Abstract: The nitrate-nitrogen concentration in soil is estimated based on the nitrate-nitrogen 200 nm absorption peak. In one embodiment, a device measures the attenuation spectrum of a soil-extractant mixture over a wavelength range that includes wavelengths in the vicinity of the 200 nm absorption peak (the spectral operating range) and then determines the nitrate-nitrogen concentration based on the attenuation spectrum.

Abstract: The nitrate-nitrogen concentration in soil is estimated based on the nitrate-nitrogen 200 nm absorption peak. In one embodiment, a device measures the attenuation spectrum of a soil-extractor mixture over a wavelength range that includes wavelengths in the vicinity of the 200 nm absorption peak (the spectral operating range) and then determines the nitrate-nitrogen concentration based on the attenuation spectrum.

Abstract: The nitrate-nitrogen concentration in soil is estimated based on the nitrate-nitrogen 200 nm absorption peak. In one embodiment, a device measures the attenuation spectrum of a soil-extractor mixture over a wavelength range that includes wavelengths in the vicinity of the 200 nm absorption peak (the spectral operating range) and then determines the nitrate-nitrogen concentration based on the attenuation spectrum.

Abstract: The nitrate-nitrogen concentration in soil is estimated based on the nitrate-nitrogen 200 nm absorption peak. In one embodiment, a device measures the attenuation spectrum of a soil-extractant mixture over a wavelength range that includes wavelengths in the vicinity of the 200 nm absorption peak (the spectral operating range) and then determines the nitrate-nitrogen concentration based on the attenuation spectrum.

Abstract: The nitrate-nitrogen concentration in soil is estimated based on the nitrate-nitrogen 200 nm absorption peak. In one embodiment, a device measures the attenuation spectrum of a soil-extractant mixture over a wavelength range that includes wavelengths in the vicinity of the 200 nm absorption peak (the spectral operating range) and then determines the nitrate-nitrogen concentration based on the attenuation spectrum.

Abstract: The nitrate-nitrogen concentration in soil is estimated based on the nitrate-nitrogen 200 nm absorption peak. In one embodiment, a device measures the attenuation spectrum of a soil-extractant mixture over a wavelength range that includes wavelengths in the vicinity of the 200 nm absorption peak (the spectral operating range) and then determines the nitrate-nitrogen concentration based on the attenuation spectrum.

Abstract: A filtration system for a soil analysis device and methods of pressure filtration and automated cleaning are disclosed for generating filtrate used in measuring characteristics of a soil sample and preparing the filtration system for repeated measurements. A mixing chamber combines a soil sample and an extractant into a liquid mixture. The filtration system receives and pressure filters the liquid mixture to quickly generate filtrate used to measure characteristics of the sample. The filtrate is passed to a measurement cell for analysis. Once the analysis is complete, the filtration system performs a cleaning process in preparation to receive a subsequent liquid mixture from another soil sample.

Abstract: A soil analysis device and a method are disclosed for measuring characteristics of a soil sample. A mixing chamber combines a soil sample and an extractant into a liquid mixture. A filtration system receives and filters the liquid mixture. The filtered liquid mixture is transmitted to a measurement cell. The measurement cell is coupled to a light source so that light propagating from the light source is attenuated and/or reflected by the liquid mixture and is measured by one or more optical detectors that are also coupled to the measurement cell. The optical detector generates an attenuation spectrum and/or a reflection spectrum indicating light received by the one or more detectors at different wavelengths. The attenuation and/or reflection spectrum is used to determine the characteristics of the soil sample.

Abstract: The nitrate-nitrogen concentration in soil is estimated based on the nitrate-nitrogen 200 nm absorption peak. In one embodiment, a device measures the attenuation spectrum of a soil-extractant mixture over a wavelength range that includes wavelengths in the vicinity of the 200 nm absorption peak (the spectral operating range) and then determines the nitrate-nitrogen concentration based on the attenuation spectrum.

Abstract: A soil analysis device and a method are disclosed for measuring characteristics of a soil sample. A mixing chamber combines a soil sample and an extractant into a liquid mixture. A filtration system receives and filters the liquid mixture. The filtered liquid mixture is transmitted to a measurement cell. The measurement cell is coupled to a light source so that light propagating from the light source is attenuated and/or reflected by the liquid mixture and is measured by one or more optical detectors that are also coupled to the measurement cell. The optical detector generates an attenuation spectrum and/or a reflection spectrum indicating light received by the one or more detectors at different wavelengths. The attenuation and/or reflection spectrum is used to determine the characteristics of the soil sample.

Abstract: A soil analysis device and a method are disclosed for measuring characteristics of a soil sample. A mixing chamber combines a soil sample and an extractant into a liquid mixture. A filtration system receives and filters the liquid mixture. The filtered liquid mixture is transmitted through a pipe with a slope to a measurement cell. The measurement cell is coupled to a light source so that light propagating from the light source is attenuated by the liquid mixture and is measured by an optical detector that is also coupled to the measurement cell. The optical detector generates an attenuation spectrum indicating light received by the detector at different wavelengths. The attenuation spectrum is used to determine the characteristics of the soil sample.

