Integrating Soil Taxonomy with Soil and Remote Sensing Indices for Site-Specific Management in the Egyptian Nile Delta Fringes

Sustainable soil management in arid regions is constrained by the limited translation of subgroup-level soil taxonomy into site-specific agronomic recommendations. Hence, this study integrated field observations and laboratory analyses from 18 soil profiles with freely available Google Earth Engine (GEE) datasets. Long-term Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) were processed in GEE and combined with land suitability index (SI) and multiple soil indices, including the Soil Quality Index (SQI), Nutrient Potential Index (NPI), Salinity-Sodicity Hazard Index (SSHI), Cation Ratio of Structural Stability (CROSS), Erodible Fraction (EF) and Soil Condition Factor (SCF). Results revealed two soil orders (Entisols and Aridisols) with considerable subgroup-level diversity, comprising Typic Torripsamments, Torriorthents, Torrifluvents, Haplocalcids, Haplogypsids, and Calcigypsids, all under thermic temperature and torric moisture regimes. Soils exhibited coarse-to-fine textures, low organic matter (mean 0.33%), variable CaCO3 (1.46%-35.04%), localized gypsum (up to 9.56%), and moderately alkaline pH (mean 8.12), under generally non-sodic and non-saline to slightly saline conditions. Integrating these indices revealed distinct patterns: SQI and NPI showed positive correlations with clay content and vegetation vigour (p < 0.05 to p < 0.001) and negative correlations with erosion risks (p < 0.001). While finer-textured Aridisols experienced greater chemical constraints from CaCO3 and ECe, they exhibited higher overall SI. Conversely, coarse-textured Entisols were primarily limited by low water- and nutrient-retention capacities, requiring organic amendments, precision drip irrigation, and erosion control. Calcareous and gypsiferous Aridisols necessitate salt-tolerant crops, irrigation management to prevent secondary salinization, and targeted amendments to mitigate nutrient fixation. This research demonstrates that coupling subgroup-level taxonomy with multi-source soil and remote sensing indices provides a scalable framework for site-specific land management in arid environments.