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 five years GeoCatch and the Department of Primary Industries and Regional Development (formerly DAFWA) 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 will continue to support at least 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 will establish two trial sites on farms to assess the effectiveness of the soil amendment Iron Man Gypsum in reducing phosphorus loss.