Soils and Agricultural Production Systems
The grain production areas of New South Wales are located in the slopes and plains regions to the west of the Great Dividing Range and on the northern coastal floodplains to the east of the Great Dividing Range. The slopes and plains region stretches from the Queensland border in the north to the Victorian border in the south, but there is considerable variation in rainfall patterns and soils. The Riverina and south west slopes typically receive most of their annual rainfall in winter and the dominant soils types found in these areas are Chromosols and Dermosols. The duplex soils are naturally hardsetting and often have sodic subsoils. This region also has some deep cracking Vertosols although not widespread. In comparison, the north west receives most of its rainfall in the summer and has a greater variety of soil types. The main soil types are Vertosols, Chromosols and Ferrosols.
In both regions the dominant winter crop is wheat with canola, barley, triticale and a variety of winter pulses including chickpea, lupin, faba bean and lentil also produced during winter. In the north, summer crops such as sorghum, cotton, maize, mungbean, sunflower and soybean dominate. Irrigation has allowed the cultivation of many grain crops in the north and south.
The north coast of NSW produces most of Australia’s soybean crop. Sugar cane is grown on the near coastal strip. Most of the coastal cropping occurs on Dermosols that have developed on alluvial material of the floodplains. The coastal region usually receives sufficient rainfall to allow double cropping of summer and winter grains or grain production in rotation with pastures or fodder crops.
All cropping activities affect the soil, so farmers are soil managers. Maintaining and improving soil condition and health is important to both agricultural productivity and the quality of ecosystem services provided by rural lands. Soil systems are complex, and the extent of changes in soil due to management can be difficult to predict. Growing our understanding of soils as active, living media is helping to develop agronomic strategies to shift soil condition in a positive direction.