Fertilisers should meet the requirements concerning, among other things, their composition and the permissible level of impurities. Placing fertilisers on the market and trading in them is regulated by relevant regulations, i.e. the Act on Fertilisation.
Fulfilment by a manufacturer or distributor of the requirements contained therein for obtaining an MRiRW (Ministry of Agriculture and Rural Development ) permit guarantees that a purchaser of a fertiliser will receive reliable information on its composition and rules of application and storage. A reliable seller will only supply the purchaser with a product that meets these conditions. Information on authorised fertilisers can be found on the MRiRW website.
Zoonotic organic fertilisers may be sold for direct agricultural use only on the basis of a contract concluded in writing. The contract shall be kept by the parties for at least 8 years from the date of its conclusion. This contract may be the basis for claiming compensation in the event of a product not meeting the declared requirements.
The possession of fertiliser purchase documents can be controlled by PIORiN (Plant Health and Seed Inspection Service) inspectors in the case of integrated production, or ARMiR (Agency for Restructuring and Modernization of Agriculture ) and WIOŚ (Provincial Environmental Protection Inspectorate ) with regard to those applying fertiliser in OSN (particularly vulnerable) areas.
Fertiliser purchase documents attest to the source of the fertiliser and are also proof of the type of fertiliser used on the farm. The purchase document may be the basis for claiming compensation in the event of a product not meeting the declared requirements.
Mineral and organic fertilisers contain impurities in addition to nutrients. Standard contents of the main ingredients in the most commonly used single and multi-nutrient mineral fertilisers are available in the literature. The full composition should be included in the fertiliser application and storage instructions, which should be attached to the fertiliser package or provided by the dealer for fertilisers sold in bulk. The nutrient content (N, P, K, Ca, Mg, Na, S) can be given in pure component form or in oxide form. The standard composition of organic fertilisers is available in the literature and these are values that take into account the average conditions for the formation of such fertilisers. Another method of estimating the composition of organic fertilisers, as well as the amount of their production on the farm, is to use a model developed by IUNG, which is available online in the form of a web-based calculator or in computerised fertiliser advisory programmes. However, each batch of organic fertiliser can vary in composition depending on the conditions of manufacture and storage. A professional, verified and certified supplier should provide chemical analysis results on the composition of organic fertilisers. Such a test can also be commissioned by yourself at a chemical-agricultural station. This will enable you to accurately determine the composition and apply the correct dose of fertiliser and avoid the introduction of unwanted biological and mineral contaminants into the soil.
In the case of a previously unknown or accidental supplier, we cannot be sure of the actual nutrient content. It is particularly important to eliminate the risk of introducing organic contaminants that pose an epidemiological risk and chemical contaminants such as heavy metals into the soil. Getting rid of such contaminants in the soil is a lengthy and costly, if feasible, process. Mineral fertilisers should therefore only be purchased from trusted suppliers.