Sodium (Na)
Function: to allow plants of the Chenopodiaceae family (beet, spinach etc.) to develop
properly.
Indicator plants: beetroot, spinach, carrot and mangels.
Symptoms: plants seem to be in poor health (D & E).
Remarks: sodium is rarely a problem, and is not easily diagnosed.
Correcting Trace Element Deficiencies
Trace element deficiencies can often be corrected by either soil or, more commonly and
efficiently, foliar (spray) applications.
Great care must be taken with soil remedies as the quantities involved are very tiny
and overdosage is usually toxic, so the application of an element on a field scale is in
general only possible when the element is incorporated with a fertiliser mixture.
Magnesium
Soil: in acid soils, apply dolomitic limestone (MgCO 3 ), or Kieserite (MgSO 4 ), or special
compound fertilisers, or Magnesian limestone.
2
Sulphur
Soil: Sulphur granules, ammonium sulphate, sulphate of potash or superphosphate
fertiliser.
Foliar: sulphur dust/wettable powder is used to control some mildews.
Zinc
Soil: 10–50 kg/ha of Zinc sulphate or Zinc oxide. Solid forms can be used in acid soils.
Foliar: 0.4% solution of Zinc sulphate (or oxide, carbonate etc.) + 3% lime, at 0.5–1.5
kg/1000 litres per hectare, or zinc chelate—also applied as a dust.
Manganese
Soil: 20–120 kg/ha solid form of Manganese sulphate, or spray 11.5 kg/ha dissolved in
450 litres water. For cereals, add 28 kg/ha when planting.
4 in 3l water per 26 m
(^2) , or 1 kg/1000 litres/ha).
Molybdenum
Soil: in acid soils, apply lime. In alkaline or neutral soils apply 100 500 g/ha of sodium
or ammonium molybdate, or apply 56 kg/ha of molybdated gypsum (for legumes, the
seed must be inoculated).
Foliar: 0.1–0.2% solution of Ammonium molybdate at 60 litres/ha.
Boron
Soil: 5–20 kg/ha of the solid form of borax or boric acid, or apply a special compound
fertiliser or bonemeal.
Foliar: 0.2% borax (28g of borax or boric acid dissolved in 9 litres of water per 17 m^2 ).
Iron
Soil: on alkaline soils apply organic matter or acidifying agents to increase soil acidity,
or chelates of Iron such as sequestrene, or ferrous sulphate at 10 kg/ha.
Foliar: 0.4–1.0% solution of Ferrous sulphate + 0.2% of lime, applied 2–3 times.
Copper
Soil: 10–50 kg/ha of Copper sulphate or copper chelates.
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28 TONY WINCH
Foliar: 28 g of Epsom Salts (Magnesium sulphate) dissolved in 4.5 l water per 0.8 m.
Foliar: 0.4% solution (28 g MgSO