What’s in Your Manure?

Humans have used animal manures to fertilize food crops for thousands of years. Manures are an organic source of plant nutrients and are often a waste byproduct that must be properly managed when raising animals. Today, many farmers and backyard gardeners continue to use animal manures to provide nutrition to their crops. However, a recent experience at our local extension office brought to our attention the need to know what else, besides nutrients, is in the manure used.

A local backyard gardener brought in samples of tomato plants that had strange new growth. She had purchased the tomato plants, along with other vegetable plants, from a local nursery. When she repotted the tomato plants into larger pots, she added horse manure from her own horses to the soil mix. She then noticed this strange growth on the tomatoes, but not in the other vegetable plants that were repotted without adding horse manure. Herbicide damage was one of the first potential causes we suggested, since the new growth was twisted and distorted, a common symptom of plants that have been sprayed by herbicides. The gardener was sure she had not sprayed any herbicides near these plants, or in the pasture where she keeps her horses.

 

Herbicide damaged tomato plants. Photo by: Mark Tancig
Herbicide damaged tomato plants. Photo by: Mark Tancig

 

Photos of the tomato plants were shared with other NW District agents and an agriculture agent with livestock and hay producer experience had the probable answer – herbicide damage due to the horses being fed hay from a hayfield that was treated with a particular herbicide. Interestingly, this agent also had experience with these symptoms after their neighbor had similar issues using manure to fertilize the garden.

Herbicides with the active ingredients picloram or aminopyralid are able to cause this kind of unexpected damage to many gardeners’ crops. Herbicides containing these active ingredients are used in hayfields to control broadleaf weeds. These herbicides are especially effective at controlling hard to manage weeds such as thistle, nightshade, and nettle. They also provide long-lasting weed control. Unfortunately, the persistence of these ingredients extends into the hay, and also persists in the manure and urine of animals who eat hay from treated fields. These ingredients pass through the animal unchanged and remain active as an herbicide. Since many vegetable crops are broadleaf plants, the herbicide’s ingredients cause injury.

So what can a farmer or backyard gardener do to prevent this problem? When purchasing hay for livestock, ask the seller if they know whether the hayfield has been treated with herbicides that contain either picloram or aminopyralid. Most herbicides are known by their common names, rather than their chemical name. If they give you a common name or brand name, the active ingredient can be obtained by contacting your local extension office. If the seller can’t tell you, then, as a precaution, do not use the manure to fertilize broadleaf vegetable crops. The same question should be asked if purchasing hay for mulch as well. Composting the manure or hay does not break down the active ingredient, and may even concentrate it.

While we continue to use animal manures to fertilize our crops as our ancestors did, it’s important to remember that many of the tools and products we use today are much more advanced. These advanced products require that we stay informed of all precautions, use them responsibly, and, in this case, inform end users of any precautions. Remember to always read and follow the label and ask questions. And if a science-based answer is what you’re looking for, your local extension office is a good place to go!

 

Warning from herbicide label.
Warning from herbicide label.

 

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Posted: May 24, 2016


Category: Horticulture
Tags: Compost, Fertilizer, General Gardening, Herbicide, Manure, Mulch, Panhandle Gardening, UF/IFAS, Vegetable Gardening, Vegetables, Weeds


Comments:

Molly Jameson

September 21, 2021

Hi Sara, Thank you for your comment! Edible ginger, Zingiber officinale, is not considered invasive and can be planted in the soil or in a pot. Here is more information, including additional links about ginger, how to grow it, and how to harvest the roots: https://gardeningsolutions.ifas.ufl.edu/plants/edibles/vegetables/ginger.html Thank you and please let us know if you have any additional questions! Sincerely, -UF/IFAS Leon County Extension

Sara
September 20, 2021

Is edible ginger invasive or does it have a lot of spread (like Boston? ferns)? The ginger sprouted in a pot from buying a fresh organic root at the grocery store. Should I plant the ginger in my yard or keep it in a pot?

bill keiser
October 7, 2020

It may be an urban legend, but I've heard that they irradiate or treat some ginger to prevent it from growing. I always look for fresh growth nubs on ginger if I'm looking for some for planting.

Molly Jameson
August 22, 2016

Hi Ann, Sorry for the confusion. What I meant to say is that while spinosad is safe in vegetable gardens, not all organic materials are safe. Rotenone and nicotine sulfate are examples of organic materials that are not safe in vegetable gardens. Does that help? -Molly Jameson

Stephanie
August 20, 2016

Must be in the same family as the cypress vine - it stinks too.

Ann Robinson
August 19, 2016

In paragraph six it states that spinosad is safe for use in vegetable gardens. And then in the same paragraph say it should not be used in a vegetable garden. I'm confused. Is it okay? I've tried everything. Digging it up. Boiling water. Cinnamon. Thanks, Ann

Dmytro
August 12, 2016

Great Article! Thank you. Dmytro

Sheryl Butler
August 3, 2016

This is the best organic way of dealing with waste. I started researching compost opportunities while ago. This is the future if we want to keep the planet's environment and resources, of course. I didn't know much about vermicomposting, only about the standard composting methods. I know most people are used to hire a company for their waste removal needs but it is good if they consider at least to try your composting method. Thank you, Sheryl

Shannon Brady
July 7, 2016

I believe that proper and regular garden waste clearance could significantly reduce the risk of your plants getting affected by fungus and bacteria. It doesn't require much effort and if you don't have the time to do this by yourself you could always hire professional rubbish removal service.

