Effectiveness of NPK Fertilizers in Relation to Soil Properties

The effectiveness of NPK fertilization was investigated on two typical Hungarian sandy soils, one a calcareous blownsand and the other humous sandy soil with chernozem character, in afield experiment using maize and rye as test plants. The soil properties namely, CaCO₃, humus content and depth of the humous layer essentially influenced the nature of the N-effect curves, the influence of the PK treatments and the efficiency of the higher fertilizer dosages (N₁₅₀P_67–100K_67–150). Higher levels of fertilization than N_50–100 and PK _30–40 did not result in a further crop yield increase on calcareous blownsand, but on humous sandy soil large NPK dosages could be applied with success. The fertility of the sandy soils is influenced in a large way by the interactions of fertilizers and soil properties and also by the degree of efficiency of the fertilizers.