Talk:Humic substance

message: This article has many serious problems, starting from its name.  Apparently "humic substance" is a relatively rarely used term and concept, which refers to compounds present in untreated humus;  whereas "humic acid", "fulvic acid" and "humin" are not "humic substances", but compounds derived from humus by chemical treatment.  While "humic acid" and "fulvic acid" have indefinite chemical composition, they are defined operationally well enough to deserve their own articles (just as "coal tar" deserves an article separate from "tar", and "turpentine" from "rosin").  There seems to be a lot of research on humic and fulvic acids and their uses.Whether "humic substance" should be a separate article or just a section of the humus article, it should focus on the unmodified substances. The article should be moved back to "humic acid", and that name should come first in bold in the lead section; and contents that refers to (unmodified) "humic substances" should go to humusMoreover, the article makes it seem that the most important thing about the concept is the controversy or controversies, which in fact are relatively peripheral. The focus of the article must be the extraction, composition, properties, and agricultural/ecological relevance (or lack thereof), with the controversies discussed in a section further down the article.. --Jorge Stolfi (talk) 02:13, 12 October 2018 (UTC)
thread_title: Humic acid is not a humic substance

message: Recently, there is a substancial amount of critique in the scientific community regarding the chemistry of humic substances, and whether these operationally defined substances are really a good good model to study natural organic matter. The critique focuses on whether extraction methods for humic substances alter their chemistry, and whether humic substances can be found in untreated soils. I think this aspect should be discussed in the article. 
Here are some key articles on the topic:
http://www.nature.com/nature/journal/v478/n7367/full/nature10386.html
http://www.sciencedirect.com/science/article/pii/S0065211310060037
Nagchampa (talk) 15:48, 22 November 2012 (UTC)
thread_title:  Scientific critic on the concept of humic substances 

message: I have been redirected here after searching for fulvic acid, which I was interested in because of its links to health issues.  However, this article does not speak about these issues at all.  Perhaps there is an argument for expanding the page on fulvic acid in regards to this? Sadly, I am a newcomer to this issue, and as such would not be the one for creating the page  —Preceding unsigned comment added by 195.171.88.236 (talk) 21:51, 1 October 2007 (UTC)
thread_title:  Health Issues 

message: This is another acid found (along with apocrenic acid) in humus. Does anyone know its composition / structure? Jeff Knaggs (talk) 17:20, 7 March 2008 (UTC)
thread_title:  [[crenic acid]] 

message: I have added the "Morefootnotes" tag because the second half or 2/3 of the article is unreferenced and one really has no way of knowing how to verify or evaluate the information provided. --UrsoBR (talk) 01:17, 23 January 2009 (UTC)
thread_title:  Inline citations 

message: It seems far more likely that the function of straw in bricks is that of fibrous reinforcement rather than modification of the clay through the reaction withhumic action. Unless this claim can be backed by a reliable citation, it should be removed. StainlessSteelDoctor (talk) 21:23, 25 May 2010 (UTC)
thread_title:  Ancient masonry 

message: Why does Fulvic Acid redirect to this page? Are they synonomous? This article discusses them as if they are two different, yet related, materials. It would help if this were explained in greater detail.  —Preceding unsigned comment added by 12.188.233.14 (talk) 15:11, 14 April 2011 (UTC)
replies: text: Above comment has it correct. As far as whether or not Fluvic and Humic acids are synonymous, remember that nature doesn't give a fig about our definitions or labels. These particular materials are less discrete (like letters of the alphabet) and on more of a continuum, like colors. You know when something is yellow, and when it is green, but where exactly do you change over from yellow-green to green-yellow? Similarly, there is no fundamental property which distinguishes fulvic and humic acids unambiguously. Scientists have generally settled on the definition given above. It is also known that fulvic acid have a higher oxygen content than humic acids, and lower molecular weights. As for the article, I will consider compiling my thoughts on an edit and presenting it to the talk page for discussion. Equilshift (talk) 21:42, 29 July 2014 (UTC)
thread_title:  Fulvic Acid 

