How organic rice farming impacts the biodiversity: A case study of the rice paddies in North Italy

Despite the continuous growth in organically farmed areas worldwide, the assumption about whether organic farming reduces negative impacts on biodiversity is still debated, particularly in complex cropping systems such as rice paddies. Since the dynamics of the rice cycle are different from other crops, it is more difficult to assess biodiversity using the traditional indices. Moreover, most works focus on the compression between organic and conventional rice management on the direct reduction of the above-ground arthropod diversity in organic farming systems and weed control efficiency, which are the major challenges for organic systems productivity. Interestingly, the main target of agriculture impacts is expected to be the soil biota, these groups are not considered enough in the studies due to the difficulties in classification and the correct sample collection. Thus, a simplified eco-morphological index that does not require the classification of organisms to species level, allows a broader application of these methodologies such as the QBS-ar (Soil’s Biological quality index). This work aimed to apply the QBS-ar in rice paddies, to highlight the differences between organic and conventional management systems targeting the soil microarthropod communities. Also, the field margins were considered to better understand the biodiversity dynamics in this agroecosystem. In addition, the flora diversity was assessed in the selected sites