Siberian Federal University: Siberian Researchers Run the In-Depth Tests of Soil for Pesticides

Krasnoyarsk scientists have studied three types of soil using a bienzyme system developed at the Department of Biophysics of Siberian Federal University. As a result of the work, the researchers came to the conclusion that in the absence of reclamation measures (applying sorbents and cleaning the soil with the help of special bacteria), the soil layer of agricultural land, the most saturated with pesticides as a result of human activity, is restored on average within 30-40 years. The simplicity and convenience of the proposed testing method enable for regular monitoring — to study the state of soils at a considerable depth and regulate the modes of their use and rest.

“Our task was to examine not only the top layer of the soil, but also to check the soil profile as a whole at a depth of about one and a half metres. Many pollutants tend to accumulate for long time — so do pesticides which are used in agriculture to improve crops and to protect them from various pests and pathogens. We can get a complete picture of the health of the soil only by examining the entire section from the fertile layer to the loam”, said Elizaveta Kolosova, junior researcher at the Laboratory of Bioluminescent Biotechnologies of Siberian Federal University.

The object of analysis was water extracts from soil samples taken from different depths. The researchers put a complex of enzymes, reacting to pollution by glowing, into all samples. This glow is called bioluminescent and is characteristic of some types of animals, bacteria, and fungi.

“We took several soil samples from arable land, which is used for growing crops in Rybinsk district of Krasnoyarsk Territory. We also considered fallow soil from land that had not been used for farming for more than ten years, and virgin soil that had never been subjected to special treatment. The first soil sample, actively involved in the pilot production farm, was the most polluted with pesticides throughout the depth of the reservoir, while the fallow and virgin soils turned out to be cleaner”, continued Ms. Kolosova.

The bioluminescent method used is highly sensitive and reacts to a wide range of pollutants. In the presence of an aqueous extract of virgin and fallow lands, the scientists registered an intense glow, but the soil actively used for growing crops extinguished the glow of the bienzyme system — according to the authors, this is a sure sign of a high content of soil pollutants. Soil analysis can now be carried out using a special device — a luminometer, designed by the scientists of the SibFU’s School of Fundamental Biology and Biotechnology. This device is portable and can be used both in the laboratory and in the field.

“The proposed method can be used in the future to create a sensitive biosensor, small and convenient for field work. Such biosensors will be in demand in state agricultural holdings and farms in order to prevent overloading the soil with pollutants of various origins”, said Oleg Sutormin, co-author of the work, senior researcher at the Laboratory of Bioluminescent Biotechnologies, Siberian Federal University.

In addition to studying the soil using a bienzymatic system, the researchers assessed the humus layer in all the samples. Humus is an organic component of the soil that contains nutrients needed by higher plants. The expectedly high percentage of humus was found in the virgin soil, but the fallow lands also showed a good result.

Scientists from Krasnoyarsk Research Centre SB RAS also took part in the study. This work was supported by the Government of Krasnoyarsk Territory, the Krasnoyarsk Regional Science Foundation and the Russian Foundation for Basic Research under project No. 20-44-242001.