In our previous work, we summed up the general basic principles and methods of fertilisation consultancy. We described the soil types that are essential from the aspect of practical crop production on the basis of their characteristics which determine their fertility. We published the physical and chemical characteristics needed to decide about the fertiliser need, as well as their limit concentrations and limit values. We described the correlations between fertilisation and environmental protection concerning unprofessional fertilisation (Kádár 2011).

In this study, we are going to present the detailed consultancy for each main crop and crop group, mostly on the basis of the 50-year-long field experiments conducted in the Research Institute for Soil Science and Agricultural Chemistry of the Hungarian Academy of Sciences. We survey the fertiliser need of cereals, maize, winter coleseed, sunflower, potato and planted grass without legumes by showing the modes of action through specific examples of the long-term experiments. It is important for the reader to realise the correlations between soil salinity (pH, CaCO3) or phosphorus and potassi­um supply (AL-P2O5 mg kg-1) and fertiliser effects. It also has to be acknowledged that soil could be exhausted and that fertiliser effect depends on the time when the fertilisation is done and they are connected to each other. Therefore, we do not present any peak yield, as it is not the absolute yield level which is important, but the morals of production, as well as principles which are lasting and directed.

The scientific consultancy based on the morals of long-term experiments are substituted by the recommendations of companies. All these led to irrational and unreasonable fertilisation which could result in a dramatic yield decrease, environmental pollution and profit loss. This phenomenon will also be shown through an example. This publication is a guide for those involved in consultancy.

Keywords: fertilizer recommendation, principle, methods, crops