煤基与生物基腐植酸配施对土壤结构改良的影响OA北大核心CSTPCD

In this study,the soil incubation method was used to investigate the effect of mixing coal-based humic acid with bio-based humic acid on soil structure and to screen for an optimal mixture ratio.In this study,coal-based humic acid and bio-based humic acid were mixed at different mass ratios to form a composite humic acid to improve semi-arid soils.No humic acid was used as a control(CK)to analyze the effects of the composite humic acid on structural indices such as soil aggregates and porosity at 10,25 d,and 50 d of incubation.The results showed that the overall improvement effect of each index was 50 d>25 d>10 d.The soil agglomerate content and average weight diameter increased with the increase of coal-based humic acid content,and was best when coal-based humic acid was applied alone.The soil agglomerate increased 116.36%compared with the CK group at 50 d of incubation and the average mass diameter increased by 21.80%compared with the CK group.In comparison,it was found that total soil porosity,and field water holding capacity changed significantly with an increase in the proportion of bio-based humic acid at 10 d of incubation,while the effect was stronger with an increase in the proportion of coal-based humic acid at 25 d and 50 d of incubation.The 7∶3 combination of coal-based humic acid and bio-based acid was optimal,and the total soil porosity and field water holding capacity of this combination at 50 d increased by 10.46%and 43.52%,respectively,and decreased by 8.25%in bulk density compared with the CK group.In a comprehensive analysis,both coal-based humic acid and bio-based humic acid could effectively improve soil structure,and the best effect was achieved when the mixing mass ratio was 7∶3.This composite humic acid mixing ratio can combine the advantages of bio-based humic acid and coal-based humic acid and provide technical support and scientific basis for the restoration of degraded soil.