Potential Role of Fertilizer Sources and Soil Tillage Practices to Mitigate Soil CO2 Emissions in Mediterranean Potato Production Systems

Agricultural practices should be approached with environmental-friendly strategies, able to restore soil organic matter and reduce the greenhouse gas emissions. The main objective of this study is to evaluate the environmental benefits, in terms of CO2 emissions and carbon balance, of some agricultural practices for potato cultivation. A randomized complete block design was adopted where the treatments were: (a) tillage systems (plowing; subsoiler and spading); (b) fertilizer sources (mineral and organic). All treatments were replicated three times. Potato yield and its carbon content, soil CO2 emissions, temperature, and volumetric water content were measured. The CO2 emissions were higher in organic than in mineral fertilizer (0.60 and vs. 0.77 g m−2 h−1, respectively), while they were low in spading compared to the other soil tillage (0.64 vs. 0.72 g m−2 h−1, respectively). Carbon input was the highest in plowing and organic fertilizer 4.76 and 5.59 Mg C ha−1, respectively. The input/output ratio of carbon varied according to the main treatments. The findings suggest that spading tillage and organic fertilizer might result in environmental and agronomical benefits, further research should be performed to evaluate to possibility to extend the results to other environments and crops.