Pastoral 21 trial Summary
The aim of the Pastoral 21 trial is to redesign farm systems so they can be more productive and profitable but at the same time have a lower environmental footprint. On 1 June 2011 two farmlets were established at Scott Farm by DairyNZ with a collaborative input from AgResearch, Ruakura, to measure nitrogen (N) leaching over a 5 year period. Funding is provided by DairyNZ Inc, the Ministry of Business, Innovation and Employment, Fonterra and Beef+Lamb.
About the Pastoral 21 trial
DairyNZ set up the Waikato Pastoral 21 trial in July 2011 with the aim of improving productivity and profitability of farm systems while lowering the environmental impact. Over a 5 year period (2011-2016) the objectives are to:
- increase current milksolids (MS)/ha from 900-1100 kg/ha/yr to 1100-1300 kg/ha/yr.
- increase operating profit by $500/ha/yr (200kg MS @ $5.00/kgMS assuming marginal costs of $2.50/kg MS)
- decrease leaching from 40-60 kg N/ha/yr to 20-25 kg N/ha/yr
A Current Waikato System (3.2 cows/ha stocking rate) with standard management practices and average BW/PW cows is being compared with an Efficient Waikato System (2.6 cows/ha). The latter has high BW/PW cows on restricted grazing management to reduce soil and pasture damage, reduced nutrient leaching and N fertiliser use, and grain feeding to meet MS potential. It is expected that replacement rates will be lower in the Efficient system.
To gauge the environmental impact, measurements are being made at key times comparing performance of the Current and Efficient systems. These measures include basal nutrients, soil minerals and physical properties, and nitrate leaching.
In the first year of the study (2011/12 season), the Efficient system produced more MS/cow, similar MS/ha, with cows milking for longer than the Current system; however the empty rate was higher (see Table 1). Even with much lower N use, more silage was able to be conserved on the Efficient system. This was due to the use of a nitrification inhibitor (dicyandiamide (DCD*)), which decreases the formation of nitrate from ammonium ions in urine patches allowing more N to be captured by plants, and the use of ProGibb (active ingredient gibberellic acid) to boost pasture growth. Reduced soil and pasture damage with a lower stocking rate and restricted grazing management also will have contributed. No differences in leaching and soil nutrients were detectable in the first season.
* Note: Due to the voluntary suspension of sales and use of Dicyandiamide (DCD) treatment on farm land, the research trial will now proceed without the use of DCD. There will be no other management changes.
Table 1. Year 1 (2011/12) results for Current and Efficient farmlets.
|Days in milk||261||278|
|BCS at dry off||4.2||4.1|
|Cow liveweight (kg) at dry off||513||526|
|Empty rate - number(%)||3 (7%)||3 (9%)|
|N fertiliser (kg N/ha)||136||51|
|Silage conserved (kg DM/cow)||259||375|
|Grain fed (kg/cow)||0||137|
In the next few seasons a large dataset will be compiled, allowing robust examination of production and profitability for each system along with evaluation of environmental impacts such as seasonal effects on nitrate leaching, and longer term consequences for soil fertility and structure. This site will be updated yearly as the trial progresses, so keep watching this space!