Environmental, Rob and Rachael Dingle (Southland)
2 min read
Rob and Rachael own Brooklea Farm Ltd at Wendonside, supplying milk to Fonterra since its dairy conversion in 2008-09. They expanded in 2020 with a 100-ha support block, allowing more in-house wintering. They apply around 200 kg N/ha to pastures and give up to 380 kg DM/cow of in-shed supplements like barley/distiller’s grain and pasture silage. The farm's features include a 220ha milking area, a 54-bale rotary with in-shed feeding, and centre pivot irrigation. They've explored various farm changes, like adjusting N fertiliser levels or integrating plantain, to assess their environmental impact and profitability.
Rob and Rachael are farm owners for Brooklea Farm Ltd at Wendonside which was converted to dairy in 2008-09. They supply milk to Fonterra.
A 100-ha unirrigated support block was purchased in 2020 allowing more of the wintering to be done in house. Approximately 200 kg N/ha has typically been applied to pasture and up to 380 kg DM/cow of in-shed supplement offered. Lactation supplement is crushed barley/dried distiller’s grain and pasture silage.
Milking platform effective area:
220ha
Support block effective area:
100ha
Operational structure:
Owner-operators
Infrastructure:
54-bale rotary with in-shed feeding. Centre pivot irrigation (190ha)
Cows wintered:
690
Planned start of calving:
14 August
Stocking rate:
3.0 cows/ha
Production:
1,327 kg MS/ha; 449 kg MS/cow
Soil type:
Brown; 100% well-drained silty loam
Annual rainfall:
793mm
Feed supplements:
634 kg DM/cow: barley/DDG, pasture silage
Fertiliser inputs:
200kg N/ha; 56kg P/ha
Purchased N surplus:
152kg N/ha (Overseer FM v6.4.0)
Predicted N leaching:
68kg N/ha (Overseer FM v6.4.0)
DairyNZ system:
4
Wintering system:
Fodder beet with baleage and cereal straw on the milking platform and support block; kale at a grazier
Scenario | Purchased N-surplus (Kg N/ha) | N leaching loss (Kg N/ha) | P loss (Kg P/ha) | Methane (Kg CO2e/ha) | N2O kg/ha (kg CO2e/ha) | HWEN GHG reporting (kg CO2e/ha) | Operating profit ($/effective MP ha) |
Baleage wintering:
Remove fodder beet from milking platform and support block and winter these cows on baleage (13 kg DM/cow/day plus 1 kg DM/cow/day pasture), additional baleage purchased for this. Note: 193 cows still wintered on kale at grazier.
|
+24% ↑ | +2% ↑ | +3% ↑ | +2% ↑ | +3% ↑ | +2% ↑ | -8% ↓ |
Reduce N fertiliser:
on pastoral blocks to 190 kg N/ha, assume pasture eaten will be maintained.
|
-15% ↓ | -7% ↓ | +1% ↑ | 0% | -3% ↓ | -1% ↓ | +3% ↑ |
Reduce N fertiliser:
on pastoral blocks to 190 kg N/ha, assume not able to maintain pasture eaten, increase imported supplement.
|
-13% ↓ | -8% ↓ | 0% | -0.3% ↓ | -4% ↓ | -2% ↓ | -1% ↓ |
10% Plantain:
farm stitched with plantain to target 10% of the sward; same pasture production; a third of the farm re-stitched annually.
|
0% | -7% ↓ | +1% ↑ | 0% | -1% ↓ | -0.3% ↓ | -2% ↓ |
20% Plantain:
farm stitched with plantain to target 20% of the sward; same pasture production; a third of the farm re-stitched annually.
|
0% | -14% ↓ | +1% ↑ | 0% | -3% ↓ | -1% ↓ | -2% ↓ |
30% Plantain:
farm stitched with plantain to target 30% of the sward; same pasture production; a third of the farm re-stitched annually.
|
0% | -20% ↓ | +1% ↑ | 0% | -5% ↓ | -1% ↓ | -2% ↓ |
Oat catch crop after fodder beet:
sown within a month of grazing the fodder beet during winter. Reduced imported baleage to account for oat silage made.
|
-5% ↓ | -2% ↓ | +1% ↑ | -1% ↓ | +0.4% ↑ | -0.5% ↓ | +2% ↑ |