Thursday, July 7, 2022

Regrassing to the max

In the next four months Canterbury dairy farmer Leo Donkers will regrass 40% of the area across his three farms. Anne Lee takes a look at how that’s possible and what he’s learned from last season’s foray into this massive exercise.

Last season Leo Donkers and the team at his family-owned Camden Group embarked on an ambitious plan to regrass the entire 800ha of the milking platform across their three pivot- and spray-irrigated Te Pirita and Bankside dairy farms in just three years.

It meant taking out a third of each farm last season, sowing half the regrassed area in perennials and the other half in short-term Italian ryegrass to give quick feed and to get two chances to spray out native and old grasses that had invaded some pastures.

This season another third of the farms will be taken out, but last year’s Italians also need to be sown in permanent pasture.

That means 40% of the milking area will be resown between now and late December.

Is it a gutsy effort or madness? Leo says it’s neither.

“It’s a calculated response to what we were seeing onfarm in terms of our increasing use of bought in supplements just to achieve the same production. We couldn’t afford not to do it,” he says.

He thought the same last season when the programme started.

With last season’s experience and analysis of the numbers he’s even more adamant despite the dramatic slide in the milk price this season.

“The regrassing we started early last season paid for itself in less than six months – on that score we’re already in profit,” Leo says.

Camden operations manager Terry Kilday, Agriseeds pasture systems manager Graham Kerr, and Leo have worked through last season’s pasture records and the results are there to see.

Top of the table calculations – planning was essential and monitoring is showing the advantages of the big regrassing programme.

In Canterbury the regional plan requires farms to hold their nitrate leaching levels to the average of the three years from 2009.

Once they have the whole farm in permanent pasture they’ll base the regrassing programme on their grazing records – his guess is some years 20% of the farm will need to be done, but some years less.

Preparation and establishment tips

Book the contractor well in advance and ensure they know exactly what your plan is and what you expect.

Choose the right endophyte for your particular pest problem and ensure seed has been stored correctly to ensure high survival rate of endophyte.


• If you’re aiming to spray out browntop and other old grasses don’t do it when the covers are too high. Lower covers (eg 1800-2000) allow the spray to get down into the more prostrate, lower-growing older species. Use a high rate of Roundup and a wetting agent.

• Leave sprayed-out paddocks for 72 hours before you graze them to get a good kill.

• Roll after spray-drilling (direct-drilling) to close up the slots and crumble the soil edge back over the seed.

• With spray-drilling use an insecticide when spraying out, and slug pellets at drilling if they are a problem just as you would if sowing a crop.

• Apply nitrogen (N) at100kg N/ha once it’s up and keep applying it monthly in the first three months to support its rapid growth.

• First grazing will be about 5-6 weeks post-drilling. Just nip the top off quickly to encourage tillering. Stay off the paddock if it’s wet.


• Spray out with high concentrate glyphosate and leave for three days before grazing.

• Don’t cultivate for two weeks to allow a good kill and time for the roots to start breaking up and letting go of the soil. This makes for better cultivation.

• Top work the paddock – two to three passes of the tractor to get a fine, firm seed bed.

• Leo sows permanent pasture with a drill that puts half the seed into drill rows and broadcasts half between rows to give good ground cover, and long-term grass weed control. Clover seed is broadcast so that it doesn’t have to compete in the drill rows.

• Lightly roll after drilling to ensure seed is in contact with the soil.

• After the first light grazing a herbicide mix is sprayed on. Leo uses an MCPA and MCPB mix. The contractor is booked before the first grazing.

• Nitrogen is applied at 100kg N/ha.

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