Glenys Christian

Northland dairy farmer Allister McCahon believes fodder beet has a place on some of the region’s dairy farms.

“Where utilisation is not a problem it offers very high feed values at important times of the year,” he says.

“It’s all about the right soil type and the crop being ‘fit for purpose’. What are you trying to mitigate and what are you trying to achieve? There’s no sense mitigating one set of risks by introducing another.”

He winter milked on his farm near Te Kopuru, south of Dargaville for 20 years.

“One of the larger risks was calving into a drought,” he says.

“You could be calving on to Weetbix and that’s not conducive to good milk production. And it also coincided with autumn kikuyu management which is one of our busiest times of the year.”

‘You need 80,000 plants a hectare and if you don’t get that you’re on the back foot to start with. There’s a lot of margin for error when playing with very small numbers of seed.’

With many Northland farmers mulching kikuyu-dominant pastures in the autumn, taking them back to very low covers, good pasture growth is needed to rebuild pastures before the spring.

“Maize alone doesn’t have enough protein to fully feed autumn calved cows,” he says.

“So in 2012 we started growing fodder beet as a potential fit for autumn-calving cows. It could be grazed in situ and it was a high quality feed.”

He grew from four to eight hectares of the crop for the next five years.

“Paddock selection all comes back to yield potential and feed utilisation,” he says.

Good pasture growth is needed to rebuild pastures before the spring.

He chose paddocks which had the lowest risk of erosion due to break-feeding the crop which meant a lot of cows on a small area.

“If you’re going to grow fodder beet on a clay soil, harvesting may be a better option.” he says.

Fodder beet can be grazed from 220 days after planting, but will grow for from 350 to 400 days after sowing in some areas of Northland, meaning that if it is planted in the spring it can still be accumulating drymatter (DM) in the following October-November.

“And in Northland we have the option of sowing it in autumn,” he says.

Farmax modelling had shown that using fodder beet on10% of a Northland dairy farm could be a very productive farm system.

“But it wouldn’t mitigate drought so to go to 10% you’d be replacing one set of risks with another when a lot of farmers grow chicory or maize on 10% of their farms with no problems.”

Around 10 years ago he made the decision to move from 60% of his herd calving in autumn to 30%. Then the next step was to all spring calving for his 1000-cow herd, starting on June 10, which better suited facilities on his farm and lessened the need to grow fodder beet. But for other Northland farmers it continued to provide a valuable strategic option for extending lactation, or improving cow condition.

“However, it is potentially in the ground growing for a long time and needs to produce superior yields to warrant this,” he says.

“This can then provide its own set of challenges when grazing large volumes on small areas.”

He believes that with climate change potentially affecting pastures, and farming systems Northland farmers may need to be prepared to consider other options.

“Fodder beet is a Mediterranean plant so has the potential to be part of a diversified feed strategy,” he says.

He’s taken the lead in looking at some of the options for Northland in a project focused on diversified feed options which is in its third year. While plot and farm trials have been carried out he said farmers now want to know if the results are repeatable.

“Persistence is a question we would like to address, but is beyond a three-year study.”

With beet, plant population and weed control are key, he says.

“You need 80,000 plants a hectare and if you don’t get that you’re on the back foot to start with. There’s a lot of margin for error when playing with very small numbers of seed.”

Fodder beet has potential production of more than 25 tonnes DM/ha, so in this respect he says it’s similar to maize, but for a different purpose. But he cautions those yields won’t be the result on every soil.

“The key is can you manage the risks and cropping isn’t without risks,” he says.

“It is unlikely that there will be a silver bullet solution. Whether we like it or not, one outcome of climate change is the anticipated spread of C4 grasses such as kikuyu.”

As C4 grasses are not winter active it is managing the transition from temperate grass to and back to temperate that is both crucial and challenging, with many farmers, particularly those on hill country, struggling to achieve this in a timely manner.

And there are other more recent factors which may also have a considerable effect.

“With the advent of Mycoplasma bovis farmers may not be able or want to move stock around as much as previously,” he says.

And drought conditions during the present European summer mean palm kernel prices are likely to rise.

However he’s adamant there’s good reason to keep reviewing prospects for fodder beet, with its yields justifying another look at it. It can also be grown with a later sown crop of tick beans and oats which can add production of another 10t DM/ha. This starts to align with results from DairyNZ’s Scott Farm research reported on at the Grasslands Conference in 2009 by Elena Minnee which showed potential annual yields of forage crops of up to 45t DM/ha in Northland and Waikato.

He’d like to see a literature review carried out to look at what might happen in Northland with climate change over the next 20 years which he says would encourage the region’s farmers to look forward. A Ministry for Primary Industries report on climate change adaptation in 2014 said new technologies could change the way dairy systems functioned under climate variability and change.

Pasture technologies could lift potential pasture yields from 20t DM/ha per year, to 25t DM/ha and increasing the rooting depth of plants could mitigate moderate to severe water shortages with pasture technologies reducing the effects of environmental stressors on plants.

And a National Institute of Water and Atmospheric Science report in 2016 said as mean temperatures and drought occurrence increases, Northland farmers are more  likely to increase their usage and dependence on existing subtropical plant species and introduce new commercial species that are heat and drought tolerant.

Kikuyu is likely to become the most prevalent forage grass in the area because it can spread quickly and is heat and drought-tolerant.

More work with a regional focus is now required to prepare for what situation might lie ahead for Northland dairy farmers, he says.

“What will it look like, where are the gaps and how do we fill them?

“We need to look at it on a holistic level because there some learnings which are likely to be positive and some not so much. People think about normal but it’s going to be different.”

Fodder beet tips

Allister McCahon’s  tips for successfully growing fodder beet are:

  • Seek good advice.
  • Form a plan and follow it as it’s not a crop with which you can take shortcuts.
  • Get the sowing rate right.
  • Weed control is critical.
  • It’s not a gross feeder and likes potassium more than phosphate.