Will you exceed the Livestock Manure Nitrogen Limit of 170kg N/ha/yr in 2008?
Alan Galbraith, Countryside Management Branch, DARD
One of the key measures within the Nitrates Action Programme is to restrict farms to 170 KG nitrogen from livestock manure per hectare per year. How can this figure be calculated to ensure that you are meeting this limit for the coming year?
Calculating the Livestock Nitrogen per ha per year
Step 1 – Estimate the average livestock numbers, that you anticipate will be on your farm for the year 1 January 2008 to 31 December 2008.
Step 2 – Use the appropriate standard figure for the amount of nitrogen excreted by the various age and type of livestock.
Table 1 – Example of livestock types and nitrogen excreted
| Livestock Type | Amount of nitrogen excreted per animal per year ( KG) |
|---|---|
| Dairy Cow | 91 |
| Suckler Cow | 54 |
| Cattle more than 2 years old | 54 |
| Cattle between 1 and 2 years old | 47 |
| Cattle less than 1 year old | 19 |
| Ewes | 9 |
| 1000 laying hens | 607 |
| 1000 broiler places | 255 |
Step 3 – Multiply the amount of nitrogen excreted per animal by the average number of livestock. The totals for each livestock type are then added together to give an overall total nitrogen. If importing or exporting livestock manure the nitrogen content of the manure must be added or subtracted accordingly. This amount of nitrogen is then divided by the farmed area controlled to give the nitrogen per hectare, per year. The example below shows the total nitrogen produced from a 66ha farm with 100 dairy cows and followers.
Example
| stock type | Stock numbers | N loading per stock | Total N loading |
|---|---|---|---|
| Dairy cows | 100 | 91 | 9100 KG |
| Cattle 1yr - 2 yrs | 30 | 47 | 1410 KG |
| Calves less than 1 yr | 30 | 19 | 570 KG |
| Total | 11080 KG | ||
| Adjusts + or - for imported or exported manure |
0 KG |
Livestock Nitrogen per ha is 11080 KG / 66 ha = 168 KG N/ha/year
Assistance is available for this calculation through the Livestock Manure Nitrogen Loading Calculator on
The area of land under your control has a significant impact on the livestock nitrogen per hectare. Ensure that you only use the land area that you control in any calculations. Remember that the owner of the land is deemed to be the controller and is responsible for the land for the period 1 January to 31 December unless evidence can be provided to the contrary. This evidence can either be if the tenant is claiming Single Farm Payment on the land for that period, or if there is a written agreement between owner and tenant, establishing control of land.
Options
Poultry, pig, and dairy farms tend to have high levels of livestock nitrogen per hectare due to the high nitrogen content of the manures produced and the intensive nature of these enterprises compared to beef and sheep farms. If you calculate that your farm could be operating above 170 KG N/ha/yr for 2008 there are a number of options that should be considered. These include reducing stock numbers, exporting slurry, taking additional land or applying for a derogation. The derogation will allow eligible farms to operate up to a maximum of 250 KG nitrogen of grazing livestock manure per hectare per year. The main criteria of the derogation are that farms must:
- have at least 80 percent grassland;
- have a farm phosphorus balance of not more than 10 KG phosphorus per hectare per year;
- carry out soil analysis to establish soil fertility status;
- only apply nitrogen and phosphorus to crop requirements;
- make an annual application by the farmer to DOE’s Environment and Heritage Service (EHS) by 1 March;
- produce and maintain annual fertilisation plans; and
- submit annual fertilisation accounts to EHS.
Nitrates Derogation Information Meetings
CAFRE will deliver a series of Nitrates Derogation Information Meetings across N.I. to support farmers who may exceed the 170 KG N/ha/yr limit. You will have the opportunity to calculate N Loading and P Balance for your farm business and discuss the implications with your local Dairy or Beef & Sheep Development Adviser. EHS staff will also be on hand to assist with the completion of the application forms.
For further information of dates and venues for the Nitrates Derogation Information Meetings please see the accompanying advert or contact Alan Gault, CAFRE, Greenmount Campus on 028 9442 6772 email alan.gault@dardni.gov.uk