1. To determine the optimum dose of sulphur fertilizer in relation to the soil S content at sowing and the manuring history, and the effect of deficiency on beet yield and quality.
2. To determine the effect of time of S fertilizer application on beet yield and quality.
3. To establish a reliable diagnostic test for sulphur deficiency in the sugar beet crop.
4. To determine where and in what circumstances sulphur fertilizer will be needed for the sugar beet crop.
Final Report 2004
No individual experiment produced a significant positive response to S application, but the treatments that received no S fertilizer produced the smallest yield in five of the six experiments. Analysis across years using REML showed that there was a positive and significant response in beet where positive responses had previously been recorded in other crops. Beet leaves collected from commercial crops that had no record of recent applications of S-containing fertilizers or manures showed that many had similar S concentrations to the unfertilized crops in the experiments. Probably beet crops in these fields should receive S fertilizer, which can be applied conveniently as ammonium sulphate.