Sulphur is an essential nutrient for plant and animal development. It is needed for a range of functions, and is a key part of some proteins, including those that make up wool and hair.
There is a range of ways in which organic farms can ensure their soil sulphur levels are high enough to support production. Altum supplies three BioGro-approved sulphur products, and these can be blended with other products to create farm-specific mixes that meet your exact nutrient requirements.
Although it is a natural form of sulphur, it’s important to realise that plants cannot take up elemental sulphur. Once applied to the soil, elemental sulphur is attacked by naturally occurring soil bacteria that break it down and release sulphate sulphur, which is the form that is used by plants.
Applying elemental sulphur to the farm thus provides a source of sulphur that is gradually released. As an added bonus, elemental sulphur is not subject to losses through leaching, so it is safe to apply in autumn as well as spring. (Sulphate sulphur can leach through soils, so autumn applications risk some degree of loss.)
Our BioGro-permitted potassium product is natural sulphate of potash (SOP). Although most SOP fertilisers are manufactured, there are naturally occurring forms of this substance. Natural SOP is usually made by allowing mineral-rich water to evaporate under the sun’s heat. Eventually the minerals crystalise and can be harvested. The natural SOP sold by Altum is not only a good source of potassium, but it also contains sulphur. SOP can be applied on its own or mixed in with other fertilisers.
Gypsum is a naturally occurring calcium sulphate mineral. Gypsum contains 18.3% sulphur.
Gypsum is most often used as a soil amendment, especially to improve soil structure, which it does by flocculating clay particles. Better soil structure can leader to improved water infiltration, and so reduce losses from run-off.
Gypsum also adds calcium and sulphur to the soil. The sulphur in gypsum is in the sulphate form, which means it is immediately available for plant uptake. This is advantageous in situations where sulphur deficiencies are hindering plant growth, and a rapid response is required.