The present international scenario recognizes organic agriculture as an innovative solution to reduce agrochemicals and practices that degrade the agroecosystem. Yet, the shift from an already well-established agricultural model to a relatively new one is a challenging task and requires further scientific support. This work investigated the influence of transitional management – TM (from conventional to organic agriculture) on the soil fungal community under citrus, in dry and rainy periods. From 2012 to 2015 on, an area in Mogi Guaçú, SP, Brazil was selected, and two treatments were installed: a conventional management (CM) system based on farming practices with agrochemicals and fertilizers use, and another, transition management (TM) based on a 25% reduction per year of the chemical substances used in CM, with soil conditioner bokashi introduced. The performance of the transition system was evaluated in the context of soil fertility and diversity index of fungal taxa, by plate culture isolation, through the richness of Margalef (Dmg), diversity of Shannon (H′) and reverse Simpson (D). Differences in the occurrence and frequency of Paecilomyces, greater under CM and Penicillium, greater under TM, highlighted the influence of the management system employed. Richness and diversity indices were higher under TM. Principal component analysis revealed that 49.9% of the differences in fungal diversity was due to the management system. Only 16.5% was a result of the season of sampling. Four years of reduction/replacement of chemical practices in TM was sufficient to modify and favor some soil fungal taxa and consequently their activity. This research brings promising results to organic agriculture initiatives with relevant results for a tropical climate area.

中文翻译：

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柑橘种植下有机农业的过渡管理有利于土壤中的真菌多样性

目前的国际情景承认有机农业是一种创新的解决方案，可以减少农用化学品和降低农业生态系统的做法。然而，从已经成熟的农业模式转变为相对较新的模式是一项艰巨的任务，需要进一步的科学支持。这项工作调查了过渡管理——TM（从传统农业到有机农业）对柑橘下土壤真菌群落的影响，在旱季和雨季。从 2012 年到 2015 年，选择了位于巴西 SP 的 Mogi Guaçú 的一个地区，并安装了两种处理方法：一种基于使用农用化学品和化肥的农业实践的常规管理 (CM) 系统，以及另一个基于过渡管理 (TM) 的系统。 CM 中使用的化学物质每年减少 25%，引入土壤调节剂 bokashi。在土壤肥力和真菌类群多样性指数的背景下，通过平板培养分离，通过 Margalef 的丰富度评估过渡系统的性能。D毫克), 香农的多样性 (H') 和反向辛普森 (D）。发生频率和频率的差异拟青霉属，在 CM 和青霉属，在 TM 下更大，突出了所采用的管理系统的影响。TM 下的丰富度和多样性指数较高。主成分分析显示，49.9%的真菌多样性差异是由于管理系统造成的。只有 16.5% 是采样季节的结果。在 TM 中减少/替代化学实践的四年足以改变和有利于某些土壤真菌类群，从而改变它们的活性。这项研究为有机农业倡议带来了可喜的成果，并为热带气候地区带来了相关成果。