Manure on root crops?

[littleminnie]

So normally my rule is never use manure on root crops of carrots, potatoes and sweet potatoes especially. Usually I use compost for them. This year I have several offers for manure. A farmer from market has cow manure waiting for me and another farm has a goat/horse mixture waiting for me. I also have a friend who piles up her pure horse manure and I will get plenty of that. So I want to get as little compost as possible.

So what I am thinking is how much is too much manure for the sweets and taters? What if instead of using compost (which I have to shovel myself and it is fine and heavy) I use manure but less of it?And frankly I don't think the carrot beds need anything for spring since my soil test still shows very high P and high K, Mag and Cal.

[rowan]

Never had a problem using manures on my root crops. Frankly I don't know how that got started but I use fresh and aged manures on my carrots, potatoes and other crops with no adverse effects at all - no carrot hairiness or forking, better potatoes, sweeter beets.

[Joseph Lofthouse]

In my garden, not importing weed seeds in manure is more important to me than the extra boost of fertility that manure might provide. I am growing in clay/silt which is plenty fertile.

If I were to add manure to my garden, I would only do it in the fall, in order to minimize the risk of contaminating my vegetables with nasty manure born micro-organisms.

[ferdzy]

Manure and even compost have NOT done good things for our carrots! At least not right away. It wasn't until we stopped putting out even a little compost that we started to get good carrots.

The catch is the first year we tried carrots, without any manure or compost (the first year we had the garden, that is) they also did very badly because the soil was so poor.

We have the garden on a 4 year rotation. We manured and composted everything for the first couple of years and the carrots just had to lump it. But last year only things in the "leaf" rotation and a few of the "fruits" (melons is what I'm talking about here) got any compost or manure. As a result, we finally got a good crop of carrots.

In short, they benefit from soil improvements - providing they are done well in advance, like at least a year maybe better two. It will depend on what your soil is like to start with, of course. Like I said, ours is pretty terrible. Nice and loose, lol, but that's about it.

We were using 2 to 4 year old composted elk manure.

[12540dumont]

Minnie, is there a place you can put the manure to mellow? Like in a windrow? Near the corn?

[littleminnie]

The manure is already aged. Should I just go light for the taters and sweets?

[steev]

I'm considering a shallow trench filled with old horse poo, with the soil back on top, as a way to plant my sweet potatoes this year. I think several inches of horse poo may deter the gophers.

[templeton]

Minie,
Manures ain't just manures.
My 'go to' reference suggests the following analysis, with the rider that these values depend on diet of the animal, and how much bedding etc is in it.
Cow N=1 P=0.4 K=0.5
Fowl N=2.1 P=1.6 K=1.0
Horse N=0.7 P=0.4 K=0.5
Pig N=1.1 P=0.7 K=0.1
Sheep N=1.8 P=0.4 K=0.5

Sorry, no listing for well rotted Elk manure - not much demand for it round these parts.

They also suggest "Root crops can follow leaf crops...without additional fertilizer but they can also be grown with NPK 5:8:4.
The rate of application will depend on the previous treatment, 75g per sq metre for previously manured or composted... 150 grams where no animal manure has been used"

This suggests moderate manuring shouldn't be a problem.

Is your aim to improve soil nutrients, or to keep up the organics?
In my experience I've never burned or overfed veges with aged horse manure, despite heaping it on. But I have noticed green veges love lashings of sheep manure. Horse manure brings all sorts of pasture weed seed, too.
Only just developing my expertise with carrots, so no specific advice there, sorry.
T

[littleminnie]

I do know the differences of the manures, that was why I mentioned the types and didn't just say manure. In 2008 I used rabbit manure on the last area I was planting, peppers, and didn't get fruit until very late. I am talking about too much nitrogen! Root crops especially dislike nitrogen. I use the richest stuff on brassicas, corn, vining crops only. The second richest goes on onions, leeks, peppers, tomatoes. The least rich goes on root crops. But this year I think I am going to have the cow-horse-goat mix and so some of that horse has to go on the root crops. The question is how much can it handle. My soil tests show a need for OM and nitrogen. I have sandy soil so I need the poop!

[littleminnie]

I got one load this evening of the goat/horse mix but it is stall cleanings not pure manure- lots of pee and shavings. I used to work with horses and that was what I would get to bring home. Not my favorite but they have tons of it. So now I have to decide what crop to put it on by tomorrow morning. I am thinking onions. Then the pile of old pure horse manure that had been meant for the onions will be for the potatoes. The cow manure piled on the other side of the field will be for corn, brassicas and squash. I still need some more loads to get everything done.

What do you find are the numbers when it is stall waste rather than straight manure?

[templeton]

Sorry, I didn't mean to imply ignorance. Just thought the numbers might help you make a decision about amounts/ratios.

Re stall waste, again I have limited experience. I would imagine available N will depend on how often the bedding material is refreshed, and whether it's straw or shavings or something else. When I have used it I haven't noticed any particular N 'kick'. Once I used stall waste made of buzzer chips = shavings, and it was actually N deficient, and stunted plant growth.

I have no experience with nor information on rabbit manure.

Is under-dressing your crops, with a subsequent top up if needed an option? Doubles the work, I know.
T

[ferdzy]

I would not personally put that stuff anywhere near root crops. I would definitely worry about it being too strong. In fact I'd want to pile it up somewhere until next year... when it should be excellent stuff.

Too bad snow isn't a soil builder...

[littleminnie]

Yeah it doesn't seem that old unfortunately. I can get tons of it and let it sit.

[rowan]

I have planted carrots into a fresh horse manure pile and they have turned out great. At the end of four months when they were ready to pull the manure had broken down fully. As I said earlier, I have never had any trouble with root crops in manure so I wonder if some of you are working on rumour and hearsay rather than testing it out for yourselves.
This is not meant to sound rude or imply critisism but just confusion about why so many people are afraid of the stuff. The only manure I am careful of is poultry, the rest is heaped on without care.

[paquebot]

Fresh rabbit manure has about 5 times more nitrogen than fresh horse manure. Neither should be used around root crops. Any manure, unless really aged, should never be used with potatoes unless only below the seed piece. Manure is invariably on the alkaline side and leads to common scab.

Martin