EPIC model simulation to assess effective agro-ecological practices for climate change mitigation and adaptation in organic vegetable system

Abstract

Mediterranean agriculture is markedly threatened by climate change and extreme events (drought and flooding). For the first time, the EPIC model was used in a long-term organic vegetable field experiment to evaluate the performance of agro-ecological practices, as adaptation and mitigation measures to cope with climate change in Southern Italy. These practices were a soil hydraulic arrangement (consisting of ridges and flat strips) combined with crop rotation (winter and summer cash crops), organic fertilization (poultry manure vs. no fertilization), and cover crops (pure or in mixture vs. no cover) managed as living mulch, green manure, or flattened by roller crimper. Seven treatments were selected for the simulation procedure. EPIC was calibrated and validated using measured crop yield and soil organic carbon stock values. The statistical metrics of EPIC showed r to be between 0.96 and 0.97, the Nash–Sutcliffe model efficiency between 0.54 and 0.94, and the relative root mean square error between 2 and 18%. Then, the model was run under baseline current climate (1985–2014) and near-future climate change (2015–2044) scenarios. Climate change increased both microbial respiration and nitrate leaching compared to the baseline, while soil organic carbon stock change and nitrous oxide emissions were mainly influenced by agro-ecological practices. Cover crop management could be an effective solution to limit negative climate effects, since it allowed improving summer cash crop yield (32%) and soil organic carbon stock change (2%), and reducing nitrogen losses (–34%), as compared to the no-cover-crop system. Finally, under climate change, green manure increased microbial respiration (5%) and reduced nitrogen losses (− 19%), compared to roller crimper flattening. Our findings indicated that the tested agro-ecological practices contribute to re-designing new climate change-resilient vegetable systems, by involving the stakeholders in promoting a co-innovation and co-research knowledge platform and fine-tuning agro-ecological practices in a wider range of environments.