Just a few months into this megarenewal programme the Canterbury farms’ general manager Leo Donkers was convinced it was completely the right decision.
It’s not that pastures on the three farms, two at Te Pirita and one at Bankside, all looked totally run out. A good percentage looked average to good for a Canterbury irrigated situation. But Camden’s detailed paddock records and its production and profitability data were telling a story of an insidious, very slow creeping decline.
The farms were converted in 1994, 1999 and 2001 and were among the top performers in the region, regularly benchmarked against the Lincoln University Dairy Farm.
Leo and operations manager Terry Kilday led the way as early adopters or even developers of best management practices. They haven’t stood still in terms of pushing for productivity gains and over the past three years the group’s made a significant investment in upgrading irrigation to make better use of the deep water they have to pump at Te Pirita to meet plant demands.
The Te Pirita farms were previously irrigated with four Rotorainers, each on an 11-day return. Both farms now have a 700m centre pivot and three Rotorainers on 6-7 day returns with the Rotorainers watering the area obstructed by power pylons.
The Bankside farm is installing a 734m pivot and will retain two Rotorainers on the remaining area operating on 6-7 day returns.
They’ve also met the challenges to pasture from porina damage and have spent the money carrying out good control programmes.
“But what we were seeing was that despite all of this, despite investing in more efficient irrigation, using strict grazing management practices and carrying out pasture renewal at a rate we thought we could sustain we were still gradually having to bring in more supplement.
“LIC will tell you there’s a 3% productivity gain with genetics but we just weren’t seeing that – something wasn’t right,” Donkers said.
The clues were in the grazing records and the correlation with what went into the vat each day.
Staff on each farm keep meticulous grazing diaries that record information for each paddock. The farms are also walked every week with covers recorded for each paddock and a feed wedge drawn up. This enabled Kilday to put a range of the collected data into a spreadsheet and estimate how much drymatter (DM) each paddock was growing and how many cow grazing days each provided across the season.
A catalyst for delving further into paddock data had been the glaringly outstanding performance from a winteractive hybrid ryegrass, Shogun, which they’d sown in several paddocks in 2012. While the rest of the farm was on a 25-day round cows were coming back to those paddocks almost twice as fast at about a 14-day round.
The analysis across all the farms showed a huge range in DM performance with paddocks producing from eight to 19t DM/ha/year.
“Once we analysed what each paddock across the farms was growing, and compared the new pastures with our old ones, we realised we needed to get into pasture renewal in a big way. In terms of our profitability, we couldn’t afford not to,” Donkers said.
“The problem was we were struggling to ever have enough cover or the confidence to regrass even 10% each year. Some years it was 3% and some years it was 7%.
“We know the benefits from regrassing – we’ve seen a 50% increase in annual DM production from
new grass in the past. I guess what we’ve decided is now we’re in catchup mode.”
Biting the bullet and doing it in big tranches each year was a no-brainer when the benefits of lifting the average paddock production quickly were taken into account.
The cost of establishment was up to $500/ha for permanent pasture and less for the annuals but the cost of not doing it far exceeded that in terms of lost production and made the investment well worthwhile, he said.
He conceded that some regrassing in the past hadn’t been done with enough attention to detail and care and that the establishment methods used hadn’t been quite right.
Enter agronomist and Agriseeds pasture systems manager Graham Kerr who reviewed their records and sat down with them to draw up a detailed plan.
“The brains trust” as Kilday called it, included Donkers, Kerr and himself and together they worked through the entire exercise.
Kerr said he couldn’t stress enough just how important it was to the success of the programme that Terry and Leo could provide good data to analyse.
“This is smart farming,” he said.
“From grazing records they knew the variation in performance of paddocks. We need to rectify what’s holding back the poorer performers and get them all up to the upper production levels.
“The big difference from this farm to most is that Leo and Terry wanted to fix things quickly. They came up with the suggestion of a 33% renewal programme whereas most dairy farms struggle to undertake 10-15% renewal. But where there is a will there is a way and we worked out a plan to achieve it,” he said.
The planning began with the preparation the farm business needed to make to enable it to sustain such a radical move but included paddock selection, establishment practices, post establishment grazing and pasture management as well as monitoring and analysis of the results.
