Structure-function relationship of vermicompost humic fractions for use in agriculture

Active chemical fractions with high fungistatic activity of humic‐like substances obtained via different extraction solvents

“…Humified residual material with high C and low N contents stimulated root growth and emission in rice ( Oryza sativa L.cv. Piaui) . Correlations between the fungistatic activity of HULIS and the S and O contents of HULIS have been reported in other studies, and the inferred mechanism might be related to the active groups like −CS 2 − and hydrophobic properties .…”

Manure Fertilization Gives High-Quality Earthworm Coprolites with Positive Effects on Plant Growth and N Metabolism

“…These HS were the only to display hormone-like activity, which likely accounted for their most pronounced positive effects on plant growth and metabolism, including accumulation of chlorophylls, mineral nutrition, and activity of nitrogen assimilation enzymes, in oat (Avena sativa L.) plants growing in a soil-less system. We conclude that manure input favored the turnover of OC towards the humification process that led to the production of high-quality coprolites and HS with superior biological activity, and suggests that OC in coprolites and HC in HS from earthworms might be used as reliable indicators of soil fertility.Agronomy 2019, 9, 659 2 of 17 they accelerate the humification process by grinding and mixing mineral and organic materials with substances occurring in their gut, and by modifying the composition of microbial populations.In recent years, earthworms have been used for the breakdown of organic substances in sewage sludges, animal and industrial wastes, and crop residues in order to obtain vermicompost [9,10]. The production of vermicompost is a process that also occurs in nature and several studies have been performed to evaluate its nutritional and ecological importance.…”

“…Some effects of HS or their constituents HA in plants are related to their hormone-like activities (auxin, gibberellin, and/or cytokine-like substances), and capacity to stimulate plant plasma membrane proton pumps (H + -ATPase), consequently promoting root growth via increased nutrient uptake, cell wall modification and cell division [25][26][27][28][29]. Bioactivity of HA is also related to their structure [10]. Muscolo et al [30] in particular, evidenced the effectiveness of aliphatic-and carboxylic-C groups of HA in interacting with cellular membranes of carrot cell cultures, while Canellas et al [31] established a relationship between the HA bioactivity and hydrophobicity.In agroecosystems, the activity of earthworms strongly depends on management practices, such as tillage [32], fertilization [33], use of organic inputs [34,35], residues handling [36] and cropping systems [37].…”

“…In recent years, earthworms have been used for the breakdown of organic substances in sewage sludges, animal and industrial wastes, and crop residues in order to obtain vermicompost [9,10]. The production of vermicompost is a process that also occurs in nature and several studies have been performed to evaluate its nutritional and ecological importance.…”

Preface—special issue in memory of Frank J. Stevenson

“…To optimize the use of HS from vermicomposts in agriculture, García et al (2018) evaluated the bioactivity of three humic fractions from vermicomposts obtained with different extraction methods.…”