Impacts of Climate Change on SOC Dynamic and Crop Yield of Italian Rainfed Wheat-Maize Cropping Systems Managed with Conventional or Conservation Tillage Practices

There is still uncertainty on the ability of conservation tillage (i.e., reduced- RT and no till - NT) in contributing to the resilience of cropping systems to climate change pressures (Powlson et al 2016). RT or NT can improve soil physical and biological proprieties thus increasing water holding capacity and fertility, stabilizing soil structure and enhancing soil biodiversity and functions. However, SOC increase occurs mostly in the upper soil layer but not always in the deeper profile (Haddaway et al., 2016) where SOC measurements are less frequently measured. In this study, we used data obtained from long term field experiments(LTE) coupled with three crop simulation models in order to assess the long-term effects of different tillage management practices on crop yield and on changes in SOC stocks in both superficial (0-20cm) and deeper layers (20-50cm) in Mediterranean rainfed cereal cropping systems at current and future climate scenarios. The simulation models, CropSyst, DSSAT, EPIC, satisfying reproduced the observed changes in SOC at different soil depths in the two sites, despite the large range of measured data. Hence, the SOC models proved to be robust over a long term period and can be effectively used to develop climate change adaptive options and assess the mitigation potential of different tillage treatments.