By: Melissa Wilson, Extension Specialist in Manure Management Have you heard the phrase “manure is the gift that keeps on giving”? It refers to many different aspects of manure, but the gift of nitrogen is one of them. The phrase refers to how quickly, or not so quickly, the nitrogen releases over time. This depends on several factors but there are still some things we are looking into through our research. Animal species and storage Manure nitrogen can come in two broad forms: organic and inorganic. The inorganic form is primarily ammonium, which is immediately plant-available once land-applied, similar to a chemical fertilizer. The organic form is nitrogen that is tied up in organic matter and carbon. It has to be decomposed and released by microorganisms in the soil before it transforms into inorganic, plant-available nitrogen. Thus, organic nitrogen is more “slow-release” – the gift that keeps on giving! When we test manure for nitrogen content, we find different ratios of organic