Killer Compost. Please Advise

Around here, the local mushroom “farm” has it for sale. However while it may be herbicide free (or not really don’t know what they use as ingredients) many muchroom composts are quite high in salts. If you do find some ask if they know the salt levels in their product.

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One of the Ag schools had a paper out testing for herbicide residue in soil/compost. IIRC they used common peas. Plant three pots with the soil to be tested and three controls. Compare germination and leaf shape after 6" tall or so.

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Thanks @JustAnne4. This is a topic that needed to be discussed. It certainly got my attention as I started using my own grass clippings/leaves and my neighbors as a weed block this year. As of now I haven’t noticed any issues but I will be observant for issues going forward. Guess I need to plant a few beans to help my observation. Bill

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That is what I’ve been trying to find without any success and the compost facility will not or cannot tell me where they get their mushroom compost.

Thanks Steve, I’ve heard of this but salts wash out, esp in my area where we get a lot of rain. And some salts are important for electrolytes in the soil. The chemicals mentioned above stick around.

OK will do that too. Good idea to try more than one plant species

Your advantage is that you can look at the label for whatever you put down on your grass and you can have that conversation with your neighbor and boom, you are good to go. I’m reaching into a cloud here not knowing how to find sources for this compost.

If it is frequent that would be tragic, BUT, that is not the issue for me. I just want to make sure I don’t ruin my garden soil, but it is like I can’t even do my homework (nerd crisis).

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Anne,

I just wanted to mention, that I don’t think some of these chemicals are quite as persistent as some of the sources leads one to believe (at least in our locale, with our local rainfall and soil profile).

Years ago, before I was a registered applicator, and didn’t know much about pesticides, I bought some (picloram) Tordon for musk thistles. At the time, thistles were everywhere on the farm we owned. They are considered a noxious weed here in the Midwest. This was in the 90s. The local elevator would sell any farmer RUP pesticides, whether they had a RUP license, or not (times have changed.)

Every year we were really on top of thistles and trying to prevent them from going to seed. The farmer we were renting our crop ground to was late in getting the fields burned down w/ RoundUp and the thistles had big purple heads and were ready to go to seed.

Without really thinking, and with my limited knowledge base, I hand sprayed all the thistles (including thistles in the field, with Tordon (picloram). Picloram is the product of choice in rangeland to kill thistles because if any of it touches the heads, it kills the seeds as well. The carryover is an advantage in this regard. I didn’t think of the consequences using it on crop ground. I was pretty inexperienced when it came to herbicides.

Anyway the farmer planted soybeans that year, and long story short, every place I sprayed a thistle, none of the beans came up (surprise, surprise :rolling_eyes:)

Our farmer tenant and I went out to look at the total damage, and considering the acres, it hardly registered. We were renting the ground to him cheaper than market, so he was OK to forget about it.

How this relates to this discussion, the beans didn’t germinate that year in the spots where I sprayed thistles. The next year, he planted corn (most farmers here in the Midwest go with a corn/soybean rotation, although a few include wheat for a three crop rotation.) The year after that (two years since I’d sprayed the picloram in the field) he came back with beans and there was no identifiable patches of herbicide damage to the beans in the field.

My takeaway is that I sprayed with a fairly concentrated mix, when I sprayed the picloram, as a direct spray, so I’d think if you did accidentally get some mulch slightly contaminated with some of these persistent herbicides, I doubt it would ruin your garden soil. Based on my experience here, I’d be very surprised if the herbicide contamination showed symptoms for more than two years.

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Thanks Olpea for this explanation. Good to know.
Do you remember how the corn crop that followed soybeans did in those spots?

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As I recall, there wasn’t any damage to the corn. One of the real limitations to using some of these persistent products on row crops, is that (at least here) there is mostly a two crop rotation (corn/beans). There is little reason to risk broad leaf herbicide persistance for the alternate year of beans. Margins are low on huge fields, so even a very minor overall reduction in yield would significantly cut in to profitability.

That’s why I was very surprised the persistent herbicide clopyralid was found in the horse feed example you listed. I’m sure it’s impossible to research, but I’d be fascinated to hear all the background details of how it got into the feed.

I’m most familiar with farming practices here in the Midwest, where most of the grain is grown, perhaps things are quite different in various minor field crop regions of the country. I know we have quite a bit different culture raising peaches here, than in CA.

