6 June 1997

When watching the grass grow can pay you big dividends

GRASS Watch is a weekly update of grass growth rates on on-farm conditions, writes New Zealand dairy consultant Paul Bird.

Data is collected from farmers who are measuring their own whole farm grass growth. This is then divided into areas receiving less than 900mm (35in) of rain per year and those more than 900mm.

The aim of a regular update such as this is to increase the interest in grass as a valuable resource and improve the timing and quality of grass management decisions.

Growth rates have been above average from March. During the dry period in April growth dropped below average but took off as soon as the rain and warmth arrived – making use of unused nitrogen that was applied earlier.

Current growth rates of 80 to 95kg DM/ha/day are enough to maintain a stocking rate of about 5.5 to 6 cows/ha (2.2-2.4 cows/acres) assuming grass dry matter consumption is 15 to 18kg DM/cow/day.

Soil moisture and temperatures are adequate in most areas so even though grass growth is expected to drop off it wont be a dramatic fall just yet.

Most first cut silage will be done now. Dont bring in too much of this area into the grazing ground if high growth rates continue as grass quality will deteriorate.

Spring-born calves

Replacement dairy stock including spring born calves, should now be consuming most of their diet from grazing. Growth rates of up to 0.8-1kg/day can be achieved on top quality grass.