Abstract: In order to study the effects of combined application of biogas manure and chemical fertilizer in different proportions on soil properties, cornfield soil was selected as experimental material. Six different fertilization treatments were selected for corn field soil, including CK（no fertilization）, HF（chemical fertilizer）, ZH20（20% biogas fertilizer + 80% chemical fertilizer）, ZH50（50% biogas fertilizer + 50% chemical fertilizer）, ZH80（80% biogas fertilizer + 20% chemical fertilizer） and ZF100（100% biogas fertilizer）. Random block design was used. The effects of each treatment on soil bulk density, pH, organic matter content and available nitrogen, phosphorus and potassium content in five key maize growth stages, including jointing stage, small bell-mouthing stage, big bell-mouthing stage, tasseling and silking stage and physiological maturity, were studied by using random block design experiment. The results showed that the application of 100% biogas manure significantly decreased the content of soil organic matter at small bell-mouthing stage, but at physiological maturity it increased the content of soil organic matter significantly; The soil bulk density decreased in all fertilization treatments during the five growth stages, and the higher the concentration of biogas fertilizer, the more obvious the decrease of soil bulk density was; Compared with group CK, soil pH decreased in group HF, while increased in group ZH20, ZH50, ZH80 and ZF100 during the five growth stages; the application of ZH50 had the most significant effect on increasing soil available nitrogen content; The application of ZF100 and ZH80 had the most significant effect on increasing soil available phosphorus content; There was no significant difference among the effects on improving soil available potassium content of all fertilization treatments.

Key words: biogas manure, chemical fertilizer, soil properties, cornfield