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.

Due to an extreme increase in population growth, Egypt suffers from a widening gap in the quantity of imported wheat compared with production and local consumption. Two field trials were conducted during the 2018/2019 and 2019/2020 seasons with three levels of humic substances (HSs) as a foliar spray (1.0, 2.0 and 4.0 g L⁻¹; HS₁, HS₂ and HS₃) and three levels (5.04, 7.56 and 10.08 kg ha⁻¹; HS₄, HS₅ and HS₆) as a soil application. These were applied three times (30, 45 and 60 days after sowing) in comparison with the control (HS₀) to evaluate the performance of three wheat varieties (Seds1 (V₁), Misr2 (V₂) and Giza168 (V₃)) grown in clay loam soil. The experiment was set up according to the split-plot structure in a randomized complete block design; however, the varieties were set as the main plot and treatments were a sub-main plot. Generally, the data indicated that the soil application treatments recorded maximum values for most growth and yield attributes, except for spike length and grain weight per spike, SPAD reading and total grain yield in the first season, and leaf area and biological yield in the second season. HS_1, HS₂, HS₅, and HS₆ were the superior treatments for most of the nutrient contents studied. Regarding the influence of variety, the results showed that V₃ recorded maximum values for LA, SpL, TGW, TGY and leaf Zn and Cu contents in both seasons; PH, GWS and leaf N content in the first season; and SPAD reading, BY and leaf K, Fe and Mn contents in the second season. V₁ was the superior variety for GWS, BY, leaf K and Mn contents in the 2018/2019 season and PH, GNS in the second season, followed by V₂, which had the greatest values for leaf P contents in both seasons, and SPAD reading, GNS and leaf Fe content in the 2018/2019 season and GWS and leaf N content in the second season.

The aim of this research was to evaluate the effect of three sugarcane waste by-products (pressmud PM, bagasse ash BA and molasse MO) which used as soil amendments of for immobilizing some heavy metals such as Cd, Cu, Cr, Ni and Pb in a contaminated soil near industrial factors of Qena Governorate, Egypt. The applied wastes at three levels of 0, 2.5 and 5 % (w/w) were incubated into the contaminated soil for a period of 120 days with wetting and drying cycles. The soil pH, organic matter content and DTPA extractable metals were determined after 30, 60 and 120 days of the incubation periods. The results indicated that BA addition to the contaminated soil have a high effective on reduce the soil content from DTPA-extractable of Cu, Ni and Pb compared with other treatments. Molasse (MO) application caused the best reduction in the mobility of Cd and Cr than BA and PM, while the application of pressmud (PM) had a moderate effect in reducing Ni and Pb of the soil.

The application of PGPB is considered a surrogate approach to reducing the amounts of phosphorus fertilizers applied in addition to its role in improving nutrient availability under stress conditions. The objective of this study was to evaluate five levels of calcium superphosphate (CSP); ultimately, CSP was applied in five levels: CSP₂₀, CSP₄₀, CSP₆₀, CSP₈₀, and CSP₁₀₀ were applied at 69, 138, 207, 276, and 345 kg ha⁻¹, respectively, and two treatments of Bacillus megaterium DSM 2894 (with and without) were applied on sweet potato (Beauregard cv.) plants grown in calcareous soils in the 2019 and 2020 seasons in Egypt. Some macro- and micronutrient (i.e., nitrogen (N), phosphorus (P), calcium (Ca), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu)) uptake, antiradical power (ARP), and protein and total root yields (TRYs) were determined. The plants inoculated with B. megaterium DSM 2894 had increased leaf N, P, and Mn contents in both seasons; in addition, Ca was increased in the second season. Furthermore, all of the root nutrient contents (except N) as well as the ARP and TRY were increased in both seasons as compared with those of the noninoculated plants. On the other hand, the maximum values of the leaf Ca, Fe, and Cu contents and the root Ca, Fe, and Zn contents were recorded with the CSP₂₀ treatment in both seasons. CSP₆₀ was the superior treatment for N (in the leaves), Mn (in the roots), ARP, protein contents, and TRY in both seasons and for the leaf Zn content in the 2019 season. The application of the CSP₁₀₀ treatment gave the highest values for the leaf and root P contents and the root Cu contents in both seasons as well as for the leaf Mn content in the first season and the root N content in the 2020 growth season. Thus, it was concluded that the application of CSP₂₀, CSP₆₀, and CSP₁₀₀ treatments with the B. megaterium DSM2894 mixture gave the best values compared to the use of CSP or DSM2894 individually to attenuate CaCO₃-induced damage.

A laboratory experiment was conducted to study the effect of filter cake and vinasse on copper and nickel adsorption on a loamy sand soil. To attain this aim, five grams of the soil were placed with 0.5 g of filter cake or vinasse in conical flasks. Then, 10 ml of Cu or Ni solutions containing 44 mg Cu or Ni / 10 ml prepared from CuSO4 5H2O and NiSO4. 6H2O, respectively, plus 25 ml of distilled water were added to the flasks to give the initial concentration of Cu or Ni of 1257 mg L-1. Two control flasks of the soil plus Cu or Ni and the soil with distilled water were used. The treatments were repeated three times.The soil suspensions in the flasks were shaken at 25 ° C for five shaking periods of 5, 10, 20, 40 and 60 minutes. The results obtained showed that organic materials resulted in increased efficiency the sorption of Cu and Ni on a loamy sand soil compared to control treatment (without organic materials), and the filter cake was more able to absorb both Cu and Ni compared with vinasse with increased shaking intervals. The highest adsorption amount was 8.53 mg g-1 for copper with the non-amended soil at reaction time 60 minute and 4.72 mg g-1 for nickel with filter cake + soil treatment at reaction time 20 minute. The results also showed that the Freundlich equation for Cu and Ni absorption was better than the Langmuir equation due to that Langmuir equation is unsuitable of adsorption equations with high concentrations of heavy metals under study.

Soil chemical characteristics are a important factors for evaluating fertility indicators in a new land reclamation. Wadi El-Saida is one of the national projects for agricultural land reclamation and an aspect of sustainable agricultural development in Aswan governorate, Egypt. The aims of this study were to evaluate the spatial distribution of the chemical properties of the soils. A 87 soil samples were randomly collected from the study area, representative of the surface and subsurface layer. All soil samples selected positions using GIS in area study (24◦57' and 25◦06' N latitude and 32◦39' and 32◦48' E longitude. Then some chemical analyzes were performed on these samples. The results demonstrated the soil pH was ranged from near natural (7.18) to strongly alkaline (9.05). ECe values fall within the slightly saline (2.23) to very strongly saline (281.10 dS m-1). Total Calcium carbonate (CaCO3) was between slightly (0.09) to strongly calcareous (13.57 %). The CEC was varied from low (8.22) to very high (53.51 Cmol/kg). The exchangeable sodium percent (ESP) varied from 0.50 to 93.49%. The soil organic matter (SOM) was varied from 0.15 % to 2.91 %. Soil texture varied from sand to silt loam content. Positive and negative relationships for soil chemical properties were found by calculating the correlation coefficient. In short, the study area can be cultivated through an appropriate reclamation plan based on the studied properties to choose the best suitable crops to treat the undesirable traits.