Key Points
- Selenium (Se) levels are naturally very low in South Island soils and, as a result, our food intake of Se is relatively low. This has a potential impact on human health.
- One simple way to increase our Se levels is by increasing bread Se levels. The Growers, Millers and Bakers have agreed that the best way to do this is by applying Se fertiliser to wheat crops - the cost is fairly low yet the potential health benefits for our society are quite large.
- The research reported here confirms previous research showing that increasing grain Se is fairly simple, low-cost and reliable. The ideal threshold of 0.1 mg/kg wheat was easily achieved.
- If applied in the autumn some Se may be leached, so the most effective application method is probably by mixing Se prills with fertiliser applied in the spring. This would cost only $2-4/ha.
- Foliar applications of liquid Se gave the best uptake in the grain but the application cost may be higher unless it is mixed with other chemicals. Any interaction of such products is not yet known.