Which organic material is expected to mineralize the most nitrogen?

Dairy manure is expected to mineralize the most nitrogen due to its composition and the microbial activity it stimulates when applied to soil. It contains a significant amount of nitrogen in a readily available form, particularly in relation to its organic matter content. When dairy manure is added to soil, the microbial community starts to break down the organic material rapidly, releasing nitrogen in the process. This mineralization occurs as microbes decompose the organic nitrogen compounds in the manure, converting them into inorganic forms such as ammonium and nitrate, which are readily usable by plants.

In contrast, compost generally contains more stable organic matter and takes longer to break down, resulting in slower nitrogen release. Chicken litter, while also nitrogen-rich, can have higher variability in mineralization rates depending on its moisture content and handling. Peat moss is primarily made up of decomposed plant material and has relatively low nitrogen content, making it less effective at mineralizing significant nitrogen compared to dairy manure. The overall efficiency in nitrogen release from dairy manure positions it as a strong contributor to soil nutrient availability.