To gain an understanding of production benefits of clay incorporation and the role of organic matter in sandy soils. 

Spading alone and the addition of more clay did not appear to increase growth in this year. This would suggest that non-wetting and soil compaction were not major constraints affecting this site. The incorporation of organic matter combined with clay did, however, provide large increases to both dry matter and yield. The incorporation of organic matter provides a large nutrient benefit, particularly nitrogen, phosphorus and potassium. However, nutrients applied by the landholder should have been adequate to meet the yields delivered. Clay addition would have provided more than enough potassium.