The team calculated what the estimated loss of DM would be over the period paddocks were out of the grazing round and determined a cut in stocking rate of almost 4% was prudent to ensure demand was matched to the reduced feed supply.
It meant cutting cow numbers from 2800 to fewer than 2700 across the three farms.
As an extra risk management tool additional supplement was secured. Paddocks for renewal were carefully selected based on their historical DM growth from cow grazing/day information.
Altogether, across the three farms, 234ha was selected for the first season. But that didn’t all have to be taken out at once.
A plan was developed that involved taking out paddocks in four tranches from October to January with about three paddocks done in each month on each farm. The problem in many paddocks had been the invasion of old pasture species and weed grasses.
Browntop was a particular problem so a specific regrassing plan was developed for those paddocks that served a double purpose. By putting in a short rotation Italian ryegrass there was an opportunity to hit the browntop with a herbicide spray twice, getting a more effective long-term kill and the Italian meant a quicker return to the grazing round for those paddocks.
The paddocks were taken out early, in the October and November tranches.
Kerr said as well as acting as a tool to knock out the browntop, using Italian drives “fast feed” to help alleviate the DM production losses created by the big renewal programme.
“By direct drilling we get it back into the grazing round maybe two to three weeks faster and Italians, by their nature, establish faster so that saves maybe another two weeks compared with perennials,” he said.
The problem browntop paddocks were sprayed out with high rates of concentrated glyphosate (3.5litres/ha of glyphosate 540) and a wetting agent to get a good kill and then direct drilled with 25kg/ha of the Italian – in this case Tabu.
About half of the regrassing this season has used Italian ryegrass. Next season the area sown in Italian will be sprayed out again, cultivated once a good kill has been achieved and a perennial ryegrass/white clover mix sown. Slug bait was put out with the Italians just as it would be with a crop to combat insect pests and about 100kg/ha of urea was applied every month over November, December and January to support the plants’ rapid growth without clover.
Areas with little browntop were assigned to be sprayed out, cultivated and drilled with perennial ryegrass and white clover but the establishment method was reviewed.
They were all irrigated before to their first cultivation then heavy rolled after drilling to give an even, uniform establishment but instead of drilling conventionally into drill rows the drill rig was set up so seed could be broadcast between the rows as well.
Kerr explained that drills and 15cm drill rows were initially developed for the cereal industry and didn’t give the ideal seed placement to create a dense, even pasture sward. The bare ground gap left between the drill rows invited invasion from weeds and old grass species.
Sowing clover within the drill row only also reduced its establishment chances as it struggled to compete with the more aggressive ryegrass plant.
A sowing rate of 15kg/ha for the drilled perennial ryegrass seed was used, with an additional 13kg/ha broadcast along with 2kg/ha of white clover between drill rows to give the dense pasture.
The perennial used was a mix of Trojan and Bealey ryegrasses, the diploid Trojan to add density, with the tetraploid Bealey adding palatability.
Endophyte selection has also been important even under a Canterbury irrigated situation. NEA2, AR1 and AR37 have been used and will confer good resistance to most pests likely to be a problem in the area. AR37 helps give a level of protection against porina but Kerr warned it’s not a silver bullet.
“You still need to be using the full range of good agronomic practices so don’t think just because you have an endophyte that will be the end of the insect problems and you don’t have to do anything else,” he said.
“It’s one of the weapons in the arsenal.”
The planning was done in autumn last year and the assumption was for an “average” 2013-14 season.
“As it turned out it hasn’t been an average season. We had a mild winter but then the coldest October ever,” Leo said.
That had an impact on vernalisation and seed set in the older remaining paddocks on the farm, causing them to flower earlier. The new grasses established well and the grazing management plan set before the season beginning had to be adjusted.
Growth and growth rates surprised the management team and instead of needing the lower stocking rate, in hindsight they could have done with the extra cows back on.
“But we didn’t know how the season was going to turn out and if we had to plan it all again we’d probably do the same thing because there’s no way of predicting early enough what the season will bring,” Kilday said.
The grazing management plan had been to stay out at a 24-25-day round to help the new grasses establish well but, again in hindsight, that was a mistake. Instead of feeding out silage they ended up making it on the platform and growth rates and average pasture covers began to take off.
They’d used gibberellic acid and nitrogen in the spring to help boost pasture growth and that probably wasn’t necessary either.
