The limitation of centre pivot irrigation systems currently is that water can only be irrigated as a blanket application across the whole site, or be limited into ‘pizza slice’ sub-sections of the paddock. This creates severe restrictions in being able to apply water to meet the specific needs of each soil type, and often results in some soil types being over-watered or under-watered depending on the location on the site. The over-watering of soil types can result in the leaching of unused water and nutrients down the soil profile and can potentially cause off-site impacts of nutrient enrichment. The aim of this project was to better understand the movement of water in the soil profile for three distinct soil types in the West Midlands region and assess the potential for the leaching of nutrients and water below the rooting depth of potatoes. This could then guide the implementation of variable rate irrigation in the region, where irrigation can be varied across the landscape to match water applied to soil water holding capacity.

Potato growers in the Gingin and Dandaragan areas face significant production challenges due to highly variable soil types under centre pivots. One problem during tuber establishment is where irrigation decisions for lighter soil types result in overwatering on heavier soil types, resulting in rotting of seed pieces on the heavier soils. On the other hand, optimizing irrigation for heavy soil types results in underwatering of seed pieces on lighter soils. The trial is being conducted in Gingin and Dandaragan on sandy and loamy soils respectively.

This trial looked at Serenade Prime as product to increase marketable potatoes and uniformity in tuber size through two applications during the growing season. Serenade Prime did not result in an increase of total yield but recorded an improved number of ‘marketable’ potatoes from the treatment through the reduction of smaller tubers and a higher percentage of medium sized, premium tubers. The trial was conducted near Dandaragan on sandy duplex soil.