Topic: Comfrey V Manure Test

[Uncle Joshua]

A while ago I posted saying that I was doing a test with comfrey V manure under potatoes, well here are my results....

I planted half a row of Maris Piper in comfrey and the other half in manure both on the same day, see if you can tell which is which....

Plant A



Plant B
















Plant A is one plant from the half that was in manure and had a total weight of 2lb 10oz.

Plant B is one plant from the half that was in comfrey and had a total weight of  15oz.

So as you can see from my test manure is by far the better of the two.

[telboy]

It seems that your manure wasn't tainted by Aminopyralid then?
 :D

[tonybloke]

was it the same weight of each product? was any moisture retaining material added with the comfrey? was it a fair test? ;)

[Uncle Joshua]

was it the same weight of each product? was any moisture retaining material added with the comfrey? was it a fair test? ;)

Yes, Yes, Yes.

All the potatoes in the row were arond the same size and  straw was added to the comfrey to retain moisture, maybe the comfrey could have done with being a little more mature but I'll never find out now because the local council came to kill some knotweed behind my plot and sprayed my comfrey too which is silly when the comfrey  seemed to be holding back the knotweed anyway.

[tonybloke]

If you added straw at the same time as the comfrey that will explain the difference. for a plant to use organic matter it needs to be of a carbon/nitrogen ratio of about 7/1, straw is approx 70/1! the nitrogen in the comfrey will have been robbed by the decomposition of the straw. (spent gro-bag or similar is a good moisture retainer)
rgds, tony ;)

[amphibian]

If you added straw at the same time as the comfrey that will explain the difference. for a plant to use organic matter it needs to be of a carbon/nitrogen ratio of about 7/1, straw is approx 70/1! the nitrogen in the comfrey will have been robbed by the decomposition of the straw. (spent gro-bag or similar is a good moisture retainer)
rgds, tony ;)

A point I was going to make.

While I admire the experimenting mind, it appears to be a test with too many variables.

I'd be keen to see the results if the test were repeated with all but the crucial variable eliminated.

Also am I correct in reading that your results are based on a single plant from each row. Really you need to base it on the whole row, to eliminate a huge range of variables coming into play.