Robert Patterson, CAFRE dairying technologist, discussed managing fertiliser applications on dairy farms during a recent joint webinar from AFBI, Agrisearch and CAFRE.
The webinar focused on using fertilisers effectively in light of recent price increases.
He presented nutrient management plans for dairy farmers planning to produce grass for turnout and first cut silage.
He generated the scenarios using the DAERA online Crop Nutrient Calculator and assumed adequate soil fertility levels with a pH of 6.2 and P index and K index of 2+.
Robert highlighted the valuable contribution slurry can make to meeting crop needs.
For example, applying 28 m3/ ha (2,500 gallons/acre) slurry using LESSE technologies came close to meeting the P and K requirements of a first cut silage grass crop.
As a result, you only need to apply an additional 330 kg/ha (2.7 bags/ acre) of CAN to meet the crop’s nitrogen needs.
Fertiliser applications on dairy farms
He presented two grazing scenarios based on an early March and mid-April turnout.
In both, he stressed the importance of getting out and walking fields early to measure grass covers and assess soil trafficability.
The CAFRE dairying technologist talked through situations where applying lower slurry rates (22 m3/ ha or 2,000 gallons/acre) to the grazing platform would be an appropriate way to reduce the requirement for early spring nitrogen (23 kg N/ ha and 19 units/ acre).
He told attendees: “Applying early nitrogen fertiliser from late February onwards can only be profitable if conditions are optimum and the grass grown can be utilised.”
Robert highlighted the need to focus on controlling factors within the farm gate to increase the efficiency of nitrogen farmers apply.
- Assessing conditions at sowing;
- Little and often applications;
- Measuring grass utilisation;
- Applying sulphur.
Patterson’s presentation followed Dr Debbie McConnell’s, highlighting the value of grass as a feed with higher fertiliser prices.