Water use by crops and pastures in southern NSW

Summary

This Primefact provides information on the key points to consider:

• Agricultural production seeks both high total water use (TWU) and high water use efficiency (WUE).
• High total water use influences the environment through minimising deep drainage, and associated waterlogging and salinity.
• Potential or water limited yield of wheat is about 20 kg/ha/mm of seasonal water use, and for broad-leaf crops is about 15 kg/ha/mm of seasonal water use (after deducting 100 to 120 mm).
• The water limited yield of annual pasture dry matter production is about 30 kg/ha/mm (after deducting about 30 mm).
• Potentially, dryland lucerne can yield about 12 kg/ha of dry matter for each mm of annual rainfall.
• Poor WUE can indicate management problems or constraints imposed by soil, nutrition, pests or disease.
• Identifying and addressing these agronomic constraints is the path to improved WUE.