What is a salt interception scheme?
Salt interception schemes are large-scale groundwater pumping and drainage projects that intercept saline water flows and dispose of them, generally by evaporation.
What is the natural way that salt could leave the basin’s rivers?
River Murray
It is not possible to prevent all salt from entering the Basin river system, but once salt has entered the water, it can leave the river system via the mouth of the River Murray. This is the only way for salt to naturally leave the system, which is why it’s so important to keep the Murray Mouth open.
How many management solutions are there for salinity in the MDB?
There are currently 18 salt interception schemes in operation, which divert more than half a million tonnes of salt away from the river each year.
How much salt is removed from the MDB each year?
The water slowly evaporates, concentrating the salt or gradually leaking it back into the groundwater systems. There are 18 of these schemes which move around half a million tonnes of salt away from the River Murray each year.
How can salinity be managed?
Treatment
- avoiding over-irrigation by monitoring soil moisture to work out water requirements.
- good crop selection such as using deep-rooted plants to maximise water extraction.
- minimising fallow periods using crop rotations and break crops.
- avoiding deep ripping and overtillage to minimise infiltration of water.
What refers to the salt content of water?
Salinity (/səˈlɪnɪti/) is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal to ‰).
How is salinity managed?
Irrigation salinity can be controlled by using water efficiently. Crops should receive only the amount of water they can actually use. Reducing water usage in irrigated areas generally requires changes to irrigation infrastructure and technology, and better matching of crops to soil types.
What is meant by the term salinity?
The term salinity refers to the amount of dissolved salts that are present in water. Sodium and chloride are the predominant ions in seawater, and the concentrations of magnesium, calcium, and sulfate ions are also substantial.
What causes salinity in Australia?
Salinity has been caused by extensive land clearing in Australia, predominantly for agricultural purposes. Land clearance can also lead to soil erosion and, when it results in a changing water balance, to dryland salinity.
How does dryland salinity work?
Dryland salinity is the build-up of salt in surface soil in non-irrigated areas, usually because of rising groundwater tables. Groundwater seeps to the surface, bringing salt with it. As the soil surface dries out, salt is left behind.
How is soil salinization prevention in agriculture?
Management to prevent soil salinization involves maintaining a mix of deep-rooted perennial vegetation and crops in order to prevent the rise of the water table, and limiting the amount of irrigation water that is applied to the system.
How do you manage dryland salinity?
Options may include improved irrigation systems, crop rotations, incorporating perennials into cropping systems, whole farm planning, interception plantings and monitoring of groundwater. There has always been a strong interest in the use of trees and revegetation in the management of dryland salinity.