Sulphur (S) is one of the secondary macro nutrients that has often been forgotten or neglected in planning a fertilizer program. The general “rule of thumb” was that crops required the same amount of S as they do phosphorus. Prior to the advent of high grade phosphates which form the back bone of todays NPK bulk blends the S requirement of crop was supplied through NPK compound containing AMS, single super phosphate, enriched super phosphate and ammoniated super phosphates such as AMP(16), and atmospheric S from industrial SO2 emissions. Alternative sources of S are found in Potassium Sulphate, ASN and Ammonium Sulphate. The cheapest source of S is from gypsum. Disclaimer: The figures published are not a guarantee of analysis, they are sourced from published Product Data Sheets and provided to serve as an indicator of typical analysis which may vary due to production processes, impurities and changes in minerology of natural sources. Please note: Consult a qualified person (Act 36 of 1947) for specific applications / recommendations.