Question
I live on a property in Bucks County, Pennsylavania that has limited, exposed top soil.  The ground contains large amounts of shale.  I recently started a leaf compost pile on the property and when ready I plan to spread leaf compost mulch around some cedars, oaks and maples in order to retain moisture, prevent erosion and provide some nourishment.  I want to know if I should mix nitrogen and limestone into my leaf compost pile over the wiinter to improve its nutritional content.  Thank you.

Answer
The addition of nitrogen is to help break down the leaves not to improve the nutrition although it will help.
Decomposition of organic material in the compost pile depends on maintaining microbial activity. Any factor that slows or halts microbial growth also impedes the composting process. Efficient decomposition occurs if aeration, moisture, particle size, and nutrient levels (nitrogen) are maintained for optimum microbial activity.

The goal in making mulch for your spring garden is NOT to decompose the leaves into compost. Rather, you want them to break down only slightly over the winter months so they will become an effective mulch for you in the spring.

First, pile your leaves and keep them dry if you haven't shredded them. Shredding wet leaves is difficult. Next, shred your leaves either with a lawn mover or a leaf shredder (wood chopper). Leaves need to be chopped or shredded before being turned into mulch. Whole leaves won't break down enough over the winter.

Once your leaves are shredded, add them to a compost bin such as the 3' by 3' bin shown below on the right. Add the leaves in 12 - 18 inch layers. On the top of each later, add a handful of urea, ammonium nitrate, bone meal, or a layer of grass clippings (any of these add the necessary nitrogen required to partially break down the leaves over the winter). Then mix the leaves and nitrogen additive with water. You want the leaves wet, but not saturated.

Repeat this layering until your bin is full. The goal is to wet your leaves while adding nitrogen.

I found that small bags of urea, available from garden centers, make an easy way to add the required amount of nitrogen. Grass clipping also work well, Use two to three inches of livestock manure or a nitrogen fertilizer, such as ammonium sulfate, at a rate of one-third cup for every 25 square feet of surface area. If these nitrogen sources are not available, one cup of 10-10-10 fertilizer per 25 square feet of surface area will also suffice. Do not use fertilizer that contains a herbicide or pesticide.

Cover your mulch bins with a tarp or plastic over the winter.

It is a good practice to mix your leaf bins in March. However, this extra effort isn't imperative.

In the Spring, your mulch will be ready to add to your garden. You might see white areas on the leaves. This is a leaf fungus that adds to the mulch's nutrient value