20 March 2025

Broiler litter as a fertiliser in tillage systems

Broiler litter boosts soil fertility and structure while cutting costs for tillage farmers. Rich in key nutrients, it must be managed carefully to maximise benefits and minimise risks. Veronica Nyhan highlights its role in sustainable farming with proper application.

Broiler litter is composed of a mixture of chicken manure and bedding material, often wood pine shavings, and is a highly potent fertiliser for tillage crops in Ireland. It can be a very cost-effective way of building soil fertility, particularly on low Phosphorus soils, by providing not only high levels of available nutrients, but also a supply of organically bound nutrients that will release slowly over time ensuring that the crops receive a steady flow of nutrition during their growing season. The high dry matter content of these manures, generally exceeding 50%, help build soil organic carbon, enhance soil water holding capacity and improve the soil physical structure and biological activity.

Broiler litter is rich in essential nutrients, including nitrogen (N), phosphorus (P), potassium (K), and trace minerals. Due to industry improvements in areas such as nutrition, shorter growing periods and housing conditions, the fertiliser value of organic manures generated from broiler production systems are very high. Under Nitrates regulations, the available nutrient content of 1000 gallons of cattle slurry, when applied by LESS to a fertile soil in spring is deemed to be equivalent to a bagged compound fertiliser of 9:5:32. By comparison, a tonne of broiler/deep litter is equivalent to 28:12:36. When applied correctly, broiler litter helps to recycle nutrients back into the soil, reducing the need for expensive and non-renewable chemical fertilisers.

Due to the high nutrient content of these products, proper nutrient management is essential to avoid nutrient imbalances or excesses, especially N and P and users should test the litter for nutrient content before application to ensure they apply the correct amount for their crops’ needs. Historically, applications of poultry manures have been often made to winter sown cereals, which gives a poor recovery of the high N content of these products and increases the environmental loading of N to our water courses and air. Spring applications, to high off-take crops, is a much better environmental and economic use of these products.

However, broiler litter can transmit botulism to cattle on the home or neighbouring farms and for this reason cannot be applied to grassland parcels. It can also pose a risk to human health if managed incorrectly and it is advisable to wear appropriate PPE including gloves, dust masks and eye protection during handling.

Due to these health risks, the transport, storage and application of broiler litter to tillage soils is regulated under EU legislation.

If importing broiler litter onto the farm, the following regulations apply:

Poultry litter cannot be stored on land and should be used promptly on the same day as delivery or securely stored as outlined below.
Poultry litter should not be shredded before being spread on land and must be fully ploughed into the soil (not just surface tilled) immediately after spreading as the dust may spread the pathogen.
Similar to other organic manures, poultry litter must not be applied near watercourses. A buffer zone of at least 5 meters must be maintained, which should be extended to 10 meters during the two weeks before and after the prescribed closed period.
End-users should only accept poultry litter from farmers who have proper systems for removing poultry carcasses from houses and disposing of them. Ideally inspect each consignment and if dead birds are found, the litter must not be used, and the consignment should be refused
If dead birds are discovered following spreading, the operation must cease, and the spread product ploughed in immediately
End-users should inform neighbouring livestock owners of the days poultry litter will be spread, so they can take steps to protect their animals by moving them from adjacent fields.
Each consignment must be accompanied by commercial documentation ensuring traceability.

Efforts should be made to avoid storing poultry litter during hot weather.
If litter needs to be stored temporarily before spreading, it should be placed on a concrete surface away from water sources, with runoff collected. The storage area should prevent access by animals, be located at least 500 meters from livestock areas and protect feed or bedding from contamination.
The stored litter should be fully covered, similar to silage, to prevent access by wildlife and pests.

Human contact with poultry litter should be minimised, and hands should be thoroughly washed after handling.
Animal manures should not be used as organic fertilizer on crops that are consumed raw by humans (e.g., lettuce).