Assessing the effectiveness of manure application timing options to minimize P loss from fields

Abstract:

It is widely understood that spreading manure before a large runoff event causes water quality problems downstream. Phosphorus (P) is a pollutant that is particularly susceptible to these types of events, as P is often disproportionately transported in overland runoff. While the benefit of avoiding the intersection of manure and runoff is unmistakable, it is less clear what length of time is needed between manure application and runoff, and also, what types of predictions can be most effective (i.e. what is the benefit of runoff predictions over simple rain predictions?). In this study, we model the effect of prediction type and avoidance window size on resultant P export. This research aims to help land managers optimize the needs of their crops with water protection goals in the age of increasing online decision support tool options.