Soil water repellency in the Brazilian neotropical savanna: first detection, seasonal effect, and influence on infiltrability

Abstract

Soil water repellency (SWR) has been detected worldwide in various biomes and climates. However, this phenomenon has not been shown yet in the Brazilian neotropical savanna. The present study addresses the following questions: a) Does SWR occur in the Brazilian neotropical savanna? If so, b) does it exhibit seasonality? c) Does it influence infiltration? To do that, we selected two similar study areas covered by the same soil and vegetation types. We performed water repellency and infiltration tests in both areas during the transition from dry to wet season. Our results indicate that SWR occurs in soils of the Brazilian neotropical savanna only during the dry season and does not influence soil water infiltration. The likely cause of SWR might be related to the chemical composition of soil organic matter since neotropical savanna plants produce hydrophobic substances as a survival strategy, especially during the dry season.