Salinity and agriculture

Salinity and agriculture
Salinity and agriculture

Salinity and agriculture

This is a key issue affecting agriculture in Western Australia, particularly in the eastern parts of the region. The implications of dryland salinity to the agricultural industry are widespread and include reduced crop yield, area of arable land, land capability and should also include the growing need to meet community and market demands for environmentally responsible agriculture.

Effects of rainfall decline to date

Effects of projected rainfall decline
Effects of rainfall decline to date

Effects of projected rainfall decline

Rainfall in the south-west of Western Australia is now around 16 per cent below the long-term average. Less rainfall results in less water flowing into rivers and aquifers and to date there has been up to a 50% reduction in average run-off into rivers and streams, and up to a 30 per cent reduction in recharge of aquifers depending on the location.

How serious is Soil Acidity?

How serious is Soil Acidity
How serious is Soil Acidity?

How serious is Soil Acidity

More than 70% of agricultural topsoils and 50% of sub-surface soils are more acidic than they should be, and such soils affect agricultural production negatively as plants are less able to take up nutrients from the soil.

Soil nutrient management

Soil nutrient management
Soil nutrient management

Soil nutrient management

On average, farm soils (i.e. pasture and arable) are over fertilised. They contain 1.3 - 1.6x as much phosphorus as is required for optimal production. Reducing the amount of phosphorus to optimal levels could lead to economic benefits (reduced fertiliser costs or redirection of fertiliser costs to removing other constraints), and reducing the off-site impacts of agriculture (reduced leaching and runoff of phosphorus).

Extent of water repellence

Extent of water repellence
Extent of water repellence

Extent of water repellence

Soil water repellence is the resistance of soils to wetting, sometimes to the extent that they remain dry even after significant rainfall events or irrigation.

Most of the soils (including in coastal and forest areas) in the South West NRM region are severely water repellent affecting agriculture production.