Alternative Methods of Estimating Forage Height and Sward Capacitance in Pastures Can Be Cross Calibrated
2007
Rayburn, Edward B. | Lozier, John D. | Sanderson, Matt A. | Smith, Brad D. | Shockey, William L. | Seymore, David A. | Fultz, Stanley W.
A variety of tools are used for measuring pasture height or capacitance. Cross calibrations between these tools would be helpful for extension staff and producers comparing measurements taken with one tool to those taken with an alternative tool. Rotationally and continuously stocked pastures in West Virginia, Pennsylvania, Maryland, and New York were sampled for forage height using a ruler, for compressed height using a falling plate meter and a rising plate meter, and for sward capacitance with a capacitance meter. Thirty to sixty measurements were made across each pasture with each device, with paddock means taken as the measurement for the device. Regressions were run using paired paddock means, testing each device as both the dependent and independent variable, with r² ranging from 0.49 to 0.99. Residual analysis was conducted to evaluate biases due to location and stocking management using the falling plate meter means as the independent variable versus means of the other techniques. No bias in pasture measurements was found due to grazing management. There was a bias due to operator for ruler height and capacitance meter reading. These cross calibrations provide a mechanism for pasture managers to translate pasture heights or capacitance taken with one tool to those taken with another tool.
显示更多 [+] 显示较少 [-]