History of Hydroponics

	Revision 4 . . November 16, 2001 2:35 am by Dmerrill [explained more clearly why soil isn't necessary -- a plant can only use nutrients dissolved in its water supply, so by supplying the nutrients artificially the need for soil is obviated]
	Revision 3 . . (edit) November 16, 2001 1:13 am by Malcolm Farmer
	Revision 2 . . (edit) November 14, 2001 12:22 am by Malcolm Farmer [typos]

---

Difference (from prior major revision) (no other diffs)

Changed: 3c3,5

It was realised by researchers into plant metabolism that plants took in their nutrients as simple inorganic ions, and that soil, while a source for such nutrients, was not essential. The first example such researcher was a John Woodward of England, who, in 1699, grew plants in water to which he had added various soils, demonstrating that earth contained various substances which the plants needed besides water.

It was realised by researchers into plant metabolism that plants took in their nutrients as simple inorganic ions, and that soil, while a source for such nutrients, was not essential. While a plant's nutrients come from the soil, the only nutrients a plant can successfully absorb are those that dissolve into the plant's water supply. By introducing the required nutrients into a plant's water supply artificially, soil is no longer required for the plant to thrive. The first example such researcher was a John Woodward of England, who, in 1699, grew plants in water to which he had added various soils, demonstrating that earth contained various substances which the plants needed besides water.