The nutrient budget displays nutrients added and nutrients removed for the farm system that has been modelled. Nutrients can be removed from the farm system in a number of ways. Table 1 describes the terminology used for nutrients removed.
Table 1: Terminology used for nutrients removed
TERM | DEFINITION |
Leaching, Run off and Direct losses | |
Leaching – urine patches | The leaching of nutrients from animals’ urine patches. |
Runoff | The removal of nutrients from the land via overland flow. |
Direct (animals, drains) | Nutrients deposited directly by animals into streams and/or drains i.e. when stock are not excluded from waterways and discharge from mole tile drainage systems. |
Leaching – other | The leaching of nutrients from inter-urine areas (incorporates the effects of soil fertiliser, effluent and other nutrient input sources). For P this includes the P loss from farm structures e.g. feed pads. |
Border dyke outwash | Nutrients discharged from the border dyke outwash. |
Direct pond discharge | Nutrients discharged directly from effluent ponds into waterways. |
As Product | Nutrients in products sold such as milk, wool, velvet, live weight, or crops. |
As Prunings | Nutrients in prunings removed from fruit crop blocks. |
Transfer | |
Transfer by animals represents the movement of nutrients through animals. It occurs when feed is eaten (nutrients ingested) in one place on the farm, and excreta is deposited in another place on the farm. For blocks, transfer out of a block (nutrients removed from the block) is positive, and into a block (nutrients added to the block) is negative. Net transfer is the sum of all the removals and additions, and hence can be negative. Four transfers are reported. |
|
To feed pad | Nutrients consumed as pasture and transferred to a feed pad (supplements, crops) in the gut of animals. |
To paddock | This is where nutrients are ingested on the paddock from pasture or supplements fed on blocks, and excreta deposited on lanes and in the farm dairy. |
From paddock | This is where nutrients are ingested on the paddock from pasture or supplements fed on blocks, and excreta deposited on lanes and in the farm dairy. |
To wintering pad | This is where nutrients are ingested on the paddock from pasture or supplements fed on blocks, and excreta deposited on the wintering pad. This is a positive transfer (nutrients leave the block). |
From wintering pad | This is where nutrients are ingested on the wintering pad as supplements, and excreta deposited on the block when animals are grazing. This is a negative transfer (nutrients are added to the block). |
Effluent Exported | Nutrients in effluent exported from the farm dairy or wintering pad/animal shelter effluent management system or from septic tank system on house pond (farm nutrient budget only). |
To atmosphere | |
Denitrification – background | The loss of dinitrogen gas to the atmosphere as a consequence of nitrogen sources other than urine deposited on the soil. |
Volatilisation – other | The loss of ammonia to the atmosphere as a consequence of nitrogen sources other than fertiliser or urine applied/deposited on the soil. |
Volatilisation – urine | The loss of ammonia to the atmosphere as a consequence of urine deposited on the soil. |
Denitrification – urine | The loss of dinitrogen gas to the atmosphere as a consequence of urine deposited on the soil. |
Volatilisation – fertiliser | The loss of ammonia to the atmosphere as a consequence of the application of nitrogen based fertilisers. |
As supplements and crop residues | |
Exported crop residues | Nutrients removed as crop residuals. |
Supplements sold/stored | Nutrients removed as supplements sold from the farm or stored |
Exported defoliation products | Fodder crops exported from a fodder crop or crop block and fed on another block or feed pad |