By Sjoerd Willem Duiker
Soil profiles are fully recharged with water and the weather forecast calls for 4 days with rainy conditions. Hold off on spreading manure to prevent runoff.
‘Incidental transfer’ is a term coined by scientists to explain the loss of sediment, nutrients, pesticides, and dissolved carbon during infrequent runoff events. Incidental transfer can be due to saturated soil conditions during certain times of the year, or to high-intensity rainfall events. Anything laying at the surface at that time is under high risk to be carried away in runoff. Incidental transfer of nutrients and dissolved organic carbon from surface-applied manure is very likely in the coming days. Perhaps you measured high infiltration rates last summer when soil was dry. However, if the soil is near saturation, which is very likely right now, infiltration is much lower and runoff much more likely. If manure is laying at the surface it may easily end up in streams or run into sinkholes and from there straight into groundwater. ‘Incidental transfer’ of manure nutrients and organic carbon in surface runoff is usually only a threat for short periods after surface manure application. After some time, the manure nutrients and dissolved organic carbon infiltrate in the soil profile and are incorporated by biological organisms. Avoid an OOPS moment that may have negative consequences for stream health and groundwater quality by not spreading manure now. If you absolutely need to (for example, because you daily haul) spread as far away from streams and sinkholes as possible.
Source : psu.edu