Use of a surface gamma-neutron gauge to measure effects of tillage, cropping, and erosion on soil properties
Using a Troxler surface gamma-neutron gauge, the authors measured soil bulk density and moisture content at field capacity 0 to 100 and 0 to 300 mm deep at 40 locations in a tilled wheat field and 20 locations in an adjacent native pasture on a silt loam soil (Udertic Paleustolls). Macroporosity at these sites was determined as total porosity minus field capacity. The bulk density of the 0- to 100-mm layer was lower than that of the 0- to 300-mm layer. The mean bulk density values were similar in both fields, but the field capacity was slightly higher, and the macroporosity lower in the grass field than in the wheat field, especially for the 0- to 100-mm later. The authors compared four methods of calculating the above soil properties from gamma readings. These methods involved the use of measured gravimetric soil water contents versus the volumetric soil water contents determined by the back-scatter neutron meter and the use of soil-core calibrated attenuation constants for soil water versus a Troxler approximation of these constants. Differences found among the four methods of calculation were small, as were the differences between the results of these methods and the soil-core values from an earlier study. The volumetric soil water content, 2 d after the soil had been wetted, did not vary much with depth within the topsoil (0 to 300 mm). Then, the surface neutron meter provided an acceptable value for the average topsoil water content and for the average bulk density calculated using that water content. The results demonstrate the tremendous utility of a surface gamma-neutron gauge for rapid hydrologic characterization of a variable field and for measuring the relative effects of tillage, cropping, and erosion depositions.
- Research Organization:
- Dept. of Agriculture, Durant, OK
- OSTI ID:
- 6299179
- Journal Information:
- Soil Sci.; (United States), Vol. 140:4
- Country of Publication:
- United States
- Language:
- English
Similar Records
Hydrogeologic Characterization of the U-3bl Collapse Zone
Carbon Sequestration in Reclaimed Mined Soils of Ohio
Related Subjects
CULTIVATION
CORROSIVE EFFECTS
DENSITY
NEUTRON-GAMMA LOGGING
EROSION
MOISTURE
SOILS
POROSITY
CULTIVATION TECHNIQUES
ENVIRONMENTAL EFFECTS
NEUTRON LOGGING
PHYSICAL PROPERTIES
RADIOACTIVITY LOGGING
WELL LOGGING
510200* - Environment
Terrestrial- Chemicals Monitoring & Transport- (-1989)