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
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.
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.
Does spent mushroom compost have much in the way of nutrients?
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
U did ask. ;D ;D ;D
Wow is that good or bad?
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.
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??
Quote from: Tee Gee on June 12, 2009, 21:09:55It 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.
CLEO, You might like to have a look at this
http://www.rhs.org.uk/advicesearch/Profile.aspx?pid=294
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