апрель 2019

Soil type monitoring by ground air composition


Gutsol N. , Нагірняк Світлана Валеріївна Нагірняк С. В. , Dontsova T. , Lapinsky A.
Химия и современные технологии
Abstract / Full Text

Gutsol N., Nahirniak S., Dontsova T., Lapinsky A. Soil type monitoring by ground air composition / Химия и современные технологии : Метериалы ІХ Международной научно-технической конференции студентов, аспирантов и молодых ученых «Химия и современные технологии», 2019. – C. 15-16


A promising method for determining the type of soil is monitoring the composition of ground air, as it is known that the composition of the gas phase of the soil directly depends on the chemical and biochemical parameters of the soil.

Each type of soil is characterized by its own chemical composition, which is the reflection of the elemental composition of all geospheres involved in the formation of soil. Therefore, all soil contains elements that are common or found both in the lithosphere and in the hydro-, atmo- and biosphere (Table 1). The change in the chemical composition of the soil leads to changes in the concentration of gas components of ground air [1].

Table 1 − Chemical composition of soil solutions of various soil types according to V.V. Volkova, I.N. Srynnikova

Content, mg/l Soil type
Podzol Chernozem Solonets Saline
Organic matter 20-760 10-50 65 3-5
Si4+ 3-20 1-5 18 1,0-2,8
Al3+ 6-12 0,1-2,0 5
Fe3+ 3-10 0,1-2,0 15 0,7-1,4
Ca2+ 5-25 200 450 920
Mg2+ 5-15 30-60 230 23000
Na+ 1-3 5-20 4400 93000
K+ 2-5 8-30 7000
HCO3 10-60 500 720 915
SO42− 8-20 80 7400
Cl 4-10 100 1800 146000
NO2 10-60 170 190

Ground air – gases that are in soil pores, free of moisture; its amount is expressed as a percentage of the volume of soil, and the content varies depending on the dynamics of soil moisture in the area. Soil air may be due to colloids in the absorbed state, may be dissolved in soil (water can absorb up to 1-2%), in a clamped state (when the air is in pores, on all sides, surrounded by an aqueous film), and in a free state. The composition of soil air is similar to atmospheric (Table 2). It contains O2, N2, CO2, as well as small quantities of methane, hydrogen sulfide, ammonia, hydrogen, etc. Soil air of well-drained soils contains 78% nitrogen, 21% oxygen 21, 0,9% argon, 0,03% carbon dioxide gas Depending on the porosity, humidity, type and species composition of the vegetation, the amount of organic matter, microorganisms, the content of O2 and CO2 in the ground air can vary from 0 to 20%. Differences in the concentration of O2 and CO2 are determined by the intensity of use of O2, the production of CO2 and the rate of exchange of gas content between atmospheric and ground air – aeration. The relationship in soils O2 and CO2 is constantly changing due to the seasonal and annual cycles of plant development and climatic factors.

Table 2 − Content of various gases and volatile organic compounds in atmospheric and soil air

Gases and volatile organic compounds Content, %
in the atmosphere in the soil
N2 79,1 68÷73
O2 21,9 5÷21
CO2 0,03 0,1÷20
H2 5·10-5 1÷8·10-6
CO 1·10-5 1÷8·10-6
NO 1·10-5 1÷10·10-4
N2O 5·10-6 4÷40·10-5
CH4 3·105 1÷8·10-7

 

To date, there are no established patterns between the type of soil and the composition of ground air [2]. Conducting research data is extremely relevant as it will allow the development of an online method for determining the type of soil that will be used to assess their quality and the choice and calculation of correct rules for the application of mineral fertilizers.

References
  1. Samofalov I. A. Chemical composition of soil and soil creating species [Electronic resource] / І. A. Samofalov // Perm State Agricultural Academy. – 2009 [in Russian].
  2. Types of soil, their features and ways of improvement Source: https://www.botanichka.ru/article/vidyi-pochv/ [Electronic resource] // Garden and garden. – 2015 [in Russian]