Not really, although some people claim that is so. Everything you add to compost contributes what it has and the total of everything is what makes compost so great.

Now, you could go to the biodynamic composting websites and find that very minute quantities of some things is supposed to make better, more nutritious, compost, but what research I have seen does not hold up that theory.

Some people add coffee grounds and egg shells, even banana peels, because they are enough of a different source of certain nutrition and vitamins that they feel won't come just from leaves, grass, paper, dirt, etc that is normally in a compost pile.

Just like a human diet, variety is the key. The more different things you can put in, the better. For example, plant matter has different levels of minerals depending upon the source. A variety of plant materials will ensure that the compost has the most complete array of minerals.

Of course, any compost is better than no compost at all, so don't get too hung up on optimization. We all use what we can get and things generally work out fine.

I'd favor leaves, which is nice because they are not in short supply. Shredded maple leaves seem to break down quickly, but shredded oak leaves make a compost that breaks down steadily and completely.

Next would be wood chips if they are small enough. Wood chips will take a long time to decompose so either compost them in a separate pile or plan on that particular compost pile taking more than a year to 'finish'.

I recommend adding some clay soil in the layers of compost. The clay will absorb humus and provide a medium for the microherd to live in.

Grass clippings decompose quickly. The first spring cuts from the lawn break down the quickest and seem to have the most Nitrogen. You'd want to prepare in advance to use fresh grass clippings, stockpiling shredded leaves and other matter to mix with the fresh grass.

Right, that's the kind of thing I was thinking about: Egg shells for calcium/minerals, coffee grounds for mainly nitrogen (or does it have other things?), banana peels for potassium I guess? Past few months grapefruit has significantly outnumbered other fruit/veggie scraps in my pile because that's what I've been eating a lot of, and I have no idea what a pile rich in grapefruit ends up as, nutrient-wise. That's what got me wondering about it.

I've got two little kids who eat a ton of fruit and veggies (and as a result, the wife and I go through tons of coffee). Combined with leaves from the yard, I'm inclined to think our pile has a pretty good variety of things in it.

And yet others, add clay...fascinating.

While coffee grounds Nitrogen levels have been known to be about 2 percent for some time the amount of Nitrogen in tree leaves has not been well known and that can range from 1.5 to 4.5 percent.

Egg shells do contain a lot of Calcium, but how quickly is that available? I have seen years old egg shells still visible in my garden beds and they are still intact after a year in the compost bin. Eventually egg shells will be digested but it is not easily done.

For many years I have heard to put Banana peels in the garden for Potassium but, again, it takes some time for the Soil Food Web to digest them and convert those nutrients into something the plants can use. All organic matter has those same nutrients, in varying amounts so if a balance of material is put into the compost bin the finished compost will have a balanced nutrient level.

What is left of Citrus fruits can be composted, the peelings, pulp from juicers, etc. although some will counsel against doing so. Citrus fruits are both acidic and oily so digestion can be slower, but what nutrients that material may contribute to the compost is, apparently, not something Google cares about since nothing I could find would provide that information.

Put all of your waste vegetative material in to be composted and the bacteria that digest it will make it into a balanced, nutritious, pH neutral, useful product for your garden. There is no need to look for "nutritious, material to add since all of it is nutritious.

kimmq is kimmsr

Only if your soil is horribly deficient in something and you had a HUGE quantity of whatever was extremely high in it. Toss it in and keep tossing, keeping a reasonable ratio of material so it doesn't go anaerobic and stinky on you.

Over time it will balance out and turn into usable compost.

All those Pinterest pins about burying ONE banana skin to fix your rose bush because it's "rich in potassium" are a pile of anaerobic pig manure,

One thing to keep in mind is that if you recycle everything that comes out of your gardens (except for the part you eat, of course), those nutrients are going back into the system anyway. And anything you import - kitchen scraps for example - will add additional nutrients.

Fruits have higher than average potassium content, and vegetables (roots and tubers) higher than average P and K content. Vegetable leaves have higher than average N, P and K. Where average could be mixed yard clippings. Generally, kitchen scraps (dominated by veggies) make the most nutritious organic amendment. Some micronutrients, such as boron, are also abundant.

Here are a few threads about this topic if you want some light reading.

http://forums2.gardenweb.com/discussions/1687259/what-gives-compost-its-nutrients?n=23

http://forums2.gardenweb.com/discussions/2807694/minerals-in-the-soil?n=50

http://forums2.gardenweb.com/discussions/1675493/mineral-content-of-green-grass-green-leaves?n=13

http://forums2.gardenweb.com/discussions/1626551/heres-a-doozy?n=17

http://forums2.gardenweb.com/discussions/1703361/has-anyone-worked-with-soilmineralscom?n=68

I was sure I had a link somewhere to a table of mineral content values for various compostables. Can't find it right now but it might be buried in one of the above threads.

Those are interesting links. I can't imagine what you searched under to find them, but I'm enjoying working my way through them.

I think you are over-thinking things. Unless you are going to do some high tech scientific experimentation, I'd work on other stuff.

Shredded leaves + grass clippings + coffee grounds + manure + kitchen scraps + time = compost

I think I searched using the term 'mineral content' or some variant with the term 'minerals'.

tn is right, of course, the main thing is to compost what you have and don't worry too much about its contents. But there's nothing wrong with the question or learning about it. glib made a good point above, about kitchen scraps being some of the richest feedstock for compost. It's a shame so much of that goes into landfills. It could change the productivity of gardens and farms, there's so much of it.

It is amazing to me that folks around my neighborhood bag up leaves and have them hauled off (though it is good for me, because I do a lot of the hauling). It is the trees in an area that are monitoring what is at the surface, because usually it is the fine roots at the surface that are adding to all the growth of the trees. The trees send roots deep in order to pull up to the surface the things needed in the soil at the surface for use - those nutrients go to the leaves, which are dropped onto the surface, where they are digested to give the soil exactly what it needs to be a perfect growing medium. In the trees' case, they are looking to grow their seeds. I know that when I include mostly leaves in my compost, and even when I spread very thin layers of ground leaves on my lawn, I am adding exactly what the trees have determined is needed for the soil in my area. By having those leaves hauled off, they are removing the wealth of the neighborhood, in my opinion. Luckily, I just end up with most of it in my yard, though at the rate I've been collecting and adding the last few years (new house, new lot), I may be living on a hill in the next 10 or 20 years!!!