soil moisture deficit
noun1
The amount of water needed to bring the soil back to full capacity. The deficit occurs in periods of prolonged drought in areas that usually have normal rainfall.
- Network Rail said this has been due to the driest ever spring and summer, which caused clay embankments to shrink unevenly in a process called soil moisture deficit.2025 November 12, “West of England services respite”, in RAIL, number 1048, page 17: