Department of Agricultural Chemistry and Food Science & Technology, Division of Applied Life Science (BK21Plus), and IALS, Gyeongsang National University, Jinju 52828, Korea.
Advanced Geo-materials R&D Department, Korea Institute of Geoscience and Mineral Resources, Pohang 37559, Korea.
Molecules. 2021 Feb 2;26(3):760. doi: 10.3390/molecules26030760.
Humic substances (HSs) are chromogenic organic assemblies that are widespread in the environment, including soils, oceans, rivers, and coal-related resources. HSs are known to directly and indirectly stimulate plants based on their versatile organic structures. Their beneficial activities have led to the rapid market growth of agronomical HSs. However, there are still several technical issues and concerns to be addressed to advance sustainable agronomical practices for HSs and allow growers to use HSs reliably. First, it is necessary to elucidate the evident structure (component)-function relationship of HSs. Specifically, the core structural features of HSs corresponding to crop species, treatment method (i.e., soil, foliar, or immersion applications), and soil type-dependent plant stimulatory actions as well as specific plant responses (e.g., root genesis and stress resistance) should be detailed to identify practical crop treatment methodologies. These trials must then be accompanied by means to upgrade crop marketability to help the growers. Second, structural differences of HSs depending on extraction sources should be compared to develop quality control and assurance measures for agronomical uses of HSs. In particular, coal-related HSs obtainable in bulk amounts for large farmland applications should be structurally and functionally distinguishable from other natural HSs. The diversity of organic structures and components in coal-based HSs must thus be examined thoroughly to provide practical information to growers. Overall, there is a consensus amongst researchers that HSs have the potential to enhance soil quality and crop productivity, but appropriate research directions should be explored for growers' needs and farmland applications.
腐殖质（HSs）是一种广泛存在于环境中的显色有机组装体，包括土壤、海洋、河流和与煤炭相关的资源。根据其多样的有机结构，HSs 被认为可以直接和间接地刺激植物。它们的有益活动导致了农业 HSs 的快速市场增长。然而，为了推进 HSs 的可持续农业实践并使种植者能够可靠地使用 HSs，仍有几个技术问题和关注点需要解决。首先，有必要阐明 HSs 明显的结构（组成）-功能关系。具体来说，需要详细研究 HSs 的核心结构特征与作物种类、处理方法（即土壤、叶面或浸泡应用）以及与土壤类型相关的植物刺激作用以及特定的植物反应（例如，根系发生和抗逆性）之间的对应关系，以确定实用的作物处理方法。然后，这些试验必须伴随着提高作物市场竞争力的手段，以帮助种植者。其次，应该比较 HSs 因提取源而异的结构差异，以制定 HSs 农业用途的质量控制和保证措施。特别是，应该在结构和功能上区分可大量获得的、用于大型农田应用的煤炭相关 HSs 与其他天然 HSs。因此，必须彻底检查煤炭基 HSs 中的有机结构和组成的多样性，以为种植者提供实用信息。总的来说，研究人员一致认为 HSs 有潜力提高土壤质量和作物生产力，但应根据种植者的需求和农田应用探索适当的研究方向。
