leach away
[for something] to erode or wash away gradually by leaching. The soft sandstone leached away under the constant rains. The flowerpots sat out in the rain, where all the nutrients in the soil leached away.
leach in (to something)
[for a substance] to seep or penetrate into something. The salt leached into the soil and ruined it. A tremendous amount of salt leached in.
leach out of something
[for a substance] to seep or drain out of something. All the nutrients leached out of the soil and nothing would grow. The phosphorus leached out of the soil after a few years.
leach something away (from something)
and leach something out (of something); leach something out; leach something awayto remove something from something by leaching. The heavy rains leached nutrients away from the soil. The rains leached away the nutrients.