story to find out more.
Reeves analyzes manure for nitrogen in the field using a prototype
near-infrared filter spectrometer. Click the image for more information
Mobile Machine Quickly Measures Manure Nitrogen By Sharon Durham
July 18, 2006
A prototype manure-analyzing device that works off a car or truck
battery has been built by an Agricultural Research Service (ARS) scientist.
B. Reeves, at the ARS
Management and Byproduct Utilization Laboratory in Beltsville, Md.,
designed the portable, easy-to-use analyzer so farmers can quickly tell how
much nitrogen and water are in a sample of manure.
Many farmers apply manure to their crops as an organic fertilizer, but
it can sometimes be too much of a good thing. They apply too much because
theyre not sure how much nitrogen or phosphorus might be in it and decide
to err on the side of excess.
But excess nutrients can run off in rainwater and eventually pollute
streams, lakes and other bodies of water.
To determine how much nitrogen or phosphorus manure contains, farmers
can send samples to a laboratory for analysis, but that takes time and money.
And they usually send only one sample from the large pit into which they flush
their manure. According to Reeves, a one-sample analysis cant reflect the
nutrient levels that often vary throughout a manure pit.
The prototype analyzer passes invisible, near-infrared light through
filters onto about two tablespoons of manure placed in a small cup. The amount
of light reflected back allows a filter spectrometer to quantify both the
nitrogen and water content. Manure samples require no preparation or chemicals,
and the analysis takes about a minute.
Having access to an accurate, inexpensive manure analyzer will become
even more important to farmers if nutrient-management regulations tighten
further. The prototype analyzer is a 15-inch cube that weighs about 20 pounds.
Reeves plans to make it even smallerabout the size of a shoebox and
weighing around 5 pounds.
more about the research in the July 2006 issue of Agricultural
ARS is the U.S. Department of
Agricultures chief scientific research agency.