Effectiveness of Mineral Fertilization on Sunflower, Cultivated on Pellic Vertisol in Southeastern Bulgaria in Favorable and Risky Meteorological Conditions

V. Koteva

Abstract: This investigation was aimed at determining the effectiveness of mineral fertilization on sunflower crops, cultivated without irrigation in years with favorable and risky meteorological conditions with variable nutritional regimes of the soil.
A 50-year long-term stationary fertilizer trial in Pellic Vertisol (FAO) was analyzed.
When analyzing the data, it was determined that there is an interdependency between the sunflower seed yield and the meteorological parameters under vegetation of the sunflower; rainfall and the air temperature in favorable and years of drought; agronomical effect of fertilizing, expressed in the sunflower seed yield in favorable and drought years; the effect of the mineral fertilizing on the contents of oil in seeds.

Keywords: effectiveness of fertilizing; meteorological risks; mineral fertilizing; sunflower

Date published: 2017-02-13