ISO/TC 134/WG 4 - Mineral soil amendments

This document establishes an overview of the relevant methods for the determination of calcium and magnesium as defined in ISO 8157. This document is applicable to any mineral soil amendment, neutral, basic or acid containing calcium and/or magnesium.

This document is applicable to the sampling of mineral fertilizers and liming materials supplied or ready for supply to third parties, as a lot or in smaller lots, where such supply or readiness for supply is subject to legal requirements. This document specifies plans and methods of sampling of a lot of solid fertilizer or liming material, if sampling in motion is not possible, to obtain samples from bulk static heaps in order to ascertain compliance with legal requirements, in particular in relation to the accuracy of compulsory or permitted statutory declarations. The methods specified in this document are not applicable to obtain samples for physical size analysis or for chemical analysis which may be altered by particle granulometric segregation. This document is applicable to single nutrient fertilizers, to uniform complex fertilizers and to milled or granulated fertilizers and liming materials. The methods described in this document are not suitable for sampling other types of fertilizer, for example blended fertilizers. NOTE The term 'fertilizer' is used throughout the body of this document and includes liming materials unless otherwise indicated.

This document specifies two methods for the determination of the neutralizing value (NV) of liming materials. Method A is applicable to all liming materials except silicate liming materials. NOTE 1 Examples of hard liming materials are limestone and dolomite. Examples of soft liming materials are chalk, marl and burnt lime. Method B is applicable to all liming materials. Neither method correctly takes into account the potential neutralizing value of material containing more than 3 % P2O5. For a more accurate agronomic assessment of products containing more than 3 % P2O5, EN 14984[8] is used to determine the liming efficiency. NOTE 2 The methods described in ISO 6598 and ISO 7497 can be used for the determination of P2O5 content. Further information on P analyses is given in References [5] and [6]. NOTE 3 Carbonate consumes H+ and removes acidity in solution with subsequent dissociation to H2O and CO2. Forms of orthophosphate can consume H+ but are not dissociated to molecular forms that remove acidity. The acidity is back titrated with alkali causing an underestimation of NV.

This document specifies two methods for the determination of the particle size distribution of liming materials. Method A (the dry sieving method) is applicable to all liming materials except wet and paste-like products. Method A is not applicable if blinding, caking, electrostatic charges or agglomeration occur after drying. Method B (the wet sieving method) is applicable to products which are susceptible to blinding, caking, electrostatic charges or agglomeration after drying. Method B can be used to determine the primary particle size distribution of granulated products. Method B is not applicable to burnt lime and liming materials containing water-soluble constituents.

This document specifies a method for determining the reactivity of calcium carbonate and calcium magnesium carbonate liming materials. It assesses the speed and effectiveness of their neutralising potential by automatic titration with citric acid. This method is applicable only to liming materials with a maximum particle size of 6,3 mm determined in accordance with ISO 20977. NOTE For marble dolomite (BET procedure as defined in ISO 9277 below 500 m2/kg), see EN 14984.