Considering the lack of technical information on the water depth and nitrogen fertilization via fertigation in protected cultivation for bell pepper production in northern Brazil, a new paper aimed to study the soil water tensions under different nitrogen doses for the cultivation of bell pepper in protected environment.
The experiment was conducted in a greenhouse at the Igarapé-Açu School Farm of the Federal Rural University of the Amazon, at 1.0 x 0.50 m spacing, using the experimental design of randomized blocks in a 5x4 factorial scheme, with three replicates. The treatments consisted of five soil water tensions (15, 25, 35, 45 and 65 kPa) and four nitrogen doses (0, 135, 265 and 395 kg ha-1).
There was interaction between soil water tension and nitrogen doses only for nitrogen use efficiency, and the best value was obtained with the combination between soil water tension of 15 kPa and nitrogen dose of 135 kg ha-1. Total number of fruits, fruit length and fruit diameter showed significant differences only as a function of soil water tensions. Production per plant, total yield and water use efficiency were statistically significant for soil water tensions and nitrogen doses.
Therefore, for the conditions in which this study was carried out, it is recommended to apply a soil water tension of 15 kPa and nitrogen dose of 265 kg ha-1 for bell pepper cultivation in protected environment.