Selected techniques based on research topics

Microsensors are of high spatial resolution, fast response and not-destructive method. Oxygen, hydrogen and sulphides dynamics could be easily monitored in soil, water and inside plant tissues. Sensors are customize for specific purposes allowing to measure gas concentrations even inside a single cell. Microsensors can be used to monitor temporal and spatial gas dynamics in soils and at the root-soil interface. Oxygen can also be measured using microoptodes, another approach based on luminescence quenching in presence of oxygen.

Planar optodes are a recent developed technique for imaging that allows spatial and temporal monitoring of gases and solutes. Commonly applied for sediments, it is widely applied in rhizosphere studies involving micro and macrofauna. Oxygen and pH are the most common variables measured. Specific application developments involved toxins (e.g. sulphides) and ions (e.g. reduced Fe, phosphate).

Methods for measuring Radial Oxygen Loss were recently summarised in a review paper - Jiménez et al. 2021

The SPS method is based on volatilisation of H2S from soil, after a treatement with concentrated HCl, followed by precipitation of sulfides as PbS on paper charts. The coulor was standardised in the lab using standard solutions and a color chart map is used in the filed for comparison. The method has the potential to be improved into smartphone applications, allowing fast mapping of wetland soils, wordlwide.

The method is described in Pellegrini et al. 2018

Microbial biomass C and N are well established methods to estimate the microbial component of a soil and to estimate soil fertility, which is usually related to the microbial biomass. Recently, we proposed an advanced approach of machine learning to assess the main soil parameters affecting soil microbial biomass, in order to estimate fertility in vineyard soils (paper Pellegrini et al. 2020).

Our lab has focused on soil ATP (Kuzyakov's portocol). The great advantage is the possibility to use a very small amount of soil to increase the spatial resolution of data collected. Moreover, soil ATP can support metagenomic analysis by quantifying the relative abundance of soil bacterial species. It is therefore a great tool supporting interdisciplinarity between soil pedologists and genetists. 

The increasing concentration of humic substances in freshwaters is expected to alter local biotic geochemical processes and interfere with soil-plant interactions. Nevertheless, humic substances can be advantageous in anoxic sediments, being able to interfere with redox processes acting as electron shuttels for microorganisms. This topic is still poorly studied and of high interest among researchers, due to the intensifying brownification of freshwaters in the northern hemisphere.

Our lab is one of the few in world where references of humic substances are prepared, certified by the IHSS (International Humic Substances Society). Prof. Maria De Nobili is a main expert with a long experience in the field. A nice Comment on the importance of humic substance at the foollowing link.

Inductively Coupled Plasma Optical Emission spectroscopy (ICP-OES) is an analytical technique based on the fact that atoms and ions can absorb energy to move electrons from the ground state to an excited state. The ICP-OES relies on those excited atoms releasing energy at specific wavelengths that are different for each element. The detection limit can be less than 1 ppm. Prof. Marco Contin is our local expert with experience on metal toxicity. A nice paper is available at this link.

Based on catalitic combustion, the mercury is retained in a gold trap and then measure based on atomic absorption spectroscopy. With a very low detection limit of less than 0.01 ng, mercury ca be measured directly on solid samples like soil or ground plant tissues.



The long term mercury contamination from the Idrija mine in Slovenia had affected the Isonzo river banks and the Grado lagoon. Moreover, tons of Hg derived from a chlor-alkali plant (now disused) through the Aussa–Corno river. Despite most of the Hg is not easily mobilised (depending on the chemical form), Hg content can be monitored in soil and in plants, especially in areas affected by flooding and seawater intrusion that can increase Hg mobility.

Other approaches and techniques