Author
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Hummel, John |
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Submitted to: American Society of Agricultural Engineers
Publication Type: Abstract Only Publication Acceptance Date: 7/20/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The objective was to modify a standard soil cone penetrometer to allow the measurement of soil moisture content simultaneously with penetration resistance. The device used a near infrared reflectance soil organic matter (OM)/soil moisture sensor in conjunction with a bifurcated fiber optic cable which transmitted the signal from the sensor through the penetrometer to the soil and back to the sensor. Moisture prediction was accomplished at the site of penetration resistance. Test results indicated that through use of a force prediction relationship, moisture effects could be removed from the penetration resistance values. The spectral reflectance sensor was able to predict moisture content while stationary and while traversing through the soil at 2.5 mm/s within +2.29% and +2.03%, respectively, using partial least squares regression (PLSR). Using multiple linear regression (MLR), the data allowed the OM sensor to accurately estimate moisture content while stationary and while traversing through the soil's profile within +1.17% and +0.83%, respectively. The force prediction equation for the data over the entire range of soil type/moisture content for all methods of estimating moisture content yielded correlation coefficients of 0.895 or higher. Commercialization of this concept could significantly increase the usefulness of soil penetration resistance data. Data collected at different times during a growing season, or even during different seasons could be reduced to a single moisture level. |
