The use of nano-fertilizers and antioxidants for specific crops to minimize the negative effect of abiotic stresses is imperative. Two field experiments were fulfilled during two summer seasons (2019 and 2020) to study the response of sweet potato (Beauregard cv.) plants grown in calcareous soil (CaCO₃ = 10.8–11.3%) to foliar nourishment with zinc oxide nanoparticles (ZnONPs) and ascorbic acid (ASA) applied individually or in a mixture. Both ZnONPs and ASA were applied in three doses: 0, 1000, or 1500 mg L⁻¹ for ZnONPs, and 0, 250 and 500 mg L⁻¹ for ASA. The highest values of iron (Fe) and manganese (Mn) contents were recorded in both seasons, while those of phosphorus (P) and copper (Cu) were recorded in the 2020 season with ZnONPs applied at 1500 mg L⁻¹. Furthermore, in both seasons, the maximum values of nutrient contents, excluding Mn content, were obtained with ASA applied at 500 mg L⁻¹. However, applying both ZnONPs and ASA in a mixture bypassed each applied alone, with the highest overall nutrient contents being recorded, with few exceptions, with the highest dose of the mixture. The trend of the tuber root nutrient contents was correlated with the corresponding values in the leaves. Maximum tuber root yield was obtained with foliar feeding with 1000 mg ZnONP and 250 mg ASA L⁻¹ in both seasons. The resulting data recommend the use of foliar nourishment with fertilizer nanoparticles and antioxidants to enable stressed plants to collect appropriate nutrient contents from the defective soils.

Among the essential micronutrients, zinc (Zn) affects vital functions in crop plants. The influences of foliar nourishing with certain Zn-containing forms on the growth, productivity, and physiology of carrot plants (cv. Fire wedge F1) and their nutritional contents when grown in Zn-deficient soil were examined in both 2019/2020 and 2020/2021 field trials. Two doses of zinc oxide nanoparticles (ZnO-NPs(1) = 20 and ZnO-NPs(2) = 40 mg L⁻¹), zinc–EDTA (Zn–EDTA(1) = 1 and Zn–EDTA(2) = 2 g L⁻¹), or bulk zinc oxide (ZnO-B(1) = 200 and ZnO-B(2) = 400 mg L⁻¹) were applied three times. The data outputted indicated, in general, that ZnO-NPs(2) were the best treatment that conferred more acceptable plant growth (measured as shoot length and fresh and dry weights), physiology (measured as cell membrane stability index, SPAD readings, and nutrient uptake), and nutritional homeostasis (e.g., P, Ca, Fe, Mn, Zn, and Cu contents). All these positive attributes were reflected in the highest yield, which was measured as fresh weight, dry matter, length, diameter, volume, and total yield of carrot roots. However, there were some exceptions, including the highest membrane stability index in both seasons, the highest Cu uptake and Mn content in the first season, and root fresh weight in both seasons obtained with ZnO-NPs(1). Moreover, the maximum P uptake and root dry matter were obtained with ZnO-B(1) and the highest content of root P was obtained by ZnO-B(2). Based on the above data, foliar nourishing with ZnO-NPs(2) can be recommended for the sustainability of carrot cultivation in Zn-deficient soils.

Among soil parameters, Soil Chemical Properties (SCPs) are a crucial factor for the evaluation of chemical and fertility indices, proper decision-making regarding land reclamation, and land cultivation. In this work, 32 samples were collected from the surface (0–30 cm) and subsurface (30–60 cm) layers from 16 selected positions using GIS in the Toshka area (23°30′ and 23°60′ N latitude and 31°32′ and 31°36′ E longitude), Aswan, Egypt. Our results revealed that the soil reaction ranged from slightly (7.25) to moderately alkaline (8.19) and was characterized as a moderately saline and calcareous soil; however, the minimum ECe and CaCO₃ values exceeded 4.30 dS·m⁻¹ and 12.80%, respectively. Furthermore, there was a significant decrease in the soil organic matter (not exceeding 0.11%) and available nutrient contents. The cation exchange capacity was moderate. The correlation coefficient between the studied SCPs fluctuated between positive and negative. In brief, the area can be reclaimed through a proper reclaiming plan and the selection of the most suitable crops to treat the undesirable characteristics.

