An Appraisal of Calcium Cyanamide as Alternative N Source for Spring-Summer and Fall Season Curly Endive Crops: Effects on Crop Performance, NUE and Functional Quality Components

Abstract

A two-year study was conducted in both spring-summer and fall seasons to evaluate calcium cyanamide (CaCN2) as an alternative nitrogen (N) source for curly endive (Cichorium endivia L. var. crispum) grown in a Mediterranean environment. Four types of N applications were administered: (i) pre-transplanting base application of 100 kg N ha−1 corresponding to 100% of the supplied N (100CC), (ii) pre-transplanting base application of 50 kg N ha−1 corresponding to 50% of the supplied N (50CC) complemented with 50 kg N ha−1 as ammonium nitrate (50AN) supplied through fertigation, (iii) standard application of 100 kg N ha−1 as ammonium nitrate (100AN) supplied entirely through fertigation, and (iv) a N-deprived control (0 kg N ha−1) used as base reference to calculate the N use efficiency indices (NUE). Fall season increased head fresh weight, head height, stem diameter and plant visual quality, compared with the spring-summer season. The CaCN2 and standard fertigation N applications were equally effective in increasing head fresh weight and other physical parameters such as, head height, stem diameter, visual quality, number of leaves and head dry matter when compared to the unfertilized control. However, in spring-summer season, CaCN2, especially when applied straight at 100 kg N ha−1, effectively increased ascorbic acid and total phenolic content, whereas, in fall season, an increase in TSS and ascorbic acid was recorded. In both, spring-summer and fall seasons, CaCN2 significantly decreased N content and nitrogen accumulation (Nacc). Furthermore, CaCN2 pre-transplant application improved NUE indices both in terms of N fertilizer recovery efficiency and in terms of physiological efficiency of applied N. Our results finally demonstrated that NUE indices increased in the fall season as compared to the spring-summer season.

Iodine Biofortification Counters Micronutrient Deficiency and Improve Functional Quality of Open Field Grown Curly Endive

“…Our outcomes, also, highlighted that the growing season did not affect SSC. This result is in accordance with the finding of Sabatino et al [28], who did not determine differences in terms of SSC between curly endive plants grown in the fall and those grown in the spring-summer season. Moreover, our outcomes showed that, regardless of the growing season, total phenolics increased as I concentration in the nutrient solution increased.…”

“…Our outcomes revealed that head fresh weight and stem diameter were not affected by the growing season. On the contrary, Sabatino et al [28] reported that the number of leaves is positively influenced by the fall season in control plants, whereas spring-summer plants treated with 50 mg I L −1 performed better than those cultivated in the fall. Moreover, the number of leaves in spring-summer grown plants treated with 250 or 500 mg I L −1 did not significantly differ from that recorded in the fall grown plants supplied with the same I dosage.…”

“…Furthermore, curly endive encloses a considerable level of bioactive constituents, such as ascorbic acid, phenolics, glucosinolates, sesquiterpene lactones, and minerals, especially potassium and calcium [25][26][27]. There is also evidence that the concentration of these compounds is significantly influenced by the growing season [28]. To the best of our knowledge, there is a lack of scientific literature on I biofortification of curly endive.…”

Application of PGPB Combined with Variable N Doses Affects Growth, Yield-Related Traits, N-Fertilizer Efficiency and Nutritional Status of Lettuce Grown under Controlled Condition

“…Vegetable production systems need specific agricultural practices [10][11][12] and depend on high quantity of mineral nutrients (especially N, P and K) to enhance growth, yield and quality [13][14][15]. However, the incessant use of artificial fertilizers may pose threats on the ecosystem survival.…”

Planting Date and Different N-Fertilization Rates Differently Modulate Agronomic and Economic Traits of a Sicilian Onion Landrace and of a Commercial Variety

“…The chlorophyll content and the photosynthetic rate are directly related to the mineral content and nitrogen fertilization of vegetables [31,42,43]. The onion is very greedy for nitrogen, and careful management of fertilizer is needed due to the shallow nature of the root system [20] and the risk of nitrogen accumulation both in the soil and the produce [44].…”