Soil loss measure from Mediterranean arable cropping systems: Effects of rotation and tillage system on C-factor

Soil erosion is one of the most serious environmental problems, widespread globally, affecting the productivity of natural ecosystems as well as agricultural and forest ecosystems. Mediterranean regions are highly exposed to soil erosion due to soil features and rainfall distribution, characterized by high intensity and degree of erosivity, especially in autumn. Several cropping systems - differing for crop species and relative biological cycle - were established with the aim to assess their ability to limit soil erosion. An experimental device was placed to measure soil losses. Four experimental plots were cultivated with different cropping systems (CS) and levels of intensification, compared to standard plot (SP) maintained in bare conditions by up and down slope tillage operations, according to Universal Soil Loss Equation (USLE). The impact of four cropping systems, managed by conventional or conservation tillage, on soil erosion was estimated by the C-factor calculation. The relationship between crop intensification and erosion was also studied. The traditional conventional cropping system (CS2) emerged as the most susceptible to erosion risks with an average soil loss of 26.41 t ha−1 and a C-factor of 0.513. The cropping system CS4 characterized by reduced tillage, shredding of crop residues with mulch function and the introduction of fodder crops, showed the lowest C-factor value (0.089), highlighting the highest ability to protect the soil from erosion compared to the other systems. In conclusion, the C-factors calculated in this study can be used as a criterion to select a suitable crop rotation system to reduce erosion risk in marginal land of Mediterranean Basin. The different stakeholders will have useful information to guide them in their choices.