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ARS Home » Midwest Area » St. Paul, Minnesota » Soil and Water Management Research » Research » Publications at this Location » Publication #90364
Title: THE ROLE OF HUMIC SUBSTANCES IN PLANT GROWTH

Author
item Clapp, Charles
item CLINE, VAN - UNIVERSITY OF MINNESOTA
item HAYES, MICHAEL - UNIVERSITY OF BIRMINGHAM
item RUILONG, LIU - UNIVERSITY OF MINNESOTA

Submitted to: International Humic Substances Society Conference
Publication Type: Abstract Only
Publication Acceptance Date: 3/30/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Humic substances (HS) are plant growth stimulating agents which have been applied in agricultural and horticultural management in recent years. However, detailed mechanisms of how these materials work in plants are still not well understood, due to their complex structures in nature. There are many reports of their roles in promoting plant biomass, stimulation of root, shoot, and flowering growth, and even direct effects on crop productivity and increases in crop yields. The HS consist of humic acids, fulvic acids and humin. They can be extracted from many natural sources such as peat, soil, leonardite, and various waste materials. Application of the HS in golfcourse and sports turf management has recently been re- discovered. They not only increase fertilizer efficiency and promote plant growth, but can reduce the potential to groundwater contamination. Plant growth research involving HS at the U of MN in the Departments of Horticulture and Soil, Water and Climate, has centered on growth chamber, greenhouse, and golf green experiments. Both basic and practical research components are under way to investigate the how and why' of HS interactions with plant and soil ecosystems. The HS from several commercial and natural sources have been tested with Creeping Bentgrass (Agrostis palustris) in growth chamber experiments. The set up consisted of micro tissue culture plates filled with sand and a wick to provide water and nutrients from a constant head plastic tray. Preliminary results indicated that the system was sensitive to nutrient and HS dynamics. Specific HS samples gave significant increases in grass root and shoot growth over fertilizer controls. The impact of recent use of HS on horticultural and agricultural utilization will be discussed.