Posted by Scott Hackett on Fri, Dec 16, 2011 @ 12:58 AM
Whilst many think of roots as the main or only route of uptake of nutrients, here’s an interesting fact; Plant leaves will absorb 95% of nutrients applied to them, whereas roots will take up only 10% of nutrients supplied in the soil!
Of course we must balance this low value with the appreciation that most soil nutrients stay present in the root zone long enough for the roots to utilize them eventually, so the remaining 90% aren’t typically wasted. Nutrients applied to tree leaves may also be subjected to evaporation and wind.
Leaves absorb nutrients through both the stomata (the breathing pores, which are more common on the under-surface of the leaf) and the cuticle (the waxy waterproof covering on top). Each route of entry admits approximately the same amount of nutrient.
Foliar application of nutrients can have beneficial effects, especially when treating a species for nutrient deficiencies.
Statistics within this article sourced from SESL