Impact of Soil Management Practices on Soil Loss and Runoff: First-Year Results from a Plot-Scale Experiment in Central Italy

It is crucial to monitor soil loss at the plot scale to evaluate the effectiveness of different soil management practices in mitigating erosion. The present study presents the first-year results from a monitoring experiment conducted in Umbria, Central Italy, on six plots (22-metre-long with a 16% slope) under three soil management systems, replicated twice: i) control (CTR), i.e., traditional soil management with bare soil during the autumn-winter period and soil preparation in spring for sowing the cash crop (sunflower); ii) cover crop (CC) traditional management (CCT) where a CC mixture of hairy vetch (Vicia villosa Roth.) and rye (Secale cereale L.) is sown in September-October and devitalized by plowing in early spring before the sowing of the cash crop; iii) CC mulch-based no-tillage management (CCM), where the same CC mixture is sown in September-October and devitalized by roller-crimping in early spring, after which the following cash crop is directly sown in the mulched CC biomass. Despite the implementation of the CC, no statistically significant differences were observed in soil loss or runoff among the treatments during the first year. The primary factor contributing to this outcome was the occurrence of erosive events shortly after the sowing of the CC, which resulted in the formation of rills in the plots where seedbeds had been prepared. These rills, in turn, exacerbated runoff and soil loss during successive erosive events, thereby undermining the anticipated benefits of the CC. In contrast, conventionally managed soils, which did not necessitate seedbed preparation, did not demonstrate such rill formation. While the study reaffirms the importance of vegetative cover for soil conservation, it also highlights a potential drawback: soil disturbance associated with CC establishment can occasionally offset the benefits of the CC under certain conditions. This finding underscores the need for careful consideration of soil preparation practices in erosion-prone areas. 

The study was financed by European Union-Next-GenerationEU-National Recovery and Resilience Plan (NRRP)–MISSION 4 COMPONENT 2, INVESTIMENT N. 1.1, CALL PRIN 2022 D.D. 104 02-02-2022–(Soil Conservation for sustainable AgricuLture in the framework of the European green deal-SCALE) CUP N. J53D23010340006.