message: 24.50.151.151 (talk) 14:32, 7 October 2014 (UTC)
thread_title:  fulvic acid 

message: I added charcoal in soil as an example of a biotic material subject to humification, resulting in humic acid. Conceptual models relating to humic acid formation do not support a large charcoal-derived component. Black carbon is normally between 5 and 50% of soil organic carbon. Ponomarenko (2001) posited that conceptually processing the reality of large char-C stocks in soil will require considerable change in conceptual understanding of soil humus.
:  
The paradigm shift is still on back-order, so basically, that one(1) edit to add charcoal, that's all I have at this point. -- Paleorthid (talk) 22:47, 10 February 2016 (UTC)
thread_title:  Charcoal 

message: I propose a new section, Criticism...:
With an explanation build around these excerpts from :
:[biogeochemical] processes convert dead plant material into organic products that are able to form intimate associations with soil minerals, making it difficult to study the nature of soil organic matter. Early research based on an extraction method assumed that a 'humification' process creates recalcitrant (resistant to decomposition) and large 'humic substances' [such as humic acid]  to make up the majority of soil 'humus'. However, these 'humic substances' have not been observed by modern analytical techniques. This lack of evidence means that 'humification' is increasingly questioned, yet the underlying theory persists in the contemporary literature, including current textbooks. 
:The conceptual problem with defining 'humic substances' [such as humic acid]  by an extraction process is threefold: 1) ... extraction is always incomplete... 2) ...the harsh alkaline treatment ... giving the resulting 'humic' and 'fulvic' fractions  ... an exaggerated chemical reactivity... 3) The development of this extraction preceded theory, tempting scientists to develop explanations ... rather than develop an understanding of the nature of all organic matter in soil. Over time, this attempt to mechanistically explain the formation of operationally defined 'humic substances' also led to their definition as synthesis products without the link to the alkaline extraction. -- Paleorthid (talk) 17:48, 26 February 2016 (UTC)
replies: text: Update: The criticism section has been tagged for the last year, as compromising the NPOV of the article. I am going through the article, distinguishing humic substances in nature vs humic acids in the lab, as a soil amendment, as a product. -- Paleorthid (talk) 19:59, 23 January 2019 (UTC)
replies: text: This section relies on a single source. If additional independent supporting sources cannot be found for it, it should go altogether. --Kent G. Budge (talk) 02:46, 26 October 2020 (UTC)
replies: text: I know nothing about humus and have no axe to grind here. However, I am a working scientist and do know that J. Random Crackpot does not get to publish a peer-reviewed Perspective in Nature. Not that I am under any illusion that if it's peer-reviewed it must be right, but it does deserve to be taken seriously. It certainly shouldn't be lumped in with the typical pseudoscience that Wikipedia's rules of thumb are designed to weed out. I would be very circumspect about any deletion of content. A good route forward might be to do a reverse lookup (Science Citation Index/Web of Science) for more recent papers citing the 2015 Nature piece and see what sort of reception it has gotten or further work it may have sparked. Gould363 (talk) 15:16, 26 October 2020 (UTC)
thread_title:  Criticism of humic acid theory 

message: Concerning the technological applications, I think we can remove this very specific application which seems still at the research state and focus on more largely used methods of removal of metals by complexation floculation for instance. I would the rename the paragraph and maybe merge it with 'health issues' to create a 'humic substances in water treatment'.
Also, the relevance of the Ancient masonry paragraph seems a bit thin . The fact that straw releases humic acid seems a bit too general to deserve a paragraph of its own in my opinion.
Hidodu (talk) 09:29, 28 March 2018 (UTC)
replies: text: Please see related discussion at Talk:Humus -- Paleorthid (talk) 00:08, 27 February 2016 (UTC)
thread_title:  Technological applications to water treament