Should more tillage farmers use poultry manure as a fertiliser?

Tillage farmers can save up to €60/ha when using poultry manure as part of their fertiliser programme, according to Teagasc’s Martin Bourke.

Bourke, a Tillage Advisor, presented the latest findings on poultry manure use on tillage farms at the Teagasc National Soil Fertility Conference in Kilkenny.

On Wednesday, Bourke told over 400 farmers that significant savings can be made when using poultry manure in conjunction with artificial fertilisers such as CAN and urea.

He said that there is no yield difference between barley crops grown with a combination of poultry manure and artificial fertilisers or solely artificial fertilisers when the nutrient content and the dry matter of the poultry manure is known.

And, when costs of €25/t for sourcing and spreading the poultry manure are applied, it can significantly reduce the fertiliser bills at farm level.

However, he stressed that farmers considering replacing part of their artificial fertiliser application with poultry manure must be aware of the nutrient content of the waste product.

There is huge variation between poultry manure from different farms and there is variation between broiler and layer manure.

“You wouldn’t go out to spread bagged fertiliser if you didn’t know what the bag contained,” he said.

Source: Teagasc

Along with producing similar yields, Bourke also said that poultry manure is an excellent source of Sulphur for cereal crops.

“If it is sourced at the right price it is an excellent source of Nitrogen (N), Phosphorous (P) and Potassium (K). It is a very well blended and balanced fertiliser source.

“Poultry manure is also an excellent source of Sulphur (S) and when it is applied at a rate of 5t/ha it can supply 22.5 units of S, which is enough to grow your entire tillage crop.

“A good cereal crop will require 15-20 units of Sulphur,” he said.

He added that once the nutrient value of the manure is known, it can be used to grow malting barely crops without having a negative impact on the protein content of the grain.

However, he said poultry manure is not a suitable fertiliser to use for winter cereal crops, as it provides too much N too early in the plants development.

Source: Teagasc
Source: Teagasc

Use of poultry manure on Irish farms

Bourke also said that a lot of farmers in the counties of Louth, Meath and Dublin are using poultry manure as a fertiliser source for the crops.

But the cost of sourcing the manure varies greatly throughout the country, with the cost generally depending on the proximity to the poultry unit.

In some cases, he said, farmers are able to source the manure for the cost of collecting it out of the yard, while some farmers are charged up to €40/t for poultry manure.

Key results:
  • Fertiliser programmes including poultry manure can achieve the same yields as chemical fertiliser programmes if the nutrient content of the manure is known.
  • Poultry manure treatments showed no significant difference in grain protein compared with chemical N when used to grow malting barley.
  • Ploughing down poultry manure gave the same grain yield as surface tilled in poultry manure in these trials.
  • Top-dressing with CAN or urea at tillering in a programme with poultry manure in the seedbed gave the same yields as a chemical N programme.
  • Significant cost savings with poultry manure, analysis is essential for efficient use.