Growing in mushroom compost

[cleo]

I took delivery of a load today and rather than throwing away a few plants I`ve planted some melons,a water melon and a few peppers directly into it.

Folly or not???--and all under cover

[cleo]

[Baccy Man]

If the plants were extras destined for the compost heap then it cant hurt. Mushroom compost is very rich & has a high lime content, not sure about the peppers but the melons should be fine growing in it.

[Digeroo]

I have just got five bags of recycled compost.  What sort of % is best with these types of rich compost. 

Tomatoes and courgettes seem to like it neat.  And beans don't seem to mind either.

[Unwashed]

Does spent mushroom compost have much in the way of nutrients? 

[Baccy Man]

Average composition of spent mushroom substrate:

Contents                   Units             Avg. Fresh    Weathered 16 mos.
N-P-K ratio           PPM Dry Wt.       1.8 - 0.6 - 2.2        2.7 - 0.8 - 0.47
Sodium, Na             % Dry Wt.        0.21 - 0.33            0.06
Potassium, K          % Dry Wt.        1.93 - 2.58             0.43
Magnesium, Mg      % Dry Wt.        0.45 - 0.82             0.88
Calcium, Ca            % Dry Wt.        3.63 - 5.15             6.27
Aluminum, Al          % Dry Wt.         0.17 -0.28              0.58
Iron, Fe                 % Dry Wt.         0.18 - 0.34             0.58
Manganese, Mn     % Dry Wt.         3.76                      3.76
Boron, B                % Dry Wt.         0.12                      0.12
Copper, Cu            % Dry Wt.         0.46                      0.46
Zinc, Zn                 % Dry Wt.         2.73                      2.73
Sulphur, S             % Dry Wt.         1.59                      1.60
Phosphorus, P       % Dry Wt.         0.45 - 0.69            0.84
Ammonia-N,NH4    % Dry Wt.         0.06 -0.24             0.00
Organic Nitrogen   % Dry Wt.         1.25 - 2.15            2.72
Total Nitrogen       % Dry Wt.         1.42 - 2.05            2.72
Solids                    % Dry Wt.         33.07 - 40.26        53.47
Volatile Solids        % Dry Wt.         52.49 - 72.42        54.24
pH                        Standard Units   5.8 - 7.7                7.1
                                            % x 10,000 = PPM

[cornykev]

U did ask.     ;D ;D ;D

[Digeroo]

Wow is that good or bad?

[Baccy Man]

It basically means spent mushroom compost is a good soil improver that will provide a lot of the trace elements plants need but as the npk value is quite low it can't really be considered a fertiliser.

[Tee Gee]

These are the key figures;

NPK =  1.8 - 0.6 - 2.2        2.7 - 0.8 - 0.47

It appears to be high in potash when fresh then high in Nitrogen when rotted!

Didn't know that!

And I can't understand why................does any one know why?...........usually with rotting material 'nitrogen' is used up in the process but in this case it doesn't  ???

If this is the case ( and I have no reason to doubt it) application times could be critical.

For example; It is not the right product for fruit & flowers but could be OK for greens!

Any opinions??

[Baccy Man]

It appears to be high in potash when fresh then high in Nitrogen when rotted!

Didn't know that!

And I can't understand why................does any one know why?...........usually with rotting material 'nitrogen' is used up in the process but in this case it doesn't  ???

Fresh spent substrate still contains a lot of of mycelium. Chitin, a polysaccharide which makes up the mycelial cell walls contains nitrogen. As the mycelium breaks down the nitrogen in the chitin is released providing additional available nitrogen within the composted material.

I haven't yet worked out where the potash disappears, it can't all leach out.

[davyw1]

CLEO, You might like to have a look at this

http://www.rhs.org.uk/advicesearch/Profile.aspx?pid=294

[nilly71]

I've used mushroom compost on everything, and according to that link i shouldn't of ::)

The blueberries are doing well, so is everything else so i will have to wait and see.

There have been some great mushrooms produced, but i haven't tried any yet, has anyone else?

Neil