by Jessica Driscoll
In 1993, Dr. Elham Ghabbour brought her research on biomaterials called humic substances (HS) to Northeastern University. Learning of the importance of these substances in all soil and natural waters, Northeastern professor Dr. Geoffrey Davies dropped the research he was conducting on catalysts and started working side-by-side with Ghabbour on HS isolation, cross comparison, structures, properties, and uses – research that has led to a recent $50,000 grant from the VK Rasmussen Foundation.
“Humic substances store and supply plant nutrients in soils,” explained Davies. “Massive use of mineral fertilizers depletes HS, leading to fertilizer run-off, pollution of rivers and streams, and dead zones like the one in the Gulf of Mexico. Fifteen percent of all pollution has this origin.”
According to Ghabbour, humic acids make up the major portion of HS in soils.
“Radiocarbon dating and other techniques show that HS have mean residence times in soils of centuries and millennia,” she said. “Other organic matter in soils, such as leaves and corn stover, is food for microorganisms and is mineralized (i.e. respired as CO2) much faster.”
Davies said the many roles of HA in soils include structural stabilization to fight wind and water erosion, enhanced water and air permeability, water retention, nutrient storage and supply in synergy with plant roots, inorganic and organic xenobiotic sequestration, carbon sequestration, and more fertile and resilient soils.
The Humic Acid Research Group was created at Northeastern in 1996 when eight talented science freshmen joined graduate students to work in teams that made huge strides in HA research. “All have gone on to successful careers, and more than 60 additional undergraduates have helped us branch out into many new aspects of HS research,” said Ghabbour.
“The National Soil Project was launched at Northeastern in 2007 based on the realization that all agency and university studies to date had measured the total organic matter content of agricultural soils, i.e. food for microbes – which rises and falls – plus HS which stay around much, much longer. In other words, HS are the baseline of any soil organic carbon measurement.”
The main goals of the National Soil Project are:
- To develop analytical methods of measuring humic substance contents of soils, demonstrate their reproducibility, and apply them to samples from all 50 U.S. states
- To advocate soil HS measurements as an essential factor in land assessment and management
- And to educate undergraduate students in HS research and the general public in the equal importance of air, soil, and water to the environment and health.
“The HS components we can now measure with a combination of gravimetric and spectral methods are organic matter, HA, fulvic acid, humin, and dissolved organic matter,” said Davies. “To date, we have analyzed nearly 1,000 samples donated by agencies and the general public from across the country. Our objective is 3,140 samples, which is the number of U.S. counties. We can also measure the HS contents of lignites, which are soft coals that are useless as fuels. Lignites are the major commercial source of HS for land and water remediation and they need to be regulated and certified.”
Davies said the Rasmussen grant award indicates recognition of the importance of healthy soils and faith in the National Soil Project. The funds will support laboratory and outreach work and will enhance the team’s ability to gain support from other foundations and agencies.
“It is an excellent match with the Rasmussen Foundation’s imprimatur, ‘The environmental mission of VKRF is to support the transition to a more environmentally resilient, stable, and sustainable planet. We believe best practices for promoting sustainability will be most effectively developed through an integrated systems approach and one which furthers the involvement of an informed public in environmental decision making’,” said Ghabbour.
Davies said the potential impact of the NSP is great. “Soils sustain life,” he said. “The NSP will generate new knowledge of the state of the nation’s – and, hopefully, the world’s – soils and stimulate much needed appreciation of the many contributions of soils to life on earth. People will do anything to get food. The Rasmussen Foundation grant will take us to the 7th year of effort, but we won’t stop until our 3,140th sample analysis is completed. This depends largely on our ability to persuade agencies and individuals to send us soil samples.”