The soils of the NAR are derived mainly from ancient sedimentary and crystalline rocks which have been subjected to extensive weathering over geological time periods. The outcome of this is that deep sandy soils are dominant in the NAR. These soils have deeply weathered proﬁles that are inherently low in nutrients (Campbell, 2008). The physical fertility of such soils, however, is usually good. NAR soils are predominantly acid to very acid, with limited alkaline soils to the east of the Darling Fault. The soil resource has been substantially altered since European settlement and farming practices have resulted in higher levels of organic carbon and nutrients than are found in the natural soils. Higher nitrogen and nutrient levels may lead to eutrophication of water bodies. Land clearing for agriculture has led to an increase of soil hazards such as wind erosion, water erosion, hard setting, nutrient leaching, acidiﬁcation, compaction, water repellence, waterlogging and salinisation.
For more information about agricultural soils visit the Department of Agriculture and Food WA website.