Alfalfa is a different story, I think it was mentioned by mistake. The main issue is that selective herbicides are applied to grasses which are used to feed horses, cows, etc. For example, GrazonPRO contains clopyralid, which is a selective herbicide used for control of broad-leaf weeds, especially thistles and clovers. According to Wiki,
Clopyralid is known for its ability to persist in dead plants and compost, and has accumulated to phytotoxic levels in finished compost in a few highly publicized cases. This first came to light in Washington State when, during 2000 and 2001, residues of clopyralid were detected in commercial compost, and compost made at a municipal site damaged tomatoes and other garden plants planted in it. Word quickly spread to other local and state governments and in 2002, DowAgro, the manufacturer of clopyralid, voluntarily deregistered it for use on domestic lawns in the US and it is banned in several US states but it is found in consumer products in Europe such as Scotts Verdone Extra and Vitax Lawn Clear 2.
Not in straight horse manure, but several popular homesteading and gardening channels on YouTube have been burned by herbicide contamination from compost in the last few years. Grazon seems to be worst offender. The bad thing about it is that the companies making lots of compost donāt realize they have contaminated manure or hay going into their compost. It starts all the way back at the landowner who is spraying his field to control weeds for hay or grazing and has no clue about herbicide contamination in compost.
Many years ago I used to regularly apply grass clippings on my tomato plants for home use. Iād gather grass clippings from finely manicured lawns, which I knew had to be sprayed with selective broadleaf herbicides. The tomato plants did wonderful.
The only time I had a problem with tomato home tomato plants was when I cut up a bunch of walnut logs in the garden with a chain saw, then planted tomato starts. The walnut saw dust stunted the tomato starts.
The aminopyralid in Grazon does have carry over. Itās in the same class as picloram (Tordon). There are a lot of restrictions on the label to keep contaminated manure out of compost. Of course it probably still happens.
I also think sometimes herbicides get blamed for plant problems caused by diseases, insects, or nutritional deficiencies. I remember an occasion where a brand new farm marketer who had no experience growing potatoes blamed contaminated mulch on the potato problems they were having. But I was pretty sure the person simply hadnāt figured out how to grow potatoes.
I read the discussion above and have a chemical related question in my mind. As we know pesticides usually last just few days then the chemical breaks down. Why the herbicides lasts forever? It starts in the field through growing season, say few months. Then to be harvested, stored, to be sold to the horse staples. This last for say a month. Horse manure to be composed, this last say three months. All adds together, at least half year, not count in the chemical reaction/breakdown in horses stomach. What makes the herbicides so tough that it went through all the sun ray in the fields, acid stomach fluid, and higher temperature composed, and still is one piece and can continue to be herbicides??
I think it is all about how the chemicals are designed/ intended for using. Imagine something liek glyphosate is intended to kill then provide some nitrogen as it breaks down. So they want that breakdown faster.
Compared to something like Oust or the ones mentioned above, that is intended to last for a solid year of weed control. The products they are applying for pasture are intended to work as long as possible because the longer they work the less broadleaf weed pressure, the better for that narrow scope of application.
it is kind of a crazy cycle, at least here there is mainly just one weed that needs to be removed from hay to avoid hurting animals that eat it. The rest of the weeds are pretty beneficial for the animals to eat, when these herbicides are used they get a clean field and hay but eventually it will lead to having to pay get rid of their waste animal manure the more people have issues with this. I stopped taking horse manure from one neighbor because we contacted their hay supplier and he uses herbicides. Iād rather pay other neighbors for their clean animal manure than having to compost it for a year was my previous assumption. Reading this thread has me more concerned than before.
Local feed stores are selling Grazon, so somebody around here is using it. Seeing others get burned with it has made me paranoid enough that I donāt bring in manure or compost from anywhere at this point. If my garden gets contaminated I canāt just go till a new garden plot. Itās worth the peace of mind to make hay by hand for my rabbits and mulch and use my chickens to make compost. The only thing I canāt control is the feed I feed my animals, but itās mostly grain and alfalfa based, so Iām not real concerned about contamination from it.
