Effects of Willow cultivation on soil health in contaminated and conventional agricultural sites (Slovakia)

The targeted cultivation of energy crops and trees enables the effective use of low-quality agricultural land, including areas degraded or contaminated by inorganic pollutants. In line with the EU Soil Strategy 2030, which promotes soil protection, sustainable use, and restoration, this study focused on soil health and phytoremediation through willow cultivation for bioenergy on contaminated and standard agricultural soils at two sites in Slovakia over a 10-year period. The study aimed to: (i) assess changes in the Soil Health Index (SHI) during willow cultivation under temperate European conditions; and (ii) evaluate willow as a nature-based solution for soil remediation. SHI was constructed using a linear combination of individual indicator values, converted into a scoring system based on indicator type and relevance to soil health. The “optimum is better” indexing method was applied. Both sites, Kuchyňa (contaminated) and Krivá na Orave (uncontaminated), responded positively overall, with no adverse impacts on soil health and quality. At Kuchyňa site, SHI increased from 3.0 to 7.5 (a 147 % improvement), indicating significant soil health recovery, enabling the land’s subsequent use for agricultural crop production. SHI at Krivá na Orave site declined slightly from 6.0 to 5.0 (a 16 % decrease) yet remained within acceptable quality levels. Profitability was achieved at both sites without the use of herbicides.