Key Points:
- Pastures that are regularly irrigated with dairy shed effl uent typically have nutrient rich soils. These soils may pose a risk to the environment through nutrient leaching and to animal health through nutrient imbalances.
- Maize is effi cient at utilising nutrients from soils and can be grown in high fertility soils, straight out of pasture, without fertiliser. Silage yield is not compromised and fertiliser costs are minimised.
- In a second year after pasture, the nutrient levels in the soil may still be high enough to support a maize crop without additional fertiliser or with minimal additional amounts. The crop requirements should be determined before planting by soil testing and the use of the AmaizeN nitrogen forecasting tool.
- In all trials (either in the fi rst or second consecutive year following pasture), side dressing was particularly inefficient because it far exceeded the crop N requirements. Most of this N remained in the soil at harvest with the potential to be leached over winter.