Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

Development of a Labour Utilisation Decision Support Tool to Efficiently Measure Grass Herbage Mass Using a Rising Plate Meter

Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan

Citation:  2018 ASABE Annual International Meeting  1800806.(doi:10.13031/aim.201800806)
Authors:   Darren J Murphy, Bernadette O’ Brien, Michael D Murphy
Keywords:   Decision Support Tool, Grassland Management, Labor Utilization, Precision Grazing, Rising Plate Meter, Sampling Strategy

Abstract. Accurate estimation of herbage mass is essential for optimizing grass utilization and increasing profit margins for pasture based livestock farming. The rising plate meter is a tool for predicting herbage mass based on average compressed sward height (CSH). Sampling resolution and distribution are the primary parameters in determining spatial heterogeneity of herbage mass. There is no definitive sampling protocol for the plate meter. The objective of this study was to develop a theoretical framework for a precision grass measurement labor utilization tool to optimize both sampling precision and labor efficiency. Blanket CSH sampling was conducted on controlled trial plots using a plate meter on a weekly basis over an entire growing season (8 months) to best estimate mean CSH per plot. Sward heterogeneity was calculated as coefficient of variation of CSH. Retrospective analysis was conducted to simulate the effect of various reduced sampling resolutions on estimated mean CSH. The results indicated that mean CSH can be estimated to within 10% standard error of the mean using a minimum of 77 samples per acre. Sward heterogeneity peaked in early spring and in non-nitrogen fertilized plots indicating the necessity for dynamic optimum sampling intensities based on seasonality and fertilization rates. Sampling cost analysis was conducted to determine the economic efficiencies associated with precision grassland measurement and a targeted sampling accuracy in the region of 5-10% was deemed feasible. The findings of this study will form the basis of the experimental framework to develop a labor utilization tool for precision grassland measurement.

(Download PDF)    (Export to EndNotes)