Influence of NPK fertilisation and harvest date on agronomic performance of Jerusalem artichoke crop in the Guadiana Basin (Southwestern Spain)

• Three field experiments were conducted in Southwestern Spain.
• Influence of NPK fertilisation and harvest date was studied.
• High crop yield could be achieved with a relatively low NPK fertilisation rate.
• Sugar yield can decrease significantly in winter harvest.
• Jerusalem artichoke is a promising crop for sustainable bioethanol production.

Three experiments were conducted during the crop seasons 2008, 2009 and 2010 to study the influence of NPK fertilisation and harvest date on the agronomic performance of Jerusalem artichoke in the Guadiana Basin (Southwestern Spain). Three NPK fertiliser rates and two harvest dates were evaluated. The crop showed a low response to NPK fertilisation. High yield (22.7 t dw ha−1 of aboveground biomass, 14.4 t ha−1 of sugar) was achieved in the autumn harvest of 2008 by the application of NPK fertiliser at a rate equivalent to 54–108–162 kg ha−1 of NPK. Soil compaction problems can cause a strong yield decrease. Harvest date had a great influence. Aboveground biomass was significantly lower in winter harvest than in autumn ones. The yield of tubers and sugars can decrease strongly in winter harvest due to rotting. Therefore, with a proper crop management, Jerusalem artichoke could be a promising crop for sustainable bioethanol production in the Guadiana Basin.