Author
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Reeves Iii, James |
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Submitted to: Meeting Proceedings
Publication Type: Proceedings Publication Acceptance Date: 7/27/2006 Publication Date: 9/11/2006 Citation: Reeves III, J.B. 2006. The present status of rapid methods for on-farm analysis of manure composition with emphasis on n and p: what is available and what is lacking?. Meeting Proceedings. DIAS report Plant production. No. 122. 1:65-70. Interpretive Summary: Biomass materials (manures and other organic wastes) found on the farm represents both potential sources of crop nutrients, energy or environmental pollutants, the potential of which varies with their nature and use; the only way to maximize the benefits and minimize deleterious effects is to know their composition. Traditionally testing has been done by shipping samples to a testing laboratory, but due to their heterogeneous nature, and frequent presence of volatile constituents, optimal utilization requires rapid, accurate and timely analysis; something difficult to achieve off site; thus, the increased interest in on-farm testing. At the present time, available testing kits for on-farm use generally test for a single nutrient and are limited to only a few at that. In the US, the emphasis is on minimizing excess nutrients from manures, specifically nitrogen (N) and phosphorus (P). However, some on-farm testing methods could be easily adapted to other materials including: farm products, soil composition, animal health, household wastes or industrial biomass materials. A term often used for on-farm tests is “Quick Tests” (QT). The analytes of interest for manures are: ammonium- and organic –N, the mineralization potential of the organic-N (conversion of organic-N to nitrate and ammonia which are useable by plants), and plant available (soluble)- and total-P. For household wastes, many farm products and biomass materials, fiber, protein and moisture would be of interest. Research has demonstrated that simple QT are available for the rapid on-farm determination of ammonium-N. However, no QT have been found that are useful for the determination of P, mineralizable N or organic-N in manures. Another rapid, but none chemical method of analyzing manure and other biomass materials is spectroscopy which uses the interaction of light, generally beyond the range of human sight, to determine the composition of materials. Efforts using near-infrared reflectance spectroscopy with dairy and poultry manures has demonstrated that rapid and accurate analysis is possible for both ammonium and organic-N, but again results for mineralizable N and P have been poor. However, spectroscopic methods also offer the potential to analyze feedstuffs, products, other biomass materials, soil composition and even animal health with the same equipment. While still too expensive for routine on-farm use, the increasing demands for analysis of both wastes and products on the farm and the increasing innovation in near-infrared instrumentation indicate that spectroscopic methods are the future for on-farm testing. Technical Abstract: Biomass materials represent both potential sources of crop nutrients, energy or environmental pollutants, the potential of which varies with its nature and use; the only way to maximize the benefits and minimize deleterious effects is to know its composition. Due to their heterogeneous nature, and frequent presence of volatile constituents, optimal utilization requires rapid, accurate and timely analysis; something difficult to achieve off site; thus, the increased interest in on-farm testing. Presently, the US emphasis is on minimizing excess nutrients from manures, specifically N and P. However, on-farm testing methods could be easily adapted to other materials including: farm products, soil composition, animal health, household wastes or industrial biomass materials. A term often used for on-farm tests is “Quick Tests” (QT). The analytes of interest for manures are: NH3- and organic (Org) -N, the mineralization potential of the Org-N, and plant available- and total-P. For C-sequestration, household wastes, many farm products and biomass materials, fiber, protein and moisture would be of interest. Research has demonstrated that simple QT are available for the rapid on-farm determination of NH3-N with R2 between laboratory and QT values often greater than .9. However, no QT have been found that are useful for the determination of P, mineralizable N or organic-N in manures. Another rapid, but none chemical method of analyzing manure and other biomass materials is spectroscopy. Efforts using near-infrared reflectance spectroscopy with dairy and poultry manures has demonstrated that rapid and accurate analysis is possible for both NH3- and Org-N, but again results for mineralizable N and P have been poor. However, spectroscopic methods also offer the potential to analyze feedstuffs, products, other biomass materials, soil composition and even animal health. While still too expensive for routine on-farm use, the increasing demands for analysis of both wastes and products on the farm and the increasing innovation in near-infrared instrumentation indicate that spectroscopic methods are the future for on-farm testing. |
