甘蔗有机物料还田对土壤理化性质、微生物及甘蔗生长的影响OA

The study systematically investigated the long-term regulatory effects of returning sugarcane organic materi-als to the field on soil physicochemical properties,microbial communities,and sugarcane growth to solve the problems of soil acidification,organic matter attenuation and structural degradation in sugarcane fields on dry slopes in China.Through a three-year barrel planting experiment(including one new planting season and two-year ratoon season),four types of sugarcane organic materials were returned to the field,including filter mud(T1),sugarcane bagasse ash(T2),sugarcane leaves(T3),sugarcane bagasse(T4),along with control(without organic amendment).Soil nutrients,physical structure,microbial diversity,root morphology,yield and sugar content were measured.The four sugarcane organic materials returned to the field reduced soil bulk density and improved soil mechanical properties and pore structure,but significant difference were observed in the effects of different materials.T1 and T2 significantly increased soil pH,total organic carbon(TOC),alkali-hydrolyzable nitrogen(AN)and available phosphorus(AP).T1 consistently optimized deep soil structure,and T2 had a significant effect on improving available potassium(AK)and water retention.T3 and T4 mainly increased soil TOC content,but T4 aggravated soil acidification during the new planting season.T3 and T4 pro-moted the formation of highly stable large aggregates,with significant short-term effect.Although T1 and T2 promoted the formation of mechanically stable large aggregates,the water stability was poor.T1 and T2 had significant and long-lasting effects on improving the diversity and richness of soil bacteria and fungi,T3 promoted microbial activity in the early stage but inhibited it in the later stages,and T4 significantly restored microbial diversity in the later stages.T1 had the most significant effect on increasing yield and sugar content,T2 had an outstanding effect on promoting root development and had significantly effects on increasing yield and sugar content.T3 had a certain yield-increasing effect in the later stages.T4 led to a yield reduction and was not conducive to sugar accumulation.Overall,the effects of re-turning different sugarcane organic materials to the field varied significantly.Filter mud(T1)proved to be the optimal material,combining long-term soil improvement,enhanced microbial diversity,and increased yield and sugar content.Sugarcane bagasse ash(T2)was suitable for short-term water retention and root growth,but the risk of deep soil com-paction must be controlled.Sugarcane leaves(T3)should be accompanied by nitrogen fertilizer.Sugarcane bagasse(T4)returning to field requires decomposition pretreatment.This study could provides theoretical support for the precise return of sugarcane organic materials to the field and the sustainable management of cultivated land in red soil areas.