Fertiliser and Pasture Management

Our Pasture & Crop Harvested target is 15 t DM/ha. To achieve this we need to grow 17-18 t DM/ha of high quality feed on farm.

Renew poor performing pastures

We use annual paddock yield, along with composition (% plantain and % clover) and pasture condition scoring, to determine which paddocks to crop.  Along with 11 ha allocated for summer crops, we also renew another 10 ha with perennial ryegrass (spray and drill), 12 ha undersown with Italian ryegrass and 8 ha of annual ryegrass for some of next year’s cropping area. 

We sow the newest proven varieties of ryegrass and cocksfoot pasture species along with 4 kg plantain, 2 x white clover and 1 x red clover.

New pastures are usually grazed lightly by calves at the end of April/early May and receive a nitrogen application following grazing.

Weekly farm walks

Every Tuesday we carry out our farm walk/drive.  Data collected is entered into Pasture Coach and we use the kg DM available to allocate paddocks for the coming week and the feed wedge to determine round length and fertiliser strategies.

Spring Rotation Planner (SRP)

We use a SRP to allocate grazing area from Planned Start of Calving (PSC) (90 day rotation) to Balance Date (22 day rotation).

Hay, grass silage and PKE ensure cows are fed to target levels under the allocated area (depending on weather and pasture growth rates through this period). Our winter feed budget from 1st June to 1st September allows us to budget how much supplements and nitrogen fertiliser to use, and provides an average pasture cover (APC) target.

Balance Date at Owl Farm is when grass is growing at approximately 56 kg DM/ha/day, and is usually 1st September. We aim to be on a 22 day rotation from Balance Date through to the end of December when we start grazing summer crops.

Pasture management through spring and summer

Approximately 55 ha of grass silage is harvested off the milking platform to be used during February-April and to carry over 40-60 t DM for the following spring.

Dry cows follow the milking mobs through July and early August and then we target residuals of 1500-1600 kg DM/ha to ensure quality pastures are maintained through peak milk production and mating. Our pre-grazing target through September-December is between 2800-3000 kg DM/ha.

Pasture samples are taken 3-4 times a year to analyse for feed quality.

From late December to mid-April we maintain a 30-50 day rotation using 4 kg DM/cow of crop, 2 kg DM/cow PKE and 3-4 kg DM/cow grass silage.

Cows are dried off, based on the DairyNZ BCS dry off calculator, and then on achieving APC target of 2400 kg DM/ha by the 1st June.

In May we extend to a 50-60 day rotation and when all cows are dried off in mid May we return to a 90 day rotation.

Fertiliser use

Soil tests are taken annually to represent the eight management blocks on the farm and each crop paddock. We work with our Ballance Agri-nutrients fertiliser rep to determine nutrient applications for the year for each block and for individual crop paddocks.

In 2020-21 Owl Farm applied 138 kg N/ha, 37 kg P/ha, 35 kg K/ha, 64 kg S/ha, 11 kg Mg/ha and 67 kg Ca/ha (including crop fertiliser).

Our budget for 2021-22 for nitrogen is 120kgN/ha applied thus:

  • 30 kg N/ha in August to fill a feed deficit
  • 30 kg N/ha in October/November during cropping and silage making
  • 20 kg N/ha in December to extend rotation length and push feed into summer
  • 40 kg N/ha in April/May for summer dry recovery and following new grass first grazing
Soil test result trends at Owl Farm