Evaluation and calibration of an automated rising plate meter for estimating dry matter yield of pasture

Abstract

An automatic rising plate meter called the Ellinbank Pasture Meter (EPM) was constructed and evaluated at the Dairy Research Institute (Ellinbank) for measuring the dry matter present on a pasture dominated by green perennial rye grass. The meter readings of pasture height were found to correlate linearly with pasture yield, and the coefficient of variation of calibrations on any one date averaged about 13%. When the data from a large number of calibrations from separate dates were pooled, the coefficient of variation increased to about 18% (RSD 370 kg ha-1). Although there was a high level of repeatability of readings within operators, a substantial degree of variation existed between operators. The diurnal variation in dry matter percentage of pasture had only small effects on the meter readings. The EPM has an advantage over other pasture measuring methods in that its automatic function enables up to one hundred pasture measurements to be made in five minutes. In direct comparison with a manual rising plate meter and a two probe electronic capacitance meter, it was found that there was no significant difference in accuracy between the three meters but the advantages of the EPM are discussed. On perennial rye grass/white clover pastures in an actively growing vegetative state, the EPM has been found to be accurate enough for research purposes yet simple enough for use by farmers and their advisers as an aid to pasture management.

Seasonal changes of herbage quality within a New Zealand beef cattle finishing pasture

“…Means with different letters within rows indicates significant differences between seasons (P < 0.05). ) was estimated with a calibrated rising plate meter using a double sampling procedure (Earle & McGowan 1979). Herbage samples were bulked and transported to the laboratory within 30 min of sampling and oven dried for 72 h at 60°C until weight loss ceased.…”

Effect of lambing policy and ewe breed cross on wool growth patterns and wool quality

“…The initial stocking rate for August-lambing ewes was 12-14 ewes/ha whereas the June-lambing ewes were stocked at 8-10 ewes/ha to take account of lower winter pasture growth rates (Hawkins et al 1989). During lactation, average pasture cover, measured weekly using the Ellinbank Pasture Meter (Earle & McGowan 1979), was kept above 1000 kg DM/ha (c. 4 cm sward surface height) by adding extra paddocks to the area available to the lambed ewes from cattle or hogget grazing areas. If pasture cover increased above 1500 kg DM/ha, as in late spring for the August-lambing group, cattle were introduced to consume the excess pasture growth.…”

Herbage intake, ingestive behaviour, and growth performance in unbred and once-bred Hereford × Friesian heifers

“…This represented a daily allowance for the heifers of 7 kg DM/head per day. Sward surface height (SSH) and compressed sward height (CSH) were measured (50 readings each) daily using the HFRO sward stick (Barthram 1986) and the Ellinbank rising plate meter (Earle & McGowan 1979), respectively. Herbage mass (kg DMlha) was estimated from quadrat samples (Frame 1981).…”