Page 1 of 1

herbicide residues in horse manure

Posted: Sun May 16, 2021 12:38 pm
by bower
I know we had threads about this before, but I don't recall...
If you put a plant into the ??? stuff as a test, how long before damage shows up?
Just having second thoughts about my potting plans without testing for that, although I never had the problem before.... :oops: :?

Re: herbicide residues in horse manure

Posted: Sun May 16, 2021 1:15 pm
by Growing Coastal
Bower wrote: Sun May 16, 2021 12:38 pm I know we had threads about this before, but I don't recall...
If you put a plant into the ??? stuff as a test, how long before damage shows up?
Just having second thoughts about my potting plans without testing for that, although I never had the problem before.... :oops: :?
I recall reading about people planting beans as a test. If they come up alright then grow ahead!

Re: herbicide residues in horse manure

Posted: Sun May 16, 2021 1:57 pm
by worth1
It won't take no time at all for a bean to show effects of an herbicide.

Re: herbicide residues in horse manure

Posted: Sun May 16, 2021 2:39 pm
by Rockoe10
It'll show signs fast. A live plant that gets a fresh soak, will show signs the next day.

You can make a "compost manure tea" and water some weeds. See what happens

Re: herbicide residues in horse manure

Posted: Sun May 16, 2021 3:29 pm
by bower
Thanks! I didn't have a bean handy but I do have many extra tomato plants, so I potted one up that was still in cell pack, into a smaller pot of the manure mix, and gave it a good soak. It's not looking unhappy yet but I'll see about tomorrow.
I had no problem with the stuff I got in other years, but there were not many weeds in this pile at all and it just dawned on me that it might possibly be tainted. A few chickweeds have sprouted in the stuff I brought inside in the fall, and they look healthy, but as I understand it the tomatoes and beans suffer the most.
I actually know nothing about herbicides or what they kill, I'm assuming if it is in hay that it doesn't affect grasses but only the broad leaved plants. The usual issue with horse manure is that it is full of grass seeds! But perhaps it was just better rotted and not the top of the pile.
I guess I'll google for herbicide damage pics, to see what my test plant should look like by tomorrow. ;)

Re: herbicide residues in horse manure

Posted: Mon May 17, 2021 12:25 am
by pepperhead212
I don't recall the posts about herbicides in the manure, but I do recall the ones about the residues in straw and hay. And similar tests to see if they are safe.

Re: herbicide residues in horse manure

Posted: Mon May 17, 2021 6:51 am
by bower
Well happily my test plant isn't looking any different this morning. So I'll take that as a "No". :D

Re: herbicide residues in horse manure

Posted: Mon May 17, 2021 12:12 pm
by SQWIB
pepperhead212 wrote: Mon May 17, 2021 12:25 am I don't recall the posts about herbicides in the manure, but I do recall the ones about the residues in straw and hay. And similar tests to see if they are safe.
There is a carryover to the manure.

https://extension.oregonstate.edu/crop- ... -clippings

https://www.motherearthnews.com/homeste ... 0z1211zkin

https://www.ncagr.gov/spcap/pesticides/ ... 9Apr09.pdf

I stopped using hay, and manures and will only use my own compost now.

I had a few bags of Timothy Hay, that I was Leary on using so I used it to make a biochar and I am running it through the composter for the fall.
I don't even get the compost from our city facility anymore. I figured either I make my own or I do without.

Re: herbicide residues in horse manure

Posted: Mon May 17, 2021 5:28 pm
by Cole_Robbie
2 4 d is the herbicide that goes through horses. Dow chemical used to have a web site warning about it in manure, but they took it down. I suspect the site was part of a settlement agreement from a lawsuit.

Re: herbicide residues in horse manure

Posted: Mon May 17, 2021 6:44 pm
by Rockoe10
Interesting. I thought 2 4 d degraded after about 40 days, and was safe to plant in? I could be completely wrong about this, and hope I'm not.

