HOW TO SCORE
Walk the field and assess grass content.
We want as dense sward as possible to elminate any invasion of unproductive species.
An Index 4 field will have a total of 60-70% sown, productive species (with ryegrass content of 60-70%, and clover making up 30-40% of the plant population).
If these levels of productive species content are achieved the clover will be adding 170-220kg N/ha/yr, coupled with a high protein content of 27%, which helps ensure high animal performance.
WHAT THIS MEANS
This field will be good for the coming season, but it will have to be monitored and planned improvement (overseeding) will be needed if the productive species drops below 60%.
WHAT TO DO
In these swards nutritional quality will generally not constrain cow performance. The energy content of good, well-grazed ryegrass swards is consistent at above 11.5 MJ/kg DM.
Nitrogen can influence the plant’s ability to tiller and the more tillers our ryegrass plants have, the denser they are, and the less prone they are to weed invasion so this is one of the reasons why clover is so important.
To keep on top of an Index 4 field you need to check soil fertility regularly and apply a light application of summer Nitrogen to encourage tillering.
This field will probably be good for the coming season but if the ryegrass content drops below 60% it will require further action.