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I don’t doubt your experience @Olpea, but I think there some other variables which likely come into play. Certainly moisture/rainfall I would think would play a role in the speed of the herbicides decay. As well as biological activity in the soil and details on the soil surface where its applied.

The experience I have is myself and others loosing crops (strawberries in my case, a GH of tomatoes and peppers for a friend) and it was traced back to compost made from lama manure. The lamas were supposedly fed organic feed, but that obviously was not the case. The persistent herbicide survived thru the lamas’ gut, thru the composting process and was still potent enough to kill plants (actually very effective at killing those plants). Perhaps if the compost has sat for another year it would have been OK, but the exposure and details of composting are obviously not the same as those of an open field. Same for an animal’s digestive track. Even though this compost was likely 2 years from the application of the original herbicide.

Just saying there are a lot of variables which may effect this, and probably the only way to know for sure is to take a sample of the soil/compost/whatever and do a test on it.

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The real problem with test, buy, use is that most commercial compost operations have fairly fast turn around. The compost you get from them today may be quite different from the compost they are selling 3 weeks from today when you’ve completed your test and that old compost looked good. And unless they were doing you a special favor, they likely no longer have that original compost around.

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Steve - You could always buy a large quantity of compost, and then test it before using. If it tests as bad make the supplier take it back.

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For those in town, that would be a good way to go.

I live in “the sticks” and the cost of delivery is typically way more than the price of the compost. And I doubt any of these compost places would refund my delivery charge. If I could spare my truck for 3 weeks, then I could just leave it sit there until the tests were complete.

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JustAnne4,
Everything I use in compost is highly controlled. I use kitchen scraps, wood chips, grass from my property, leaves etc from my own property. I bring in manure but the grass the cows eat comes from my farm or a farm like mine where we use only nitrogen on our hay fields. I refuse to take grass clippings from anyone due to the problems you’ve done a great job of explaining.

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Oh my, I couldn’t imagine this happening. There isn’t a day gone by we don’t eat something from the garden all year 'round and losing all of it like that would be so tragic.[quote=“Steve333, post:29, topic:12281”]
And unless they were doing you a special favor, they likely no longer have that original compost around
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Hmmm. Well I think they are annoyed enough at my badgering that I might could convince/coerce them. One letter to the newspaper about killer compost comes to Yorktown would def get their attention, but I don’t want to do that. They can easily test each batch - they even have a nursery associated with that compost facility so the materials and now-how are there. I sent them articles on lawsuits. That was my original question: The persistent herbicide labels specify that info is passed along that sprayed stuff is not to enter the compost stream. Sigh

Man you are so fortunate. I can’t generate enough on my little acre so I will forage from known sources. I have 4 cu yds of mushroom compost sitting under a tarp in my back yard from them that I hope I can use. I don’t think their taking it back will be an issue if it is bad. But it might get them to start testing it…but truly, knowing what I do now, I’ll probably test it anyway.

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There is still untapped compost sources on my property such as pond moss, cattails, etc… Many compost piles I made 10 years ago I have not needed yet. Some plants generate a lot of compost e.g. Weeds.

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Whoops, I forgot to ask: What did you do in the greenhouse and those other locations? Did you wind up removing the soil? Waiting for it to break down? Plant some crop that was not sensitive?

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Well actually since I started composting in a leaf bag I’ve learned a lot. I compost every blade of weed I pull from the garden, and of course other garden wastes. The bag is on a support and I fill it full, pressed down shaken together, and tie it off. That huge compacted mass reduces to 1/4 of the volume. Haha, so just when I thought I’ll have lots of compost, here is this less than 1 & 1/2- 5 gal buckets of compost.

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You are right. The contaminated manure comes mostly from dairy operations, not meat operations.

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There is no grazing restriction when applying picloram and when the livestock eats the grass it concentrates the picloram. I think there is a 12 or 18 month suggested waiting period after applying picloram when overseeding clover.

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It wasn’t my GH, so I can’t tell you how they dealt with it. I suspect bought starter plants that year but I did not follow up as to what they did in the future.

My strawberry plants however all died out, 3 beds worth. This was several years ago and I have not replanted. I may try a test bed with some more berries next year. It should have been long enough for that stuff to have broken down…

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grow your own fertilizer and compost . grow comfrey and raise chickens fed on you comfrey and free range in the yard. mine barely eat any feed anymore. the little feed i buy is from a small organic farmer who makes his own for his chickens. he doesn’t spray anything on his land.

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