Slow release and conventional N fertilizers for nutrition of bell pepper

Bell pepper (Capsicum annuum L.) high-quality and yield implies the management of N nutrition. Field and pot experiments with bell pepper and Italian ryegrass were carried out during 2009 and 2010. The experimental design included three N delaying fertilizers (Sulfammo Meta 46-5-0, controlled-release fertilizer; Nitrophoska Gold 15-9-15, slow-release fertilizer; Entec 26 26-0-0, stabilized fertilizer), two conventional N fertilizers, urea and calcium nitrate and one N-unfertilized control. The fertilizer's rate was 150 kg N/ha. A pot experiment with bell pepper followed by ryegrass with the same fertilizers treatments was carried out in 2009. Dry matter (DM) yield, plant N concentration, plant N recovery and fruit mineral concentration were measured. Calcium nitrate and urea produced statistically higher DM in both field and pots. Sulfammo Meta produced always lower yields. In the field plants recovered a minimum of 18% and a maximum of 82% of the N applied, respectively, in Sulfammo Meta and calcium nitrate. In the pot experiment, bell pepper + ryegrass recovered only 32.5% of N applied with Sulfammo Meta and nearly 100% of N applied in the other fertilized pots. None of the slow-release N materials provided clear advantages over conventional fertilizers to be used in this crop.