Fertilisers should be used in a way that does not pose risks to human and animal health and the environment, while allowing for optimal use. General information and restrictions on how fertilisers should be used are contained in the Fertiliser Act (Journal of Laws 2018, item 1259).
Details of the method of application should be contained in the instructions for use and storage of the fertiliser and, for fertilisers sold in bulk, the documents with which they are supplied by the supplier. This should include information on the form or solubility of the nutrients and on the composition, i.e. the declared macro- and micro-nutrient content, to enable the required dose of fertiliser to be determined. In addition, the instructions should state the methods of application, the post-application steps required, such as mixing in with the soil, the permissible splitting of doses, and, in the case of specially formulated fertiliser mixtures, the plant species for which they are recommended. In the case of lime fertilisers, doses may be given according to the acidity of the soil and the agronomic category of the soil. Soil application of fertilisers, especially in granular form, is advantageous due to the location of the granules directly in the soil, out of the reach of surface run-off and rain. In sustainable agriculture, it is necessary to apply fertilisers with optimal quality and quantity (see Lesson 26) and in a manner optimally adapted to the needs of the plants (see Lesson 28). In the increasingly frequent dry spells, topdressing is preferable to surface fertilisation, as there are not the same dynamic fluctuations in soil moisture as there are at the surface, and therefore the availability of fertiliser to the plants is more predictable.