[neil1967]

Maybe a silly question but everyone says don't put root veg in a plot that's been manured.

So is it o.k to put them where I have dug in the contents of my compost bin? or will it have the same effect?

All help appreciated.

[mumofstig]

I don't think that compost  hurts anything

[Stoatus]

Good question! I have often wondered about this myself, but came to the conclusion that compost is OK after reading here about people planting carrots in containers using a compost/sand mixture.

No idea why though. I guess the nutrients are more concentrated in manure.. is that it? Or possibly the balance of nutrients is different?

[mumofstig]

it's the highly acid nature of manure (unless it's very old) i think that causes the problem.
Home made compost is more of a soil conditioner than a feed, so doesn't cause any damage. It's full of goodies.....but nothing harmful...if you get my drift

[GreenOwl]

I thought it was down to the fineness of the particles in the manure/compost.  As in manure has large lumps in it.  Compost is fine if its well-rotted down and sieved.

Large lumps cause the carrots to fork.

Well thats what I understood anyway.

[penance]

Its the nitrogen levels in manure that causes forking.

[Stoatus]

That's what I thought too. But nitrogen levels are not much lower in compost than cow manure according to John H http://www.allotment-garden.org/fertilizer/index.php . Perhaps the nutrients are released more slowly from compost than from manure?

[Stoatus]

Right. Just spent a bit of quality time with Google and I think I have an answer.

High nitrogen content causes chemical burning to the roots of seedlings and this causes carrots and parsnips to fork.

In terms of N content, all manures are not the same. Cow manure is low in nitrogen whereas chicken manure is very high in nitrogen. Manure needs to be composted first to reduce pathogens. This will also lower the nitrogen content, so manures that have been composted will be less likely to burn the roots.

Homemade compost will vary depending on it's contents. If it contains a lot of coffee grounds for example the N content will be high. Shop-bought multi-purpose compost is usually fairly low in nitrogen and therefore safe for carrots. Other commercial composts may have N added though.

... so I guess you are safe with MP compost, possibly Ok with rotted cow manure, not necessarily OK with home-made compost or specialised commercial composts, and definitly not with fresh manure or rotted chicken manure.

Phew!

[diggerjoe]

thanks Stoatus - was going to put chicken manure on my raised bed for carrots this year think I will leave it out  :happy:

[WebSiteEvo]

Fully composted manure is fine in my limited experience. I grow carrots in a heavy manure bed last year, with no forking or burn issues at all, ended up with a very nice crop indeed.