Manure users know that the organic portion of their nitrogen is naturally slow-release. For many years, the University has used a recommended equivalence of 47% available over the course of 3 years for feedlot manure, 37% for compost, and 52% available for poultry manure with litter. Recent research shows that these numbers may be a little low, but they are intentionally conservative so as not to limit yield due to nitrogen deficiency. Find out more about whether you should use higher availabilities when calculating your fertilizer equivalencies by reading more about the research on CropWatch.