Changes in microbial utilization and fate of soil carbon following the addition of different fractions of anaerobic digestate to soils
Changes in microbial utilization and fate of soil carbon following the addition of different fractions of anaerobic digestate to soils
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DOI：
10.1111/ejss.13091
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发表时间：
2021-02-15
影响因子：
4.2
通讯作者：
Surridge, Ben W. J.
中科院分区：
文献类型：
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作者：
Cattin, Marta;Semple, Kirk T.;Surridge, Ben W. J.
将厌氧消化的残余物-亚硝酸盐施入土壤，作为无机肥料的替代物，在农业上越来越受到关注。然而，不同组分的碳酸盐对土壤碳（C）循环的影响仍然不清楚，并提供了重点的研究报告在这里。我们研究了应用全固态（WD）和固态（SD）对二氧化碳（CO2-C）排放，溶解有机碳（DOC），微生物生物量C（C-micro）和磷脂脂肪酸的浓度，以及碳利用效率（CUE）的影响。采用21天的实验室微宇宙培养法，研究了不同初始养分含量的两种草地土壤施用不同浓度的有机肥对土壤养分的影响。SD和WD的施用量是基于这些有机材料向草原土壤中推荐的氮（N）输入。与对照相比，施用WD和SD后，土壤CO2-C累积排放量和DOC浓度显著增加，但仅在低养分土壤中。无论初始土壤养分含量如何，SD施用后C-微生物和真菌与细菌的比例均显着增加。这些观察结果可能反映了更大的C输入，以及更强烈的木质素化合物的主导地位，与SD相比，WD实现恒定的N施用率。我们的结果还表明，两种消化物组分产生显着不同的CUE。施用SD后，C-micro增加，CUE为正值，而施用WD后，C-micro下降，CUE为负值。这些研究结果强调，需要仔细规划农业生产系统中的可持续发展管理，最大限度地减少对土壤中碳储量的负面影响，同时最大限度地提高碳源的农学价值。过去的研究还没有完全阐明碳源组分对土壤碳循环的影响。土壤养分状况+碳源组分对微生物群落和CO2-固态组分对微生物生物量和碳利用效率有积极的影响。
Applying digestate, the residue from anaerobic digestion, to soil as a replacement for inorganic fertiliser is of growing interest in agriculture. However, the impacts of different fractions of digestate on the soil carbon (C) cycle remain unclear and provide the focus for the research reported here. We examined the effects of applying whole digestate (WD) and solid digestate (SD) on carbon dioxide (CO2-C) efflux, the concentrations of dissolved organic carbon (DOC), microbial biomass C (C-micro) and phospholipid fatty acids, alongside carbon use efficiency (CUE). A 21-day laboratory microcosm incubation was used to investigate the impacts of digestate when applied to two grassland soils of high versus low initial nutrient content. Application rates for SD and WD were based on recommended nitrogen (N) inputs to grassland soils for these organic materials. Compared to control treatments, cumulative CO2-C efflux and the concentration of DOC increased significantly after WD and SD application, although only within the low nutrient soil. Both C-micro and the fungal-to-bacterial ratio increased significantly following SD application, regardless of the initial soil nutrient content. These observations are likely to reflect the larger input of C, alongside the dominance of more strongly lignified compounds, associated with SD compared to WD to achieve a constant N application rate. Our results also indicate that the two digestate fractions generated significantly different CUE. The application of SD led to increases in C-micro and positive values of CUE, whereas decreases in C-micro and negative values of CUE were observed following WD application. These findings emphasize the need to carefully plan the management of digestate in agricultural production systems, to minimize negative impacts on C storage within soils whilst maximizing the agronomic value derived from digestate.HighlightsPast research has not fully elucidated the impacts of digestate fractions on the soil C cycle.Soil nutrient status + digestate fraction shown to impact microbial community and CO2-C efflux.Solid digestate fraction has positive impacts on microbial biomass and carbon use efficiency.