Good pasture relies on correct timing

Common weed seedlings found in new pastures. Photo / Paul Addison

Good management over the next few months is crucial to establishing persistent and productive pastures. Key objectives now are to minimise competition from weeds, promote ryegrass tillering by ensuring the first grazing is done at the right time and to promote clover establishment.

Spraying the best method

Now is the best opportunity to control weeds in pasture. Many weed species establish rapidly, and if left to establish, will out-compete the sown grass and clover for light and nutrients. Most weeds have poor palatability, so you end up with patchy grazing and reduced animal performance.

A post-emergence spray is the best method to control weeds effectively because it offers an opportunity to kill seedling weeds before they become established. Spraying weeds in new pastures is usually advantageous even if there are few weeds.

Aim to apply herbicide six to seven weeks after sowing. If seedling clover is present, correct herbicide selection and use is critical -- always seek advice when selecting herbicides. For help identifying weeds visit pestweb.co.nz or weeds.massey.ac.nz

Test determines when to start

The timing of first grazing is critical for promoting ryegrass tillering and clover seedling development by allowing light to reach the base of the sward. Avoid high pasture covers at the first grazing. Graze as soon as the pasture survives the "pluck test', which is usually six-to-eight weeks after sowing.

Pluck test for ryegrass

To test the pasture, grasp a ryegrass seedling between your thumb and forefinger and pluck in a single, quick movement.

The pasture is strong enough for grazing if the leaves break off and the roots stay in the ground. If the grass roots pull out then the pasture is not yet strong enough for grazing.

Ensure the herd grazes only the top 2cm to 3cm, which at a high stocking rate may be for only an hour of two. Remember the aim is a light grazing to promote tillering. Choose dry conditions for the first few grazings to avoid damage to the soil and new plants.

After the first grazing, continue to promote ryegrass tillering.

* Avoid grazing at high pre-grazing covers above 3200kg DM/ha.

* Maintain an even post-grazing residual of seven to eight clicks on the rising plate meter (RPM).

* Apply nitrogen fertiliser as required to avoid creating a pasture cover that is too high.

- Inside Dairy, Dairy NZ