ABSTRACT Splitting nitrogen (N) fertilizer application can be an efficient nutrient management technique to improve productivity and plant quality, as well as to reduce the negative environmental impact caused by N losses. In this context, the present study investigated how the management of N affects the agronomic characteristics of field-grown arugula plants. Nine treatments were assessed in a randomized complete block design, in a 4 x 2 + 1 factorial scheme, with three replicates. The evaluated factors were doses of N (60, 120, 180 and 240 kg N ha-1), split N fertilizer applications at side-dress (two and three times) and an additional treatment without a N supply. Maximum height was obtained with the application of 198 kg N ha-1. Nitrate content, fresh mass and productivity increased with increasing N doses. There was no effect of split N fertilizer applications on the characteristics evaluated. Therefore, the supply of 240 kg N ha-1 divided into two portions was considered as the best management strategy.

ABSTRACT Nitrogen is the second nutrient most demanded by arugula. However, the positive effect it has on yield can negatively impact the quality of this vegetable, with negative effects on human health. Two experiments (summer and autumn) were carried out to evaluate the effect of N rates (0, 50, 100, 150, 200 and 250 kg ha−1) on the arugula growth, yield and quality (nitrate content). Each experiment was set up in a randomized block design with four replications. Increasing rates of N reflected positively on leaf N content and thus, higher and desirable values of height, leaf number, leaf area and plant dry mass were obtained in both growing seasons. Consequently, the yield had significant increase, which N was maximized in summer (4.9 kg m−2) and autumn (2.6 kg m−2) and leaf N of 29.4 and 27.0 g kg−1, respectively, at rates of 250 and 213 kg ha−1 and both growing seasons. The higher rate the higher foliar nitrate content of arugula, in summer (2931.3 mg kg−1) and autumn (4218.4 mg kg−1). The foliar nitrate content in both crop season do not reach the risk level to human being heath.

ABSTRACT Vegetable intercropping systems use complementarity between species to increase agricultural profitability. This study evaluated the effects of intercropping chicory and arugula species with collard greens on crop yield and land use efficiency (LUE). Six treatments, consisting of species planted as monocultures or intercropped in various combinations, were evaluated in a randomized block design with four replicates. The cultivars ‘Top Bunch’ (collard greens), ‘Pão de Açúcar’ (chicory) and ‘Folha Larga’ (arugula) were used. The yield of collard greens in monoculture did not differ from those obtained when they were intercropped with chicory, arugula, or both species, whereas chicory and arugula yields were higher in monoculture. However, even with yield losses for chicory and arugula in intercropping, LUE indices were greater than 1.0 in all intercropping systems, indicating their viability. The highest LUE index (2.41) was obtained in the chicory-arugula-collard green intercropping system.