Thomas Duke
May 25, 2016

couple of comments.....(1) As an organic farmer, mushroom compost seemed a no-brainer addition to my yearly mulch pile. However, I stopped using it a couple of years ago because of an article discussing the chemicals the mushroom folks use to reduce certain diseases peculiar to mushroom. (2) I also used straw bales to boarder three sides of my yearly mulch/compost pile and then at the end of the year incorporated the rotted straw into the compost as a "plant-based manure." However, a couple of years ago I came to understand that since straw is generally not consumed when used as a bedding material, straw farmers liberally sprays their fields with herbicides to improve the straw's "purity" from weeds Again, concerned with residual chemicals I discontinued using straw. Results from (1) & (2) = my raised-bed garden with 100% organic growing medium (no dirt) has yielded healthier plants and better crop yield. Took two years, with each year showing improvement. CONCLUSION: carefully "vet" the origins/history of the ingredients that go into your compost so you can more closely realize that garden of your dreams!

Shari Farrell
April 27, 2016

I've been growing container veggies on my deck for years. Some don't do so well and others are astounding! Tomatoes never did well for me in-ground, but large pots on the deck are perfect. Green snap beans, banana peppers and salad greens too. what few pests found are easily disposed of and soil borne troubles are nil. I will never go back to any other system.

Mary Derrick
April 26, 2016

The best time to plant potatoes here is in January/February. Also, russet potatoes are more commonly grown in more northern climes and generally not grown in Florida. See our publication on potatoes: http://edis.ifas.ufl.edu/pdffiles/HS/HS18300.pdf But you can give it a try and see what happens!

Matthew
April 25, 2016

Nice piece! Proud of the work of this great organization, a model for all of Florida and the country.

Matthew Orwat
April 21, 2016

http://pasco.ifas.ufl.edu/gardening/mulches.shtml This should explain the situation well. Thanks!

Stephanie Dickens
April 16, 2016

why is cypress mulch not recommended for use as mulch?

Lisa madine
April 11, 2016

My husband wants to plant a MICROWAVE Able potato. It is all ready wrapped in Plastic. It has roots growing out. We got it at Publix. It is called MICRO TATER Russet. Is it worth doing it. ?

(Rosalie) Lia
October 9, 2015

Wonderful article! Thank you! Makes me feel better about wanting to eat peanuts in ways besides the traditional Southern way which has too much salt.

LINDA MINOR
September 5, 2015

I live in the fountain area, and I know I will not have the lush green grass I had in Nebraska, I have problems in my yard I do not know what to do about. Yes I have lots of turkey oaks with white around them that seems to kill the tree after time. But my main concern is I will have a nice green patch of grass, but then the edges die. Sometimes a big circle will be there with just weeds growing in it. I also have a vine that goes underbeath the soil and kills plants I can get to grown. I also have a tree in my yard that almost has leaves like a mimosa but is bright orange in the fall. Can you heip. I do not know when to go to get answers for my questions

LIA OBREGON
August 28, 2015

Thank you so much for focusing on this important topic! Since moving to FL not as connected to local sources as was in NM. But I will continue to seek out local vendors, growers, farmers. I always grow things myself. Lia

RubbishBeGone
June 23, 2015

Food waste is a worldwide problem, but in the US it seems it is the most major issue, excluding hazardous waste... Recently many supermarkets began a program in which they use their waste to convert it into power and use that power. As a professional dealing with almost any kind of waste, household rubbish and house clearances in London, I can really say that now is the time to make innovations and start the change - to recycle more and to produce less waste.

Cody English
February 5, 2015

Great article!

Donna Legare
January 23, 2015

Excellent article Taylor - very important. Donna

Taylor Vandiver
August 12, 2014

Donna, Thank you for the information! I will definitely add it to my list. Taylor

Donna Legare
August 5, 2014

Hi Taylor You might want to add the native hoptree (Ptelea trifoliata) and the herb rue to your list for larval plants for the giant swallowtail. Rue fits nicely in the butterfly garden and also is used by black swallowtails. Hoptree can be used outside of the garden since it makes a small tree or large shrub, doing well in a lightly shaded mixed border. Enjoyed the article. Donna Native Nurseries

Matthew Orwat
July 3, 2014

Sounds like you have a very nice wildflower garden!

Whitney Gray
July 3, 2014

Thanks, Taylor! Great info!

Lois Jones
July 3, 2014

About 15 years ago, I attended a slide-illustrated program at a Garden Club meeting. The Florida DOT's District 1 staff person for road-side wildflowers was the presentor. The Wildseed Co. of Fredericksburg, TX was recommended as source for our home landscapes. I have been planting this company's Southeastern US mix..and cosmos specialty seeds...ever since. I love to give small bouquets. I love to look at my beds in front and read of my home. In addition,my photo of coreopsis in a roadside ditch won "First Place" in photo contest! Lois Jones / Marianna since 2000; previously-Chipley

Faye Blanton
May 1, 2014

Great information! Thank you.

Sharon
May 1, 2014

Hello Taylor: Thanks for the diagnosis flow charts! I have a fruit and vegetable garden at home in addition to our landscaping, and what would be helpful is a couple of definitions, and some instructions what to do once we've diagnosed the problem. Hopefully at some point someone wrote an article about how best to do that, and perhaps you could add a link. With regard to definitions, what are mobile vs. immobile nutrients? I would think "necrotic" means something similar to yellowed or scorched, but since you used the latter terms in other places in the charts, does it mean something different? What does "chlorotic" mean? Thanks for any additional information you can provide. -- Sharon McAuliffe

Kenneth Smith
February 26, 2014

Thanks for the info, now are there sources for any of mentioned plants? I live in Eastpoint-Apalachicola, FL. I did have my sandy soil tested and it is very high-very sandy!

Donna Legare
January 22, 2014

nice article, Taylor - I'm looking forward to planting our potatoes soon.

Yahya
November 6, 2013

Worm composting like any other job, does require a lot of skills and patience...

Patricia
November 5, 2013

Thanks for sharing a great article on vermicomposting

Comments are closed.

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