Tiller survival in spring

Tiller survival in spring

1 November 2016

During the spring and early summer period most farms will grow and harvest between 45 to 65 percent of their total annual feed.

The way these pastures are managed over the next few months will impact pasture grown, milk production up to Christmas, pasture quality in summer, pasture density and total pasture harvested this year.

To maximise pasture during this part of the season the factors to consider are surplus management, tiller survival, supplement use and summer preparation.

Surplus management

Pasture growth rates usually increase after balance date and this creates surpluses. Frequently monitoring average pasture covers and plotting these on a feed wedge allows surpluses to be ‘seen’ 10 to 14 days ahead of time so it’s easier to make proactive decisions around managing this surplus (e.g. organising a silage contractor or speeding up the rotation). For information on how to use a feed wedge visit dairynz.co.nz/feedwedge.

Tiller survival

This is the one time of year when ryegrass tillers that have gone through a winter (’mother’ tillers) produce ‘daughter’ tillers. The daughter tillers separate from the mother tiller and result in a new plant. Each mother tiller can produce two to three daughter tillers.

Keeping pre-grazing yields between 2600 and 3200 kilograms of Dry Matter per hectare (kg DM/ha) prevents shading and allows sunlight to reach the base of the plant. This encourages daughter tillers to grow from the plant base, rather than forming above the ground where most won’t be able to take root and survive.

Supplement use

Good quality ryegrass-based pastures are a well-balanced feed for dairy cows, supplying energy, protein, lipids, vitamins and minerals. A pasture-only diet is sufficient for production and good reproductive performance. This means there is little benefit feeding supplements when the farm has a pasture surplus. Save supplements for later in the season if the farm gets dry and pasture growth is too slow, or for extending the round when it rains.

Setting up for summer

Another aspect of pasture management in the spring period is ensuring high quality feed is taken into the summer. On summer dry farms, nitrogen (N) can be applied in late November or early December at 20-25 kilograms of Nitrogen per hectare (kg N/ha) per application (up to 40-50 kg N in total). This will promote new tiller growth, increase pasture cover and extend the round. Nitrogen needs to be applied before moisture starts limiting growth and will only be beneficial if residual targets of 1500-1600kg DM/ha continue to be met. Achieving this target consistently is key to controlling the development of reproductive tillers (and emergence of seed heads) which impacts on pasture quality available at the next grazings.

Extending the round is also important because as moisture becomes limiting, the rate new leaves emerge slows down. A longer round allows the two and a half to three leaf target to still be met, ensuring maximum growth is achieved before grazing, consequently giving greater annual pasture yields.

To discuss your pasture renewal plan get in touch with your local Fonterra Farm Source Technical Sales Rep or in-store team.

Article supplied by DairyNZ