Author
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Dao, Thanh |
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ZHANG, HAILIN - OK STATE UNIV |
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Submitted to: Annals of Environmental Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/19/2007 Publication Date: 8/19/2007 Citation: Dao, T.H., Zhang, H. 2007. Rapid composition and source screening of heterogeneous poultry litter by energy dispersive x-ray fluorescence spectrometry. Annals of Environmental Science. 1:69-79. Interpretive Summary: Over 537 million broilers were produced in MD and DE in 2004. A massive net importation of nutrients to the Delmarva peninsula in fertilizers and feed exists to support the production levels. Concerns are raised about nutrient accumulation and surpluses as manures are generated at rates exceeding the storage and assimilation capacity of the region. High variability in manure composition often lead to overapplication rates of manure creating nutrient-enriched soils, in particular soil high in phosphorus. Also, feed additives may cause soil enrichment to levels that reduce the availability of essential nutrients such as phosphates, and may reach potentially phytotoxic levels when poultry litter is repeatedly applied to the same production fields. Routine and frequent manure analysis are recommended to avoid the predicaments. However, analysis of manure by traditional wet chemistry analysis require large investment of time and labor. Energy-dispersive x-ray fluorescence spectrometry (EDXRF) allows fast and accurate multi-elemental analysis of large number of litter samples to better determine manure composition. EDXRF and inductively coupled plasma spectrometric results for P, S, K, Ca and Fe, Cu, and Zn were linearly related. EDXRF method proved a highly effective alternative to more labor-intensive wet methods for performing routine simultaneous measurements of macronutrients and trace elements in poultry litter to quantify P and other elements between Al and Ca and trace elements. Therefore, the robustness of EDXRF and accurate knowledge of litter composition strengthen nutrient specialists' ability to evaluate more frequently and accurately nutrient balance on the farm or accumulation status in intensive poultry producing watersheds. Technical Abstract: High variability in manure composition limits the value of poultry litter as a fertilizer in crop production. Macronutrients and feed additives may pose risks of soil enrichment to levels that reduce the availability of essential nutrients such as inorganic and organic phosphates, and may reach potentially phytotoxic levels when poultry litter is repeatedly applied to the same production fields. As analysis of manure by traditional wet chemistry and spectrometric analysis require large investment of time and labor, energy-dispersive x-ray fluorescence spectrometry (EDXRF) may allow fast and accurate multi-elemental analysis of large number of samples to better determine manure composition. The results of EDXRF analysis for P was well correlated (r2 = 0.83**) with those of concentrate acid digest and P determination by the phosphomolybdate-ascorbic acid method for 71 samples collected throughout poultry producing regions of Arkansas, Oklahoma, and Maryland. Relationships between the EDXRF and inductively coupled plasma atomic emission spectrometric results for P, S, K, Ca and Fe, Cu, and Zn were linear. EDXRF effectively differentiated litter originating from layer and broiler hens, based on their Ca, As, and Cl contents. The EDXRF method proved highly suitable analytical alternative to more labor-intensive wet methods for performing routine simultaneous multi-element measurements in poultry manure and litter to quantify P and other elements between Al and Ca and trace elements of higher atomic number. The analytical alternative widens our ability to evaluate more frequently and accurately nutrient balance on the farm or nutrient accumulation status on large spatial scale in intensive poultry producing watersheds. |
