Plant presence significantly influenced soil total nitrogen and the C/N ratio ( p < 0.05), and exerted highly significant effects on the C/P and N/P ratios ( p < 0.001), whereas aggregate size showed no significant main effect.
Both inoculants significantly enhanced acid phosphatase activity under planted conditions, whereas their stimulatory effects on enzyme activity C/P and N/P ratios were markedly weakened or reversed in the presence of plants, although these changes did not reach statistical significance.
Specifically, NL-15 decreased NAG activity under no-plant conditions but exhibited an increasing trend when plants were present.