How much money is slurry worth in nutrient terms?
Springtime is fast approaching and with the arrival of spring, farmers and agri-contractors will be busy spreading nutrient applications in the form of slurry, dung or chemical fertiliser onto farmland, when permitted.
Often, on farms, the value of slurry that is produced can be taken for granted but in recent years, more farmers are beginning to appreciate the value of their home-produced fertiliser and are taking a more targeted approach to their nutrient applications.
Slurry and farmyard manure (FYM) or dung, where possible, should be targeted at the fields which most require the nutrients, not the fields that are most conveniently located to the slurry store.
Teagasc has recently assembled a table detailing the nutrient values of various slurries and FYM and the monetary values of these, based on average nutrient and Dry Matter (DM) contents:
| Organic fertiliser type | N kg/m³ (units/1,000gal) | P kg/m³ (units/1,000gal) | K kg/m³ (units/1,000gal) | Value €/m³ or (€/1,000gal) |
|---|---|---|---|---|
| Liquid manures | ||||
| Cattle (6% DM) | 1.0 (9) | 0.5 (5) | 3.5 (32) | 6.3 (29) |
| Pig (4% DM) | 2.1 (19) | 0.8 (7) | 2.2 (20) | 7.1 (32) |
| Soiled water | 0.48 (4) | 0.08 (0.7) | 0.6 (5) | 1.5 (6.8) |
| Soiled manures | N kg/t (units/t) | P kg/t (units/t) | K kg/t (units/t) | Value €/t |
| Dungstead manure | 1.4 (3) | 0.9 (2) | 4.2 (8) | 8.6 |
| Farmyard manure | 1.35 (3) | 1.2 (2) | 6.0 (12) | 11 |
| Poultry | ||||
| Broiler / deep litter | 14 (28) | 6.0 (12) | 18.0 (36) | 53 |
| Layers (30% DM) | 6.85 (14) | 2.9 (6) | 6.0 (12) | 23 |
| Layers (50% DM) | 11.5 (23) | 5.5 (11) | 12.0 (24) | 42 |
| Turkeys | 14 (28) | 13.8 (28) | 12.0 (24) | 68 |
| Spent mushroom compost | 1.6 (3) | 1.5 (3) | 8.0 (16) | 15 |
Some notes to consider when reading the table:
- The value of N in cattle slurry is 9 units/1,000 gallon (based on total N of 2.4kgN/m³ at 40% N availability by low emissions slurry spreading (LESS) application; Conversion: kg by 2=units;
- Spring application of organic manures is required to maximise N recovery. Manures should be tested to determine manure nutrient content;
- In relation to pig manure, incorporation of hig N manures within 2-6hrs after application, assume 50% N availability;
- Value of N = €1.26/kg; P = €2.73/kg; K = €1.05/kg for 2024 (nutrient values based on price/volume of range of fertiliser products;
- The cost of spreading or transport is not included in the value;
- Replace P availability to 50% on P Index 1 & 2soils;
- Values under units/1,000gal or per/t have been rounded to the closest unit.
The table above provides guideline figures, and farmers who wish to get accurate nitrogen (N), phosphorus (P) and potassium (K) values for slurry on their own farms can do so by getting their slurry tested.
Using an N value of €1.26/kg, a P value of €2.73/kg and a K value of €1.05/kg, the table indicates that 1,000gal of cattle slurry with a DM content of 6% has a value of €29.
1,000gal of pig slurry with a DM content of 4% has a value of €32, according to the table.
The costings do not include the cost of spreading and transporting the slurry.
Before determining what chemical fertilisers are needed for the farm this year, farmers should first consult a recent soil sample analysis taken of their farm.
Where no recent soil samples have been taken, now is the ideal time to take a soil sample, where nutrients have not been spread on land in the past three months.
An up-to-date soil sample will help farmers identify areas of ground on their farm that should be targeted with slurry and areas on the farm that may need a lime application.
Often farmers who soil sample their land are surprised to see they may need to purchase much less chemical P and K fertiliser than they originally thought.