Nutritional status improvement is a surrogate approach to overcoming undesirable soil conditions. This study was performed in sandy clay loam soil that was characterized by certain undesirable parameters (ECe = 6.4 vs. 7.2 dS m⁻¹, CaCO₃ = 8.8 vs. 9.2%, and pH = 7.78 vs. 7.89) on olive (Olea europaea, Arbequina cv.) in the 2020 and 2021 seasons to investigate the influence of two highly soluble phosphorus fertilizers, mono-ammonium phosphate (MAP) and urea phosphate (UP). The treatments included 0.336, 0.445, and 0.555 kg tree⁻¹ for MAP₁, MAP₂, and MAP₃ and 0.465, 0.616, and 0.770 kg tree⁻¹ for UP₁, UP₂, and UP₃, respectively, in comparison to granular calcium super-phosphate (GCSP) at the recommended rate (0.272 kg P₂O₅ equal 1.75 kg tree⁻¹). This experiment was established according to a randomized complete block design. Generally, our results indicated that both MAP and UP applications surpassed GCSP for all studied parameters except leaf copper uptake in the 2021 season. Moreover, among the HSPFs applied, it was found that applying the maximum levels gave the best results. However, MAP₃ gave the maximum values for shoot length, SPAD reading, and dry fruit matter. Moreover, UP₃ produced the best results for the leaf area, olive tree yield, total olive yield, total fresh weight, flesh weight (FlW), fruit length (FrL), and leaf Fe content in both seasons.

The objective of this study was to study the influence of three organic manures, farm yard manure (FYM), poultry manure (PLM), and pigeon manure (PGM), on soil physical and chemical properties on tuber yield of Jerusalem artichoke in a newly reclaimed saline calcareous soil. A field experiment was conducted applying the three manures, alone and/or in different combinations. Soils were investigated at surface (0–30 cm) and subsurface (30–60 cm) layers before and after planting, and analyzed for physical and chemical properties. The results indicated that the application of 31.5 kg ha⁻¹ of PLM+10.5 kg of PGM T7 recorded highest available nitrogen, zinc, copper, and moisture content at the surface layer. The same results were obtained for iron and manganese at both layers. While, applying 21.0 kg ha⁻¹ FYM+21.0 kg ha⁻¹ PLM T10 recorded the best treatment for pH, phosphorus, zinc, copper, moisture content, and saturation percentage at the subsurface layer. Applying 21.0 kg ha⁻¹ PGM + 10.5 kg ha⁻¹ FYM+10.5 kg ha⁻¹ PLM T15 recorded the best treatment for organic matter content and bulk density at surface layer and reduced the electrical conductivity and inulin tuber content at both layers. On the other hand, calcium carbonate and sodium adsorption ratio were reduced in both layers by applying 21.0 kg ha⁻¹ PLM+10.5 kg ha⁻¹ FYM+10.5 kg ha⁻¹ PGM T14. The best treatment for tuber nitrogen content and total yield was obtained with applying 42.0 kg ha⁻¹ PLM T2 only and 31.5 kg ha⁻¹ FYM+10.5 kg ha⁻¹ PLM T4, respectively.

Soil pH is the most important factor in evaluating plant nutritional status due to its close association with nutrient availability. In the 2018 and 2019 seasons, two field experiments were conducted to evaluate the performance of olive trees (Olea europaea, Picual cv.) grown in sandy clay loam soil under multi-abiotic stresses with the application of three different acidifying agents (AAs), acetic (AC), citric (CA), and sulfuric (SA) acid, at two doses (25 and 50 cm³; AC₁ and AC₂, CA₁ and CA₂, and SA₁ and SA₂, respectively), as compared with a control treatment. This study was established according to a randomized complete block design. In general, our results showed that all the AAs applied surpassed the control treatment with respect to all the studied parameters except for the leaf iron content. Furthermore, the trees treated with CA yielded the best results in terms of the leaf nitrogen, calcium, and magnesium contents; the physiological and growth parameters (except for the performance index); the total fruit weight, flesh weight, and flesh dry matter; the fruit diameter; the oil content; and the total olive yield. Furthermore, the maximum leaf potassium, manganese, zinc, and copper contents were obtained in the trees growing in soil injected with AC. The correlation coefficient fluctuated between positive and negative among the studied characteristics.