Key Laboratory of Microbial Resources Exploitation and Application of Gansu Province, Institute of Biology, Gansu Academy of Sciences, Lanzhou 730000, China; State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China.
State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China.
Sci Total Environ. 2024 Sep 20;944:173975. doi: 10.1016/j.scitotenv.2024.173975. Epub 2024 Jun 12.
Arbuscular mycorrhizal fungi (AMF) establish symbiotic relationships with roots of most plants, contributing to plant water uptake and soil carbon (C) sequestration. However, the interactive contribution and of long-term field AMF inoculation and water conservation on maize yield and soil organic carbon (SOC) sequestration in drylands remain largely unknown. After 7-year long-term field inoculation with AMF Funneliformis mosseae, AMF suppression by fungicide benomyl, and no-AMF/no-benomyl control, and two water conservation practices of half-film and full-film mulching (∼50 % and ∼100 crop planted area covered with plastic film), this study thus applied in situ CO-C labeling and high-throughput sequencing to quantify newly photosynthetically assimilated C into different soil C pools including soil aggregates and respiration, and their effects on maize growth and productivity. Results showed that 7-year long-term AMF inoculation significantly increased the relative abundance of F. mosseae in rhizosphere soil and root AMF colonization, indicating that F. mosseae successfully dominated in AMF communities. Compared to no-AMF/no-benomyl control, AMF colonization significantly increased shoot biomass and maize yield by 17.9 % and 20.3 % while mitigated the less water conservation effects of half-film mulching on maize performance. The SOC content under field AMF inoculation SOC was increased from 7.9 to 8.4 g kg and also the mean weight diameter of aggregates (1.21 to 1.35), e.g. aggregate stability. After 1 and/or 40 days C labeling, the enhanced C translocations into macro-aggregates with decreased C emissions from microbial decomposition under field AMF inoculation had contributed to SOC conservation in bulk soil. These results suggest that AMF inoculation in dryland crops is promising to increase crop yield while promoting more atmospheric CO fixation in soil aggregates. A long-term field AMF inoculation will enhance our understanding of applying beneficial mycorrhizal fungi to enhance soil C sequestration and also crop yield via plant-fixed atmospheric CO in semi-arid and arid farmlands.
丛枝菌根真菌 (AMF) 与大多数植物的根系建立共生关系，有助于植物吸收水分和土壤碳 (C) 固存。然而，长期田间 AMF 接种和节水措施对旱地玉米产量和土壤有机碳 (SOC) 固存的相互贡献仍然知之甚少。经过 7 年的长期田间接种丛枝菌根真菌摩西管柄囊霉、杀菌剂苯菌灵抑制 AMF 以及无 AMF/无苯菌灵对照，以及半膜和全膜覆盖两种节水措施（约 50%和约 100%的作物种植面积覆盖塑料薄膜），本研究应用原位 CO-C 标记和高通量测序技术，定量了新光合作用同化的 C 进入不同的土壤 C 库，包括土壤团聚体和呼吸，及其对玉米生长和生产力的影响。结果表明，7 年的长期 AMF 接种显著增加了根际土壤中摩西管柄囊霉的相对丰度和根 AMF 定殖，表明摩西管柄囊霉在 AMF 群落中成功占主导地位。与无 AMF/无苯菌灵对照相比，AMF 定殖显著增加了地上生物量和玉米产量，分别增加了 17.9%和 20.3%，同时减轻了半膜覆盖对玉米性能的节水效果较小。田间 AMF 接种 SOC 下的 SOC 含量从 7.9 增加到 8.4 g kg，团聚体的平均重量直径（1.21 至 1.35），例如团聚体稳定性。在 1 天和/或 40 天 C 标记后，增强的 C 向大团聚体的转移和减少的微生物分解产生的 C 排放有助于土壤团聚体中的 SOC 保存。这些结果表明，在旱地作物中接种 AMF 有望在提高作物产量的同时，通过植物固定大气 CO 来增加土壤团聚体中的 CO 固定。长期田间 AMF 接种将增强我们对应用有益菌根真菌来增强半干旱和干旱农田土壤碳固存和作物产量的理解。
