The fertilising values of poultry manure

Manure’s nutrient value varies, depending on several factors:

• the age of the birds that produced it;

• their production type, eg layers, fattening birds;

• the feed they’re eating, and its quality. The poultry digestive system is not very efficient; around 40-70 per cent of the nutrients they eat are expelled in the manure. Adult birds, eating the maximum amount of feed per day, will produce significantly more manure than young birds eating a quarter of the amount.

The main fertiliser nutrients in manure are nitrogen, phosphorous and potassium (NPK). Micronutrients include calcium, copper, magnesium, zinc, manganese, chlorine, boron, iron, sulphur and molybdenum.

Layer hens provide an extra benefit. They excrete more calcium than other poultry as they eat a high calcium diet (to help them produce shells).