Ferrous Sulphate 30% (Iron)

Ferrous Sulphate 30% (Iron)

Ferrous Sulphate (iron sulphate) is a soluble iron salt, 30% iron and 17% sulphur, used in small amounts to correct iron deficiency from a soil test. It suits advanced growers and certified organic growers working to a soil prescription.

At a glance

• Type: trace element salt (soluble powder)
• Supplier certificate on file: BioGro licence 297. See the certificate and its dates.
• Analysis: iron 30%, sulphur 17% (ferrous sulphate monohydrate)
• Use for: correcting iron deficiency (yellow new leaves with green veins) shown by a soil or leaf test
• Rate: apply from a soil test; dissolve in water and spray for even distribution

What it is

Ferrous sulphate monohydrate is a water soluble iron salt that also supplies sulphur as sulphate. It dissolves in water for spraying or irrigation.

What it does

• Iron is needed to make chlorophyll and for photosynthesis and respiration.
• Deficiency shows as yellow new leaves with green veins. It is usually a pH problem: iron is there but locked up in alkaline or over limed soil, not absent.
• Because soil applied ferrous sulphate is quickly converted to insoluble forms in high pH soil, a foliar spray is the more reliable way to green up iron short leaves.
• The sulphate half supplies sulphur, and ferrous sulphate is acidic in solution, so it nudges pH down where it lands.

Analysis

• Iron (Fe) 30%
• Sulphur (S) 17%
• Form: ferrous sulphate monohydrate

How to use

• Dissolve in water and spray for even distribution.
• Foliar: 50 to 100 g per 100 L of water (0.05 to 0.1%). Iron does not move within the plant, so three or four sprays a few weeks apart may be needed.
• Soil: apply the rate your soil test or prescription calls for, watered in evenly.
• Iron is needed in small amounts: apply from a soil or leaf test and do not exceed the rate.

Learn more in fifteen seconds

• Iron: what it does
• Soil pH, water pH: how to move it
• What's blocking your minerals

Handling and storage

• Wear a mask to avoid inhaling particles and open in a well ventilated area.
• Wear gloves and eye protection, and wash hands after use.
• Once opened, keep sealed and dry.