Department of Soil and Environment, Lennart Hjelms väg 9, Uppsala (Rooms A3071 and A3075) 

Delivery address

Department of Soil and Environment
Gerda Nilssons väg 5
756 51  Uppsala, SWEDEN

Page editor: cajsa.lithell@slu.se