Abstract

Degraded landscapes covering approximately 2 billion hectares globally require innovative restoration approaches that restore soil functionality while providing multiple ecosystem services. This comprehensive study evaluates phytotechnology approaches for enhancing soil functionality across 156 degraded sites spanning mining areas (47 sites), contaminated lands (38 sites), eroded agricultural fields (43 sites), and urban brownfields (28 sites) in 22 countries. We implemented diverse phytotechnological interventions including phytoremediation, phytostabilization, constructed treatment wetlands, and agroforestry systems over a 7-year monitoring period. Results demonstrate significant improvements in soil functionality indicators, with aggregate stability increasing from 23.4 ± 8.7% to 67.8 ± 12.4%, water infiltration rates improving 3.4-fold, and soil organic carbon accumulating at 1.8 ± 0.6 Mg C ha⁻¹ year⁻¹. Microbial biomass carbon increased 5.2-fold (from 89 ± 34 to 463 ± 127 mg kg⁻¹), while enzyme activities for carbon (β-glucosidase), nitrogen (urease), and phosphorus (phosphatase) cycling showed 3.1-, 4.2-, and 2.8-fold increases respectively. Heavy metal concentrations decreased by 45-78% through phytoextraction, with hyperaccumulator species Pteris vittata removing 2,340 mg As kg⁻¹ soil and Brassica juncea extracting 890 mg Cd kg⁻¹ soil. Constructed treatment wetlands achieved 89% removal efficiency for nitrogen and 94% for phosphorus while supporting biodiversity recovery with 2.3-fold increases in plant species richness. Economic analysis reveals benefit-cost ratios of 2.8-4.7 for phytotechnology implementations, with combined restoration and production values of $1,240-3,680 ha⁻¹ over 10-year periods. However, success varies significantly with site conditions, requiring 3-8 years for full functionality restoration and careful species selection for local adaptation. Spatial analysis identifies optimal implementation zones based on climate, soil type, and degradation severity, with potential application to 847 million hectares globally. These findings demonstrate that strategically implemented phytotechnologies provide cost-effective, sustainable solutions for landscape-scale soil functionality restoration while delivering multiple co-benefits including carbon sequestration, biodiversity enhancement, and ecosystem service provision.