Anyone know what this is?

[katynewbie]

It's underneath a pathetic row of peas. There is a white kind of scummy/dusty thing there. I water with water from the communal tap, but it is nowhere else on the plot, nit even another row of healthier looking peas.

[katynewbie]

[katynewbie]

Got a pic now...

[Jayb]

Mold or salts from fertiliser?

[brown thumb]

I have that in  places on my allotment, i thought it was from the mushroom compost that was put on previous to taking over the plot