▎ 摘　　要

NOVELTY - Modified maize-cob biochar-based slow-release compound fertilizer, comprises 5-23.7 pts. wt. modified maize-cob biochar, 71.3-82 pts. wt. chemical fertilizer and 5-8 pts. wt. bentonite. Preparing the modified maize cob biochar comprises (1) mixing maize-cob residue powder and graphene oxide to obtain a mixture, (2) sequentially heating the mixture at 90-110° C for 55-65 minutes, 290-310° C for 1.8-2.2 hours and 490-510° C for 2.5-3.5 hours to obtain a biochar raw material, (3) crushing and sieving biochar raw material to obtain biochar particles. (4) mixing the biochar particles with ferric chloride solution, standing is carried out at 58-62° C, removing the moisture, and carrying out heat treatment at 250-350° C for 1.5-2 hours to obtain the modified maize-cob biochar. USE - The modified maize-cob biochar-based slow-release compound fertilizer is useful in crop planting (claimed). ADVANTAGE - The modified maize-cob biochar-based slow-release compound fertilizer: increases the organic matter content of the soil; improves the physical properties of the soil; improves the microbial activity of the soil; accelerate the material and energy cycle of the soil; and improves the productivity of the soil. The ability of modified maize-cob biochar-based slow-release compound fertilizer to improve the maize yield was tested by measuring maize yield using field trial assay. The result showed that the field treated with 60 kg/mu modified maize-cob biochar-based slow-release compound fertilizer (comprised of 9 kg modified biochar, 5 kg bentonite, and a granular chemical fertilizer, 39 kg urea, 22 kg ammonium perphosphate, 20 kg potassium chloride, 9 kg modified biochar, 5 kg Aspergillus nigerH201 culture) exhibited 583 kg/mu of maize yield as compared to control fertilizer who exhibited 562 kg/mu of maize yield. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the slow-release compound fertilizer comprising mixing modified maize-cob biochar, a chemical fertilizer and bentonite to obtain a mixture, and granulating the mixture at 80-100° C to obtain the slow-release compound fertilizer.