Changes of the Amount of Nitrogen, Phosphorus and Potassium in Grey Forest Soil as a Result of Increasing Norms of Nitrogen and Potassium Mineral Fertilizers

Z. Petkova, E. Zlatareva, N. Nikolov

Abstract: The field experiment with raspberry has been conducted to established changes in available nitrogen, phosphorus and potassium as a result of fertilization with increasing norm of mineral fertilizers. Results have shown significant change in ammonium and nitrate amount in soil with the increase of norm of fertilization. This tendency is observed also in the amounts of mobile phosphorus and potassium in soil in the experiment with increasing norm of phosphorus fertilization. In the experiment with nitrogen fertilization the situation is different. With the increase of nitrogen fertilizing norms the amount of mobile forms of phosphorus has decreased.
The availability of potassium has depended weaker from phosphorus as a result of the increase of fertilizing norms.

Keywords: available amount of nitrogen; mineral fertilization; phosphorus and potassium; raspberry

Date published: 2017-03-07