Re: herbicide residues in horse manure

Posted: Mon May 17, 2021 9:27 pm
by pondgardener
[mention]Rockoe10[/mention][mention]Bower[/mention] Your post(s) got me interested enough to do a little online searching and I found the article listed below. It seems that 2,4-D can take up to a year to break down and there is also some information of how you compost material may influence the effectiveness of whether herbicides are broken down.

https://www.natureswayresources.com/inf ... mpost.html

Re: herbicide residues in horse manure

Posted: Tue May 18, 2021 5:01 am
by patihum
Grazon or other Aminopyralid-containing herbicides are sprayed on pastures because they don’t kill grasses, only plants such as horse nettle, pigweed and blackberries. Then after application, the cows, horses and other animals graze on the grass, ingesting the herbicide which passes undigested through their systems and into their manure.

The manure can be composted for a year or more and it will STILL kill your garden.

Re: herbicide residues in horse manure

Posted: Tue May 18, 2021 5:59 am
by bower
I read something about aminopyralid last night - they said the damage may only show up when the plants set their first fruit. :( There's a long list of crops that it affects, just about everything.

On the less worrying side, the friend who got me this manure has been using it every year in his garden, from the same source. He doesn't grow tomatoes but a lot of other things on that list, and he had no complaints.
So I can only assume that the stable owner is not using any feed with those residues, and hope there wasn't any change in that supply.
Fingers crossed, because I went ahead with it yesterday so it's too late now.
Test plant and others are looking fine so far.

The problem here is that there isn't much hay or pasture, so feed is often imported, and that is expensive... IDK how careful horse owners are about the things they import. Read this yesterday about the hay issue:
https://vocm.com/2021/05/17/nfld-pony-complications/

Re: herbicide residues in horse manure

Posted: Tue May 18, 2021 7:18 am
by Rockoe10
I used that herbicide for the first time in my garden to kill any weed seeds that got into the garden. I had a couple last year and thought I'd get a jump on it.

I sure hope I haven't made a big goof. I planted yesterday. This morning they all look good. I'll check back in a week to let you know.


🤞

Re: herbicide residues in horse manure

Posted: Tue May 18, 2021 12:22 pm
by rossomendblot
Over here we have problems with manure and even bagged compost from shops being contaminated with clopyralid/aminopyralid. Clopyralid is an ingredient in some lawn weedkillers available for use by home gardeners. I guess if they mow the lawn and put the clippings in the garden waste bin for collection, the resulting compost is contaminated.

Re: herbicide residues in horse manure

Posted: Tue Jun 29, 2021 5:29 am
by svalli
Manures are not any more the only organic fertilizers with herbicide residue problems. There has been a lot of reports of damaged plants in Scandinavia last years and now finally there are actual test results. Quite many plant based organic fertilizers have now been pulled of the shelves, even some of the manufacturers did not initially admit that there is anything wrong in the products.

Here is some information in English from Norwegian Institute of Bioeconomy Research (NIBIO): https://www.nibio.no/en/news/high-conte ... ertilizers

Swedish home gardeners association (FOR) has a good report about the tests, but unfortunately the full report is currently in Swedish and also translated to Finnish.
This is the report in Swedish: https://www.for.se/wp-content/uploads/2 ... 1_webb.pdf

Here is the FOR's English summary, which I got via e-mail:
During the spring season 2020, many recreational growers suffered unexplained damage to plants of tomato, chili and pepper. The plants had deformed top shoots, with twisted stems and withered leaves. The affected plants had in common that their growers had used organic plant nutrition based on vinasse, a residual product from the sugar beet industry. The vinasse was suspected to be contaminated with the herbicide clopyralid or aminopyralid. First to connect the observed damages with contaminated plant nutrients in Sweden was the journalist Lena Israelsson.

