Analysis key to pasture renewal

 That was the headline message Agriseeds’ Graham Kerr and colleague Matt Smith had for the recent Lincoln University Dairy Farm focus day.

Kerr said he often finds there’s no data to support pasture renewal decisions which is probably why an Agresearch study of returns from renewals showed, on average, no gain.

“Quite a lot of paddocks are chosen because they are ugly, not because they are not productive,” he told the focus day crowd.

When pasture monitoring and/or grazing data is analysed some ugly paddocks will be found to be as productive as those that look great, and some that look good will not be producing.

For farms using pasture monitoring software “all the data is in there. You just need to press the button and analyse it,” he stressed.

Having picked the right paddocks to renew from data, rather than perception, investigating why they’re performing poorly and putting any inherent problems right, such as fertility or drainage, as part of the renewal process is essential.

“It’s like a chain. The renewal process is only as strong as its weakest link. You’ve got to get all these things (see panel) right.”

Kerr says the checklist should be put on the wall and worked through systematically.

There’s still time to renew pasture this autumn and with a low payout the opportunity cost of production foregone while the paddock is out of the round is lower than in a high payout year, he points out.

There’s also at least one bank, ANZ, offering special low interest loans for pasture renewal, he adds.

During the focus day Kerr was asked if tall fescue or lucerne might have helped LUDF with its pasture quality problems during the summer heat.

While it was “a good question” he warned tall fescue must be grazed at lower covers to retain quality than ryegrass, which in practice means unless a large block of the farm is put into that pasture, it is hard to integrate it in a grazing round. “If you only sow one or two paddocks with it you tend to let the management slide.”

Fescue’s greater root mass than ryegrass could help it mop up more nitrogen which might be an environmental positive, he added, but Lincoln University’s professor Grant Edwards pointed out the problem is it only does that in warm weather. “It lacks cool season growth when uptake [of nitrogen] is very important.”

As for lucerne, Edwards said it has lasted well for three years in a diverse ryegrass pasture mix managed with 100-200kg/ha/year of nitrogen fertiliser.

Choosing the right paddock

Identify under-performing paddocks and rectify reasons for poor performance.

Soil test 6-12 months prior to reseed and address fertility issues.

Choose appropriate sowing date and renewal method; book contractors early.

Check for pests and plan controls: seed treatment, insecticides, endophytes?

Spray out prior to cultivation or direct drilling.

Prepare fine, firm, level seed-bed if cultivating.

Match cultivar and seed mix to farm system.

Check seed certificate for germination, purity and endophyte.

Control weeds in early establishment.

Light, early graze once it passes pluck test to promote tillering.