## 3 Results
### Nitrogen and Carbon Pools in Soil  
Soil N pools significantly differed (\(p<0.05\)) between the treatments and among the sampling times, with the exception of TN that shows significant differences among sampling times only (\(p<0.05\)) (Table S1, Supplementary Materials). High TN were detected in Nov-2012 and Sep-2013, while a depletion was observed in May-2013 and Jun-2013. Similar behavior is recorded for Fix N-NH4\({}^{+}\) pool but in this case, all ZT shows slightly lower values (\(p<0.05\)) in Nov-2012 with respect to the CNTR, while in Jun-2013 only 15 NZ treatment is significantly lower (Table S1, Supplementary Materials). At the beginning of the experiment, N-NO3\({}^{-}\) content was significantly higher in the CNTR and 7 CZ parcels than in those amended with NZ (5 NZ and 15 NZ, respectively) (\(p<0.05\)). In May-2013 a general depletion of N-NO3\({}^{-}\) pool is noticed in all the treatments, increasing in Jun-2013 after urea addition especially in CNTR parcel. N-NO3\({}^{-}\) values of ZT (especially 5 NZ and 15 NZ) were remarkably lower in this period with respect to the CNTR (\(p<0.05\)) (Table S1, Supplementary Materials). Exch N-NH4\({}^{+}\) was significantly affected by NEZ addition in Nov-2012 (\(p<0.05\)) (138 mg kg\({}^{-1}\) vs 50 mg kg\({}^{-1}\) of 7 CZ and CNTR, respectively) while starting from May-2013 these differences completely disappeared (\(p>0.05\)). In Jun-2013, there were no differences between the treatments (\(p>0.05\)) while a relative enrichment of the bulk soil Exch N-NH4\({}^{+}\) with respect to the rhizosphere was apparent in Sep-2013. Generally, at the beginning of the experiment, all treatments showed a low Nmic content, following the order 7 CZ \(>\) CNTR \(>\) 5 NZ = 15 NZ, suggesting that zeolites differentially affected the Nmic pool. Nmic was increased by NEZ addition while it was decreased by NZ addition. The Nmic pool increases in May, while it decreases in June after the chemical fertilization; as expected, Nmic content in rhizosphere soil is higher than that determined in the bulk soil at the harvest (Table S1, Supplementary Materials). A remarkable increase of Cmic and Nmic and a contemporaneous decrease of N-NO3\({}^{-}\) in all the treatments was observed in May-2013 (Figure 4). During the monitored period, Cmic ranged from 16 to 432 mg kg\({}^{-1}\). At the beginning of the experiment large differences (\(p<0.05\)) were detected among the various treatments. In this period, Cmic content decreases following the order CNTR (148 mg kg\({}^{-1}\)) \(>\)15 NZ (98.5 mg kg\({}^{-1}\)) \(>\) 7 CZ (43.2 mg kg\({}^{-1}\)) \(>\) 5 NZ (16.1 mg kg\({}^{-1}\)). In May-2013, Cmic increased in all treatments, except for 15 NZ, and decreased again in Jun-2013. As expected, Cmic content in the rhizosphere is higher than that determined in the bulk soil. The average Cmic/Nmic ratio ranges from 3.3 to 94 (Figure 5). In Nov-2012, low values of Cmic/Nmic were observed in 5 NZ and 7 CZ treatments; concerning 5 NZ, the low ratio is due to the lower Cmic with respect to the other treatments, while for 7 CZ the low ratio may have been due to the high Nmic. All ZT have a higher Cmic/Nmic ratio than CNTR after May-2013 because of the lower Nmic; on average, Cmic/Nmic ratio increased in order of 15 NZ \(>\) 5 NZ \(>\) 7 CZ \(>\) CNTR. TOC showed significant differences between the treatments and among the sampling times (\(p<0.05\)). In particular, a depletion of TOC content was observed in 7 CZ in Nov-2012 and in Jun-2013, after urea addition (Table S1,