1. This test can be done alongside your basal ground cover transect. Moving along approximately the first 10m of your transect away from your sample site, collect a handful of plant material by tearing – like a cow or a sheep munching at the plants.
N.B: Do not sample diseased, insect attacked or stressed plants.
2. Collect two separate measurements for ‘Brix of grass or crops (%)’, and ‘Brix of weed (%)’ in Soilmentor – the Brix Barometer indicator works by examining the difference between these two brix readings.
3. Squish the handful of material into the garlic crusher.
4. Hold refractometer in one hand, flip back the plastic flap to expose the glass face.
5. Hold filled garlic crusher in the other and squeeze ‘juice’ from picked grasses onto the glass face of the refractometer.
6. You need just one drop of ‘juice’ on the glass screen. Then drop the refractometer’s plastic flap on top of the drop so it smears across the screen.
7. Hold the refractometer up to the sky (about 15degs) and look into the lens.
8. There will be an area/line on the scale where it changes from light blue below to dark blue above.
9. Record the number on the scale and make a note of whether the line is fuzzy or not in the notes section.
N.B. As a general rule of thumb, an optimum Brix value for grasses is 12 (and above).
10. Clean and dry the glass screen with your water ready for the next test
11. Remove residues from garlic crusher.
Watch the video below to see the brix method in action!