Wettability of soil surface as a property of solid phase studied for Chernozems of Kursk region

Abstract

Soil surface wettability is the main physical property that defines organization of elementary soil particles into soil structure. Human impact affects the changing in properties of soils under arable land use. The objective of this research is to study this impact by the example of two profiles of Chernozems (Kursk region), located under the forest and at the arable field. For both profiles some soil solid phase properties (contact angle, aggregate composition, aggregate waterstability) were measured. There was a positive correlation between the content of organic matter and soil’s wettability in studied soils – a growth of contact angle with the increasing the content of organic matter. Under the forest the content of soil organic matter was changed from 6.41% on the surface to 1.9% at the depth of 100 cm. In the Chernozem under the arable land use the organic carbon content in arable horizon is almost two times less. The maximum of hydrophobicity (78.1°) was observed at the depth of 5 cm under the forest. In the profile at the arable field the contact angle value at the same depth was 50°. The results of the structure analysis showed a decrease in the content of agronomically valuable and water stable aggregates in the profile under arable land.