Effects of organic fertilizer on microbial characteristics and enzyme activities of soil degraded by highway construction

Objective  To study the short-term effects of different fertilizers on microbial characteristics and enzyme activities of lateritic soil degraded by highway construction.

Method  Greenhouse pot experiments were performed using Neyraudia reynaudiana. The lateritic soil degraded by highway construction was used as control(CK). Three fertilization treatments included chemical fertilizer(HF) with the same NPK degree as vermicompost, cattle manure (NF) and vermicompost (YF). The effects of different treatments on soil microbial characteristics and enzyme activities were investigated by principal component analysis.

Result  Compared with HF treatment, soil microbial biomass carbon, microbial biomass nitrogen, soil respiration, amounts of metabolic entropy, bacteria, fungi and actinomycetes significantly increased by 70%, 96%, 1 239%, 699%, 300%, 1 155% and 272% respectively in NF treatment, and increased by 80%, 130%, 1 458%, 773%, 295%, 324% and 285% respectively in YF treatment(P<0.05). Soil invertase, urease, catalase, acid phosphatase,β-glucosidase, acetylglucosaminidase, polyphenol oxidase and peroxidase activities significantly increased by 61%, 37%, 36%, 119%, 259%, 1 973%, 175% and 550% respectively in NF treatment, and increased by 66%, 40%, 52%, 128%, 302%, 1 641%, 182% and 428% respectively in YF treatment (P<0.05).

Conclusion  In short-term, applying organic fertilizer such as cattle manure and vermicompost is better than using chemical fertilizer for improving soil microbial properties, enhancing soil enzyme activities and improving comprehensive quality of soil degraded by construction. NF and YF treatments have no significant differences in their effects on soil microbial properties and enzyme activities. Applying organic fertilizer is an effective way to repair rapidly the soil degraded by construction.