Other sources represent non-block total losses from farm structures such as raceways, yards, leaching or runoff from unlined pads and effluent storage systems.
For nitrogen, the proportion of N that is leached varies with rainfall.
For phosphorus, a part of the animals excreta is deposited on lanes and races and is lost as leaching.
These Other sources can be influenced by reducing dietary intake of P (by reducing animal numbers or diet P content), or by making changes to the farm system, for example, shifting from a 2-pond to spray effluent system, lining standoff pads or changing Once A Day Milking options.