The results from the plant nutrition producers own analysis of the products showed residues of the herbicide clopyralid in several cases. A majority of the products were approved for use in organic farming and were KRAV-labelled (KRAV- Swedish standard for organic production). No analysis were conducted by an independent party, but rather this was left to the producers, as no authorities take responsibility for following up such questions concerning recreational cultivation that affect many millions of leisure growers in Sweden. Therefore, Fritidsodlingens Riksorganisation, FOR (Swedish organization for recreational growers) chose to carry out their own investigations. The first step was to perform a survey of affected recreational growers to get more information about observed damages and the products used. Subsequently, 14 organic plant nutrition products, suspected of being contaminated, were collected and analysed. Plant nutrition products were also applied to broad beans, which are extra sensitive to clopyralid, according to the manufacturers' instructions and any symptoms were recorded.

In total, 151 answers were collected from the survey. From the submitted pictures of the injuries, more than 80% showed symptoms that were assessed to be associated with herbicides. The plants most affected were tomato, chili and pepper. Of the analysed liquid plant nutrition products, 10 contained residues of clopyralid. The concentration in the products ranged from 0.098 to 3.0 mg / kg. This should be put in relation to the fact that tomato plants can get visible damages from low μg / kg. Clopyralid was found also in leaf and fruit samples of tomato. However, in three examined pelleted plant nutrients no pesticide residues were detected. The bioassay confirmed the results from the lab analysis, all collected products with liquid organic plant nutrients gave symptoms to the exposed plants.

The overall picture shows that liquid organic plant nutrients sold to Swedish consumers in 2020 have been contaminated by the herbicide clopyralid and probably resulted in tens of thousands of plants destroyed and financial losses for many recreational growers. Several different brands of liquid organic plant nutrients were contaminated with clopyralid. This is explained by the fact that vinasse to a large extent is purchased from a few large wholesalers and originate from a limited number of producers, mainly German companies, which manufactures plant nutrients for several different brands. The raw material originates from France, Germany and Poland where clopyralid and aminopyralid are used in much larger to a greater extent than in Sweden. The recreational growers who responded to the survey are just the tip of an iceberg. Many more are most likely affected without knowledge of the underlying cause. FOR therefore urges everyone who considers themselves affected to contact the manufacturers for compensation both for the purchased product and for the damaged plants. FOR also assumes that the manufacturers of plant nutrition, based on vinasse, can guarantee that their products are completely free from herbicide residues by the growing season 2021. If the manufacturers cannot guarantee this, it is not possible to recommend recreational growers to use their products.


I first time encountered problems in 2010 with a fertilizer containing vinasse. It has taken long time to get the issue noticed and many people though that I am some kind of tin foil hat wearing paranoid nut, when I talked about the possible herbicide residue in fertilizers. So please be aware of the risks of contamination in the organic fertilizers, because it is a real issue.

Sari

Re: herbicide residues in horse manure

Posted: Tue Jun 29, 2021 6:37 am
by bower
That's terrible, Sari. When you can't even buy a product labeled organic and be safe... !!! It's crazy. :evil:

The horse manure which I got here, also turned out to be the perfect amendment to my container mix. It's retaining moisture much better and the plants are large and healthy and setting lots of fruit, putting up with our weather extremes quite well. My thanks to bjbebs for showing his plants using well rotted horse manure in containers, I would not have thought of it otherwise. Fantastic stuff.

Re: herbicide residues in horse manure

Posted: Tue Jun 29, 2021 8:04 am
by bjbebs
My current manure source is from a large stable of a dozen horses. Pasture fed outside the barn that has had no chemical applied. But what they eat inside is of more concern. No control over this food source.

I use the manure fresh and composted. If applied and tilled in, its age does not matter. Manure from a horse is more of an ammendment than a fertilizer. My garden at home sees a few trailer loads a year.

As Bower said, manure composted along with leaves, etc. makes up the bulk of my container mixes. Always keep a small pile tucked away that sits. It's this dark, heavy stuff I use in containers.