P and K Accumulation by Rapeseed as Affected by Biostimulant under Different NPK and S Fertilization Doses

Abstract

Biostimulants are gaining growing importance among preparations used for plant production. They may cause increasing the effectiveness of nutrient uptake. The aim of the study was to assess P and K accumulation by winter rapeseed after the application of a biostimulant under conditions of varied NPK and S fertilization levels. The field experiment was established on Alfisol, and the factors were: Two levels of NPK fertilization (high 180 N, 70 P, 132 K (kg ha−1) or low 144 N, 35 P, 66 K (kg ha−1)); elementary S fertilization (36 or 0 kg ha−1) and application of seaweed biostimulant or without that treatment. Biostimulant caused an increase in P and K accumulation in the shoots of rapeseed during generative development. Application of biostimulant in rapeseed fertilized with lower NPK rates or not fertilized with S increased P and K accumulation in shoots to the level obtained at higher NPK and S rates without that treatment. Increased level of NPK fertilization caused an increase in P and K accumulation in both shoots and roots at flowering and ripening stages. At the fruit development stage, under higher NPK fertilization there was higher uptake of P and K in rapeseed shoots after presowing fertilization with S.