Nutrient run-off from agricultural land is a significant source of nutrients entering estuaries in the Geographe catchment. Excess nutrients entering waterways from fertiliser and effluent reduces water quality, which can lead to algal blooms, low oxygen and fish kills. Farmers have a vital role to play in improving water quality through reducing nutrients loss off farm.
Through a range of Revitalising Geographe Waterways projects, GeoCatch and industry groups, along with farmers are working together to reduce nutrient run off from farms.
Nutrients from agricultural fertiliser are the major contributor of nutrients entering Geographe waterways. Improving fertiliser decisions on farm benefits both the farmer’s profitability and the water quality of Geographe waterways.
Over the last six years GeoCatch and the Department of Primary Industries and Regional Development (DPIRD) have been working in partnership with farmers and industry to improve fertiliser management through various fertiliser management projects. These projects support farmers through soil testing, nutrient mapping, farmer workshops and access to agronomic advice to ensure fertiliser and profits stay on the farm and out of Geographe waterways. 80 additional farmers have had the opportunity to participate in soil testing programs through Revitalising Geographe Waterways.
The Geographe Catchment supports close to a quarter of the dairy farms in the state and is an important industry on a local and state scale. With the average cow producing up to 50kg of manure each day the management of effluent is an important issue for farmers and Geographe waterways. Over the last decade GeoCatch have been working with Western Dairy and dairy farmers to improve dairy effluent on Geographe farms. Revitalising Geographe Waterways has supported 10 dairy farmers develop and implement effluent plans to improve dairy effluent and reduce nutrient loss from dairy sheds.
Healthy waterways provide habitat to aquatic wildlife and help reduce nutrients and sediments entering Vasse Wonnerup wetlands and Geographe Bay. In recognition of this important function GeoCatch have been working with farmers over the last 20 years to protect and enhance Geographe waterways by installing stock exclusion fencing and restoring native vegetation. An additional 40km of fencing and 10Ha of revegetation has been carried out to date under Revitalising Geographe Waterways.
Soil amendments are products that bind with phosphorus, keeping it within the soil available for plant growth rather than washing into waterways. Using soil amendments can significantly reduce phosphorus loss when combined with good fertiliser management. Revitalising Geographe Waterways has established and continues to monitor two trial sites on farms to assess the effectiveness of the soil amendment Iron Man Gypsum in reducing phosphorus loss.
Development of a framework for nutrient management best management practices (BMPs) for high rainfall grazing land is being led by GeoCatch and overseen by the BMP working group. The BMP Framework will allow farmers to compare their current farming operations to ‘best practice’ for improving nutrient management on farm by using a self-assessment benchmarking tool. The tool will easily track progress over time to demonstrate sustainable farming practices. GeoCatch will be piloting the BMP framework with Geographe farmers through the development of nutrient plans. The tool will be available online in June 2022.