Table 2.

Concentration of nutrients in full strength (100%) nutrient media used in the present study. Columns 2–4 are for maize, lettuce and wheat treated for 4–5 days with silicon. All plant species cultivated for three weeks with Si were grown in Hoagland nutrient medium (Column 5). For comparison, literature data on concentration in soil solution of the various nutrient elements are indicated.

Nutrient	Maize	Lettuce [53]	Wheat	Hoagland Medium [54]	Soil Solution [55]
	μM	μM	μM	μM	μM
NO3	7500	16,000	16000	14,000	750
NH4	0.16	1000	1000	1000	100
K	2700	11,500	11,500	6000	250
Ca	2500	3000	3000	4000	250
Mg	1000	2000	2000	2000	100
P	200	2000	2000	1000	0.04–25
S	1000	2000	2000	2000	100
Fe	122	25	50	25	2
B	23	10	20	46	3
Mn	4.6	16	16	9	1
Zn	0.38	0.35	0.35	0.8	0.5
Cu	0.16	0.16	0.16	0.3	0.1
Mo	0.25	0.21	0.21	0.1	0.02
Cl	9.2	107	182	18	100