I will begin to worry about herbicides in composted manure when I see real proofā¦ that is a failed crop followed by analysis of manure from the same source, or if an experienced gardener that I know has some pretty convincing experience from a given source.
Decades of use of composted manure and being involved with a community of skilled gardeners who do the same leaves me pretty sanguine about the true danger of this. I donāt trust blogs written by young and enthusiastic gardeners ore beginning farmers who are the most likely people in the world to misread anecdotes, especially when it takes the blame from their inexperience.
Call me a crotchety old timerā¦ I donāt care. Iāve got over 5 decades of paying my dues in the soil. Occasionally some youngster actually respects that.
Now Iām not saying such contamination never happens, only that there are a lot of bigger things to worry aboutā¦ especially when growing fruit.
I think the use or frequent and compounding use leading to these issues are not as old. I just have the concern to be almost solely fertilizing my orchard with horse manure that could compound into damaging them in the short to long term. So my main alternative is to be more strict, or use purchased fertzā¦ (I got a new source found today for a small trailer full every other week with free delivery, woohoo). 2 clean 1 dirty sourced and free to little delivery work.
I was thinking to mention that I appreciate seeing all your posts through the history of the forum, Until i just read your crotchety old timer statement here, so Iāll just leave it unsaid since it seems unnecessary.
Thatās a good question. The EPA has pretty much banned the organochlorine pesticides, which persist for a very very long time (i.e. DDT, chlordane, etc.). So those are pretty much gone.
The persistent herbicides nowadays break down to become ineffective in about a year (+/-, given the climate conditions.) They are designed to ācarry overā (i.e. will carry over to the next season) for a couple reasons. First, as mentioned, one application will provide season long control. If a herbicide breaks down very quickly (i.e. short half life) it must be reapplied multiple times throughout the season because it has a short effective life to do itās job. So in the end, a lot more pesticide is applied with pesticides with short half lives. More persistent pesticides solve this problem.
The other reason some pesticides are designed to persist longer is that most less persistent pesticides wonāt kill the seeds. So, if the field is sprayed and the weeds have already formed seeds, the pesticide wonāt keep the weed seeds from germinating. More persistent pesticides will coat the seeds and ground so that when weed seed hits the ground, itās still unable to germinate the next season because the herbicide is still effective either on the seed itself, or on the ground. Again minimizing the requirement for more frequent applications of herbicide.
Of course the drawback of more persistent herbicides is that they have more potential to contaminate ground water, for longer periods of time (if they have a high leach potential) or contaminate manure, as discussed on this thread.
Iām not sure thatās necessarily true. Picloram (i.e. Tordon) started to be used in 1964 and is very persistent. Very effective for controlling broad leaves in wheat and pasture. It wasnāt even āRestricted Useā until 1978. Over 5 million gallons of Agent White (2-4,D and picloram) were used in the Vietnam war to defoliate forests, in operation āRanch Handā.
I couldnāt find many historical records back to the 60s for picloram use on ag land in the U.S., but it was used heavily on ag land. I remember it as a kid. According to this chart, itās use has decreased since about 1993. This is the oldest use records I could find.
There are a number of other herbicides which are persistent and were created and sold more than 50 years ago to farmers and ranchers (i.e. Terbacil, atrazine, etc.)
I know I am being a bit of the devilās advocate,
I wonder how many new chemicals have come onto the market for this use, or if the old ones have had any alterations making them degrade slower, be more effective or if their application areas have changed making them more likely to be used vs salt fertilizersā¦ maybe there are some more aspects to consider but we get the gist that I want to try and think of the variables at play.
I appreciate you digging up this info and sharing it. That is motivating to just disregard it and use the shit I can get.
We know organochlorines pesticides are as bad as chemicals get. Many were used here in Kansas and we are still paying for them.
