Submitted to: Humic Science and Technology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2011
Publication Date: 3/9/2011
Citation: He, Z., Ohno, T. 2011. Comparative characterization of water extractable organic matter of conventional and organic dairy manure by FT-IR and fluorescence spectroscopies. Humic Science and Technology Conference. March 11-13, 3011; P39. Interpretive Summary:
Technical Abstract: Organic dairy farming has increased rapidly in recent years. Organic dairy farms have significant differences from conventional counterparts, including fewer imports of protein and energy feeds, and a higher proportion of forage crops in the ration. Although these differences may impact availability, utilization, and cycling of manure nutrients, little information is available to aid organic dairy farmers in making nutrient and manure management decisions. FT-IR and fluorescence are two rapid and inexpensive methods in manure organic matter characterization. In this work, we comparatively characterized the water extractable organic matter (WEOM) of animal manure samples collected from eight conventional dairy farms and 15 organic dairy farms in Maine. These WEOM samples showed two FT-IR patterns: one with largest bands at 1650/1625 cm-1, another with a large band at 1569 cm-1. Quantitative analysis of the relationship of the band intensity and the type of manure is under way. Parafac analysis of the excitation-emission matrix fluorescence spectra indicated five fluorophore components in these WEOM samples. Components 1 and 4 had two excitation spectral peaks and a single emission peak characteristic for humic substances. Component 2 was associated with proteins containing tyrosine. Component 5 had two maxima peaks with excitation at 240 (strong) and 360 (weak) nm and emission at 445 nm, related to humic acid. Generally, Component 1 was more abundant in organic dairy manure than in conventional manure. Information in this work increased the knowledge on organic matter of organic dairy manure.