L_A (low NH₄ ⁺)

8.36 ± 0.03^a

8.34 ± 0.02^a

0.86 ± 0.03^a

0.44 ± 0.02^b

M_A (medium NH₄ ⁺)

8.66 ± 0.01^b

8.61 ± 0.04^b

1.16 ± 0.01^c

0.71 ± 0.04^a

H_A (high NH₄ ⁺)

8.78 ± 0.18^b

8.77 ± 0.07^b

1.28 ± 0.18^c

0.87 ± 0.07^a