If all you did was mow over the leaves in place instead of raking them up, you can achieve a fineness that will fall between the grass blades. It will rot down within a year and return all those nutrients to the soil to nourish the lawn. Youtube has a plethora of clips, run a search on Leaf Mulch. Alternately, if you mulched the leaves than added them to a compost heap you can reduce their volume to a quarter or less of their previous volume.
I spent much of the past week studying leaves. Besides sand, grass and hillbillies, it is the next most abundant resource around here. About half an acre here is forested primarily with
water oaks. The forest floor is deep with leaves from the past couple of years. The drought for the last year and a half has slowed down decomposition, allowing them to build up. I have 3 acres of pasture surrounded on 3 sides by oaks for miles. Across the street is 75 acres of planted pines. The only limits on how much leaf volume I can gather are time spent and method used.
Oak leaves NPK: 0.8 0.35 0.2
CN: 40-60
pounds per acre: about 4000
acres available: several
total pounds available: many, many tons
Fact (not verified by me): 50% of the nutrients taken up by a tree remains in the leaves when they fall.
I have tried several methods of gathering.
Easiest: grab bags by the side of the road that others have raked up. God love em.
Lowest impact: mulching mower with a bagger, dump bag into wheelbarrel
Fastest overall: rake leaves onto tarp, drag tarp to heap, then mulch with the mower.
I've got 6 piles of leaves around here, plus a dump truck load of spent
mushroom compost. It's starting to look like a humus farm. Most of these piles are nothing but leaves, some older than others. Left alone, these leaves will decay in 2-3 years, but this requires at least some regular rain. It's going slow, but takes no additional effort.
I have the main compost heap to which I add whatever greens I gather. This is coffee grounds, kitchen scraps,
chicken litter, bull manure, and grass clippings. I'm in Florida, there are plenty of spots where the grass is green and still growing-I gathered up 4 heaping wheelbarrel loads just today 12/31. The main heap gets watered when I think of it, but for the most part it gets little attention. I keep the main heap in an area enclosed on 3 sides by
pallets I screwed together to stay upright, about 12'x12'x4' high. The last batch took about 9 months to reach a point where I was comfortable using it. This had reduced to about 1/4 of the volume of the bin after much stuff was added over the
course of the batch. That last batch was not mulched, all I did was dump out bagged leaves to fill the bin.
Last week I found a tarp in the big truck-it was under the seat. I thought my brother had 'borrowed' it. I had to apologize to him for all those things I said while I was looking for it. This allowed me to rake up a pretty big area, then drag the load over to the bin. I spread them out then ran over the things repeatedly with the mower, bag removed. To my excitement the mower shredded the leaves into tiny bits. I raked up several more loads and repeated the shredding, leaving me with an area about 20'x20', as deep as a cinder block, 8". The math says this is about 10 cubic yards, but it is still light and fluffy. Maybe 5 cuyds is more in line with reality.
Its a lot of leaves. Still, I didn't rake up half the area under the 3 oaks in the corner.
I ran some through a sifter made with 1/4" construction mesh. A good half of the material went through. The stuff that didnt I tossed down in the same spot so I can mow them some more if the urge strikes me. I sifted enough to fill a 5 gallon bucket so I could play with it some more. The finer the material, the faster the compost process. I expect this batch to run its course much faster than the last one. To achieve a blend of grass and oak leaves with a CN ratio of 30:1, 2 parts grass to 1 part leaves
should be close. The problem I'm having now is the stuff is shredded so well it is difficult to scoop it up with a pitchfork. Instead of tossing the stuff in the bin, I'm building the heap right where it is.
The next problem is water. I filled a 16 oz solo cup with the fine sifted leaves, weight=4 ounces, then add a measured amount of water to try to estimate its water holding capacity. I ended up adding 16 ounces of water, filling the cup, without the leaves floating out. After two days I tipped up the cup, the lightest trickle came out. These things slurp up MASSIVE amounts of water. Once in the soil, the water retention property of this stuff should give the beds a big
boost. My single data point experiment says 1:1 by volume, 1:4 by weight. I've got 5 cuyds of this stuff. For the amount of water this stuff will require for compost, I'll have to leave the hose running all night. I'll wait for the rain. For now, I gave it a spray while adding grass clippings.
I've been looking at leaves as a possible replacement for peat moss. With the finely sifted material, I think it might do the job in my potting soil mix. More examination and comparison needed here.