Key findings
Key findings from of the ACP to date:
- Declining Soil Test Phosphorus Trends across catchments
- Low use of Nutrient Management Plans by farmers
- Improved nitrogen and phosphorus use efficiency on farms
- Soil type and geology override soil P level as a predictor of P loss risk
- P loss to groundwater through the soil can be important in some settings
- Point sources have a disproportionately large summer influence
- Closed period is effective but extension is not warranted
- Sediment losses are low and from roadways, stream banks and beds
- Importance of Critical Source Areas for targeting mitigation
- Identified the main influencers on farmers’ nutrient management practices
- Climate and weather are important pressures on nutrient losses and the response differs depending on catchment typology
- Groundwater Nitrate below 11.3 mg/L in all 6 catchments
- Hydrogeological and agronomic factors controlled groundwater hydrochemical signatures
- Groundwater nitrous oxide was found to be a net source of greenhouse gas emission
- Dairy expansion can increase loss of N to the environment due to increased N loading
- A new conceptual model of P loss and retention with new categories of risk assessment for a karst catchment is created
- Improving river ecological quality requires improved management of sediment inputs and a reduction in point sources
- E. coli transfers are correlated with P transfers in some catchments
- There is a need for improved support to knowledge transfer for better farm and soil specific nutrient management planning strategies
- Improving river ecology requires a reduction in point sources