The primary concern is space - biodegradable waste in landfills takes up space that other non-biodegradable material could be using, and space is at a premium in most landfills. If you add a lot of yard waste to an existing landfill, you’ll have to build another one sooner than you otherwise would, and they’re awfully expensive. From a cost-benefit perspective, yard waste is about the worst use of a landfill, because you don’t need all the precautions that landfills have to go through to safely dispose of it… from an environmental standpoint, you don’t want to add yard waste to landfills because you’ll just end up with more of them to worry about.
As a secondary answer, the way the landfill is operated slows the biodegradability. The waste added to a landfill is periodically compacted and covered with a layer of fill. This is intended to compress the waster, remove as much of the air as possible, and prevent too much water from infiltrating into the waste (water leaches contaminants out of the garbage and can transport them down into the water table if it’s not properly contained). When a cell is closed, it’s capped with a clay liner that does a better job than the daily fill of preventing water from getting to the waste.
If you take the clippings and dump them in the woods, they’ll be degraded aerobically. Aerobic degradation is a relatively fast process that requires oxygen and water - two things that aren’t available in a landfill. Anaerobic degradation will happen, but it’s a much slower process. It won’t happen before the cell is closed, so the amount of space that your yard waste takes up is permanently lost.
More than you ever wanted to know about landfills, I’d bet. They’re actually pretty interesting operations, if you’re a giant nerd.
Some might make a fuss about the traces of weed-killer on the clippings, but I don’t think the trees care. If she takes care to scatter them somewhat, rather than make one big pile, they’ll probably rot without stinking.
If she’s aware that she doesn’t own that land, then she is knowingly dumping shit on someone else’s land. Posting the area explicitly as private property/no trespassing/don’t dump here should be sufficient.
We live in the middle of nowhere. If my neighbor were to dump his clippings in our yard, my reaction would be dependent on a couple issues.
If I saw him do it and know he did not see me, I might make mention “hey – have you seen anyone dumping stuff in my yard? Someone dumped a pile of clippings in my yard, and I am in shock that anyone would do that.” Thus letting him know that I don’t appreciate it, giving him a chance to come forward with a “oh I didn’t think you would mind” or whatever.
If he knew I saw him, I would have said something at that point along the lines of “hey, what is that you’re dumping?” Really, it’s no big deal if you dump clippings in my yard, but ask me first is my way of life.
I’d second the notion that many issues are best solved over a few beers. One day you might collapse on the lawn and she’ll be the only one around to administer CPR. You don’t want her to spend precious time debating whether it’s worth her time to save your grumpy ass.
