Table 3. δ15Nair in Tomato Plants Grown under Conventional and Organic Fertilizer Applications in 2014 and 2015a,e,f.
| tomato
leaflet δ15Nair (mean ± std (‰)) |
tomato
peel δ15Nair (mean ± std (‰)) |
tomato
juice δ15Nair (mean ± std (‰)) |
|||||
|---|---|---|---|---|---|---|---|
| soil treatment | soil δ15Nair (mean ± std (‰)) | immatureb | maturec | C1d | C2d | C1d | C2d |
| 2014 season | |||||||
| no fertilization | 1.8cd ± 1.1 | 4.9b ± 1.0 | 6.4ab ± 2.5 | 4.3c ± 1.9 | 4.8c ± 0.3 | 4.6c ± 1.3 | |
| MG | 1.0d ± 0.5 | 0.4e ± 0.5 | –0.3b ± 0.6 | 0.4d ± 0.2 | 0.3d ± 0.4 | 1.9d ± 1.0 | 1.9a ± 0.2 |
| BB | 2.1cd ± 1.0 | 4.5c ± 1.3 | 6.8a ± 2.1 | 6.7bc ± 0.5 | 7.7b ± 1.3 | 8.5b ± 1.4 | |
| BBL | 2.9bc ± 1.0 | 4.6b ± 1.4 | 5.6a ± 2.2 | 6.8bc ± 0.3 | 6.9b ± 0.4 | 6.9b ± 1.3 | 7.2a ± 0.2 |
| BB w/VC | 4.8a ± 0.2 | 6.5a ± 0.4 | 7.1a ± 0.9 | 8.2a ± 0.4 | 9.1a ± 0.3 | 11.1a ± 2.9 | 8.5a ± 0.8 |
| BBL w/VC | 4.8a ± 0.2 | 8.1a ± 1.7 | 7.6a ± 2.0 | 9.6a ± 0.6 | 9.2a ± 1.5 | 8.6b ± 2.3 | 8.3a ± 0.9 |
| MG w/VC | 4.0ab ± 0.4 | 2.9d ± 1.0 | 2.6b ± 0.6 | 1.2d ± 0.4 | 1.0d ± 0.9 | 2.6d ± 0.5 | 2.9a ± 0.8 |
| VC only | 4.6ab ± 0.5 | 8.3a ± 1.0 | 8.1a ± 1.5 | 10.1a ± 0.9 | 8.5a ± 2.1 | 10.2a ± 2.4 | 9.1a ± 1.6 |
| P-value | 0.0001 | 0.0014 | 0.0001 | 0.0001 | 0.0001 | 0.009 | 0.0922 |
| 2015 season | |||||||
| no fertilization | 0.9ab ± 2.1 | 6.6b ± 0.8 | 5.5b ± 1.7 | 5.7c ± 0.6 | 3.4c ± 2.3 | 5.2c ± 0.8 | 2.3c ± 0.0 |
| MG | –1.4b ±1.7 | –3.0c ± 0.6 | –0.9d ± 0.8 | –1.1d ± 0.7 | 0.3d ± 2.2 | –0.9e ± 0.8 | –0.8d ± 0.0 |
| BB | 1.2a ± 0.7 | 6.5b ± 0.5 | 6.7a ± 2.3 | 5.4bc ± 0.8 | 6.7b ± 1.2 | 6.1b ± 0.9 | 7.5ab ± 1.2 |
| BBL | 0.5ab ± 1.4 | 7.1b ± 1.0 | 6.0b ± 1.5 | 6.0b ± 0.1 | 6.5b ± 0.3 | 6.7b ± 0.9 | 6.9b ± 0.4 |
| BB w/VC | 3.4a ± 0.6 | 11.9a ± 2.0 | 8.1a ± 1.2 | 9.4a ± 1.2 | 7.6a ± 1.1 | 9.4a ± 0.7 | 8.0a ± 0.9 |
| BBL w/VC | 4.4a ± 0.6 | 9.7a ± 0.7 | 6.4ab ± 1.3 | 6.7b ± 1.2 | 7.0a ± 0.6 | 6.9ab ± 1.0 | 6.8b ± 0.8 |
| MG w/VC | 3.6a ± 0.9 | 2.8c ± 2.0 | 3.1c ± 2.0 | 0.3d ± 1.2 | 0.6d ± 1.1 | 1.2d ± 0.7 | 1.9d ± 0.5 |
| VC only | 2.4a ± 1.4 | 11.9a ± 0.7 | 8.1a ± 2.0 | 8.7a ± 0.7 | 8.8a ± 1.6 | 8.3a ± 5.0 | 2.3c ± 0.0 |
| P-value | 0.0049 | 0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.005 | 0.005 |
a
Fertilizer treatments had mean separations (e.g., a or ab) by Fisher’s least significant differences (LSD) at P ≤ 0.05. Values with the same letter are not significantly different at P = 0.05 according to LSD.
b
Immature = first leaflet harvest (9 Sept 2014 and 5 Sept 2015).
c
Mature = second leaflet harvest (13 Oct 2014 and 7 Oct 2015).
d
C1 and C2 = fruit cluster 1 and cluster 2 tomatoes.
e
3 replicates per treatment.
f
Standard deviation calc. on intra treatment variation.