Author: Karl Shaffer, Soil Scientist, North Carolina State University

Yes. However, most states do not attempt to track this “carryover” amount of nutrient. Depending on manure treatment and application methods, only a portion of total plant nutrients are available to the first crop grown after manure application. The remainder of the nutrients slowly become available for subsequent crops. There are so many variables that affect this rate that it is difficult to track these nutrients with great accuracy, and hence it is typically not done. Further, these carryover nutrients usually only amount to a small percentage of the total nutrients applied. In watersheds that are nutrient sensitive or regions with groundwater nitrate concerns, a planner may wish to credit these carryover nutrients with the carryover coefficients used in their state, which can be obtained from the land-grant institution, Cooperative Extension Service, Natural Resources Conservation Service, or state department of agriculture.

The issue of carryover nutrients is generally only applied to organic nitrogen. Carryover consideration is of greatest value for manures where the nitrogen source is primarily organic nitrogen such as manure solids from open lot beef and dairy facilities and composted manure from most sources.