Theme 32: Use of Information and Analytical Systems
Publication Date
2001
Location
Brazil
Description
Sward height (SH) is widely used in pasture research and farm practice to evaluate pasture conditions. Visual estimates can take less time than actual measurements. This study compared visually estimated SH, of continuously grazed cool-season permanent pasture with plate meter height. Weekly estimates, by five people, were made on 12, 0.75 to 1 ha fields, grazed at two intensities. Paired data (visual estimate and plate meter height) were subjected to variance and covariance analyses and prediction equations were developed. Average visual height accounted for 86% of the variability in plate meter height. Inclusion of other sources of variability in the model (treatment, date and interactions) accounted for only a further 8% of the variability in plate meter height. On the basis of the strong linear relationships found between visual and plate meter heights, a procedure combining both methods is proposed that would reduce by 25% the time required to make weekly SH measurements of 12, 0.75 to 1 ha fields.
Citation
Bryan, W. B.; Prigge, E. C.; Nestor, E. L.; Gekara, O. J.; and Schettini, M. A., "Sward Height; Visual Estimate Compared with Plate Meter Height" (2001). IGC Proceedings (1985-2023). 2.
(URL: https://uknowledge.uky.edu/igc/19/32/2)
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Sward Height; Visual Estimate Compared with Plate Meter Height
Brazil
Sward height (SH) is widely used in pasture research and farm practice to evaluate pasture conditions. Visual estimates can take less time than actual measurements. This study compared visually estimated SH, of continuously grazed cool-season permanent pasture with plate meter height. Weekly estimates, by five people, were made on 12, 0.75 to 1 ha fields, grazed at two intensities. Paired data (visual estimate and plate meter height) were subjected to variance and covariance analyses and prediction equations were developed. Average visual height accounted for 86% of the variability in plate meter height. Inclusion of other sources of variability in the model (treatment, date and interactions) accounted for only a further 8% of the variability in plate meter height. On the basis of the strong linear relationships found between visual and plate meter heights, a procedure combining both methods is proposed that would reduce by 25% the time required to make weekly SH measurements of 12, 0.75 to 1 ha fields.
