Fenhexamid adsorption behavior on soil amended with wine lees

Area of Science:

• Environmental Chemistry
• Soil Science
• Agricultural Chemistry

Background:

• Fenhexamid (FEN) is a fungicide used in vineyards.
• Wine lees (WL), a byproduct of winemaking, are increasingly used as soil amendments.
• Understanding FEN's fate in soil amended with WL is crucial for environmental risk assessment.

Purpose of the Study:

• To investigate the effect of wine lees (WL) on the adsorption of fenhexamid (FEN) in vineyard soil.
• To determine the role of different wine lees fractions (solid vs. liquid) in FEN adsorption and mobility.

Main Methods:

• Adsorption/desorption experiments using vineyard soil amended with different fractions of wine lees (SWL, LWL).
• Solubility tests of FEN in wine lees extracts.
• Soil column leaching studies to assess FEN mobility.

Main Results:

• Solid wine lees (SWL), particularly the yeast fraction (Saccharomyces cerevisiae), significantly increased FEN adsorption.
• Whole wine lees amendment decreased FEN adsorption, likely due to dissolved organic matter.
• Liquid wine lees (LWL) increased FEN solubility and significantly enhanced its mobility in soil columns.

Conclusions:

• The fraction of wine lees used as soil amendment critically influences fenhexamid's environmental fate.
• Solid wine lees can act as a sorbent for fenhexamid, reducing its mobility.
• Liquid wine lees can increase fenhexamid's mobility, potentially leading to greater environmental exposure.