Mapping of heavy metal contamination in alluvial soils of the Middle Nile Delta of Egypt

Areas contaminated by heavy metals were identified in the El-Gharbia Governorate (District) of Egypt. Identification used remote sensing and Geographical Information Systems (GIS) as the main research tools. Digital Elevation Models (DEM), Landsat 8 and contour maps were used to map physiographic units. Nine soil profiles were sampled in different physiographic units in the study area. Geochemical analysis of the 33 soil samples was conducted using X-ray fluorescence spectrometry (XRF). Vanadium (V), nickel (Ni), chromium (Cr), copper (Cu) and zinc (Zn) concentrations were measured. V, Ni and Cr concentrations exceeded recommended safety values in all horizons of the soil profiles, while Cu had a variable distribution. Zn concentrations slightly exceeded recommended concentration limits. Concentrations were mapped in each physiographic unit using the inverse distance weighted (IDW) function of Arc-GIS 10.1 software. Pollution levels were closely associated with industry and urban areas

Effect of Nano-Fertilizers on Alfalfa Plants Grown under Different Salt Stresses in Hydroponic System

In light of climate change and the ever-increasing population, salt stress has become a critical issue for agriculture and food security. The use of nano-fertilizers in agriculture is a promising application for salt stress management. Therefore, we investigated a hydroponic experiment to evaluate the effect of different nano-fertilizers: macro-nutrient (K2SO4) and micro-nutrient (ZnO and SiO2) on two alfalfa (Medicago sativa L.) genotypes: (Susceptible: Bulldog 505, and tolerant: Mesa-Sirsa) grown with different salt concentrations (6 and10 dS m−1) in split-split design. The results demonstrated that nano-K2SO4 enhanced shoot dry weight, plant height, number of flowers, number of tillers, root length, root fresh weight, and root dry weight under both salt levels. Addition of nano-K2SO4 enhanced plant relative water contents and electrolyte leakage with both genotypes under different salt levels. Nano-SiO2 promoted proline and SOD production with high salinity with values of (0.78 and 1.06 µmol g−1 FW) and 191.15 and 143.46 U. g−1 FW under Bulldog and Mesa-Sirsa, respectively. The application of nano-ZnO promoted plant micro-elements under 6 dS m−1 with both genotypes. The incorporation of nano-fertilizers into hydroponic systems provides a promising strategy, especially in regions with low water quality