RESIDUE PLACEMENT AND FUNGICIDE EFFECTS ON FUNGAL COMMUNITIES IN CONVENTIONAL AND NO-TILLAGE SOILS
RESIDUE PLACEMENT AND FUNGICIDE EFFECTS ON FUNGAL COMMUNITIES IN CONVENTIONAL AND NO-TILLAGE SOILS
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DOI：
10.2136/sssaj1993.03615995005700020018x
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发表时间：
1993-03-01
影响因子：
2.9
通讯作者：
COLEMAN, DC
中科院分区：
文献类型：
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作者：
BEARE, MH;POHLAD, BR;COLEMAN, DC
我们研究了杀菌剂克菌丹（cis-N-三氯甲硫基-4-环己烯-1,2-二甲酰亚胺）和长期常规（CT）和免耕（NT）管理对农作物残留物和矿质土壤中真菌群落大小和组成的影响。在 Hiwassee 砂质粘壤土（粘土、高岭土、热 Rhodic Kanhapludult）的 CT 和 NT 样地中建立了克菌丹和参考处理。每隔一段时间，收集高粱 [Sorghum Bicolor (L.) Moench] 垃圾袋和土壤，用于计数和鉴定真菌菌丝和真菌菌落形成单位 (CFU)，并确定残留物分解率。与表面残留物 (NT) 相比，埋藏残留物 (CT) 的真菌菌丝密度较高，但真菌 CFU 较少。掩埋残渣的衰减速率 (k = 0.0136 d-1) 比地表残渣 (k = 0.0040 d-1) 快 3.4 倍。 NT 矿质土壤中的真菌菌丝比 CT 矿质土壤中的真菌菌丝更为丰富，但真菌 CFU 没有差异。高粱残渣具有一系列常见的真菌，包括叶际定植菌（例如，链格孢、黑附球菌）和其他常见分解真菌（柱果霉、镰刀菌、毛霉和茎点霉）。真菌群落被分化为表面残留物（例如链格孢属、附球菌属）和土壤（例如曲霉属、木霉属）专家，而埋藏残留物缺乏专门的群落。无根根霉和黑曲霉在统计上显示出对 CT 土壤的偏好，而疣状青霉在 NT 中最常见。克菌丹降低了 NT 和 CT 残留物中的真菌 CFU 和菌丝密度，导致其腐烂率分别降低 23% 和 7%。我们没有发现任何证据表明克菌丹对残留物或土壤中真菌群落的组成有不同的影响。
We investigated the effects of the fungicide captan (cis-N-trichloromethylthio-4-cyclohexene-1,2-dicarboximide) and long-term conventional (CT) and no-tillage (NT) management on the size and composition of fungal communities from crop residues and mineral soil. Captan and reference treatments were established in CT and NT plots on a Hiwassee sandy clay loam soil (clayey, kaolinitic, thermic Rhodic Kanhapludult). At intervals, grain sorghum [Sorghum Bicolor (L.) Moench] litterbags and soils were collected for enumeration and identification of fungal hyphae and fungal colony-forming units (CFU) and to determine residue decomposition rates. Buried residues (CT) had higher densities of fungal hyphae but fewer fungal CFU than surface residues (NT). Buried residue decay rates (k = 0.0136 d-1) were 3.4 times faster than surface residues (k = 0.0040 d-1). Fungal hyphae were more abundant in NT than CT mineral soils but there were no differences in fungal CFU. Sorghum residues had a common succession of fungi including phyllosphere colonizers (e.g., Alternaria alternata, Epicoccum nigrum) and other common decomposer fungi (Cylindrocarpon, Fusarium, Mucor, and Phoma). Fungal communities were differentiated into surface residue (e.g., Alternaria, Epicoccum) and soil (e.g., Aspergillus, Trichoderma) specialists, while buried residues lacked a specialized community. Rhizopus arrhizus and Aspergillus niger showed a statistical preference for CT soils, while Penicillium verruculosum was most common in NT. Captan reduced fungal CFU and hyphal densities in residues of both NT and CT, resulting in 23 and 7% reductions in their decay rates, respectively. We found no evidence for differential effects of captan on the composition of the fungal communities in residues or soils.