Process of Adding Organic Material to Top of Soil

This page is the CodyCross answer for the clue below from Science Lab, Group 312, Puzzle 3 (Reagent Bottle).

Question is: Process of Adding Organic Material to Top of Soil

and the answer is: MULCHING

Word Meaning:

MULCHING — (agriculture) Used for applying a mulch.

Definitions from Wiktionary.