Abstract: The nitrate-nitrogen concentration in soil is estimated based on the nitrate-nitrogen 200 nm absorption peak. In one embodiment, a device measures the attenuation spectrum of a soil-extractant mixture over a wavelength range that includes wavelengths in the vicinity of the 200 nm absorption peak (the spectral operating range) and then determines the nitrate-nitrogen concentration based on the attenuation spectrum.

Abstract: A system and a method are disclosed for combining a soil sample and extractant in a mixing chamber to produce a liquid extractant-soil mixture. A portion of the liquid extractant-soil mixture is directed from the mixing chamber through a sample measurement chamber coupled to the mixing chamber. The sample measurement chamber is coupled to a light source so that light propagates from the light source through the portion of the liquid extractant-soil mixture to an optical detector which generates an attenuation spectrum indicating light received by the detector at different wavelengths. The sample measurement chamber may include an attenuation cell having a specified optical path between a first measurement window and a second measurement window and angular surface directing particulates in the liquid extractant-soil mixture away from the attenuation cell.

Abstract: A system and a method are disclosed for combining a soil sample and extractant in a mixing chamber to produce a liquid extractant-soil mixture. A portion of the liquid extractant-soil mixture is directed from the mixing chamber through a sample measurement chamber coupled to the mixing chamber. The sample measurement chamber is coupled to a light source so that light propagates from the light source through the portion of the liquid extractant-soil mixture to an optical detector which generates an attenuation spectrum indicating light received by the detector at different wavelengths. The sample measurement chamber may include an attenuation cell having a specified optical path between a first measurement window and a second measurement window and angular surface directing particulates in the liquid extractant-soil mixture away from the attenuation cell.

Abstract: A system and a method are disclosed for combining a soil sample and extractant in a mixing chamber to produce a liquid extractant-soil mixture. A portion of the liquid extractant-soil mixture is directed from the mixing chamber through a sample measurement chamber coupled to the mixing chamber. The sample measurement chamber is coupled to a light source so that light propagates from the light source through the portion of the liquid extractant-soil mixture to an optical detector which generates an attenuation spectrum indicating light received by the detector at different wavelengths. The sample measurement chamber may include an attenuation cell having a specified optical path between a first measurement window and a second measurement window and angular surface directing particulates in the liquid extractant-soil mixture away from the attenuation cell.

Abstract: A device and method for measuring field samples in a liquid form removes the need for dry-and-grind type testing. A field sample is received taken from a location in a field. A soil subsample is separated from the field sample. The soil subsample is mixed with water, and a soil-water subsample is selected and transferred for testing. The soil-water subsample is measured to determine attributes of the field sample. The field sample may be measured in the field where it was taken, at a local field office located close to the field, or at a remote laboratory. To test remotely, a test well device is prepared which stores a number of soil-water subsamples. Time and cost savings allow for area-based pricing of soil analysis, largely independent of the density at which field samples are tested.

Abstract: A system and a method are disclosed for combining a soil sample and extractant in a mixing chamber to produce a liquid extractant-soil mixture. A portion of the liquid extractant-soil mixture is directed from the mixing chamber through a sample measurement chamber coupled to the mixing chamber. The sample measurement chamber is coupled to a light source so that light propagates from the light source through the portion of the liquid extractant-soil mixture to an optical detector which generates an attenuation spectrum indicating light received by the detector at different wavelengths. The sample measurement chamber may include an attenuation cell having a specified optical path between a first measurement window and a second measurement window and angular surface directing particulates in the liquid extractant-soil mixture away from the attenuation cell.

Abstract: A soil analysis device and a method are disclosed for measuring characteristics of a soil sample. A mixing chamber combines a soil sample and an extractant into a liquid mixture. A filtration system receives and filters the liquid mixture. The filtered liquid mixture is transmitted through a pipe with a slope to a measurement cell. The measurement cell is coupled to a light source so that light propagating from the light source is attenuated by the liquid mixture and is measured by an optical detector that is also coupled to the measurement cell. The optical detector generates an attenuation spectrum indicating light received by the detector at different wavelengths. The attenuation spectrum is used to determine the characteristics of the soil sample.

Abstract: A tissue measurement device can provide for rapid, robust analysis of large volumes of plant tissue samples in the field. The tissue measurement device measures tissue samples in a liquid state. The tissue measurement device uses a spectrometer to determine an absorbance spectrum over a range of wavelengths. The absorbance spectrum provides information about the properties of the tissue sample. Tissue samples may be mixed with various extractants or reagents to further improve the accuracy of measurements or allow measurement of a wider variety of nutrients or properties. The tissue measurement device may also take calibration measurements to improve the measurement of tissue sample properties.

Abstract: The nitrate-nitrogen concentration in soil is estimated based on the nitrate-nitrogen 200 nm absorption peak. In one embodiment, a device measures the attenuation spectrum of a soil-extractant mixture over a wavelength range that includes wavelengths in the vicinity of the 200 nm absorption peak (the spectral operating range) and then determines the nitrate-nitrogen concentration based on the attenuation spectrum.