Effect of Long-Term Set-Aside Management System on Soil Health by Evaluation of Biodiversity Indicators

The loss of organic matter and the decline of biodiversity pose significant threats to soil health and the sustainability of agriculture. Managing set-aside land through mowing remains a practical strategy to prevent land abandonment while preserving soil biodiversity and essential soil functions that support fertility. The primary objective of this study was to evaluate the effectiveness of long-term set-aside (12 years) in preventing soil degradation. In an experimental field in Vicarello (Pisa, Italy), set-aside management was compared to land abandonment and conventional crop rotation. Soil chemical and microbiological analyses were conducted, and various indicators were used to assess soil fertility conservation. Soil biodiversity was evaluated through nematode and microarthropod indices. Total organic carbon increased in abandoned fields and, to a lesser extent, in set-aside areas, following a similar trend to microbial biomass values. Nematode and microarthropod indicators revealed a more stable soil structure in set-aside areas, followed by abandoned fields, highlighting their role in regulating ecosystem services such as carbon mineralization. On the whole, the results indicate that set-aside management serves as an intermediate step in the transition from conventionally managed fields to naturalized grasslands, confirming its potential benefits for soil biological diversity and function.