Responses of Bell Pepper to Nitrogen Sources1

Maintenance of adequate available soil N for bell pepper ( Capsicium annuum L.) growth is essential to high production in Florida and requires mulching, fertilizer placement, and timing of fertilizer application. Slow-release N was supplied as sulfur-coated urea, isobutylidene diurea (1BDU), or ureaformaldehyde and was compared at 3 N rates with soluble sources such as urea, ammonium nitrate, and ammonium sulfate on ‘Yolo Wonder’ pepper. In the first season, highest yields and N concentrations of tissue occurred where IBDU and urea were applied broadcast with mulch as compared with band placement. In the second season, broadcast fertilizer placement with mulch was compared with 3 split-fertilizer applications without mulch. Fruit yield was affected by a significant interaction among N sources, N rates, and mulch. Highest fruit yields were obtained with SCU and IBDU applied under mulch at 224 kg N/ha. Leaf N was higher during the season with slow-release N than with soluble N. Soil analyses data from samples taken throughout the season showed that N source and rate significantly influenced the soil available N measured as urea-N, NH 4 -N, and NO 3 -N.