**5. Conclusions**

The organic conservative system tested in our experiment (ORG+) revealed to be ine ffective in terms of crop yield and N uptake for the four vegetable crops. Nevertheless, potentialities in terms of reduction of environmental pollution risks by avoiding nitrogen surplus in the soil and better exploitation of natural internal resources (N from N2-fixation and higher availability of soil P) were highlighted. As organic cover crop and no-till based cropping systems should express their potential when designed tailored to local pedoclimatic and agronomic conditions, we encourage further development of the system through additional investigations on soil nutrient cycling processes and weed dynamics in no-till systems, as well as on developing and testing innovative technologies for the managemen<sup>t</sup> of cover crops, weeds, irrigation, and fertilization adapted to such systems.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2073-4395/9/12/810/s1, Figure S1: Total fresh marketable yield (Mg ha−1) of the entire crop sequence under the three cropping systems (INT, ORG, and ORG+). Bars are standard errors. Confidence level 95%, Table S1: Agricultural practices carried out in Field 1 for each crop in the whole experimental period, Table S2: Agricultural practices carried out in Field 2 for each crop in the whole experimental period, Table S3: Type III analysis of variance table with Satterthwaite's method of the model lmer (y~cropping system\*year+(1|block)+(1|year) for savoy cabbage. Confidence level: 95%, Table S4: Type III analysis of variance table with Satterthwaite's method of the model lmer (y~cropping system\*year+(1|block)+(1|year) for fennel. Confidence level: 95%, Table S5: Type III analysis of variance table with Satterthwaite's method of the model lmer (y~cropping system\*year+(1|block)+(1|year) for spring lettuce. Confidence level: 95%, Table S6: Type III analysis of variance table with Satterthwaite's method of the model lmer (y~cropping system\*year+(1|block)+(1|year) for summer lettuce. Confidence level: 95%, Table S7: Field log of Field 1 and Field 2 with dates and operational details on each field operation practiced in the three years of the experiment.

**Author Contributions:** Conceptualization, D.A., M.F., and C.F.; methodology, D.A., C.F., and L.M.; validation, D.A., C.F., and M.M.; formal analysis, L.M.; investigation, D.A., M.S., C.F., and L.A.C.; resources, C.F., M.M., A.P., and M.R.; data curation, D.A., M.S., and C.F.; writing—original draft preparation, D.A. and L.M.; writing—review and editing, D.A., C.F., M.M., A.P., L.A.C., M.F., and M.R.; project administration, C.F.; funding acquisition, C.F.; statistical analysis of data, L.M.

**Funding:** This research was carried out within the project SMOCA "Smart Management of Organic Conservation Agriculture" (http://smoca.agr.unipi.it/) funded by the Italian Ministry of University and Research (MIUR) within the program FIRB-2013 (Future in Research) and MIUR-FIRB13 (project number: RBFR13L8J6).

**Acknowledgments:** The authors would like to acknowledge the sta ff at the "Enrico Avanzi" Centre for Agro-Environmental Research of the University of Pisa who managed the field trials and provided technical support throughout. In particular, we are grateful to Alessandro Pannocchia, Giovanni Melai, Marco Della Croce, and Paolo Gronchi, who were in charge of field operations. We also thank Roberta Del Sarto, Nadia Ceccanti, Rosenda Landi, and Serena Sbrana for their help in sample processing. Finally, we acknowledge also Rosalba Risaliti and Sabrina Ciampa for their support in the chemical analysis of plant samples.

**Conflicts of Interest:** The authors declare no conflict of interest.
