United States Department of Agriculture–Agricultural Research Service, New England Plant, Soil, and Water Laboratory, Orono, ME 04469, USA.
Phytopathology. 2011 Jan;101(1):58-67. doi: 10.1094/PHYTO-04-10-0100.
Four different potato cropping systems, designed to address specific management goals of soil conservation, soil improvement, disease suppression, and a status quo standard rotation control, were evaluated for their effects on soilborne diseases of potato and soil microbial community characteristics. The status quo system (SQ) consisted of barley underseeded with red clover followed by potato (2-year). The soil-conserving system (SC) featured an additional year of forage grass and reduced tillage (3-year, barley/timothy-timothy-potato). The soil-improving system (SI) added yearly compost amendments to the SC rotation, and the disease-suppressive system (DS) featured diverse crops with known disease-suppressive capability (3-year, mustard/rapeseed-sudangrass/rye-potato). Each system was also compared with a continuous potato control (PP) and evaluated under both irrigated and nonirrigated conditions. Data collected over three potato seasons following full rotation cycles demonstrated that all rotations reduced stem canker (10 to 50%) relative to PP. The SQ, SC, and DS systems reduced black scurf (18 to 58%) relative to PP; SI reduced scurf under nonirrigated but not irrigated conditions; and scurf was lower in DS than all other systems. The SQ, SC, and DS systems also reduced common scab (15 to 45%), and scab was lower in DS than all other systems. Irrigation increased black scurf and common scab but also resulted in higher yields for most rotations. SI produced the highest yields under nonirrigated conditions, and DS produced high yields and low disease under both irrigation regimes. Each cropping system resulted in distinctive changes in soil microbial community characteristics as represented by microbial populations, substrate utilization, and fatty acid methyl-ester (FAME) profiles. SI tended to increase soil moisture, microbial populations, and activity, as well result in higher proportions of monounsaturated FAMEs and the FAME biomarker for mycorrhizae (16:1 ω6c) relative to most other rotations. DS resulted in moderate microbial populations and activity but higher substrate richness and diversity in substrate utilization profiles. DS also resulted in relatively higher proportions of FAME biomarkers for fungi (18:2 ω6c), actinomycetes, and gram-positive bacteria than most other systems, whereas PP resulted in the lowest microbial populations and activity; substrate richness and diversity; proportions of monounsaturated and polyunsaturated FAME classes; and fungal, mycorrhizae, and actinomycete FAME biomarkers of all cropping systems. Overall, soil water, soil quality, and soilborne diseases were all important factors affecting productivity, and cropping systems addressing these constraints improved production. Cropping system approaches will need to balance these factors to achieve sustainable production and disease management.
四种不同的马铃薯种植系统，旨在针对土壤保持、土壤改良、病害抑制和现状标准轮作控制的具体管理目标，评估了它们对马铃薯土传病害和土壤微生物群落特征的影响。现状系统（SQ）由大麦与红三叶草混播，然后种植马铃薯（2 年轮作）。土壤保持系统（SC）在 3 年轮作中增加了一年的饲草和减少耕作（大麦/梯牧草-梯牧草-马铃薯）。土壤改良系统（SI）在 SC 轮作中每年添加堆肥改良剂，而病害抑制系统（DS）则采用具有已知病害抑制能力的多种作物（3 年轮作，芥菜/油菜-苏丹草/黑麦-马铃薯）。每个系统还与连续马铃薯对照（PP）进行了比较，并在灌溉和非灌溉条件下进行了评估。在完成整个轮作周期后的三个马铃薯季节收集的数据表明，与 PP 相比，所有轮作都降低了茎溃疡病（10%至 50%）。SQ、SC 和 DS 系统降低了黑痂病（18%至 58%），与 PP 相比；SI 降低了非灌溉条件下的结痂，但在灌溉条件下没有；与其他所有系统相比，DS 中的结痂病更少。SQ、SC 和 DS 系统还降低了普通疮痂病（15%至 45%），与其他所有系统相比，DS 中的疮痂病更少。灌溉增加了黑痂病和普通疮痂病，但也使大多数轮作的产量更高。在非灌溉条件下，SI 产生了最高的产量，而 DS 在两种灌溉制度下都产生了高产和低病害。每个种植系统都导致了土壤微生物群落特征的独特变化，表现为微生物种群、基质利用和脂肪酸甲酯（FAME）谱。与大多数其他轮作相比，SI 倾向于增加土壤水分、微生物种群和活性，并且导致更高比例的单不饱和 FAME 和菌根（16:1 ω6c）的 FAME 生物标志物。DS 导致中等微生物种群和活性，但在基质利用谱中具有更高的基质丰富度和多样性。与大多数其他系统相比，DS 还导致相对较高比例的真菌（18:2 ω6c）、放线菌和革兰氏阳性菌的 FAME 生物标志物，而 PP 导致所有种植系统中微生物种群和活性最低；基质丰富度和多样性；单不饱和和多不饱和 FAME 类的比例；真菌、菌根和放线菌的 FAME 生物标志物。总的来说，土壤水分、土壤质量和土传病害都是影响生产力的重要因素，而针对这些限制的种植系统提高了产量。种植系统方法需要平衡这些因素，以实现可持续生产和病害管理。
