QuestionQUESTION: Which is best for vegetables gardens, cow or horse manure? I live in Connecticut and have used both in the past. Is horse manure any good at all.
Thank you
ANSWER: Manure in Vegetable plots makes me nervous. But that could just be me. To each his/her own. I am a little squeamish, admittedly, and you may simply be the wiser here. So let's get to your question.
'Manure' as an amendment is one of the richest sources of organic matter you can put on the table. Manure carries valuable, slow-release levels of N-P-K PLUS micronutrients, soil structure enhancements -- improved tilth, water holding capacity -- and other components of great Soil.
How much, exactly, varies.
And not just between species.
And no one agrees on how much.
Horses, Rabbits, Pigs, Chickens, Cows yield very different Manures. But even the same Horse will supply varying values of minerals and other qualities, depending on what that Horse had for breakfast.
So we ask the question: What's the difference between Cow and Horse Manure? And what else matters?
The book 'Teaming with Microbes' by gardening columnists Jeff Lowenfels and Wayne Lewis takes a look at Manures. For these authors, the key to soil amendments is having keen knowledge of the KIND of Nitrogen your vegetables need. Will Manure give you that kind of Nitrogen? How much should you add?
There are two kinds of Nitrogen. Most vegetables -- and most short-lived annual flowers and grasses -- do best in soil that provides Nitrogen in NITRATE form. Your tastiest, healthiest vegetables, your greenest greens, will grow in Soil that gives them the Nitrogen that they like and need. Nitrates. NO3-.
Since the bacteria that make NO3- thrive in alkaline soil, with a pH above 7, your Vegetable are going to need
The other kind of Nitrogen is Ammonium form. These bacteria thrive in acidic soil, with a pH below 7.
Perennials, trees, and other plants do much better when they get their Nitrogen as Ammonium.
Not Vegetables.
Now, chemical fertilizers provide their Nitrogen in the form of VERY high concentrations of Nitrates. At first that may sound like a good thing. Nitrates are exactly how your Vegetables like their Nitrogen. Too bad these chemical Nitrates are all Salt. They annihilate the microbes in the Soil that digest your Manure and other organic matter for slow-release plant nutrition. Then they burn the roots of your Vegetables, maybe not killing them but at the very least doing damage that is going to lower the quality and quantity of your harvest. The Earthworms run for the hills. The Soil structure quality plummets. All of which means that your Vegetables will always do better with organically supplied Nitrogen. Preferably Nitrates-based, converted via your friendly local Soil Bacteria:
'Carrots, Lettuce, Broccoli ... prefer an F:B of 0.3:1 to 0.8:1,' they write. 'Tomatoes, Corn, Wheat go for an F:B of 0.8:1 to 1:1.' That F:B notation is their shorthand for 'Fungal to Bacterial Biomass', the F:B ratio. You want less Brown matter in Compost headed for the Vegetable Garden; more Green matter. Fewer friendly Fungi; more of your Best Buddy Bacteria. Let me know if you need an expansion on this -- I have much more too put down here and I don't want the website to crash on me before I finish my talking points.
Going back to the original point, Cow v Horse, authorities do not agree on the standard for different Manures. On one hand, see the Manure data on the link to The Farmer's Almanac Manure Guide:
www.almanac.com/edpicks/manureguide.html
As far as they're concerned, Cow and Horse Manure are basically the same stuff. They maintain that these, along with Chicken Manure, would all be excellent choices for a Vegetable Garden.
But other qualified authorities assert these are completely different amendments. Some put the NPK breakdown of fresh Cow Manure at around 12-20:0.6-1.0 -- LOTS of N, barely any P, a token of K. But if another authority puts Horse Manure at around 0.6-0.3-0.5, Horse Manure is much lower in Nitrogen. I could go on. Perhaps this is why you posed the question in the first place.
Yet, according to yet another authority, perhaps more important than precise analysis of the amount of NPK is the quick availability of the RIGHT KIND of N timed for when your Vegetables need it most:
'The importance of N supply at the BEGINNING of crop growth was simply demonstrated by Weier (1992) in Broccoli... In field experiments ... the head weight of Broccoli was reduced ... where smaller amounts of fertiliser were applied at planting...'
A lot of this depends of course on the Crop itself. Their table, 'Nitrogen Requirements of a Selection of Field Vegetable Crops Based on KNS (Lorenz et al 1989) system', is posted at the same web page. As they explain in their description of analysis of nutrient use by a crop of Leeks, 'The maximum demand is associated with the beginning of the rapid growth phase and falls as the proportion of the crop that is photosynthetically active declines.'
How do you make sure the right N is available at the right place, at the right time? They offer this tidy solution:
'Plant demand for N can be satisfied from a COMBINATION of Soil and Fertiliser N to ensure optimum growth. The major source of plant available N in soil is the N mineralised from Soil organic matter and fresh crop residues. The rate of these processes is dependent on Soil temperature and to a lesser extent Soil moisture content ...'
Just a few more points to make here.
