Where do the minerals come from

[rary]

I grow in raised beds with either a thick matting or a concrete base this is to keep tree roots out of the veg beds, so the roots of any plants that I am growing can only access any nutrient or minerals that I add when adding compost, so if it was solely garden compost I added this would deplete any nutrient and minerals in the soil, I do add seaweed to my veg beds and also any shredded tree branches that I remove from the surrounding trees, but could anyone tell me if this would be enough to maintain a good mineral content, and how could I keep the content up when I am no longer able to collect seaweed or shred trees

[Runtpuppy]

As far as I'm aware, minerals mostly come from the soil. Rocks are made up of minerals, and they break down into smaller and smaller pieces to become the mud/soil. In artificial environments, like containers, you would need to add them in form of fertilisers and feeds. I guess compost would contain some amount of minerals but I don't know how much and if simply refreshing the compost would be effective long-term in replenishing them.

[Penellype]

You can add minerals in the form of rock dust, eg https://www.unwins.co.uk/remin-volca...E&gclsrc=aw.ds.

[Potstubsdustbins]

^^^^^^I use it in my containers and have seen an improvment

[rary]

Thanks for the above replies, Potty I would think that what I have will be similar to your containers just in a larger scale, and I know you have always advocated reusing the compost, so if you have noted an improvement with using rock dust, that's a good recommendation. It's a hobby-horse of mine, about the lack of minerals in our veg nowadays

[Potstubsdustbins]

^^^^^^^Rary the pic shows my Kelvedon Wonder 2017.

I have no idea how long the compost has been in the containers but I sweetened it with a general base fertiliser Grow-more I think, pea and bean pelleted fertiliser and for the first time rock dust. The improvement was noticeable in the growth after all these plants are only supposed to go to 18" high and the crop was very good, we had the last portion of frozen peas a month ago.

[mothhawk]

Where do the minerals come from? Mine blow in from the quartz-diorite granite quarry up the road

[Jay-ell]

The non organic parts of soil - the sand, silt and clays, are all products of weathering and erosion of rocks and contain variable amounts of minerals depending on what the original rocks were.

The actions of acidic rain, frosts, bacteria and root excretions break these down and transform the non soluble minerals into soluble plant available form.

Any compost you add also contains minerals which were held in the plants. As the organic materials will be made up mainly of carbon and hydrogen if you put a sample into a test tube and heated it the water would be driven off, the carbon reacted to make carbon dioxide and the hydrogen reacted to make H2O.

The Ash that's left in the test tube will be minerals. Comparing the weight of the initial sample to the weight to the weight of the residue should give an indication of how much of the compost is minerals.

You can do the same thing with any plant material - such as the ash left over after a wood fire.