Estimating Herbage Mass in Stargrass (Cynodon nlenfuensis var Nlenfuensis) Using Sward Surface Height and the Rising Plate Meter

Presenter Information

D. E. Oliveira, University of São Paulo, Brazil
S. R. Medeiros, University of São Paulo, Brazil
L. J. M. Aroeira, EMBRAPA, Brazil
L. G. Barioni, University of São Paulo, BrazilFollow
D. P. D. Lanna, University of São Paulo, Brazil

Description

Estimation of herbage mass is necessary both in research and farm management. Methods for such estimations should be inexpensive, rapid and reliable. Since estimations through hand clipping are time consuming, a range of indirect methods have been developed and tested in the literature. This study had the aim of comparing precision of two indirect methods, sward surface height (SSH) and the rising plate meter (RPM), to estimate herbage mass in stargrass pastures (Cynodon nlenfuensis var. nlenfuensis). Pre-grazing measurements of SSH and RPM readings were taken and compared with the paddock herbage mass. RPM readings were converted into centimeters. Average readings were related to herbage mass through linear regression analysis. Equations obtained were Herbage Mass (kg DM/ha) = - 212,94 + 50,59 SSH (cm) (r² = 0.88 ; Residual Standard Deviation (RSD) = 378 kg DM/ha) and Herbage Mass (kg DM/ha) = 522,21 + 108,42 RPM reading (cm) (r² = 0.51; Residual Standard Deviation (RSD) = 800 kg DM/ha). The results suggest that SSH was a better predictor to herbage mass than the RPM readings, probably because the lodging of the plants caused by the rising plate. However there was a quadratic trend for the relationship between herbage mass and height with poor adjust when pastures were over 70 cm average height.

Citation

Oliveira, D. E.; Medeiros, S. R.; Aroeira, L. J. M.; Barioni, L. G.; and Lanna, D. P. D., "Estimating Herbage Mass in Stargrass (Cynodon nlenfuensis var Nlenfuensis) Using Sward Surface Height and the Rising Plate Meter" (2022). IGC Proceedings (1993-2023). 11.
https://uknowledge.uky.edu/igc/19/32/11