Weight Comparison before and after Composting

Has anyone ever tried estimating the difference between weight of compostable material and the resulting compost? I know it would be a hard to scientifically do, but just curious of people's gut feeling. Someone doing bin composting might have some luck.

I just see all the leaves being thrown into the dump and wonder how much compost or leaf mould they would generate.

I wonder if I was to take 10 or 15 of the bags, roughly weigh them, and then pile the leaves in the middle of the woods and come back a few years later, would whatever I piled up would weight close to the same? I imagine you'd have to let it dry for a while to get a good comparison since leaves are fairly dry.

Senil King wrote:I just see all the leaves being thrown into the dump and wonder how much compost or leaf mould they would generate.

There are soooo... many factors.

I have a ring of "fencing" and two years in a row I dumped all the "dead" leaves from my maple trees into it. This year before adding more leaves, I tried to dig out some of the leaf mold that was there, and I got about 3 buckets.

I've read that the reason deciduous leaves turn colours before dropping is that the tree is collecting and storing many of the valuable chemicals, like the constituents of chlorophyll, before letting the leaves drop. Thus, even though it looks like a lot of material, by the time it decomposes, there isn't a lot there.

I've also read just how slowly soil builds in many forests. Most of the useful material in a forest is in the living trees. In my ecosystem, most new trees start on the decomposing trunks of trees that have fallen (we call them Nurse Logs).

However, those 3 buckets I got was really nice material and since I had to rake the leaves anyway, it was very little effort on my part to contain them and let Mother Nature do her thing. If you have a place you can contain the leaves (packing pallets could make a quick and cheap containment spot) I would rescue as many as possible from the landfill. In our area, such things are now banned from the landfill and the Municipality composts them. They do so in my sisters' city also.

Sometimes it doesn't matter what the "science" says - if you do the right thing to get some good leaf mold for adding to gardens or under trees that could use the organic matter,  that's good enough for me!

I think most of the weight is going to be water in any composting system; so it may be little relevance to before and after measurements.

In an open system, e.g. one with worms, bugs, and other critters coming and going, these helpers may both add and remove materials.  In an open system you may also have leaves blown in and out by wind. And water added through rain and lost through evaporation.

Even a system like the enclosed backyard tumbler must have some ventilation and drainage, so I don’t see as you could be sure how much weight change was due to the effects of composting vs condensation/evaporation or other processes.

Yeah, I've been composting large piles of leaves and grass and have been getting quite a bit of good soil material. Last year was something like a pile 5'x15'x1.5' of mostly finished compost. I've also been dumping something like 8-10" of cut up and quite compacted leaves over the garden for several years, and there is definitely a layer of soil a few inches thick above the solid clay that was there before.

But at this point that line is getting mixed in with the clay, which I'm really excited about! But I was just curious if anyone had tried paying close attention.

I like removing leaves from the dump, but it also takes fuel to go get the leaves as I don't usually drive the gas chugging truck to town, compared to the little sipper car. Not sure if it would be doing harm or good in the long run, either on the pocket book vs buying soil or on the environment in general.

I don't *need* more soil necessarily, I'm getting to good spot over a few years just doing what I already am, and I enjoy the journey and slowly improving. But I wouldn't deny more good soil that was going to the dump anyways if it made sense.

Senil King wrote:I like removing leaves from the dump, but it also takes fuel to go get the leaves as I don't usually drive the gas chugging truck to town, compared to the little sipper car. Not sure if it would be doing harm or good in the long run, either on the pocket book vs buying soil or on the environment in general.

Yes, "the devil is in the details," as the expression goes.

That said, there are some pretty interesting pictures here on pemies of things people move in little cars! Get roof racks for it and make a box that can easily be strapped to the racks? If you're grabbing them as part of a regular or required trip, the slight decrease in millage would be less of an issue. If you know people in town near the places you go, they might even save their leaves for you, if the dump isn't as convenient to get to.

As for clay soil... I'm finding in my 'compacted glacial leftover dirt' that if I dig a hole (and remove the rocks) and layer back in various compostable things along with the dirt, it's really helpful at getting water to infiltrate. It is a lot of work in my dirt, so I only do this in key places that will be really helped by it. Punky wood is normally a part of the process, as was horsey doo before my horsey friends retired to the Mainland, veggie scraps, dead animals, saw dust etc. I wouldn't normally put leaves down there, as they're happier to decompose on their own as they tend to matt if added to compost. The exception is really small leaves like Wisteria. They call them "Big Leaf Maple" for a reason!