Quick Case Study: Soils underpin profitability

Wednesday 25.03.2020 , news

A combination of good soil health, nutrient management and reseeding means this Northern Irish dairy farm is producing 14tDM/ha.

“We are not chasing yield – we’re chasing profit,” states Cathal McAleer, farm manager for Omagh Dairy Farm and Germinal NI customer.

The business model for the 200ha (494 acre), Northern Irish farm business keeps a firm grip on costs by optimising output for as little inputs as possible. The farm milks 300 spring block calving crossbred cows, split between two milking platforms.

According to Cathal, this means taking a holistic approach to cow and grassland management to safeguard financial performance from preventable inefficiencies.

“Within our herd, this means keeping a more moderate sized cow that has been bred using genetics from EBI bulls selected primarily on fertility and maintenance sub-indices,” he explains. “We run two spring calving herds with a target of more than 80% calving within the first six weeks of a 12 week calving period.”

To develop a herd with high metabolic efficiency, fed predominantly on a forage diet, mature cow weight is targeted at 550kgs. With Irish and New Zealand Friesian breeding making up most of the genetic base, Jersey sires will be used on any cows more than 600kgs to reduce liveweight, or on any cows with low milk quality.

Operating on a milk yield contract with quality premiums, cows average 6,000 litres per cow per year at 4.4.% butterfat and 3.65% protein. The herd achieves 3,500 litres from forage and receives one tonne of concentrate a head.

In order to optimising output while keeping costs low, Omagh Dairy Farm focuses on soil health and fertility.


Looking after soil

With a reliance on forage production to keep feed costs to a minimum, improving soil health has been one of the farm’s biggest priorities to optimise grass performance. According to Cathal, soil is managed with the same philosophy the farm uses to maximise production from the cows – fertility is everything. 

“If you don’t feed your soil, you’re not going to reach your forage production potential. We aim to have a pH of 6.5 or greater on all paddocks, with phosphate and potassium at high index 2’s. Soil potassium levels are difficult to increase so we have to spread some MOP (potash) on the steep parts of the farm if we want to maintain or build indices,” says Cathal.

Nutrient application has significantly helped increase forage production. Since 2014, soil samples have been taken every year to determine P and K distribution and pH levels. The farm also blanket spreads slurry twice a year in the spring and autumn and has recently started nutrient testing. This tailored approach to uplifting soil fertility through efficient nutrient application has resulted in the farm increasing forage production from 10tDM/ha in 2013 to 14tDM/ha in 2019.

Managing forage production

Operating on a rotational grazing system, cows are introduced into a paddock at 2,800-3,000kgDM/ha and moved out at 1,550kgDM/ha.

“To manage the grazing wedge, anything over 3,100kgDM/ha is baled for silage,” explains Cathal. “To maintain high grass quality, we aim to keep within a 16-18 day rotation during the mid-season to maximise grass quality.”

Around 105ha (260 acres) of grassland is cut for silage each year before being used for youngstock grazing. The first two cuts typically yield 4,000kgsDM/ha with an ME of 11.5 MJ/kg and 14-15% crude protein. The third cut will yield 4,500kgDM/ha with an ME of 10.5 MJ/kg and 13% crude protein and is only fed to dry cows.

To maintain grass growth and quality in both grazing and silage platforms, implementing a robust reseeding and nutrient application programme has been paramount. With 85% of the farm in reseeded grass, the bottom three performing paddocks each year are reseeded with AberGain, AberChoice and AberClyde varieties to maintain grass growth and quality levels. The soil type of the paddocks being reseeded dictates which varieties will be used. 

“We want late-intermediate or late grass varieties that are ranking the highest for quality on the Pasture Profit Index (PPI). Where more than one variety is used in a mixture, heading dates of the varieties used must be within seven days of each other. Before we invest in a specific variety, we want to see what research has gone into them and how they have performed in on-farm grazing trials,” explains Cathal.

25-30kg N/ha is applied between each grazing rotation. For silage ground, 125kg N/ha is applied in a combination of slurry and fertiliser, along with 30kg P/ha and 110kg K/ha.

“If we want to increase and maintain forage tonnage and quality, we must feed the soil and the crop – failure to do so will drop our tonnage very quickly. Paddocks growing more than 14tDM/ha are using a high level of soil N, P and K. We have to make sure we are feeding the soil so we can sustain this level of growth in years to come,” concludes Cathal.


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