Water shortage is a major problem limiting the expansion of green areas and landscapes. Using seawater as an alternative source of potable water is not a novel idea, but the issue of salt stress needs to be resolved. Salinity has a negative impact on growth and the aesthetic value of ornamental plants. In order to overcome these challenges, Lathyrus odoratus seeds were hydro-primed and halo-primed with silicon (Si) and silicon nanoparticles (SiNPs), and exposed to seawater levels. Seawater markedly reduced seed germination and growth of Lathyrus seedlings, but halo-priming was shown to significantly alleviate its negative effects. Broadly, SiNPs increased the germination percentage, reduced photosynthetic pigments and carbohydrates decrease, and enhanced water relations, despite having a negative effect on germination speed. Halo-priming significantly increased the proline content and the activities of certain enzymatic (SOD, APX and CAT) and nonenzymatic (phenolic and flavonoids) compounds, that positively influenced oxidative stress (lower MDA and H₂O₂ accumulation), resulting in seedlings with more salt stress tolerance. Halo-priming with Si or SiNPs enhanced the Si and K⁺ contents, and K⁺/Na⁺ ratio, associated with a reduction in Na⁺ accumulation. Generally, halo-priming with Si or SiNPs increased Lathyrus seedlings salt stress tolerance, which was confirmed using seawater treatments via improving germination percentage, seedlings growth and activation of the antioxidant machinery, which detoxifies reactive oxygen species (ROS).

The progressive reduction of synthetic agrochemical fertilizers is one of the key factors in the shift from conventional agriculture to sustainable farming. Nitrogen (N) is the ruling element in the development of agricultural production, but its use in the mineral form or its excessive use causes several environmental issues. Since the release of N nanocomposites coincides with their uptake by crops, N loss reduces while enhancing plant uptake due to nano fertilizers application. Additionally, an intercropping legume with cereal as an eco-friendly pattern could improve and rationalize the nitrogenous inputs. Therefore, a two-year field trial was conducted to determine the efficacy of nano-chitosan-loaded N (CS-NNPs) for saving mineral N amounts applied in maize-based on maize-soybean intercropping and enhancing land productivity. Methods In a randomized split-plot design in three replicates, three intercropping patterns, in addition to the sole crops, and three N levels were implemented. Intercropping involved three intercrop configurations [planting maize rows (M) alternated with soybean rows (S) in patterns of 4M:2S, 2M:4S, and 3M:3S)], in addition to planting sole maize crop (SMC) and sole soybean crop (SSC). N fertilization treatments included adding 288 kg N ha⁻¹ (MN100%) and two levels of CS-NNPs composite involving 216 kg N ha⁻¹ + 2 foliar sprays of CS-NNPs (MN75% + 2CS-NNPs), and 144 kg N ha⁻¹ + 3 foliar sprays of CS-NNPs composite (MN50% + 3CS-NNPs). Under the tested treatments, the agronomic traits, intercropping indices, and economic benefits were estimated. Results Findings revealed that the application of SMC × MN75% + 2CS-NNPs, followed by 4M:2S × MN75% + 2CS-NNPs showed the highest growth, biological yield, and grain yield of maize. The interaction of SSC × MN75% + 2CS-NNPs, followed by 2M:4S × MN75% + 2CS-NNPs resulted in the highest seed yield components, biological yield, straw yield, and seed yield of soybean. Application of 2M:4S × MN100%, 2M:4S × MN50% + 3NNPs, and 3M:3S × MN100% recorded the maximum total land equivalent ratio. While applications of 2M:4S × MN100%, 2M:4S × MN75% + 2CS-NNPs, and 3M:3S × MN100% achieved the highest land equivalent coefficient, land-use efficiency, area time equivalent ratio, and percent yield difference. Likewise, both interactions of 2M:4S × MN75% + 2CS-NNPs and 3M:3S × MN100% recorded the highest system productivity index. Better yield advantage of maize-soybean intercrop compared with the monocrop since total actual yield loss values were positive and higher than zero in all interactions of intercropping pattern × N fertilization. Fertilizing maize with MN50% + 3CS NNPs grown under the 2M:4S pattern had the highest positive aggressivity values. Conclusion The productivity shortfall accompanying the 25% N reduction was compensated by the application of CS-NNPs. Thus, N applied to the maize intercropped with soybeans can be rationalized. This undoubtedly has a good economic payoff for the maize growers with the conservation of the agricultural environment. In maize production systems, it is advisable to fertilize the plants using 216 kg instead of 288 kg nitrogen ha⁻¹ when nano chitosan-loaded nitrogen composite twice (0.48 kg nitrogen ha⁻¹) applied.

