When soil is waterlogged, plants literally drown. Water fills all the air spaces between the soil particles and this prevents oxygen from reaching the roots.
Much as we use p.H. when we talk about soil acidity we can talk about p.F. when referring to soil water. However the terms Saturated soil, Field capacity and then Wilting and Hygroscopic Coefficient are important to know and understand.
Saturated soil. This kind of speaks for itself. Prolonged rainfall, soil becomes waterlogged and if walked on or driven over becomes “compacted” and drainage gets worse.
Field Capacity. It rains, water percolates through the soil. With time this downward movement ceases. The water remaining “hangs on” to the soil particles and no longer runs through under the force of gravity.
For all farmers the difficulty is that of managing soil when moisture levels are between Saturated and Field Capacity. This is the time we must travel on the land for cultivation or ultimately to plant seed. But “too much” travelling results in compaction which results in a water logged conditions in which plants literally drown.