First post for me, so here goes…
I am not much of a composter. However, recently I had a possible opportunity to get a lot of thatch clippings from some athletic fields nearby engaged in fraise/fraze mowing. From my understanding this form of mowing removes up to an inch of the thatch layer of the sod in these fields to help rejuvenate their grass. The clippings are mostly grass, thatch, and a bit of topsoil that is picked up in the process. Also, the grass is still green at the time the thatch is being removed, so at least some of the organic material will be “green,” rather than “brown.” That is the background, but here are my concerns and ideas that I really would like input upon.
I live in the South (zone 7b), and my soil here is not great. My yard and surrounding land are in a hilly area of primarily clay. I think the word to describe the soil type would be ultisol. So, any organic matter, especially a large free supply sounds good to me.
First concern is that this stuff will need to rot a good bit before I use it. My thinking is that even with the bit of soil included and the green parts of the still growing grass, the majority of this stuff will be cellulose in the form of thatch. In my mind, the danger of immediately using it from this point of view would be that it will leach nitrogen away from my existing, nitrogen-poor, soil in order for the microbes to do their decomposition. Does this sound legit or do you think the soil and green matter will be enough to compensate?
Second consideration is that this comes from athletic fields which are almost pure Bermuda. If I use it in my lawn, there is no issue in terms of seeds, but if I do use it in any beds, I definitely could see a lot of Bermuda coming up in it. This is not a huge deal for me, but might be another reason to let it lie for a year or so to maybe kill some of the seeds as it decomposes. What also concerns me about this is that here in the South to get those “pure” fields of Bermuda grass, I feels sure herbicide has been applied regularly and in great quantities to this stuff each and every year. I suspect MSMA, 2-4D, and prodiamine among other herbicides (glyphosate, etc.) have been heavily used. I’m not a true organic grower by any stretch, but my main concern on that is the potential for residual effects on other plant life from those herbicides. What are your thoughts on this? Is there a length of time that everything residual would be considered as having broken down or become inert? I am not as concerned about it affecting my food, as I don’t plan to grow food crops in areas I am using this thatch product, but I am concerned if it might kill my plants, aside from the sod grasses in my own yard. Again, if I use it in the lawn area, I guess there are no worries, as my main grasses are Bermuda and zoysia which should not be affected to much by those chemicals. I would hate to use it around something like my maple trees or in my flower beds and have some sort of die off of those plants though.
Final thought that I would want some input on is circling back to the first point. So let’s say I get this stuff, and make a big mound out of it. In my mind this stuff will eventually rot, even in such a mound, correct? If the concern about nitrogen leeching with predominantly cellulose rich organic matter is that the microbes have to have nitrogen, then where does the nitrogen come from to break down the pile, if the vast majority of it has no soil contact to pull it from the soil? I mean do certain microbes “fix” nitrogen from the air to break it down? Or do different types of microbes not require nitrogen for their breaking down of the cellulose? I am still a bit unclear in my mind of how it eventually would rot, and I assume it would, without such soil contact, unless nitrogen fixing takes place or it is some other process that does not need as much nitrogen?
Anyway, I appreciate any input on my potential situation as I try to educate myself on this topic and hopefully make better decisions on how to proceed.
Thanks!
