Author
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REEVES III, JAMES |
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Submitted to: Livestock Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/6/2007 Publication Date: 11/23/2007 Citation: Reeves III, J.B. 2007. The present status of "quick tests" for on-farm analysis with emphasis on manures and soil: What is available and what is lacking? Livestock Science. 112:224-231. Interpretive Summary: There has been an increasing interest in on-farm testing of a variety of products produced and utilized on the farm including manure and soil composition. Several issues involved include which constituents are of interest, e.g., fiber and protein in forages versus inorganic- and organic-nitrogen and phosphorus in manures; the nature of the testing, e.g., conventionally based assays using solutions or test strips versus portable instrumental methods; the potential advantages or disadvantages of on-farm versus conventional laboratory testing, e.g., speed, timeliness, etc., and finally cost. The availability of on-farm testing methods varies greatly with both the media in question and the analyte of interest. For example, for manures, several methods exist for the determination of ammonium-nitrogen which can be quite accurate, fast and reasonably inexpensive, while no such methods exist for the determination of organic-nitrogen in the same samples. Similarly, soil test kits have existed for years for determining nitrogen, phosphorus and potassium, but no such test exists for determining soil carbon content (organic or inorganic), and no inexpensive method exists for forage quality determinations (fiber, protein, etc.). This paper discusses the present state of methods suitable for on-farm testing of the wide variety of products and by-products utilized and produced on a farm with manure testing serving as an example of what can be done, the future potential and the problems which exist. Technical Abstract: There has been an increasing interest in on-farm testing of a variety of products produced and utilized on the farm including manure and soil composition. Several issues involved include which constituents are of interest, e.g., fiber and protein in forages versus inorganic- and organic-N and P in manures; the nature of the testing, e.g., conventionally based assays using solutions or test strips versus portable instrumental methods; the potential advantages or disadvantages of on-farm versus conventional laboratory testing, e.g., speed, timeliness, etc., and finally cost. The availability of on-farm testing methods varies greatly with both the media in question and the analyte of interest. For example, for manures, several methods exist for the determination of ammonium-N which can be quite accurate, fast and reasonably inexpensive, while no such methods exist for the determination of organic-N in the same samples. Similarly, soil test kits have existed for years for determining N, P and K, but no such test exists for determining soil C content (organic or inorganic), and no inexpensive method exists for forage quality determinations (fiber, protein, etc.). This paper discusses the present state of methods suitable for on-farm testing of the wide variety of products and by-products utilized and produced on a farm with manure testing serving as a surrogate example. |
