不同湿热条件下真菌发酵玉米秸秆残留物还田对土壤胡敏酸结构的影响OA北大核心CSTPCD

Straw returning is one of the main ways to realize corn straw resource utilization,and the effect of corn straw residue returning after solid-state fermentation is better than that of corn straw re-turning directly.However,it is rarely discussed whether the return effect of corn straw residue under different humid and hot conditions is the same.Therefore,in this study,6 treatments were set up,which were blank control(ck),direct straw returning(CS),temperature 25℃,humidity 70%(T25H70),temperature 30℃,humidity 70%(T30H70),temperature 30℃,humidity 60%(T30H60)and temperature 25℃,humidity 60%(T25H60)straw residues returned to the field.The effects of solid-state fermen-tation corn straw residue return to the field on soil HA(humic acid)structure under different humid and hot conditions were investigated by means of elemental composition,infrared spectroscopy and thermal stability analysis,to provide theoretical basis for corn straw returning to the field in agricul-tural production.The results showed that returning corn straw residues to the field under different hu-mid and hot conditions led to the simplification of soil HA structure.Among them,T30H70 treated O/C was 0.686,H/C was 1.268,T25H70 treated I2920/I1620 was 0.78 and high/medium weight loss ratio was 0.87.Fermentation temperature of 25 humidity 70%straw residue returned to the field(T25H70)treat-ment showed the best effect in enhancing aliphatic properties of soil HA molecules and reducing the degree of aromatization.