Concentration and size of gravel in relation to neutron miosture and density probe calibration
| dc.creator | Lal, R. | |
| dc.date | 1979 | |
| dc.date | 2017-05-22T09:56:38Z | |
| dc.date | 2017-05-22T09:56:38Z | |
| dc.date.accessioned | 2026-06-27T16:00:42Z | |
| dc.description | The effects of four gravel concentrations (0, 20, 40, and 60 percent by weight) and three gravel size fractions (4-8 mm, 8-15 mm, and 15-40 mm) on the calibration of a neutron moisture meter and density probe was investigated for a beach sand and a clayey tropical Alfisol (Oxic Paleustalf). The slope of the regression line of the calibration curve relating neutron count ratio with volumetric moisture content of gravel-free sand was statistically significantly different from that of three gravel-sand mixtures. The calibration curve of three gravel-sand mixtures was statistically identical. For the gravel-soil mixtures, the slope of the calibration curve generally decreased with increased gravel concentration. The statistical comparison of the regression lines for the 4-8 mm gravel size fraction indicated that the slope coefficient of the calibration curve of only 60 percent gravel-soil mixture was significantly lower than that of 0, 20, and 40 gravel percentages. For the 8-15 mm gravel size fraction, the slopes of the regression lines of 40 and 60 percent gravel-soil mixtures were similar and significantly lower than that of 0 and 20 percent gravel concentrations. Gravel size had no effect on the calibration curve in the gravel-sand mixtures. In the gravel-soil mixtures, for 20 and 40 percent gravel concentrations, 4-8 mm gravel size had a significantly higher slope coefficient of the regression equations, compared with the 8-15 mm size fraction. The slope of the regression equation relating density count ratio with dry density significantly decreased with an increase in gravel concentration for 40 and 60 percent, compared with 0 and 20 percent gravels for gravel-soil mixtures. Heterogeneity of tropical soils, with regard to variations in texture and gravel concentrations, may necessitate a detailed calibration of the neutron moisture meter prior to its use on large watersheds. | |
| dc.identifier | https://hdl.handle.net/10568/81152 | |
| dc.identifier.uri | http://hdl.handle.net/123456789/119968 | |
| dc.language | en | |
| dc.rights | Limited Access | |
| dc.source | Lal, R. (1979). Concentration and size of gravel in relation to neutron miosture and density probe calibration. Soil Science, 127(1), 41-50. | |
| dc.subject | gravel concentrations | |
| dc.subject | gravel size | |
| dc.subject | soil | |
| dc.subject | calibration | |
| dc.title | Concentration and size of gravel in relation to neutron miosture and density probe calibration | |
| dc.type | Journal Article |