Water repellency of soils with various content of organic matter in north-eastern Poland

The objective of the work was to investigate hydrophobic properties of soil formations with various amounts of organic matter and occurring in young glacial landscape. The research was carried out in mineral, mineral-organic and organic (slightly and strongly silted mucks, sedge peat, alder wood peat, reed peat) soil formations. Water repellency is very important in soil protection. It favors the formation of stable aggregates and prevents from soil erosion. The study was carried out applying two methods - water drop penetration time test (WDPT) and alcohol percentage test (AP). Among 51 analyzed soil samples in WDPT test, 64.7% of mineral and mineral-organic soil formations were hydrophilic. Among organic soil formations 37.6% was slightly and strongly hydrophobic and they represented strongly silted mucks. Unsilted and slightly silted mucks, weakly and strongly decomposed peats, were very strongly (18.8%) and extremely (43.6%) hydrophobic. AP test showed that strongly silted mucks were moderately and very strongly hydrophobic. Slightly silted mucks, and peats were very strongly and extremely hydrophobic. It can be stated that water repellency decreases simultaneously with the degree of siltation of organic soil formations.