Field tests on the nitrogen efficiency coefficient and nitrogen release period of pelleted laying hen manure on grain corn and oat crops

Description

Pelleted laying hen manure is a nitrogen source that is interesting an increasing number of growers, both organic and conventional, because of its efficiency. The first edition of the fertilization guide Guide de référence en fertilisation assigned a high (75.85%) efficiency coefficient (EC) to poultry manure. However, the second edition assigns much lower EC for crops requiring less nitrogen (EC 50–60%; C/N ratio of 8) and higher levels of nitrogen (EC: 60–70 %; C/N ratio of 8).

This is not the same performance of pelleted laying hen manure observed in commercial production. Moreover, the references used to establish the EC do not mention pelleted laying hen manure, but rather cow manure and paper mill sludge that contain much different carbon and nitrogen contents.

Due to the type of carbon and nitrogen in laying hen manure, it has a very low biological stability index (38), i.e. a high mineralization rate, nearer that of raw pig manure (ISB=36) than that of raw cow manure (ISB=47) or composted paper mill sludge (ISB=65). This lack of information leads to significant variability in the ECs used. In fact, consultants and extension agents often ask IRDA for advice on what EC to use. This uncertainty limits the use of laying hen manure and can affect yields and environmental quality if too little or too much fertilizer is applied.

Objective(s)

• Determine the nitrogen efficiency coefficient (EC) of pelleted laying hen manure for nitrogen loving crops and crops that require less nitrogen
• Compared to mineral fertilizer, establish:
  • Rate of uptake and use of nitrogen in pelleted laying hen manure by grain corn and oats
  • Nitrogen release time of pelleted laying hen manure
  • Available nitrogen and phosphorus dynamics in the soil throughout the season
  • Yields
  • Residual nitrate in the soil and total nitrogen that could release nitrate after harvesting