Arugula production and nitrate accumulation as function of nitrogen fertilization

Abstract

The arugula has been standing out among vegetables due to its nutritional composition, spicy flavor and pleasant scent. However, there are few studies on mineral nutrition and product quality, especially for ‘Savage’ species. Aiming to supply this deficiency, an experiment was carried out under greenhouse conditions, to evaluate the effect of nitrogen fertilization on the production and accumulation of nitrate in the leaves of ‘Savage’ arugula. The
experimental design was made in randomized blocks, in a 2 x 5 factorial scheme with four replications. The treatments resulted from the combination of two nitrogen sources (urea and ammonium nitrate) and five doses (0, 40, 80, 120 and 160 mg dm^-3 N). The crop was harvested 39 days after transplanting. The ‘Savage’ arugula, when grown in a protected environment, responds to doses of 135 and 160 mg dm^-3 of N, as ammonium nitrate and urea, respectively. The content and accumulation of N-organic + N-NH₄ + (NOA) and nitrate (NO₃^-) in the arugula leaves increased linearly with the nitrogen doses. However, it is noteworthy that the NO₃^- levels were below the maximum permissible level for the cultivation of vegetables under greenhouse conditions.