[plopleuk]

i was told to get manure on the brassica bed but not to do the same time as liming.
i limes the planting holes last year and had great success.
am i safe to manure the bed now and lime when planting out later in the year?
the manure has had 12 months to rot down.

[gobs]

Yes, leave a few months between.

Some do not bother with that even.

[Salmo]

If they are put on together the urea in the manure may react with the lime and ammonia, which it nitrogen (NH₃, is released into the air and is therefore lost as fertilizer.

I can see that could be a problem if both were spread on the surface but I wonder just how important it is if either the lime is worked in or the manure is buried before the other is applied.

Perhaps others have an informed opinion on this?

[JayG]

My understanding of it is that if the reaction Salmo refers to takes place in the soil rather than at the surface, the ammonia released will dissolve in the soil water and be converted back to nitrates, and hence not be lost to the atmosphere.

In that case digging either (or both) of them into the soil at the same time should do the trick.

It would also seem logical that if you chose to dig neither of them into the soil, sprinkling lime on to manure would probably cause a greater loss of ammonia than chucking the manure onto the lime, but that is quite frankly a guess.