NZ Farmer - Canterbury dairy farm gets serious about nitrogen leaching

Heather Chalmers highlights five dairy farms in Mid-Canterbury working together to reduce nitrate leaching. 

Mid-Canterbury dairy farm Align Longfield is taking on the challenge of reducing its nitrogen leaching while maintaining profitability.

Longfield is part of the Align Farms group which has four dairy farms and a dairy support unit in Mid-Canterbury, totalling 1600 hectares and milking 4000 cows. Align is owned by John Buchanan who spends half a year in New Zealand and the other half in the United States.

Situated alongside SH1, just north of the Rangitata River, Longfield is managed by Matt and Sam Bell. In their first season, 2015, Matt won the Young Farmer of the Year title.

The 283ha farm was bought in 2012 and converted to dairy, redeveloped and totally regrassed ready for milk supply by July 2013. Longfield milks 1100 cows at peak (4 cows a hectare), with milk solids production of 464,500kg, or 1689kg/ha.

Align Farms head of operations Rhys Roberts says a focus is to provide quality infrastructure on-farm from the start. "You don't have to look too far on the farm to see that there are new cowsheds, pivot irrigators, houses and fences. " This will reduce on-going repairs and maintenance costs.

Align also aims to provide good pay and working conditions to attract the best staff.

"We believe that if you have high human capital skills and good management practices and do the basics well on-farm, then good production and profit will come from that. We are not chasing the highest production in the district, but sustainable milk long-term.

"We want to lead in good management practices and ultimately turn that into a value-add product. Currently Align attracts a premium of about 13 cents a milksolid for value-add milk across the group, for supplying A2, grass-fed and Lead with Pride milk to Synlait.

"The way dairy commodity prices are going and with business owners wanting a return on their assets, it is difficult to drive down farm working expenses any further.

"So the goal is to gain 25c/kg/MS in value-add premiums in the next five years above the dairy base price. If we can do this then we can spend this additional money on improvements such as environmental planting and variable rate irrigation."

Two Align farms supply Synlait and the other two, including Longfield, supply Westland Milk Products.

As the group is self-contained, having its own support land for wintering cows, "it can't pass the buck to anyone else" in terms of meeting nitrogen loss targets. "This means we understand our nitrogen loss requirements over our entire business," Roberts says.  

The group aims to meet its triple bottom line by putting social and environmental responsibilities at the forefront of all commercial activities. "Our aim is to be leaders in the industry while reducing our environmental footprint."

Under the nutrient modelling programme Overseer, Longfield has a baseline nitrogen loss of 56kg a ha/year. In the 2016-17 season this had already dropped to 46kg/ha, partly through the conversion from borderdyke (flood) irrigation to centre pivot spray. Soil moisture monitoring has also been introduced to ensure no irrigation is wasted by overwatering. Future developments include adding the new environmental plantain variety Ecotain, bred to reduce nitrate leaching from the urine patch, to the current ryegrass and white clover pastures.

Longfield is looking to further reduce nitrogen losses to 40kg/ha by about 2020, ahead of the required time-frame.    

Roberts says Align is trying to set up its operations so it has 50 per cent in the red zone and 50 per cent in orange zone land to give it options when utilising group assets. Environment Canterbury defines red zones as catchments where water quality outcomes are not met and orange zones where water quality outcomes are at risk, both triggering a specific set of rules and actions.

"If we can condense our calving in August on red zone farms, then we can dry our cows off earlier in May and still achieve the same production." Cows are wintered on the group's 550ha orange zone support block Align Hinterlands, near Mt Somers in the Mid-Canterbury foothills. Hinterlands also carries all Align's young stock from six months through to 23 months.  

"We feel that May is more of a risk time for leaching in Canterbury than August. So if we can have fewer cows on farm in May, that is an option to reduce our nitrogen leaching number."

Align farms are predominantly grass-based, while feeding grain in the shoulders of the season to maintain milk production.  

Longfield is rated an A grade farm by its farm environmental plan (FEP) audit, an independent on-farm assessment. This checks that the risks identified in the FEP are managed effectively and that good management practices are being implemented. Significant support comes from Mayfield Hinds Valetta Water (MHV), the community scheme between the Rangitata River and the south branch of the Ashburton River, from which Longfield receives a water allocation of 4.2mm a day

"There isn't a lot of support for those on groundwater, compared with being part of MHV Water. One Align property is just groundwater and you are on your own," says Roberts.

Representatives for MHV Water visit every farm in its scheme at least once a year to update their FEP and farmers are required to implement good management practices. All shareholders have received an A or B grade audit to date.

Matt Bell says Longfield has five full-time staff including himself. "It's getting people to buy into the environmental aspect and engaging them. I like the saying on-farm that everyone can do everything. So during the irrigation season it is not reliant on me being there. So it doesn't matter who is on-farm. If a pivot breaks they can go out and fix it, or they know the process involved to fix it."

Engagement with staff includes good rosters. "We are on 6+2 and on June 1 will swap to 5+2. This means that everyone gets an opportunity to have consecutive weekends off. The year will be split into fours. So for June, July and August someone will have two consecutive days off, say Monday and Tuesday, and this will rotate every three months so that everyone gets a period when they get the weekend off.

"If staff have good housing and rosters then they are able to concentrate on farming issues. They are starting to solve problems such as where do the cows go tomorrow, before they even talk to me," says Bell.  

Longfield has precision tracking for all fertiliser applications and from April will start grid sampling. "So instead of applying fertiliser on a paddock basis, grid sampling will divide the farm into 1ha blocks. The extra cost of grid sampling is expected to be off-set by savings in fertiliser. It's putting fertiliser where it is needed. As it was previously a cropping farm the original layout was different to now with old races and borderdykes and grid sampling will help address this."

While plans are to introduce Ecotain into pasture mixes at Longfield, this will not be easy as all pastures are relatively new perennial ryegrass and white clover mixes.

Agricom lead scientist Glenn Judson says that as plantain has weed origins it is easy to establish. "You can undersow, oversow and broadcast it." However, it is most difficult to establish in well covered pastures such as at Longfield.

"Plantain can be added where you are patching up damaged pasture, sowing a new pasture mix, and oversowing where you have gaps in pastures."

At least 70 per cent and up to 90 per cent of all nitrate leaching out of a farm system comes from a cow's urine patch. "So if you can manage that you can largely manage the problem."   

Maximum leaching reduction occurs when Ecotain makes up 40 per cent of a sward, which without further intervention will drift back naturally to 5 to 10 per cent. "So farmers will have to come back at regular intervals, every two to four years and broadcast seed to maintain Ecotain rates. You can't plant it and walk away for 10 years."  

As it is likely to take two years before Ecotain is recognised by Overseer, farmers using the forage herb will have to wait to receive a reduction in their nitrate-loss figure.

Longfields is also planting natives for aesthetics and shelter, with plans to plant one or two fence lines a year.