" organochlorines are considered as the most persistent pesticides in the environment as they contain more than five chlorine atoms in each molecule that poses the degradation process very slow. The US EPA has classified several organochlorine pesticides, including aldrin; dieldrin; chlordane; p ,p -dichlorodiphenyltrichloroethane (DDT); mirex; and toxaphene as highly persistent bioaccumulative and toxic (PBT) chemicals. The PBT pollutants thus pose a risk to the human health and ecosystem. These pesticides generally bind strongly to soil particles and may remain in surface soils from a few months to many years (US EPA, 2000). While persistent pesticides tend to have long-term effectiveness in pest control, they have toxic and harmful effects on the soil flora and fauna. At the same time, they pose chronic toxicity to the environment
" https://www.sciencedirect.com/topics/earth-and-planetary-sciences/organochlorine
Few people realize ddt was still widely used in Mexico until recent years. Many products from other countries contain contaminates outlawed in the usa in the 1970s.
Olpea, thanks for taking the time to enlighten me on the subject of the herbicides. I now understand that the goal of the herbicides is to control the designated weeds for at least one crop season. The herbicides stay effective for so long in the ground really make me think twice before using any herbicides in my yard. Really nasty stuff! It feels like I would be surrounded by the herbicides poison if I sprayed the herbicides. Will any herbicides chemicals be observed by the crops and get into our food chain and poison us at the end?
Data on pesticide residues does not provide a clean answer to the question of differences in safety of imported and domestically grown produce. FDAās regulatory monitoring program has shown that imported produce violates tolerance limits more frequently than domestically grown produce. However, both for imports and domestic produce, the violation rates are very low. Further, a greater frequency of violations in and of itself does not indicate that there are differences in the level of health risks. To answer the health questions, it is necessary to know the amount of the specific pesticide ingested and the pesticideās toxicity. To distinguish health risks of domestic and imported produce, the critical question is the level of exposure to each chemical from each source.
Results from pesticide residue testing programs finds some pesticides are detected only in domestic produce, some only in imported produce, and some found in both, sometimes at clearly different levels. Because different chemicals have different health effects, there is no way to compare the safety of imported and domestic produce. We do know that consumer exposure to pesticide residues (from all sources) is very low and that scientists tell us they pose a neglible health risk.
In conclusion, there is no clear evidence that health risk due to pesticide residues or microbial bacterial contamination is greater with imported produce than with domestically grown.
Essentially it says that it is happening more often than it used to, although it is still very scattered. One significant thing mentioned was the first case brought to their attention of a commercial compost seller having contamination. He recommended the same thing I believe you mentioned above, just test it if you have any questions by growing some beans in it before you spread it around everywhere. Ultimately he tells people to keep uding compost, just check it if you are unsure of the sources. Contamination can become a boogeyman blamed for all sorts of things it isnāt actually doing, but we donāt want to fall into the āitās never happened to me so it canāt be a problemā camp.
Something that bothers me more than compost is that Grazon lasts up to 3 years in hay. For people that are doing Ruth Stout style hay mulching, that means you have to know if your old hay was sprayed, and plenty of farmers around here were just sourcing hay wherever they could in recent years without asking many questions.
As for crotchety old gardeners, theyāre some of my favorite people to talk to. One of my pet projects is videoing some of my favorite old timers in their 80s while I interview them. I learn all sorts of stuff doing that, and it seals away some good memories in a way that can be easily accessed down the road after theyāve been gone a while.
Thanks, that is interesting, but it does seem that issues discussed are about annual plants being mulched and not woody perennials like fruit trees. It also doesnāt really explain if by widespread they mean in their region or nationally.
I donāt think it has been a particular problem in NYS. I canāt find any Cornell based articles highlighting the issue. Break down may be quicker in humid climates that get evenly spread precip throughout the year, as is the case around here- I donāt know.
You are correct that it seems to only be aimed at annuals. I wonder if the same compost could be used on fruit trees or bushes with no ill effects. I have a theory that contamination happens more in the Midwest and South, but I have zero evidence to really susbstantiate that.
