Farmyard manure

Farmyard manure composition reflects the livestock species it comes from, their feed ration, the type and amount of bedding mixed in, and how long and under what conditions it has been stored. These factors together determine its moisture content, organic matter content, and nutrient concentration.

Nutrient content

Low and variable; depends on species, diet, bedding, and storage

Organic matter content

High; a major source of soil organic matter over time

Nitrogen form

Mixture of readily available and organically bound forms

Storage losses

Ammonia volatilisation and leaching can reduce nutrient content before application

Farmyard manure supplies nitrogen, phosphorus, and potassium, along with secondary nutrients and micronutrients, in a mixture of readily available and slowly mineralising organic forms, together with a substantial contribution of organic matter.

• Nitrogen availability depends on the proportion in readily available versus organically bound forms
• Phosphorus and potassium are supplied alongside nitrogen
• Repeated use contributes cumulatively to soil organic matter

Farmyard manure has long been used in mixed crop-livestock systems to recycle nutrients from livestock production back into cropland, while also improving soil organic matter, structure, and water-holding capacity over repeated applications.

• Recycles nutrients from livestock production within a farming system
• Builds soil organic matter and improves soil structure over time
• Long history of use across mixed crop-livestock systems worldwide

Because nutrient content and availability vary so widely, general practice is to test manure where feasible, account for storage and handling losses, and consider the manure’s nutrient contribution as part of an overall nutrient budget alongside any other fertilizers used.

Poorly stored or over-applied manure can contribute to nitrogen losses through ammonia volatilisation and nitrate leaching, phosphorus accumulation and runoff, and, in some conditions, pathogen or odour concerns, all of which are addressed by many countries’ manure-management regulations.