Alkaline soil inhibits the growth and productivity of chia plants (Salvia hispanica L.). Microalgae as biofertilizers have been reported to induce alkalinity tolerance and enhance yield and quality. However, limited information is known concerning the influence of microalgae application on medical plants, including chia. Our experiments were performed to evaluate the effect of microalgae strains of Arthrospira platensis, Chlorella vulgaris, Nostoc muscorum, and Anabaena azollae with two application methods, foliar spray and soil drench, on morpho-physiological and biochemical parameters, yield, seed and oil quality, and fatty acid profiles of chia plants cultivated under alkaline soil conditions, as well as the on soil microbial activity. The results obtained reveal that both application methods positively influenced the growth and productivity of chia plants. However, the foliar application showed significant differences in the herb’s fresh and dry weights and leaf pigments, whereas the drenching application caused more effect than the foliar spray application at the reproductive stage. Untreated chia plants showed a slight decline in the growth, productivity, and antioxidant level with an increase in Na content. However, microalgae applications significantly ameliorated these impacts as they induced an enhancement in the growth, leaf pigments, total protein and carbohydrate contents, nutrient content, seed and oil yields, as well as an increase in linolenic and linoleic fatty acids, with a reduction in saturated fatty acids, namely, palmitic and lauric acid. Soil drenching generated an improvement in the soil microbial activity and caused a reduction in the pH. The treatment of A. platensis with drenching application resulted in higher seed and oil yield, with an increase of 124 and 263.3% in seed and oil yield, respectively.

Salinity is linked to poor plant growth and a reduction in global food output. Therefore, there is an essential need for plant adaptation and mitigation of salinity stress conditions. Plants combat salinity stress influences by promoting a set of physiological, biochemical, and molecular actions. Tremendous mechanisms are being applied to induce plant stress tolerance, involving amino acid application. For evaluating the growth and productivity of Moringa oleifera trees grown under salt stress conditions, moringa has been cultivated under different levels of salinity and subjected to a foliar spray of proline (Pro) and phenylalanine (Phe) amino acids. Moringa plants positively responded to the lowest level of salinity as the leaves, inflorescences, seeds, and oil yields have been increased, but the growth and productivity slightly declined with increasing salinity levels after that. However, Pro and Phe applications significantly ameliorate these effects, particularly, Pro-treatments which decelerated chlorophyll and protein degradation and enhanced vitamin C, polyphenols, and antioxidant activity. A slight reduction in mineral content was observed under the high levels of salinity. Higher osmoprotectants (proline, protein, and total soluble sugars) content was given following Pro treatment in salted and unsalted plants. A significant reduction in oil yield was obtained as affected by salinity stress. Additionally, salinity exhibited a reduction in oleic acid (C18:1), linoleic (C18:2), and linolenic (C18:3) acids, and an increase in stearic (C18:0), palmitic (C16:0), eicosenoic (C20:2), and behenic (C22:0) acids. Generally, Pro and Phe treatments overcome the harmful effects of salinity in moringa trees by stimulating the osmoprotectants, polyphenols, and antioxidant activity, causing higher dry matter accumulation and better defense against salinity stress.

The effect of silica nanoparticles (SiNPs) preservative solutions on the postharvest quality of rose cut flowers was investigated in this study. SiNPs were used at the concentrations of 0, 1, 2, and 3 mg·dm ⁻³ . Treatments of SiNPs increased flower longevity compared to untreated flowers. Relative fresh weight, relative water content, and water uptake were improved because of SiNPs treatments. The enhancement in chlorophyll content, total soluble sugars, as well as total phenol and flavonoid contents were positively correlated with SiNPs treatments. Malondialdehyde (MDA) content significantly increased by control roses relative to treated ones. Activities of peroxidase (POX) and polyphenol oxidase (PPO) enzymes significantly increased because of SiNPs treatments compared to the control. The treatment of 2 mg SiNPs·dm ⁻³ maximized the longevity and improved the postharvest quality of cut roses. The results obtained suggested that SiNPs treatments could improve the longevity and postharvest quality of cut roses by reducing lipid peroxidation and motivating antioxidant machinery, therefore, retaining the membrane integrity.