The purpose of fertilisation is to introduce organic and inorganic substances into the soil that maintain and improve the soil’s composition, chemical and physical properties and biological condition, and have a positive effect on soil fertility and crop yields. Fertilisers are substances that increase the fertility of the soil. Direct fertilisers (plant manures), which meet the nutrient needs of plants. Indirect fertilisers (manures), which mainly affect the physical and colloidal properties, structure and biology of the soil and their application (lime, gypsum, etc.) often falls under the heading of soil improvement.