Supplement wrapping information ('wrapped or covered in plastic') is used to estimate the embodied plastic energy and CO2 emissions from plastics. It is assumed that less plastic is used for silage stacks and this is about a 1/3 of that used for wrapping bales.
Leachate from silage stacks can be a point source of pollution; supplement nutrients lost through storage are added to the farm nutrient budget as immobilised nutrients. For silage made on blocks, some of the storage loss is assumed to leach if the stack is not contained - when the ‘Silage stack used’ tick box is checked a second box appears to determine if ‘Effluent from stack contained’ which is then taken in to account in the model calculations.