Burying a full metal canister of lye is an old-fashioned garden remedy for encouraging or improving nut production and health in pecan trees. While there are differences of opinion on the usefulness of this method, there is some consensus on the science that may underpin the practice.
Lye raises the pH of the soil, which is favorable for pecans, as they do not like acidic soil. Second, the metal canister that typically houses the lye and is buried near the tree roots contains zinc, which leaches into the soil. Pecan trees use large amounts of zinc and can deplete the soil of the nutrient. Third, lye contains potassium, which the tree uses for flowering and fruiting.
Dig a hole at least 1 foot deep approximately located along the drip line of the pecan tree canopy.
Remove the lid from the lye and set the can in the hole sideways or upside down.
Bury over the can with the excavated soil and compact the soil in place with your palm or foot.
Water the area until drenched and leave the lye to do its work over many years.