Guidelines for using the Biomass App and Trimble Greenseeker Handheld NDVI Sensor to estimate Greed Dry Matter in Pastures

Summary

The Biomass Business II (BB2) project evaluated the potential for active optical sensors (AOS) to provide reliable estimates of pasture biomass. The project was focussed in the high rainfall zone of south–eastern Australia and aimed to develop calibrations for AOS and provide a data management package that can be easily used by producers. The project was part of the Grazing Systems Management Pillar of MLAs Feedbase Investment Plan and was supported by MLAs Participatory Research Groups (PRG).

Six pasture types were assessed – tall fescue, phalaris, perennial ryegrass, white clover, lucerne and cocksfoot. Data collection involved measuring normalised difference vegetation index (NDVI), pasture height, taking cuts to ground level, sorting into green, senescent and clover, and measuring the dry weights. Green dry matter was regressed against NDVI and height for each campaign, and again for pooled data regional data.

The most commonly suitable models were simply the NDVI, height, or a combined NDVI x height index. The calibrations are available to graziers through the Biomass mobile device application. The objective feed estimates provided through the Biomass app can allow pasture growth to be monitored and support stock management decision making.