A bloke on our site told me that I should be using lime all over the plot, except on potatoes. I thought it was only for brassicas, which I don't grow. Is it really necessary to do it?
Another thing, how would it be possible to test the ph of my soil when it is so different all over the plot? Some parts have had horse manure, other parts lots of grass cuttings, compost, cow manure, rotted leaves, straw,
or am I just being thick (don't answer that!)
Test it in lots of places and average them out. I don't lime at all; my soil is slightly acid, and everything seems to grow fine.
Lime helps to sweeten the soil and release minerals, I usually lime where my brassicas are to be planted, and since I use a 6 year cycle that mean that the whole plot gets lime. As for testing the soil I do that after the winter so that I can adjust my dressings to make up for any minerals that have leached out during the winter months. I take samlpes from each section of the 6 years cycle plots
I don't test mine...I do use lime a little around brassicas..but generally I find it is not necessary for my soil..I use a lot of wood ash, which have similar effect. But as I still have to use lots of commercial compost there is plenty of lime in that for what my crops/soil needs.
If you crops are growing fine and you get satisfactory results..well..that is good indicator everything is ok.
Now if you were to grow show veg...that is different "ball game"..
Lime also reduces claggyness in heavy soils.
I've heard wood-ash can make claggyness worse, though if you've got brilliant soil it probably won't matter.
Bob (hallowed be his name) Flowerdew wrote an article a while back about this subject and opined that most plots would benefit from more regular liming, as it would have the aforementioned 'unlocking' effect of minerals and nutrients that added manures alone cannot provide.
This year I have been liming more liberally and will see if it makes a difference on my heavy clay soil which has had a lot of manure and mushroom compost added to it over the past three years.