Managing water repellence at seeding: soil wetting agents.

Soil water repellence causing patchy and poor crop establishment depends upon seasonal conditions, but wetting agents can mitigate the risks.

Key points

• Modern soil wetting agents comprise surfactant blends that combine penetrant (promoting water infiltration) and humectant (promoting water retention) properties
• Significant crop establishment benefits have been achieved in recent trials in South Australia from soil wetting agents applied in the seed zone or split-applied between the seed zone and furrow surface
• Crop establishment and grain yield benefits seem to be greatest when combined with stable furrows that remain effective for water harvesting over the growing season
• It is difficult to predict which soil wetter chemistry is best suited to different local water repellence contexts, but all soil wetting agents have some potential to provide benefits under best practice.