When the public thinks of compost, if it is not the homemade variety, the next type considered is mushroom compost.  Mushroom compost has many wonderful qualities e.g. its high nutrient level, which is due to the manure used in its production.

Now I have been wondering if this is just a marketing coup, or is the product really better? What if you took two composts, one made from landscape waste, the other from manure and straw (the main ingredients in mushroom compost).  If both are manufactured according to strict industry standards, what would be the differences?

The main points often raised are that mushroom compost has a high nitrogen content, between 2-3% according to industry literature (true, as are most composts with a manure feedstock), it does have an odor, which can be troubling to neighbors, and the concern is the high salt content of mushroom compost, which is often downplayed by that industry, but can have a negative impact on plants if not handled correctly.  Finally, mushroom compost will often have a C:N ratio (carbon:nitrogen) of about 13:1

Landscape compost on the other hand does not have as much nitrogen, but a good quality mix can have as much as 1.7%, which is close to the low end of mushroom compost.  There are no odor concerns with the landscape compost.  The landscape compost can also match the C:N ratio 13:1.  And of course the most important consideration is the lack of soluble salts, so there are no extra steps before using a landscape compost.

So what are your thoughts about the two?