11140048 Sulphur Recommendations for Potatoes

Background

About one quarter of the GB potato crop receives an application of sulphur (British Survey of Fertiliser Practice 2016). However, the 2016 review during the revision of the potato section of RB209 (Allison & Sagoo 2016) highlighted the paucity of experimental data relating to the S nutrition of the UK potato crop, especially with decreasing atmospheric inputs of S. Reports published in Scotland in the mid-1980s were used to formulate the recommendation for 25 kg SO₃/ha (10 kg S/ha) when sulphur deficiency was “expected” (TN633, October 2013). Other field studies in the UK (Muttucumaru et al. 2013) have investigated the effects of N and S applications on tuber sugar and amino acid concentrations and on acrylamide-forming potential. These trial data were inconclusive but suggested that S applications might help reduce acrylamide formation in crops given excess N. In 2016 CUPGRA funded three fully randomised and replicated experiments looking at the responses of pre-emergence applications of S fertiliser. Overall there were no effects of S applications on tuber yield or quality, however this was only for one season and more data is required.

Aims and Approach

Aim: The purpose of this project is to specify conditions under which applications of sulphur to the potato crop can be economically justified.

Objectives:

1. To better quantify the risk to potato yield and quality from sulphur deficiency in potato crops
2. To determine an appropriate S application rate in S deficient circumstances
3. To provide these data and an interpretation to AHDB to enable an update to the new versions of the Nutrient Management Guide.
4. To determine the effect of sulphur application on the accumulation of acrylamide and/or its precursors in cooked potato products.