One, there are other potential problems to consider:
1. Fertilizer Burn. This is potent stuff. You will have to 'age' it before it's safe to use. You'll find full instructions on 'How to Compost and Use Horse Manure' at the University of Illinois website:
www.age.uiuc.edu/clmt/manure_composting-farm-basics.pdf
2. Weed Seeds. Yes, manure is filled with them. You will have to age it to use it without sowing a field of Weeds on your Garden plot.
The NRCS at the USDA posts a treatise on this subject, aimed mainly at farmers, but of interest here:
www.nrcs.usda.gov/technical/ECS/nutrient/animalmanure.html
Why is this important?
Here's what they say at the ENVEG project:
'The importance of N supply at the beginning of crop growth was simply demonstrated by Weier (1992) in Broccoli. In field experiments ... the head weight of Broccoli was reduced (not significantly) where smaller amounts of fertiliser were applied at planting...'
The whole report, 'Nitrogen and Field Production of Vegetable Crops,' is posted on their website:
www.hri.ac.uk/enveg/nitrogen/generaln.htm
Composting Manure drives temps up to 150 degrees F, killing(theoretically at least) all possible pathogens. Commercial Manures should indicate the contents are 'Pasteurized'; it means the product was heated prior to packaging. If you are not sure, let the Soil go through a full year's 'Fallow' treatment -- growing nothing for human consumption. A Cover Crop will continue to enrich the plot all year, until you are ready to plant again.
OK. I'll stop now. I hope this is food for thought haha and I'm open to your questions. Promise to get to them quickly. It's only Monday, after all. Thanks for writing.
L.I.G.
---------- FOLLOW-UP ----------
QUESTION: WOW...great response to my question. I had to read it several times because of the quantity and quality of the data.
It appears that both cow and horse used correctly produce similar amounts of nitrogen, although one would probably use cow if they had a chose.
If I do not use cow, horse or other animal manure then what else is out there. For example, is using fireplace ash as good a source of nitrogen to use on plants as is animal manure because I have plenty of that. Over the past three to four years I have seen my vegetable plants go down in size and quality. I rotate and do other things that suppose to help but I think the soil is tired and lacking something and maybe that something is nitrogen. I have used horse and cow manure in the past but maybe I need to use more of it and use it more often.
Anyway, thank you very much for all your help and if you have other ideas for me or have an opinion on the wood ash as a nitrogen source please let me know.
Thank you again.
Mike
AnswerI don't know why I did not say this sooner... I guess I am trying to keep it out of every answer I give, but sooner or later is always boils down to the same answer:
GET A SOIL TEST!
This is easy to get from your local Connecticut Cooperative Extension Service:
www.canr.uconn.edu/ces/garden/factsheets/SoilTestingforLawnsGardens.html
You give them dirt and money, they give you a detailed analysis of your Soil. THIS IS GOING TO EXPLAIN EVERYTHING I.M.H.O.
Just be careful when you follow their instructions. Give them a valid sample.
If you are in the mood to throw a lot of money into this project, get the Rolls-Royce of testing:
www.soilfoodwebnewyork.com
They will supply you even better analysis of your Soil -- reports on potential pathogens, various data you may or may not need eventually (Vegetables however can be very tricky so this is a heads up), etc.
It costs a lot of money. But it's worth its weight in gold.
Testing your Soil saves you money, by the way. You don't have to pay
for anything you already have in your Soil. And you'll stop wondering and guessing what could be missing -- IF ANYTHING.
I am trying not to be so long winded on this answer, and I hope you don't get overwhelmed with all this material, but I would just like to point out one more thing here about your Soil: Be aware that plants need generally 13 nutrients, but these nutrients MUST be correctly balanced in the Soil, for 2 reasons:
1. Too much of 'x' ends up replacing 'y'. You now have a shortage of 'y'. No matter how much 'y' you give it, no matter what form, there is NO ROOM for the 'y', and the plant suffers from a shortage of it. Please read this paragraph over so I don't have to repeat myself. It is a basic chemical rule and it is something no one seems to realize, even after I explain it. Plus remember you don't know what you have a shortage of unless you have one of those scientists at your Coop Ext test it for you in their lab. You can't tell any other way.
2. Remember 'The Weakest Link'? Which nutrient is The Weakest Link in your Soil -- the one that is most severely lacking in your waning Vegetable Garden? THIS is the ceiling! THIS is the limiting factor for the health of the entire plant! You cannot swim faster than the slowest person in the group, even if the rest of the group is Olympic swimmers. And if you re-read Item #1 above, you now know that simply adding lots of nutrients 'just to make sure' is always going to prevent smaller nutrients from taking their rightful places with the bigger nutrients, because the bigger nutrients will out-place them. You MUST get your Soil tested.
This is not a gardener's favorite thing to do, sir. It is the step most people do not want to bother with. But it is the ONLY way for you, in YOUR plot, to know what's going on there. Without a Soil Test, you are totally blind. You can't know your Soil by guessing what's in it. Get your Soil tested. Please.
I have more to say about Manures, but if I keep typing, the answer will crash or corrupt, and then I'll be very upset.
