中药渣堆肥过程中氮素转化及相关微生物菌群变化的研究

Study on nitrogen transformation and related microbial community changes during the composting process of Chinese medicinal herbal residues

为了促进中药渣废弃物资源化利用,以中药渣、芦苇渣和酱油渣为原材料,采用不同配比和添加有机物料腐熟菌剂进行堆肥处理,分析堆肥过程中的温度、微生物总数(细菌、放线菌和真菌)、氮素相关微生物菌群(自生固氮菌、氨化细菌、硝化细菌、反硝化细菌)、全氮、铵态氮、硝态氮和种子发芽指数的变化,探讨不同处理堆肥前后养分变化差异的原因。结果表明,在中药渣不同配比堆肥过程中,细菌数量最多,是放线菌和真菌至少10 000倍,细菌、氨化细菌数量变化是"高—低—高—低"走势,而自身固氮菌、硝化细菌、反硝化细菌数量变化是"高—低—高"走势。中药渣∶芦苇渣∶酱油渣的配比为45∶30∶25时,升温快,温度基本上维持在62℃左右,堆肥前后氮素损失率为4.0%,堆肥结束时发芽指数为74.4%;而中药渣∶酱油渣的配比为75∶25时,升温慢,氮素损失率为53.3%,堆肥结束时发芽指数仅为34.4%。中药渣中的抑菌物质影响了不同处理堆肥过程中微生物总数和氮素相关微生物菌群的变化,导致了堆肥前后养分变化的差异。研究表明,中药渣∶芦苇渣∶酱油渣的配比为45∶30∶25时,氮素损失少,腐熟快。该研究为中药渣废弃物高温好氧快速堆肥、减少氮素损失提供参考和借鉴。

In order to promote the utilization of waste materials from Chinese medicinal herbal residues, the Chinese medicinal herbal residues, reed residue, and soy sauce residue were mixed and composted with different proportions by adding microbial agents. All the mixtures were adjusted to the same C/N ratio. The temperature, microbial quantity（bacteria, actinomycetes and fungi）, nitrogen related microbial community（azotobacter, ammonifiers, nitrifying bacteria and denitrifying bacteria）, total nitrogen, ammonium nitrogen, nitrate nitrogen and seed germination index were investigated during the composting process, and the nutrient variation of different treatments before and after the composting were also discussed. Results showed that the number of bacteria was at least 10 000 times that of the actinomycetes and fungi, and the change in the number of bacteria and ammoniated bacteria tended to follow the trend of ＂high-low-high-low＂, whereas the number of azotobacter, nitrifying bacteria and denitrifying bacteria tended to be ＂highlow-high＂ trend during the composting. When the ratio of Chinese medicinal herbal residues：reed residue：soy sauce residue was 45 ∶ 30 ∶ 25, the temperature rised fast and maintained at about 62 ℃, only 4% of nitrogen was lost and germination index was 74.4% after the composting. However, when the ratio of Chinese medicinal herbal residues：soysauce residue was 75 ∶ 25, the temperature rised slowly and 53.3% of nitrogen was lost, the germination index was only 34.4% consequently. The antimicrobial substances in traditional Chinese medicine residues influenced the number of microorganisms and the change of nitrogen related microorganisms, which further resulted in the change of compost nutrient during the composting. Our results indicated that when the ratio of Chinese medicinal herbal residues：reed residue：soy sauce residue was 45 ∶ 30 ∶ 25, the compost decayed fast and was accompanied by less nitrogen loss. This study could provide reference for the high-temperature aerobic fast composting of Chinese medicinal herbal residues.