Does mulch deplete nitrogen levels in the soil?
As the mulch wood breaks down initially, it will use up some of the nitrogen in the soil. However, after the fiber decomposes, it will restore the nitrogen back to the soil. The best way to maintain good plant growth is to implement and follow recommended fertilizer programs, a good horticultural practice regardless of whether or not mulch is used. For example, you may want to gently work a specially formulated fertilizer (like 16-9-12, 18-11-12, or 20-10-10) into the soil before mulching. Another alternative is to use landscape fabric as a barrier to cut down on potential depletion.
