Murray Gibson, dean of the College of Science, opened the 15th annual Humic Science and Technology Conference — held last week at Northeastern — by admitting that he, like many people, didn’t know what humic substances (HS) were for most of his life.

According to the International Humic Substances Society (IHSS), HS “are complex and heterogeneous mixtures” of materials that form in the biodegradation of organic matter. HS are the long-lived organic components in soil and natural bodies of water; as such, they are required to maintain fertile farmland.

At the conference – co-chaired by professor Geoffrey Davies and principal research scientist Elham Ghabbour of Northeastern’s Department of Chemistry and Chemical Biology – Gibson pointed to a statistic from the Food and Agricultural Organization of the United Nations that 25 percent of the world’s arable land is severely degraded due to unsustainable farming practices. Commercial HS are additives that can assist in crucial soil-remediation programs.

“Unfortunately, there have been instances of application of fake humic acids from a few overseas companies which has decreased the fertility of farms,” said Diane McKnight of the University of Colorado and a member of the National Academy of Engineering. “These farmers are inadvertently impairing the productivity of their land.”

For this reason, the conference attendees — who came from industry and academia alike — spent much of their three days in Raytheon Amphitheater engaged in a heated debate about the definition of HS. Ghabbour said that a panel discussion led by Steve Azzarello, president of the newly formed Humic Products Trade Association, was intended to reach consensus on a standard HS analytical method.

In a lecture just before the panel discussion, Davies presented a new method for analyzing the HS contents of soils and commercial HS products. Davies, Ghabbour and a team of undergraduate researchers have extracted and characterized HS from more than 800 soil samples from around the country.

Ghabbour and Davies’ straightforward method, which has just been described in Northeastern’s online journal Annals of Environmental Science, will help the humics industry to measure HS in its products and in soil samples.

“These methods are potential standards,” Davies said. “I was always taught that the most accurate measurement you can make in the lab is gravimetric — weigh something.”
The conference’s Honorary Chair Teodoro Miano, of Università di Bari in Bari, Italy, and President of IHSS, said, “This is a world problem. There are so many differences in regulations and needs from different markets and countries. So we need to face the problem at the global level.”

Azzarello said the industry wants to move ahead with a pragmatic approach. “We’ve developed a code of ethics, which, if you join our group, you have to follow. We have a list of adulterants that we do not allow folks who are in our group to use.”

While nothing was settled by the end of the day, there was a clear passion among the group to eventually define HS in a way that allows for straightforward, reproducible validation. This effort will be essential in the global mission to minimize fake material that can further destroy valuable farmland.