Table 1 Soil variables at the depths of 0–15 cm beneath four different graft clones under well-watered and water deficit conditions. Each value is the mean ± SE (n = 3 pots). Means with the different letter in the same row are significantly different according to Tukey’s post-hoc test (P < 0.05). EOC Soil extractable carbon, NAG β-1, 4-N-acetyl-glucosaminidase, LAP leucine aminopeptidase; NH₄⁺-N ammonium nitrogen, NO₃⁻-N nitrate nitrogen

pH

5.7 ± 0.2a

5.6 ± 0.2a

5.7 ± 0.1a

5.7 ± 0.3a

5.8 ± 0.2a

5.5 ± 0.3a

4.8 ± 0.1b

4.6 ± 0.1b

EOC (mg kg⁻¹)

352.4 ± 30.3ab

349.4 ± 37.6ab

354.8 ± 29.7ab

339.6 ± 14.7b

225.9 ± 11.2c

226.8 ± 7.8c

458.5 ± 3.6a

445.5 ± 19.6ab

NAG (nmol g C⁻¹ h⁻¹)

11.8 ± 0.4b

14.8 ± 1.6b

14.2 ± 0.9b

15.2 ± 0.7ab

13.5 ± 1.b

12.6 ± 0.8b

18.8 ± 0.5a

18.5 ± 0.7a

LAP (nmol g C⁻¹ h⁻¹)

236.6 ± 7.1ab

245.8 ± 11.7ab

237.8 ± 19.1ab

246.9 ± 17.6 ab

237.3 ± 13.1ab

217.8 ± 10.2b

306.3 ± 38.0a

313.9 ± 13.4a

NH₄⁺-N (mg kg⁻¹)

15.0 ± 0.3b

15.5 ± 0.4ab

14.9 ± 0.3b

15.3 ± 0.2ab

16.6 ± 0.4a

16.4 ± 0.5ab

11.0 ± 0.1c

11.3 ± 0.3c

NO₃⁻-N (mg kg⁻¹)

14.5 ± 0.2b

13.2 ± 0.4b

13.4 ± 0.3b

13.2 ± 0.4b

15.0 ± 0.6ab

16.5 ± 0.5a

9.9 ± 0.1c

9.6 ± 0.6c

Soil δ¹⁵ N (‰)

5.25 ± 0.14a

5.21 ± 0.08a

5.25 ± 0.15a

5.20 ± 0.12a

5.12 ± 0.12ab

5.22 ± 0.13a

4.58 ± 0.09b

4.56 ± 0.07b