Influence of Nitrogen Sources Applied by Fertigation to an Enriched Soil with Organic Compost on Growth, Mineral Nutrition, and Phytochemicals Content of Coriander (Coriandrum sativum L.) in Two Successive Harvests

Growth, productivity and phytochemicals of Coriander in responses to foliar application of Acacia saligna fruit extract as a biostimulant under field conditions

The application of natural extracts to vegetable plants can increase production, optimize nutrient and water uptake, and mitigate the effects of stress on vegetable plants by enhancing primary and secondary metabolism. In this study, Acacia saligna (Labill.) H.L.Wendl. fruit aqueous extract (FAE) was applied as a foliar application to assess and demonstrate its effects on growth, productivity, and phytochemicals of coriander (Coriandrum sativum L.) plants. A. saligna FAE (2%, 4%, and 6%), each combined with 50% of the recommended dose of N fertilizer was applied to coriander plants over the course of two successive seasons in the field. These treatments were compared with the control treatment, which used a 100% recommended dose of N. The four tested treatments were set up in a randomized complete block design with three replicates for a total of 12 experimental plots. Each replicate (experimental plot) was 3 m2 (2 × 1.5 m2) in size and included 300 seeds/m2. The phytochemicals were examined using chromatographic and spectrophotometric methods, where the essential oils (EOs) extracted from leaves were analyzed by Gas chromatography-mass spectrometry (GC-MS), while the phenolic and flavonoid compounds were analyzed by High Performance Liquid Chromatography (HPLC). With the application of A. saligna FAE (4%) + 50% N fertilizer, the levels of total solid content, total carbohydrates, total protein, total phenols, and total antioxidant activity, as well as chlorophyll a, chlorophyll b, chlorophyll a + b, and carotenoids, were increased at harvest. The treatment A. saligna FAE at 6% + 50% N fertilizer did not observe significant improvement in the growth parameters of coriander plants because of the anticipated allelopathic effects. By GC-MS analysis, the major compounds in the EO from control treatment were 2-octyn-1-ol (23.93%), and 2-butyl-1-octanol (8.80%), in treated plants with 2% of A. saligna FAE + 50% N fertilizer were (E)-2-decen-1-ol (32.00%), and 1-methoxymethoxy-oct-2-yne (13.71%), in treated plants with 4% A. saligna FAE + 50% N fertilizer were E-2-undecen-1-ol (32.70%), and 3,5,5-trimethyl-1-hexene (8.91%), and in the treated plants with A. saligna FAE (6%) + 50% N fertilizer were phytol (80.44%), and (Z)6,(Z)9-pentadecadien-1-ol (13.75%). The flavonoid components 7-hydroxyflavone, naringin, rutin, quercetin, kaempferol, luteolin, apigenin, and catechin were presented with variable concentrations according to the treatments utilized as identified by HPLC analysis from the methanol extracts of the treated plants with the combination treatments of A. saligna FAE (2, 4, and 6%) and N fertilization (50% from the recommended dose) and control coriander plants (100% N recommended dose). The combination of 50% N fertilizer treatment and the biostimulant A. saligna FAE (4%) seems to improve coriander plant growth while simultaneously lowering N fertilizer consumption. Future research will be needed to further study the effectiveness of several concentrations of A. saligna FAE in various conditions and/or species.

Growth, Yield and Photosynthetic Performance of Winter Wheat as Affected by Co-Application of Nitrogen Fertilizer and Organic Manures

The application of organic manures was found to be beneficial, however, the integrated use of organic manures with chemical nitrogen fertilizers has proven more sustainable in increasing the photosynthetic attributes and grain yield of the winter-wheat crop. A multi-factor split-plot design was adopted, nitrogen and manure fertilizer treatments were set in the sub-plots, including nitrogen-gradient treatment of T1:0 kg N ha⁻¹, T2:100 kg N ha⁻¹, T3:200 kg N ha⁻¹, and T4:300 kg N ha⁻¹ (pure nitrogen -fertilizer application) The 25% reduction in nitrogen combined with the manure-fertilizer application includes T5:75 kg N ha⁻¹ nitrogen and 25 kg N ha⁻¹ manure, T6:150 kg N ha⁻¹ nitrogen and 50 kg N ha⁻¹ manure, and T7:225 kg N ha⁻¹ nitrogen and 75 kg N ha⁻¹ manure. The maximum results of the total chlorophyll content and photosynthetic rate were 5.73 mg/g FW and 68.13 m mol m⁻² s⁻¹, observed under T4 in Zhongmai 175, as compared to Jindong 22 at the heading stage. However, the maximum results of intercellular CO₂ concentration were 1998.47 μmol mol⁻¹, observed under T3 in Jindong 22, as compared to Zhongmai 175 at the tillering stage. The maximum results of LAI were 5.35 (cm²), observed under T7 in Jindong 22, as compared to Zhongmai 175 at the booting stage. However, the maximum results of Tr and Gs were 6.31 mmol H₂O m⁻² s⁻¹ and 0.90 H₂O mol m⁻² s⁻¹, respectively, observed under T7 in Zhongmai 175 as compared to Jindong 22 at the flowering stage. The results revealed that grain yield 8696.93 kg ha⁻¹, grains spike⁻¹ 51.33 (g), and 1000-grain weight 39.27 (g) were significantly higher, under T3 in Zhongmai 175, as compared to Jindong 22. Moreover, the spike number plot⁻¹ of 656.67 m² was significantly higher in Jindong 22, as compared to Zhongmai 175. It was concluded from the study that the combined application of nitrogen and manure fertilizers in winter wheat is significant for enhancing seed at the jointing and flowering stages. For increased grain yield and higher economic return, Zhongmai 175 outperformed the other cultivars examined. This research brings awareness toward the nitrogen-fertilizer-management approach established for farmers’ practice, which might be observed as an instruction to increase agricultural management for the winter-wheat-growth season.