Subclover (Trifolium subterraneum L.) Cover Cropping as a Soil Management Strategy to Enhance The Sustainability Of Pear (Pirus communis) Orchards

Introduction Given the growing challenges of climate change and increasing consumer demand for highquality fruits, optimizing agricultural management practices is crucial to achieving high yields and ensuring the sustainability of orchards. Bare soil management exacerbates the loss of soil organic carbon (SOC), whereas cover crops (CCs) are recognized as an effective agronomic practice for enhancing SOC sequestration in orchards. Objective The objective of this study is to assess the effects of subclover cultivation in the inter-row of pear orchards as an alternative to conventional soil management practice. Material and methods A two-year field experiment was conducted in the pear orchard of the “Fondazione Navarra” in Ferrara, Italy. Three inter-row soil managements were evaluated: (1) tilled soil at 30 cm depth (TILL); (2) natural grassing (NAT); and (3) controlled grassing using subclover as a legume CC (CLO). A randomized block design with three replicates was adopted in both years. Regular soil monitoring of carbon dioxide (CO2) emissions, moisture and compaction were conducted at 15 days interval using EGM-5 Portable gas analyser, a TDR FieldScout 350 soil moisture meter, and a FieldScout SC-900 soil compaction meter, respectively. Results and discussion Results showed that, in 2023, soil CO2 emissions were similar across all treatments. Peaks of soil CO2 emissions were observed under TILL management after the initial soil treatments. However, CLO soil management has recorded higher CO2 emissions for the May-September period. In 2024, no significant differences in CO2 emissions were observed between treatments. Soil moisture at a depth of 7.5 cm was slightly higher under CLO management in 2024, likely due to the late establishment of clover in 2023, which created a mulch that reduced soil evapotranspiration. Furthermore, at pear harvest, soil under CLO management was less compacted than soil under TILL and NAT managements, probably due to the effect of subclover roots that improved the soil aeration and structure.