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United States Department of Agriculture

Agricultural Research Service

Research Project: NUTRIENT CYCLING AND UTILIZATION ON ORGANIC DAIRY FARMS

Location: New England Plant, Soil and Water Research Laboratory

Title: Preferencial Affinity of Humic-Metal Interactions Coupled With Phosphatase Hydrolysis of Humic-Organic Phosphorus Complex

Authors
item Tazisong, Irenus - ALABAMA A&M UNIV
item Senwo, Zachary - ALABAMA A&M UNIV
item Taylor, Robert - ALABAMA A&M UNIV
item He, Zhongqi

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 27, 2008
Publication Date: April 2, 2008
Citation: Tazisong, I., Senwo, Z., Taylor, R., He, Z. 2008. Preferencial Affinity of Humic-Metal Interactions Coupled With Phosphatase Hydrolysis of Humic-Organic Phosphorus Complex. Humic Science and Technology Conference Abstract. p. 53.

Technical Abstract: Information is limited on the enzymatic hydrolysis of P compounds associated with indigenous Humic (HA) and fulvic (FA) acids extracted from an Ultisol, and even less information is available on the resistance to phosphatase hydrolysis of known P compounds complexed to HA and FA. Little information is also available on the effect of tillage, cropping, and manure applications on Ultisol humic substances (HS). This study was conducted to evaluate phosphatase hydrolysis of humic-organic P complexes and to evaluate preferential metal ion adsorption on humic substances. HA and FA were extracted from air-dried soils. Phosphatase hydrolysis of humic-organic P complexes was carried out by incubating 2 mM of various organic P compounds with HA and FA and then hydrolyzing the complexes with 0.08 U per mL of phytase or 0.25 U per mL of acid phosphatase. Preferential metal ion adsorption was conducted by shaking Fe, Pb, Cd, Ni, Zn, and Cu ions ranging in concentration from 1 to 50 ppm with 0.1g HA. Approximately 70-90% of the simple monoester-HA reaction mixture was hydrolyzed while less than 10% of phytate-HA reaction mixture was hydrolyzed. Relative amounts of trace metals on HA showed that Fe was preferentially adsorbed the most. These data support the proposition that HA and FA play significant roles in soil nutrient status and soil biological activity.

Last Modified: 4/18/2014
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