Alongside the research, the project captured farmer experience through the use of P21 Focus Farms and case studies.

P21 research programme

Farmlets were set up in four regions (Southland, Canterbury, Manawatu and Waikato) with the aim to address issues relevant to each region, the farmlets:

Aimed to reduce nutrient loss by:

• Reducing Nitrogen (N) inputs (N fertiliser and supplements)
• Capturing urine (N) in late summer-winter
• Protecting wet soils in autumn and spring to decrease sediment and phosphorus runoff.

Maintained milk production with fewer inputs through:

• Achieving more production per kg of liveweight
• More milk per cow per day
• More days in milk
• Applying well-known principles of pasture management and grazing
• Using N fertiliser to fill deficits, not boost surpluses
• On wet soils, using standoff to protect paddocks and grow more pasture.

See DairyNZ Technical Series March 2017 for a summary of the P21 research programme.

P21 regions

• Waikato

  DairyNZ's Scott Farm, Hamilton

  Project leader: Kevin MacDonald, Dairy NZ senior scientist

  Project goal: To show that an average Waikato farm could increase annual milk production by up to 200kg/ha with increased profit per hectare, while reducing N leaching from 35-50+kg/ha/year down to 20-30kg/ha/year.

  Project details: Two 13ha farmlets were compared. One represented a typical Waikato farm (Current), with a stocking rate of 3.2 cows/ha. The other with a stocking rate of 2.6 cows/ha, represents a farm managed more efficiently (Future).

  Summary: Using a combination of approaches (lower N inputs, a stand-off pad, higher BW cows) on the 'Future' farmlet, N leaching was reduced by 40-50% over the four winters measured.

  However, milk production for the Future system was not improved, with milksolid/ha yields at c. 97% of the Current farmlet. This resulted in net profitability of the Future farmlet being about 5% less than for the Current farmlet, the difference being the cost of the standoff pad. Both farms performed at c. 20% better than the median for Waikato dairy farms.

  Download full site summary here

  For further reading on this project click here.

• Manawatu

  Massey University's No. 4 Dairy Farm, Palmerston North

  Project leader: Professor Mike Hedley, Massey University

  Project goal: To develop a practical housing system for the lower North Island region, that combines high production and profit with lower nitrogen (N) leaching and phosphorus (P) loss.

  Project details: Two dairy systems, one with cows housed part-time in the freestall barn (2.8 cows/ha). This was compared to a more typical management system with a herd grazed-off in winter and a feed pad used on wet days in spring and winter (2.7 cows/ha).

  Summary: By the 2015/2016 lactation season both the standard and housed systems had met the productivity (1,250kg MS/ha) and environmental targets (N and P loss less than 15kgN/ha/yr and 1.6kg P/ha/yr). This was mainly achieved through improved feed utilisation and longer lactations and lower urine N loads, respectively.

  In 2015/2016, urinary N loads on pasture, which drives N leaching, were on average 19% lower for the house system compared with the standard system. Using autumn housing only, the subsequent N leaching reduction between the standard and house systems averaged 28% between the 2014 and 2015 drainage seasons. Total milk solids production per hectare was on average 8% higher on the house system than the standard system across the trial period. This increased production was not sufficient to cover the costs of the increased capital investment and supplementary feed required by the housed system. In 2014-2015 season the breakeven milk prices to cover capital and operating costs for Standard and House systems would need to be $4.45/kg MS and $5.75/kg MS. 

  Download full site summary here

  For further reading on this project click here

• Canterbury

  Lincoln University Research Dairy Farm and Lincoln University's Ashley Dene Farm

  Project leader: David Chapman, DairyNZ principal scientist

  Project goal: To develop practical dairy farming systems that combine high production and profit with lower nitrate leaching.

  Project details: The project included two farmlets, one with a stocking rate of 3.5 cows/ha and the other with 5 cows/ha, plus three different wintering systems (kale only, kale and oats, fodder beet only).

  Summary: Environmental targets for the Dairy Farm were achieved. Averaged across the 3-year monitoring period, estimated N losses (including wintering) were reduced by >30%. Milk solids production from the farmlet 4% greater than target. Operating profit was driven greatly by milk price, a milk price of $6.30 was the tipping point, greater than this and 5 cows/ha was more profitable, less than this and 3.5 cows/ha was more profitable.  

  Download full site summary here

  For further reading on this project click here

• South Otago

  Telford Farms Dairy Unit, Telford Farm Training Institute, near Balclutha

  Project leader: Ross Monaghan, AgResearch senior scientist and Dawn Dalley, DairyNZ senior scientist

  Project goal: To investigate ways dairy farmers in the region can manage soils, animals and forage crops during the challenging shoulder and winter seasons, so they optimise their business and reduce environmental footprint.

  Project details: The project included two 110 cow farmlets, plus a 385 cow control herd. One farmlet treatment was managed more traditionally, using winter crop feeding while the other involved the use of and off paddock facility for indoor wintering.

  Summary: Environmental targets set for the project were achieved. Averaged across the 3-year monitoring period, estimated whole-system N and P losses were reduced by > 24%, while sediment losses were reduced even further. Operating profits were not increased, however, and milk solids production from the treatment farmlets was 2-3% less than for the control.

  Downloads

  Download full site summary here.

  Using short-rotation ryegrass to improve matching spring-pasture supply with cow feed demand.

  For further reading on this project click here

P21 Focus Farms

DairyNZ is working with three commercial farms that have made or are making changes to their farm system based on the P21 trials. Farms include:

1. A Family owned and operated farm - Tihio, South Waikato
2. Lincoln University Demonstration farm
3. A Ngai Tahu cooperative farm - North of the Waimakariri River

Find out about the background and experiences of these farms, their advice for considering and undertaking change, and operating a "new" farm system here.

P21 Case studies

Eleven P21 case studies from Southland, Canterbury and Manawatu captured farmer experience in:

• Reducing N inputs (mainly supplements), and
• using off-paddock facilities to capture urinary N at critical times and protecting critical source areas (soils, gullies and swales).

Find out about farmer participants' key learnings and experiences here.

*DairyNZ, Fonterra, Dairy Companies Association of New Zealand, Beef + Lamb New Zealand and the Ministry of Business, Innovation and Employment, PGG Wrightson, Blue Pacific Minerals, and managed by AgResearch.

Downloads

• Ryegrass trial summary - Trial summary for Using short-rotation ryegrass to improve matching spring-pasture supply with cow feed demand.
• Sequence cropping - Using a winter 'catch crop' of oats after a kale crop to reduce nitrogen leaching.
• Reducing surface run off - Reducing surface run off on grazed winter forage crop paddocks by strategic grazing management.
• Decision triggers for using off-paddock facilities during autumn & spring - Research trials at Telford by AgResearch have established that restricting the time cows spend grazing on wet soils in spring and autumn will reduce N leaching and pugging damage.
• Pasture and Grazing Management: Pastoral 21 experience - research summary
• Management guidelines for reducing nitrogen fertiliser use: an approach to reduce nitrate leaching from Dairy systems - research summary
• Management guidelines for a loose house soft bedding shelter for wintering dairy cows

Transitioning onto winter crops

• The Pastoral 21 experience
• Developing a plan