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T&D > Programs Areas > Inventory & Monitoring > Herbaceous Measurement Device Comparison Program Areas
Herbaceous Measurement Device Comparison
Lois Sicking, Mechanical Engineer

Executive Summary

Introduction and Scope

Inventory and monitoring are key components to land management practices. This includes the measurements of forage production to determine stocking rates and the effectiveness of certain land treatments such as burning, herbicide applications, and fertilization.

Forage production values are used in conjunction with measurements of residual forage on areas that were previously grazed so forage utilization levels can be monitored on grazing allotments. Wildlife habitat managers, range management specialists, and other land monitoring employees use these plant production measurements to monitor whether livestock use levels are in compliance with maximum allowable use standards prescribed in the allotment management plans. There are various methods used to obtain plant productivity measurements. The current standard for herbaceous plant productivity is a time consuming process of clipping, weighing, and drying vegetation in an oven.

This study involved a comparative analysis between various commercially available herbaceous measurement devices. Precision, accuracy, correlation, and performance characteristics of capacitance probe, oven meter, and sliding plate technologies were compared to the standard clip and weigh oven method.


The Sigma Delta Technologies Pty Ltd, Fuel and Soil Moisture Meter Neosystems II (Neosystems II) had the highest degree of correlation, accuracy, and consistency when compared to the standard oven. It had a 94 percent positive correlation, followed by the Tru-Test Limited GrassMaster (GrassMaster) capacitance probe with 74 percent and Jenquip Filips Folding Plate Pasture Meter (Filips Folding Plate Pasture Meter) with 58 percent. All other devices had a lower correlation. The Neosystems II unit has a better than 99 percent accuracy, unlike all the other devices tested. Development of forage constants for specific pasture plots and the issue of minimum stubble height needs to be addressed before field use for any application requiring less accuracy than currently provided by the standard oven or Neosystems II.

The Neosystems II is an improvement over the standard oven. Key differences include a decreased amount of time necessary to determine forage production values, automation to reduce human error, and the capability to download data to a personal computer. It takes 21 hours for the standard oven to determine forage production values, 1 hour if using 3 Neosystems II meters or 3 hours if using 1 Neosystems II meter.

In addition to the forage production measurements, there is a need to develop a field users guide for sampling, collection, and processing forage production samples, including sampling collection, handling, and processing techniques for use with the standard oven or Neosystems II meter.