Abstract: To investigate the effects of biochar and organic fertilizer application on the improvement of aeolian sandy soil, a study was conducted using maize (Zea mays L.) as the test crop, with pear branch-derived biochar and chicken manure organic fertilizer as amendments. Nine treatments were established: CK (control, without biochar and organic fertilizer), biochar application (1, 4, 20 t/hm²), organic fertilizer application (1, 4, 20 t/hm²), and combined applications (4 t/hm² biochar + 4 t/hm² organic fertilizer, 4 t/hm² biochar + 8 t/hm² organic fertilizer). The contents of organic carbon, alkali-hydrolyzable nitrogen, and available phosphorus in rhizosphere soil, and the variation characteristics of plant height, stem diameter, and root length at different growth stages (seedling, jointing, filling, heading, and maturity stages) were analyzed. The results showed that the application of biochar (20 t/hm²) and organic fertilizer (20 t/hm²) significantly increased rhizosphere soil organic carbon content at the seedling and heading stages, with increases of 28.79% and 36.21%, respectively. The application of biochar and organic fertilizer promoted plant height, stem diameter, root length, and cell differentiation in the root tip maturation zone across all growth stages. The radial diameter of root tips, and the number and diameter of xylem vessels in the maturation zone were significantly enhanced. The results of correlation analysis showed that biochar application rate was significantly positively correlated with rhizosphere soil organic carbon and alkali-hydrolyzable nitrogen content (P<0.05). The application amount of organic fertilizer was significantly positively correlated with available phosphorus content and corn stem diameter (P<0.05).

Key words: corn (Zea mays L.), aeolian sandy soil, biochar, organic fertilizer, rhizosphere soil, nutrient content