THE EFFECT OF NITROGEN FERTILIZATION ON RADISH YIELDING

In two field experiments carried out in 2006–2008, with two radish cultivars Treto F1 and Wernar F1 the effect of differentiated nitrogen fertilization on yield and biological value of radish grown for autumn harvest was examined. Mineral N content in the soil before seeds sowing was raised up to the level of: 50, 100 and 150 mg N·dm-3 by using: ammonium nitrate 34% N – [NH4NO3], calcium nitrate 15.5% N – [Ca(NO3)2·H2O], ammonium sulphate 20.0% N – [(NH4)2SO4], and ENTEC 26% N – [NH4NO3+(NH4)2SO4 + 0.8% DNPP]. The highest marketable yield of radish Treto F1 cv. was achieved in the case of ammonium nitrate use. In the case of Wernar F1 cv. kind of fertilizer didn’t affect the yield. Irrespective of the kind of fertilizer, increment of nitrogen content in the soil from 50 to 100 mg N·dm-3 caused the significant enhancement of radish yield. The similar yielding was recorded at nitrogen concentration equal to 150 mg N·dm-3 and 100 mg N·dm-3. Increasing mineral nitrogen concentration in the soil resulted in increment of nitrates content in radish roots, however their amounts not exceed permissible level. Plants fertilized with ammonium sulphate and ENTEC 26 contained lower amount of nitrates in edible parts in comparison to those supplied with ammonium nitrate and calcium nitrate.