[omits]

On this page https://www.allotment-garden.org/vegetable/brassica-information/fertiliser-requirements-cabbages-leafy-brassicas/ under this para:
We値l start with an assumption that the existing soil is in good heart, fairly fertile and has a high pH (low acidity). Over the growing season your cabbages are likely to need an additional 23g/M2 of Nitrogen and 5g/M2 of Phosphorus and Potash respectively.
What is this 'M2' mean? It does not define it on the page.
I'm also confused by the definition e.g. 5/5/5 etc. There seems to be so many of them!
Advice appreciated.

[mumofstig]

M2 = metre squared.
5/5/5 is explained "Fish, blood & bone is usually 5:5:5 which means 5% of each major nutrient, Growmore 7:7:7 which is 7%

[omits]

M2 = metre squared.

Thanks! Obvious! What threw me was the capital M which should be small m.

[Yorkie]

Just to add to the above, the ratio that you've seen is N:P:K or in long hand, nitrogen (good for leafy crops): phosphorus (good for roots): potassium (for flowers and fruit).

If the ratios are different, you can tell which is the highest proportion of fertiliser, and therefore when to use it. So, for example, sulphate of potash (potassium) would be 0:0:x. Tomato fertilisers will always have the highest number in the K position.