LABORATORY OF SOIL HYDROLOGY AND ENVIRONMENTAL MONITORING

The laboratory is used to investigate the mechanisms of water and nutrient transport  in the plant-soil-atmosphere continuum, study the problems related to the use of conventional and unconventional (saline) water and assess the risk of soil and ground water pollution from contaminants. The instrumentation provided enables the measure of soil hydrological properties.

The technical and scientific activities combine laboratory and field works and are described below.

Laboratory analyses

• Soil physical analyses: determination of texture; pH and electrical conductivity, bulk density and particle density of undisturbed soil samples;
• Measure of soil water content in disturbed and undisturbed soil samples;
• Determination of soil hydraulic properties: water retention and hydraulic conductivity under saturated and unsaturated conditions using Stackman’s beds, multi-step chambers, permeameters and tension infiltrometers;
• Measures of the soil extract electrical conductivity (ECw) to determine salinity levels on disturbed soil samples using ad-hoc instruments: conductivity meters and spectrophotometers.

Field trials

• Measure of water contents, hydraulic conductivity under saturated and unsaturated conditions and soil bulk electrical conductivity in the space and over time using TDR (Time Domain Reflectometry) probes.
• Disturbed and undisturbed soil sampling for a physical and hydrological characterisation of soils.
• Measure of water retention and hydraulic conductivity using field techniques (tensiometers, TDR probes, tension infiltrometer).
• Monitoring of soil salinity using the following geophysical methodologies: multi-electrode geoelectric (ERT) and electromagnetic (EM) tomography and Time Domain Reflectometry (TDR).

Soil Hydrology Laboratory Equipments

The laboratory equipments are shown in the description sheet below.

Stackman’s beds

It enables determination of experimental points of water content θ and soil water potential h in the laboratory on undisturbed soil samples. Water retention curve θ(h) is characterised by interpolating points using empirical models

Permeameter

It enables determination of saturated hydraulic conductivity Ks on undisturbed soil samples

Multistep chamber

It determines the relation between water content θ and soil water potential h and measures the unsaturated hydraulic  conductivity K(h) on undisturbed soil samples

Tension infiltrometer

It enables measures of soil hydraulic conductivity. This is a field measurement technique

Tensiometer

It enables the measure of soil water potential both in the laboratory and in the field

TDR 100

It is a reflectometer that collects simultaneously water content and soil bulk electrical conductivity data using TDR probes

TDR probes

Sensors measuring water contents and soil electrical conductivity

Lysimeter

It enables running different kinds of trials either in the field or in the greenhouse to monitor evaporation, infiltration or deep runoff processes on arious scales of observation

Spectrophotometer

It determines the concentrations of the existing substances in water samples or in soil solutions

Conductivity meter

It enables the measure of electrical conductivity and temperature

Ph-meter

It measures the pH

Dryer

It allows the hygroscopic substances of soil samples to be maintained anhydrous

Equipment for particle-size analysis

It determines sand, silt and clay percentage in a soil

Sieves

They enable soil samples to be sieved by different size classes

Mechanical vibratory sieve shaker

It shakes a pile of sieves for a given lapse of time. Sieves differ in the size mesh. It enables the determination of soil sand fraction

PT 100

Soil temperature sensor

Samplers

Taking undisturbed soil samples

Augers

Taking disturbed soil samples

Precision balances

Weighing different types of samples

Multielectrode geoelectrical prospecting (ERT)