The farms focused on maintaining an even, low residual and to do that the mower came out in front of and behind the cows in the older grass paddocks.
“We really underestimated how much these new grass paddocks would grow,” Donkers said.
Instead of having a huge feed gap as most farmers would assume with such a big renewal programme they’ve found themselves with the opposite problem.
Staff had monitored the new grass paddocks closely in terms of cover, looking at them between the weekly farm walk days. Data collected showed just how much more grass they’ve produced only a couple of months into the programme.
From November to the end of January Italians sown in October have almost doubled production out of the same paddocks the year before.
“For example one of the Tabu paddocks grew 5.6t DM/ha from November to the end of January and last season that same paddock grew 3t DM/ha,” Kilday said.
A selection of the perennial paddocks has been sown in the more winter-active Shogun. It’s a tetraploid hybrid ryegrass, a cross between an Italian and a perennial. Winter growth rates across the farm have typically been 5-7kg DM/ha/day but Shogun was growing up to 30kg DM/ha/day over that period in Canterbury.
Its winter-active nature might be of significance in helping reduce nitrate leaching although that benefit can’t yet be captured in Overseer 6. It also provides good early season feed but is likely to require close management through the winter.
Kerr is advising that winter production of new perennials is about 30% more than 20 years ago, and coupled with greater use of winter-active Italian and hybrid ryegrasses some cows might have to remain on the milking platform in winter or, in Camden’s case, be brought back as needed off the neighbouring runoff.
He dubbed it a “Hotel California” situation in that it might be necessary for some cows to never leave. With winter-active pastures it’s important to make sure they’re either grazed hard just before cows leave the farm in autumn, or controlled over winter, to prevent opening covers being too high. That can create a quality domino effect with first grazing round residual targets not met then knocking on to quality and regrowth problems in the second and subsequent grazings.
Monitoring winter-active pastures is essential so that options to control extra growth can be looked at early.
Both Donkers and Kilday agree they’ve gained a lot more confidence already in how to manage such a big renewal programme and will be more flexible next season when the second phase begins.
“We know now just how much these new grasses will grow,” Donkers said.
Instead of a third of the farm next season the area being renewed will be closer to 45% – that’s the next third of the farm, plus the Italian area from this season to sow into perennial. It’s sure to test that newfound confidence but neither Kilday nor Donkers is too perturbed. They’re already looking at new grass paddocks and feeling pretty satisfied with the results.
But it doesn’t stop there – ensuring these new paddocks persist isn’t just a given.
“If you treat them the way you treat your old paddocks you’ll quickly get the same performance as an old paddock,” Kerr warned.
“You can turn your best paddock into your worst paddock overnight,” Donkers said.
Extra care needs to be taken with grazing – nil tolerance for pugging for instance is a must.
“We have to think of our pastures as a crop – a 200t DM/ha crop – and take more care with how we sow, establish and then manage them,” Kerr said.
“We put a lot of effort into crops, but often not the same effort into pasture – our most important feed.”
Donkers agreed, saying they’d never used slug bait before with grass like they had with the Italians but they do with their crops.
“If we want more from these pastures we’re going to have to pay a bit more attention.”
Easy eating
One of the reasons new grasses can Lift productivity is that it’s easier to get a bigger mouthful with each bite.
Studies looking at the mechanics of cow grazing show that bite size and rate of harvest decrease the rougher and tougher the pasture.
Try it yourself – not the biting bit of course but take a handful of pasture and break it off the way a cow would when it wraps its tongue around it and pulls. An older, rougher sward will be harder to pull, it’s harder work for the cow, and there will be less pasture in your handful.
In new grass the difference can be quite dramatic as the leaf and sheath remain tender and break off with little effort, particularly with tetraploid ryegrasses.
For less effort cows get more, and watching them mow it down in the paddock it’s clear why intakes can jump quite dramatically.
Top tips for a big renewal job
Plan early.
Look at why paddocks aren’t performing.
Rectify underlying problems.
Look at short term stocking rate reduction.
Have extra supplement at hand.
Use annuals for some paddocks to give fast feed early.
Take out paddocks in tranches.
Be precise and pay attention to detail when sowing and establishing.
Treat new grass varieties well in subsequent years.
