Effects of two kinds of tree litter leaf extracts on the growth and rhizosphere soil enzyme activity of Festuca arundinacea

This study investigated whether tree leaf extract affected the growth of Festuca arundinacea and rhizosphere soil properties. Through laboratory simulation experiment, taking irrigation with fresh water as the control, different concentrations 10 (T₁), 40 (T₂), and 80 g·L⁻¹ (T₃) of tree litter leaf extracts from Ginkgo biloba and Acer palmatum were employed to irrigate F. arundinacea seedlings. The effects of two kinds of tree litter leaf extracts on the growth and rhizosphere soil enzyme activity of F. arundinacea seedlings were studied. The results were as follows: Compared with the control, the catalase (CAT) activity of F. arundinacea changed little under the treatment of two kinds of tree litter leaf extracts. Superoxide dismutase (SOD) and Peroxidase (POD) activity first increased and then decreased, but the content of malondialdehyde (MDA) content first increased, then decreased, and then increased with increasing G. biloba litter leaf extract concentrations. MDA content increased by 60.33% under T₃ treatment compared to the control group. As the concentration of A. palmatum litter leaf extracts increased, the SOD activity of F. arundinacea gradually decreased, and the MDA content initially increased and then decreased. The POD activity first increased, then decreased, and then increased. Under T₃ treatment, the POD activity increased by 151.03% compared to the control group (P < 0.05). When F. arundinacea was treated with two kinds of tree litter leaf extracts, the xylosidase (XYL), β-Glucosidase (BG), α-Glucosidase (AG), cellobiohydrolase (CBH), and total soil enzyme (TSE) activity increased significantly compared to the control. However, leucine aminopeptidase (LAP) decreased first and then increased. Compared to the control, the LAP activity decreased to 31.69% and 70.40% under T₁ treatment of G. biloba and A. palmatum litter leaf extracts respectively, which caused a low nitrogen utilization efficiency of substrate soil and significantly reduced growth and physiological indicators of F. arundinacea. The results indicated that two kinds of tree litter leaf extracts had a significant inhibitory effect on the height, root length, and chlorophyll content of F. arundinacea. Additionally, the allelopathic inhibitory effect of the litter leaf extract from G. biloba was stronger than that from A. palmatum.