|
Determining Forage Supply - Pasture Plate Method
Participants from the grazing Management In-service training using a pasture plate to estimate amount of forage (Limpograss, Hemarthria altissima) available for cattle.
In each pasture, or representative area in the pasture, walk in a selected direction and every 10 steps drop the plate from a predetermined height above the forage (~24 - 36 in.). Measure the height of the grass. Clip the forage under the circular disk and weigh the clipped forage. Clip the forage to a consistent height for all frames. Dry the clipped forage to estimate percent dry matter (DM). Calculate the amount of forage in the given area clipped. Convert to lbs DM/acre. The calibration of the pasture plate uses the heights measured plotted against the weight of the forage clipped. A linear regression model is developed and future measurements can then be plotted on the graph and lbs of forage
available can be determined.
For practical on-farm use, additional calibrations are needed over pastures differing in species composition, season of year, and regrowth age.
The pasture plate used for this example had a 10 in. radius. Surface area = pr2
150 g per 314.16 in2 150 g/454 g lb-1 = 0.33 lb
314.16 in2 = 5.01 x 10-5 acre 0.33 lb/5.01 x 10-5 acre = 6,587 lb/acre
Back |
